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SVXLINK.CONF(5)			 File Formats		       SVXLINK.CONF(5)

NAME
       svxlink.conf - Configuration file for the SvxLink server

DESCRIPTION
       svxlink	is  a  general purpose voice service system for	ham radio use.
       This man-page describe the SvxLink server configuration file format.

       SvxLink look for	configuration files in a number	of  places.  First  it
       try to find a user specific configuration file. SvxLink will look for a
       user specific configuration file	in:  $HOME/.svxlink/svxlink.conf.   If
       no user specific	configuration file can be found, SvxLink will look for
       the system  wide	 configuration	file  /etc/svxlink/svxlink.conf.   The
       --config	 command  line option may also be used to specify an arbitrary
       configuration file.

FILE FORMAT
       The configuration file is in the	famous INI-file	format.	A generic  ex-
       ample of	how such a file	might look like	is shown below.

	 [SECTION1]
	 VALUE1=1
	 VALUE2="TWO "
	 VAULE3="Multi "
		"line"

	 [SECTION2]
	 VALUE1=2

       This  is	a simple format	that contain name=value	pairs that belong to a
       section.	In written text, a specific configuration variable can be  re-
       ferred  to as SECTION1/VALUE2 meaning "configuration variable VALUE2 in
       section SECTION1".

       The same	variable name can exist	in two different sections. For example
       VALUE1  in section SECTION1 have	the value 1 and	VALUE1 in section SEC-
       TION2 have the value 2. Values containing spaces	at  the	 beginning  or
       end  of	the  line  must	be surrounded by citation characters (see SEC-
       TION1/VALUE2). Likewise with a multi line value (see SECTION1/VALUE3).

CONFIGURATION VARIABLES
       Here is the description of all configuration variables that SvxLink un-
       derstands.  The	configuration variables	are described section for sec-
       tion.

   GLOBAL
       The GLOBAL section contains application global configuration data.

       MODULE_PATH
	      Specify where the	SvxLink	modules	can be found.  If  MODULE_PATH
	      is  not  specified,  the standard	search paths for library files
	      will be used. If that also fails a hard-coded  default  will  be
	      used.  What that default is depend on the	architecture but typi-
	      cally on a x86_64	system it is /usr/local/lib64/svxlink.	 Leav-
	      ing this variable	unset should work in most cases.

       LOGICS Specify  a  comma	 separated  list of logic cores	that should be
	      created. The logic core is the thing that	ties  the  transceiver
	      and the voice services (modules) together. It contains the rules
	      for how the radio	interface should  be  handled.	The  specified
	      name of a	logic core must	have a corresponding section specified
	      in the config file. This is where	the behavior of	the logic core
	      is specified.

       CFG_DIR
	      Specify the path to a directory that contain additional configu-
	      ration files.  If	a relative path	is specified, the path will be
	      relative	to  the	directory where	the main configuration file is
	      at. All files in the specified directory will be read  as	 addi-
	      tional  configuration.  Filenames	 starting  with	 a dot (hidden
	      files) or	not ending in .conf are	ignored.

       TIMESTAMP_FORMAT
	      This variable specifies the format of  the  time-stamp  that  is
	      written  in front	of each	row in the log file. The format	string
	      is in the	same format as specified  in  the  strftime(3)	manual
	      page.  The default is "%c" which is described as:	"the preferred
	      date and time representation for the current locale". The	 envi-
	      ronment  variables LC_TIME, LC_ALL and LANG will affect how this
	      time format will look. For example, setting LC_TIME="sv_SE.UTF8"
	      will  give you Swedish time-stamp	representation.	Other examples
	      of format	specifiers are:

	      o	  %d - The day of the month as a decimal number	(range	01  to
		  31)

	      o	  %b - The abbreviated month name according to the current lo-
		  cale

	      o	  %Y - The year	as a decimal number including the century

	      o	  %H - The hour	as a decimal  number  using  a	24-hour	 clock
		  (range 00 to 23)

	      o	  %M - The minute as a decimal number (range 00	to 59)

	      o	  %S - The second as a decimal number (range 00	to 60)

	      o	  %f - Fractional seconds in millisecond resolution (000-999)

	      The last one (%f)	is a SvxLink specific formatting specifier.

	      Example:	TIMESTAMP_FORMAT="%d  %b  %Y %H:%M:%S.%f" would	give a
	      time-stamp looking something like: "29 Nov 2005 22:31:59.875".

       CARD_SAMPLE_RATE
	      This configuration variable determines the  sampling  rate  used
	      for audio	input/output. SvxLink always work with a sampling rate
	      of 16kHz internally but there still are some benefits from using
	      a	 higher	 sampling  rate.  On some sound	cards the filters look
	      pretty bad at 16kHz and the amplitude response will not be  uni-
	      form  which  among other things can cause	problems for the soft-
	      ware DTMF	decoder.

	      Some sound cards also sound very bad at 16kHz  due  to  insuffi-
	      cient  anti-alias	 filtering or resampling effects. These, often
	      cheaper, sound cards sound OK at 48kHz.

	      The downside of choosing a higher	sampling rate is that it  puts
	      a	little bit more	load on	the CPU	so if you have a very slow ma-
	      chine (<300MHz), it might	not have the  computational  power  to
	      handle it.

	      Supported	sampling rates are: 16000 and 48000.

       CARD_CHANNELS
	      Use  this	configuration variable to specify how many channels to
	      use when opening a sound card. For normal	sound cards  the  only
	      practical	 values	 to  use  are 1	for mono and 2 for stereo. The
	      latter is	the default.

	      When using the sound card	in stereo mode it is possible  to  use
	      the  left	 and  right channels independently to drive two	trans-
	      ceivers. When using the sound card in mono mode, both  left  and
	      right channels transmit/receive the same audio.

       LOCATION_INFO
	      Enter  the  section  name	that contains information required for
	      transferring positioning data to location	servers. Setting  this
	      item  makes  the system visible on the EchoLink link status page
	      and the APRS network.

       LINKS  Enter here a comma separated list	of section names that contains
	      the  configuration  information for linking logics together (see
	      Logic Linking).

   Common Logic	configuration variables
       A logic core is what define how SvxLink should behave on	the  RF	 chan-
       nel.  The SvxLink server	can handle more	than one logic core and	so can
       be connected to more than one transceiver. The configuration  variables
       below  are  common to all logic types. Configuration variables that are
       specific	to a certain logic core	type are described below in a  section
       of its own.

       TYPE   The  type	 of logic core this is.	The documentation for the spe-
	      cific logic core type you	want to	use  describe  what  to	 write
	      here.

       RX     Specify  the  configuration section name of the receiver to use.
	      All configuration	for the	receiver is done in the	specified con-
	      figuration section.

       TX     Specify  the  configuration  section  name of the	transmitter to
	      use. All configuration for the transmitter is done in the	speci-
	      fied configuration section.

       MODULES
	      Specify a	comma separated	list of	configuration sections for the
	      modules to load. This tells SvxLink which	 modules  to  actually
	      load on startup.

       CALLSIGN
	      Specify  the  callsign that should be announced on the radio in-
	      terface.

       SHORT_VOICE_ID_ENABLE
	      A	basic toggle to	enable the voice ID  announcement  during  the
	      short  ID	 announcements.	  Set value to "1" to enable the voice
	      option, and "0" to disable.

       SHORT_CW_ID_ENABLE
	      A	basic toggle to	enable the CW ID announcement during the short
	      ID announcements.	 Set value to "1" to enable the	CW option, and
	      "0" to disable.

       SHORT_ANNOUNCE_ENABLE
	      A	basic toggle to	enable	the  custom  announcement  during  the
	      short  ID	 announcements.	  Set  value  to "1" to	enable the an-
	      nouncement option, and "0" to disable.

       SHORT_ANNOUNCE_FILE
	      The full path to a file to use for custom	 announcements	broad-
	      casted during a routine short ID.

       LONG_VOICE_ID_ENABLE
	      A	 basic	toggle	to enable the voice ID announcement during the
	      long ID announcements.  Set value	to "1" to enable the voice op-
	      tion, and	"0" to disable.

       LONG_CW_ID_ENABLE
	      A	 basic toggle to enable	the CW ID announcement during the long
	      ID announcements.	 Set value to "1" to enable the	CW option, and
	      "0" to disable.

       LONG_ANNOUNCE_ENABLE
	      A	basic toggle to	enable the custom announcement during the long
	      ID announcements.	 Set value to "1" to enable  the  announcement
	      option, and "0" to disable.

       LONG_ANNOUNCE_FILE
	      The  full	 path to a file	to use for custom announcements	broad-
	      casted during a routine short ID.

       CW_AMP Specify the amplitude of the CW that should be used  during  any
	      cw  traffic, typically announcements. The	amplitude is specified
	      in dB. Default: -6.

       CW_PITCH
	      Specify the pitch	(frequency in Hz) of the  CW  that  should  be
	      used  during  any	 CW traffic, typically announcements. Default:
	      800.

       CW_CPM Specify the Characters Per Minute	of the CW that should be  used
	      during  any  CW traffic, typically announcements.	If both	CW_WPM
	      and CW_CPM is set, CW_CPM	will be	used. Default: 100.

       CW_WPM Specify the Words	Per Minute of the CW that should be used  dur-
	      ing  any CW traffic, typically announcements. If both CW_WPM and
	      CW_CPM is	set, CW_CPM will be used. Default: 20.

       PHONETIC_SPELLING
	      Specify if the spelling of callsign and other  words  should  be
	      announced	 on the	radio interface	using phonetic or non-phonetic
	      spelling.	 "1" to	use phonetic sounds (legacy default),  or  "0"
	      to  use  non-phonetic  sounds.  Note that	this option may	not be
	      available	for all	language packs.

       TIME_FORMAT
	      Specify  what format the time should be announced	as, valid  op-
	      tions are	"12"/"24".  NOTE: may not work for all language	packs

       SHORT_IDENT_INTERVAL
	      The number of minutes between short identifications. The purpose
	      of the short identification is to	just announce that the station
	      is on the	air. Typically just the	callsign is transmitted. For a
	      repeater a good value is ten minutes and for a simplex node  one
	      time  every 60 minutes is	probably enough. The LONG_IDENT_INTER-
	      VAL must be an even multiple of the SHORT_IDENT_INTERVAL	so  if
	      LONG_IDENT_INTERVAL   is	 60   then   the   legal   values  for
	      SHORT_IDENT_INTERVAL are:	1, 2, 3, 4, 5, 6, 10, 12, 15, 20,  30,
	      60.  If unset or set to 0, disable short identifications.

       LONG_IDENT_INTERVAL
	      The  number of minutes between long identifications. The purpose
	      of the long identification is to transmit	some more  information
	      about  the station status	(new voice mails etc). The time	of day
	      is also transmitted. A good value	here is	60 minutes.  If	 unset
	      or set to	0, disable long	identifications.

       IDENT_ONLY_AFTER_TX
	      This  feature controls when identification is done.  By default,
	      identification is	done every time	the  SHORT_IDENT_INTERVAL  ex-
	      pires.  If  this feature is enabled, identification will be done
	      only if there has	been a recent transmission.  This  feature  is
	      good  for	 nodes	using  an RF link to provide echolink to a re-
	      peater. Often, in	this situation,	it is not  desirable  for  the
	      link   to	  identify   unless   legally	necessary.  Note  that
	      SHORT_IDENT_INTERVAL still have to be set	for  this  feature  to
	      work. That config	variable will then be interpreted as the mini-
	      mum   number   of	  seconds   between    identifications.	   The
	      LONG_IDENT_INTERVAL will not be affected by this parameter.

       EXEC_CMD_ON_SQL_CLOSE
	      Specify a	time, in milliseconds, after squelch close after which
	      entered DTMF digits will be executed as a	 command  without  the
	      need  to	send the # character.  To disable this feature,	either
	      comment out the configuration row	or set it to a value  less  or
	      equal to zero.

       EVENT_HANDLER
	      Point  out  the  TCL  event handler script to use. The TCL event
	      handler script is	responsible  for  playing  the	correct	 audio
	      clips  when  an  event  occur.  The default location is /usr/lo-
	      cal/share/doc/svxlink/events.tcl.

       DEFAULT_LANG
	      Set the default language to use for announcements. It should  be
	      set  to an ISO code (e.g.	sv_SE for Swedish). If not set,	it de-
	      faults to	en_US which is US English.

       RGR_SOUND_DELAY
	      The number of milliseconds to wait after the  squelch  has  been
	      closed  before  a	roger beep is played. The beep can be disabled
	      by specifying a value of -1 or commenting	out this  line.	 Often
	      it  is best to use the SQL_HANGTIME receiver configuration vari-
	      able to specify a	delay instead of specifying a delay here. This
	      configuration variable should then be set	to 0.

       REPORT_CTCSS
	      If  set,	will  report the specified CTCSS frequency upon	manual
	      identification (*	pressed).  It is possible to specify fractions
	      using  "."  as decimal comma. Disable this feature by commenting
	      out (#) this configuration variable.

       TX_CTCSS
	      This configuration variable controls if a	CTCSS tone  should  be
	      transmitted.  Use	a comma	separated list (no spaces!) to specify
	      when to transmit a CTCSS tone. These are	the  possible  values:
	      SQL_OPEN,	LOGIC, MODULE, ANNOUNCEMENT or ALWAYS.	Commenting out
	      this configuration variable will disable	CTCSS  transmit.   The
	      tone  frequency  and level is configured in the transmitter con-
	      figuration section.

	      o	  SQL_OPEN will	transmit CTCSS tone when the squelch is	 open.
		  This	is  only  useful  on  a	repeater. On a simplex node it
		  doesn't make much sense.

	      o	  LOGIC	will transmit CTCSS tone when there is incoming	 traf-
		  fic from another logic core.

	      o	  MODULE will transmit CTCSS tone when there is	incoming traf-
		  fic from a module.

	      o	  ANNOUNCEMENT will transmit CTCSS tone	when  an  announcement
		  is  being  played. Repeater idle sounds and roger beeps will
		  not have tone	sent with them though.

	      o	  ALWAYS will always transmit a	CTCSS  tone  as	 soon  as  the
		  transmitter is turned	on.

       MACROS Point out	a section that contains	the macros that	should be used
	      by this logic core. See the section description for macros below
	      for more information.

       FX_GAIN_NORMAL
	      The  gain	 (dB)  to use for audio	effects	and announcements when
	      there is no other	traffic.  This gain is	normally  set  to  0dB
	      which means no gain or attenuation.

       FX_GAIN_LOW
	      The  gain	 (dB)  to use for audio	effects	and announcements when
	      there is other traffic.  This gain is normally set to  something
	      like  -12dB  so that announcements and audio effects are attenu-
	      ated when	there is other traffic present.

       QSO_RECORDER
	      The QSO recorder is used to write	all received audio to files on
	      disk.  The  format  for  this  configuration  variable  is <com-
	      mand>:<config section>. The specified command is used  to	 acti-
	      vate  or deactivate the QSO recorder. If the command for example
	      is set to	8, 81 will activate the	recorder and 80	 will  deacti-
	      vate  it.	 The command may also be left out. It will then	not be
	      possible to control the QSO recorder using DTMF  commands.  Even
	      if  the  command is left out the colon must always be specified.
	      The config section point out a section in	the configuration file
	      that  holds  configuration for the QSO recorder.	Have a look at
	      the QSO Recorder Section documentation for more information.

	      Example: QSO_RECORDER=8:QsoRecorder

       SEL5_MACRO_RANGE
	      Define two comma separated values	here to	map the	Sel5 tone call
	      to    your    macro    area.   E.g.   if	 you   have   defined:
	      SEL5_MACRO_RANGE=03400,03499 then	all  incoming  Sel5  tone  se-
	      quences  from  03400  to	03499 are mapped to the	macros section
	      (refer to	Macros Section,	next chapter). Other sequences but the
	      one  defined under OPEN_ON_SEL5 are ignored so it	can be used to
	      call other stations via the repeater without  a  repeater	 reac-
	      tion.

       ONLINE_CMD
	      Define  a	 DTMF  command that is used to switch the node between
	      online and offline mode. When in the off-state, the  transmitter
	      will  not	 be turned on by any event. If a module	is active when
	      the node is brought offline, it will be deactivated and no  mod-
	      ule  activation  will  be	allowed	in offline mode. No other com-
	      mands than the online command will be accepted  in  the  offline
	      state.

	      If  the  command	for example is set to 998877 then 9988771 will
	      set the node online and 9988770 will set it offline. If a	module
	      is  active  or  if  the ACTIVATE_MODULE_ON_LONG_CMD is used, the
	      command must be prefixed with a star to work  as	expected.  The
	      star means "force	core command".

       STATE_PTY
	      Using  this  configuration  variable it is possible to specify a
	      path to a	UNIX 98	PTY that SvxLink state events is published to.
	      The  published  events  is in a simple text format using a space
	      separated	list of	values.	SvxLink	will create a softlink to  the
	      actual  slave PTY. For that reason, SvxLink must have write per-
	      missions in the directory	where the softlink should be  created.
	      Monitoring   the	PTY  output  is	 as  simple  as	 doing	a  cat
	      /path/to/pty after starting SvxLink. See STATE  PTY  FORMAT  for
	      more information on the format of	the state messages.

	      Example: STATE_PTY=/tmp/state_pty

       DTMF_CTRL_PTY
	      Using  this  configuration  variable it is possible to specify a
	      path to a	UNIX 98	PTY that allows	a dtmf control of each	single
	      SvxLink  logic.  SvxLink	will  create  a	softlink to the	actual
	      slave PTY. For that reason, SvxLink must have write  permissions
	      in  the  directory where the softlink should be created. Sending
	      commands to the PTY is  as  simple  as  doing  a	echo  '*1#'  >
	      /path/to/pty  after  starting SvxLink. The device	works bidirec-
	      tional, received dtmf characters (from Rf) are output  via  this
	      interface.

	      Example: DTMF_CTRL_PTY=/dev/shm/dtmf_ctrl

   Simplex Logic Section
       The  Simplex  Logic  section  contains configuration data for a simplex
       logic core.  The	name of	the section, which in the  example  configura-
       tion  file  is SimplexLogic, must have a	corresponding list item	in the
       GLOBAL/LOGICS config variable for this logic core to be activated.  The
       name "SimplexLogic" is not magic. It could be called what ever you like
       but it must match the namespace name in	the  SimplexLogic.tcl  script.
       The  configuration  variables  below  are those that are	specific for a
       simplex logic core.

       TYPE   The type for a simplex logic core	is always Simplex.

       MUTE_RX_ON_TX
	      Set to 1 to mute the receiver when the transmitter is  transmit-
	      ting  (default)  or  set	it  to	0 to make the RX active	during
	      transmissions.  One might	want to	set this to 0 if the  link  is
	      operating	 on  a split frequency.	 Then the link can accept com-
	      mands even when it's transmitting.  The normal setting is	1,  to
	      mute the RX when transmitting.

       MUTE_TX_ON_RX
	      Set  to  1 to mute the transmitter when the squelch is open (de-
	      fault) or	set it to 0 to make the	TX active during squelch open.
	      One  might  want	to set this to 0 if the	link is	operating on a
	      split frequency or if it's connected to some full	duplex device.
	      The  normal  setting  is	1,  to mute the	TX when	the squelch is
	      open.

       RGR_SOUND_ALWAYS
	      Set to 1 to always send roger sound after	 squelch  close,  even
	      when no module is	active.

   Repeater Logic Section
       A  Repeater  Logic  section  contains configuration data	for a repeater
       logic core.  The	name of	the section, which in the  example  configura-
       tion  file is RepeaterLogic, must have a	corresponding list item	in the
       GLOBAL/LOGICS config variable for this logic core to be activated.  The
       name  "RepeaterLogic"  is  not magic.  It could be called what ever you
       like but	it must	match the  namespace  name  in	the  RepeaterLogic.tcl
       script.	The  configuration variables below are those that are specific
       for a repeater logic core.

       TYPE   The type for a repeater logic core is always Repeater.

       NO_REPEAT
	      Set this to 1 if you do NOT want SvxLink to play back the	incom-
	      ing  audio. This can be used when	the received audio is directly
	      coupled by hardware wiring to the	transmitter. What you  win  by
	      doing  this  is  that there is zero delay	on the repeated	audio.
	      When the audio is	routed through	SvxLink	 there	is  always  an
	      amount  of delay.	What you loose by doing	this is	the audio pro-
	      cessing done by SvxLink (e.g. filtering,	DTMF  muting,  squelch
	      tail elimination)	and the	ability	to use remote receivers.

       IDLE_TIMEOUT
	      The  number of seconds the repeater should have been idle	before
	      turning the transmitter off.

       OPEN_ON_1750
	      Use this configuration variable if it should be possible to open
	      the  repeater  with  a  1750Hz tone burst. Specify the number of
	      milliseconds the tone must be asserted before  the  repeater  is
	      opened. Make sure	that the time specified	is long	enough for the
	      squelch to have time to open. Otherwise the repeater  will  open
	      "too  soon"  and	you will hear an ugly 1750Hz beep as the first
	      thing.  A	value of 0 will	disable	1750 Hz	repeater opening.

       OPEN_ON_CTCSS
	      Use this configuration variable if it should be possible to open
	      the  repeater with a CTCSS tone (PL). The	syntax of the value is
	      tone_fq:min_length. The tone frequency is	specified in whole  Hz
	      and  the	minimum	 tone length is	specified in milliseconds. For
	      examples if a 136.5 Hz tone must be asserted for two seconds for
	      the repeater to open, the	value 136:2000 should be specified.

       OPEN_ON_DTMF
	      Use this configuration variable if it should be possible to open
	      the repeater with	a DTMF digit. Only one digit can be specified.
	      DTMF digits pressed when the repeater is down will be ignored.

       OPEN_ON_SEL5
	      Use  this	 configuration	variable  if you want to open your re-
	      peater by	using a	selective tone call that is often used in com-
	      mercial  radio networks.	Example: OPEN_ON_SEL5=03345 opens your
	      repeater only if that sequence has been received.	 You  can  use
	      sequence lengths from 4 to 25.

       CLOSE_ON_SEL5
	      Use  this	 configuration	variable if you	want to	close your re-
	      peater by	using a	selective tone call that is often used in com-
	      mercial  radio  networks.	  Example:  CLOSE_ON_SEL5=03345	closes
	      your repeater if that sequence has been received.	 You  can  use
	      sequence lengths from 4 to 25.

       OPEN_ON_SQL
	      Use this configuration variable if it should be possible to open
	      the repeater just	by keeping the squelch open for	a  while.  The
	      value  to	 set is	the minimum number of milliseconds the squelch
	      must be open for the repeater to open.

       OPEN_ON_SQL_AFTER_RPT_CLOSE
	      Activate the repeater on just a squelch opening  if  there  have
	      been  no more than the specified number of seconds since the re-
	      peater closed.

       OPEN_SQL_FLANK
	      Determines if OPEN_ON_SQL	and OPEN_ON_CTCSS should activate  the
	      repeater when the	squelch	open or	close. If set to OPEN, the re-
	      peater will activate and start retransmitting audio immediately.
	      No  identification  will	be sent. If set	to CLOSE, the repeater
	      will not activate	until the  squelch  close.  An	identification
	      will be sent in this case.

       IDLE_SOUND_INTERVAL
	      When the repeater	is idle, a sound is played. Specify the	inter-
	      val in milliseconds between playing the idle sound. An  interval
	      of 0 disables the	idle sound.

       SQL_FLAP_SUP_MIN_TIME
	      Flapping	squelch	suppression is used to close the repeater down
	      if there is interference on the frequency	that open the  squelch
	      by short bursts.	This configuration variable is used to specify
	      the minimum time,	in milliseconds, that a	transmission must last
	      to  be classified	as a real transmission.	A good value is	in be-
	      tween 500-2000ms.

       SQL_FLAP_SUP_MAX_COUNT
	      Flapping squelch suppression is used to close the	repeater  down
	      if  there	is interference	on the frequency that open the squelch
	      by short bursts.	This configuration variable is used to specify
	      the maximum number of consecutive	short squelch openings allowed
	      before shutting the repeater down. A good	value  is  in  between
	      5-10.

       ACTIVATE_MODULE_ON_LONG_CMD
	      This  configuration  variable activate a feature that might help
	      users not	aware of the SvxLink command structure.	The idea is to
	      activate	the  specified	module	when a long enough command has
	      been received. The typical example is an EchoLink	user  that  is
	      used  to	just  typing  in  the  node ID and then	the connection
	      should be	established right away.	Using this configuration vari-
	      able,  specify  a	minimum	length and a module name. If no	module
	      is active	and at least the specified number of digits  has  been
	      entered,	the  given module is activated and the command is sent
	      to it. To	be really useful this feature should be	used in	 coop-
	      eration with EXEC_CMD_ON_SQL_CLOSE.

	      For   example,   if   this  configuration	 variable  is  set  to
	      "4:EchoLink" and the user	types in 9999, the EchoLink module  is
	      first  activated	and then the command 9999 is sent to it, which
	      will connect to the ECHOTEST server.

       IDENT_NAG_TIMEOUT
	      Tell repeater users that are not identifying to  identify	 them-
	      selves.	The  number  of	seconds	to wait	for an identification,
	      after the	repeater has been activated, is	set using this config-
	      uration  variable.  A valid identification is considered to be a
	      transmission longer than the time	set by the  IDENT_NAG_MIN_TIME
	      configuration  variable. We don't	know if	it's really an identi-
	      fication but it's	the best we can	do.  Setting it	to 0  or  com-
	      menting it out disables the feature.

       IDENT_NAG_MIN_TIME
	      This  is	the minimum time, in milliseconds, that	a transmission
	      must last	to be considered as an identification. This is used as
	      described	in the IDENT_NAG_TIMEOUT configuration variable.

   ReflectorLogic
       The  ReflectorLogic  is	used to	connect	to an SvxReflector server. The
       SvxReflector will distribute all	audio to all connected nodes. To actu-
       ally  send  audio to the	reflector from a logic core, set up a link be-
       tween the two logics using LogicLinking.	More than one logic  core  can
       be connected.

       TYPE   The type for a reflector logic core is always Reflector.

       HOST   The hostname or IP address of the	reflector server.

       PORT   The  TCP/UDP  port  number used by the server. The client	do not
	      need to open any ports in	the firewall. Default: 5300.

       CALLSIGN
	      The callsign of this node. The callsign also serves as the user-
	      name when	authenticating to the SvxReflector server.

       AUTH_KEY
	      The authentication key, or password, used	when authenticating to
	      the SvxReflector server.

       JITTER_BUFFER_DELAY
	      A	jitter buffer is used to prevent gaps in the  audio  when  the
	      network  connection  do  not  provide a steady flow of data. Set
	      this configuration variable to the  number  of  milliseconds  to
	      buffer before starting to	process	the audio. Default: 0.

       It  is  also possible to	set audio codec	parameters using the same con-
       figuration variables as documented for networked	receivers  and	trans-
       mitters.	 For example, to lighten the encoder CPU load for the Opus en-
       coder, set OPUS_ENC_COMPLEXITY to something lower than 9.

   QSO Recorder	Section
       The QSO recorder	is used	to record all received audio to	files on disk.
       All  audio  from	 receivers,  modules and logic links are recorded. An-
       nouncements are not recorded.

       REC_DIR
	      Use this configuration variable to specify in which directory to
	      write	the	audio	  files.     A	   good	   place    is
	      /var/spool/svxlink/qso_recorder.

       MIN_TIME
	      If the duration of the recorded content for a file is less  then
	      MIN_TIME milliseconds, the file will be deleted when the file is
	      closed. Default: 0 (empty	files will be deleted).

       MAX_TIME
	      Setting this configuration variable will set an upper limit  for
	      the  file	 size of a recording. No more than MAX_TIME seconds of
	      content will be recorded to a single file. When the maximum time
	      have  been  reached, the file is closed and another file is cre-
	      ated. Note that it is not	the maximum time  that	the  recording
	      has  been	 active	that we	are setting a limit for	but rather how
	      much content that	have been recorded to the file.	If nothing  is
	      recorded,	 the  file  can	stay open indefinitely.	Default: 0 (no
	      limit)

       SOFT_TIME
	      To not get abrupt	breaks in recordings it	is possible to	set  a
	      soft break time.	Let's say that MAX_TIME	is set to 3600 seconds
	      (one hour). If we	set SOFT_TIME to 300  seconds  (five  minutes)
	      the  QSO recorder	try to close the file on a squelch close some-
	      where between 55 and 60 minutes. In this way we may  avoid  get-
	      ting transmissions split up between files. Default: 0 (no	limit)

       MAX_DIRSIZE
	      Specify  the maximum total size in megabytes of the files	in the
	      recording	directory. If the limit	is exceeded, the oldest	 files
	      are  deleted.  The  directory size is checked upon file close so
	      the size may grow	temporarily past the limit with	 at  most  the
	      size  of	one  recorded  file.  Only files which have a filename
	      starting with "qsorec_" will be considered for deletion. If  us-
	      ing  an ENCODING_CMD, make sure that the "qsorec_" prefix	is not
	      removed from the target filename	unless	you  really  want  the
	      MAX_DIRSIZE feature to skip them.	 Default: 0 (no	limit)

       DEFAULT_ACTIVE
	      If  this	configuration  variable	 is set	to 1, the QSO recorder
	      will be activated	by default when	SvxLink	start. Default:	0 (de-
	      fault inactive)

       TIMEOUT
	      If  a  timeout  is  specified,  the  activation state of the QSO
	      recorder will return to the value	specified in  the  DEFAULT_AC-
	      TIVE  configuration variable when	the node has been idle for the
	      specified	number of seconds. When	DEFAULT_ACTIVE is unset	or  0,
	      if  the  QSO recorder is manually	activated it will be automati-
	      cally deactivated	after the specified amount of time of inactiv-
	      ity.   When  DEFAULT_ACTIVE  is set to 1,	if the QSO recorder is
	      manually deactivated it will be  automatically  activated	 after
	      the  specified  amount  of  time	of inactivity.	Default: 0 (no
	      timeout)

       QSO_TIMEOUT
	      Set this configuration variable if you want to  close  the  cur-
	      rently opened file and open a new	one after each QSO. The	number
	      of seconds the node should  be  idle  before  closing  the  file
	      should be	specified. Default: 0 (no QSO timeout)

       ENCODER_CMD
	      Specify  a command to be executed	after a	new wav	file have been
	      written to disk. This makes it possible to use an	 external  en-
	      coder  utility  to  encode  the wav file to another format. Even
	      though this configuration	variable was added to run an  external
	      encoder  it  could  do  more complicated things with the file if
	      needed. A	couple of examples would be to transfer	 the  file  to
	      another  computer	 or to send a notification e-mail. If the com-
	      mand line	get too	complicated it may be a	good idea to  write  a
	      script instead.

	      The  encoder  command  will be run under a shell so normal shell
	      operators	like redirects and pipes may be	used. The shell	speci-
	      fied  in	the SHELL environment variable will be used and	if not
	      set, /bin/sh will	be used. The "-c" command line option will  be
	      added  so	 the complete command will look	something like:	$SHELL
	      -c "$ENCODER_CMD". A number of %-codes can be  included  in  the
	      command.	They have the following	meaning:

	      o	  %f - The full	filename with full path

	      o	  %d - The directory part (what	REC_DIR	is set to)

	      o	  %b  -	 The  basename,	that is, the filename without path and
		  extension

	      o	  %n - The filename without path but with extension

	      The encoder will be started in the background and	it will	not be
	      stopped even if SvxLink exits. It	will run in the	background un-
	      til it's done. As	long as	SvxLink	is running  it	is  monitoring
	      the  encoding  processes.	 If  a process run for longer than one
	      hour it will be killed.

	      Note that	SvxLink	will never remove the  original	 recording  so
	      that  have  to be	done in	the encoder command. Here are a	couple
	      of examples:

	       ENCODER_CMD=/usr/local/bin/oggenc -Q \"%f\" && rm \"%f\"
	       ENCODER_CMD=/usr/local/bin/lame --quiet \"%f\" \"%d/%b.mp3\" &&
	      rm \"%f\"
	       ENCODER_CMD=/usr/local/bin/speexenc     \"%f\"	 \"%d/%b.spx\"
	      2>/dev/null && rm	\"%f\"
	       ENCODER_CMD=/usr/local/bin/opusenc    \"%f\"	\"%d/%b.opus\"
	      2>/dev/null && rm	\"%f\"

   Macros Section
       A  macros section is used to declare macros that	can be used by a logic
       core. The logic core points out the macros section to use by using  the
       MACROS  configuration  variable.	 The name of the MACROS	section	can be
       chosen arbitrarily as long as it	match the MACROS  configuration	 vari-
       able  in	 the logic core	configuration section. There could for example
       exist both a [RepeaterLogicMacros] and a	[SimplexLogicMacros] section.

       A macro is a kind of shortcut that can be used to decrease  the	amount
       of  key presses that have to be done to connect to common EchoLink sta-
       tions for example.  On the radio	side, macros are activated by pressing
       "D"  "macro  number"  "#". A macros section can look something like the
       example below. Note that	the module name	is case	sensitive.

	 [Macros]
	 1=EchoLink:9999#
	 2=EchoLink:1234567#
	 9=Parrot:0123456789#

       For example, pressing DTMF sequence "D1#" will  activate	 the  EchoLink
       module and connect to the EchoTest conference node.

   Logic Linking
       A  logic	 linking  configuration	section	is used	to specify information
       for a link between two or more SvxLink logic cores. Such	a link can for
       example	be used	to connect a local repeater to a remote	repeater using
       a separate link transceiver.  The link is  activated/deactivated	 using
       DTMF  commands  and/or  automatically  depending	on your	configuration.
       When the	link is	active,	all audio received by one logic	will be	trans-
       mitted by the other logic(s).

       The  name of the	logic linking section can be chosen freely. In the ex-
       ample configuration file, there is a section [LinkToR4].	To use a logic
       linking	section	 in  a	logic core it must be pointed out by the LINKS
       configuration   variable	  in	the    GLOBAL	 section.     Example:
       GLOBAL/LINKS=LinkToR4

       CONNECT_LOGICS
	      A	 comma	separated  list	 of logic specifications for the logic
	      cores to connect together. Each logic  specification  has	 three
	      parts  separated by colons: <logic name>:<command>:<announcement
	      name>. The "logic	name" is the name of the logic to  include  in
	      the  link.  To manually activate or deactivate the link from the
	      just specified logic, "command" is used. The "announcement name"
	      is  used when announcing link related activities like activation
	      or deactivation.	Both "command" and "announcement name" may  be
	      left  empty  if  no manual control is wanted.  An	example	config
	      line may look like this:

	      RepeaterLogic_2m:99:SK3GW,RepeaterLogic_70cm:94:SK3GK

	      It will include two logics in the	link, RepeaterLogic_2m and Re-
	      peaterLogic_70cm.	 From  the 2m side, the	link will be activated
	      when the user send command 991 and  deactivated  when  the  user
	      send  command  990. Upon activation, an announcement like	"acti-
	      vating link to SK3GW" will be played back. From  the  70cm  side
	      the  command  will be 941	and 940	respectively. The announcement
	      when activating the link from the	70cm side  will	 be  something
	      like "activating link to SK3GK".

       DEFAULT_ACTIVE
	      The  link	 will  be  connected  automatically  during startup of
	      SvxLink if this configuration variable is	set to 1. Also,	 if  a
	      link is manually disconnected by a user it will be automatically
	      reconnected after	some time of inactivity. The time is specified
	      by  setting  the	TIMEOUT	configuration variable.	If the TIMEOUT
	      variable is not set, no automatic	reactivation will be done.

       TIMEOUT
	      The number of seconds after which	the link will be automatically
	      deactivated if there have	been no	activity. If 1 have been spec-
	      ified for	DEFAULT_ACTIVE,	this configuration variable will spec-
	      ify  after  how  many seconds the	link will be reactivated after
	      being manually deactivated.

       AUTOACTIVATE_ON_SQL
	      Enter a comma separated list of logics, which  should  automati-
	      cally activate the link if there is activity (e.g. squelch open)
	      in it. One possible application for this is for example to  make
	      the connection of	a microphone/speaker combination (without DTMF
	      encoder) for brief announcements	but  without  having  to  con-
	      stantly listen in.  Example: AUTOACTIVATE_ON_SQL=MicSpkrLogic

   Local Receiver Section
       A local receiver	section	is used	to specify the configuration for a re-
       ceiver connected	to the sound card. In the default  configuration  file
       there  is  a  Local configuration section called	Rx1.  The section name
       could be	anything. It should match the RX configuration variable	in the
       logic  core  where the receiver is to be	used. The available configura-
       tion variables are described below.

       TYPE   Always "Local" for a local receiver.

       RX_ID  A	single char uniquely identifying this receiver.	The  RX	 iden-
	      tity  can	 for  example  be used in the TCL event	scripts	to get
	      different	rogers sounds for different receivers when using a re-
	      ceiver voter.

       AUDIO_DEV
	      Specify  the  audio device to use. Normally oss:/dev/dsp.	Have a
	      look at the AUDIO	DEVICE SPECIFICATIONS chapter for more	infor-
	      mation.

       AUDIO_CHANNEL
	      Specify the audio	channel	to use.	SvxLink	can use	the left/right
	      stereo channels as two mono channels. Legal values are 0 or 1.

       AUDIO_DEV_KEEP_OPEN
	      The normal behaviour for SvxLink is to open an audio device when
	      needed  and  close  it when it does not have to be open anymore.
	      This may cause problems in some applications or with some	 sound
	      hardware.	 Set  this  variable to	1 to force SvxLink to keep the
	      audio device open	from application start to exit.

       SQL_DET
	      Specify the type of squelch detector  to	use.  Possible	values
	      are: VOX,	CTCSS, SERIAL, EVDEV, SIGLEV, PTY, GPIO	or HIDRAW.

	      The VOX squelch detector determines if there is a	signal present
	      by calculating a mean  value  of	the  sound  samples.  The  VOX
	      squelch  detector	behavior is adjusted with VOX_FILTER_DEPTH and
	      VOX_THRESH. VOX is actually a bit	of a  misnomer	since  it's  a
	      "Voice  Operated Squelch"	and VOX	actually means "Voice Operated
	      Transmitter". However, the term VOX is widely understood by hams
	      all over the world so we'll stick	with it.

	      The  CTCSS  squelch  detector  checks for	the presence of	a tone
	      with the specified frequency. The	tone  frequency	 is  specified
	      using  the  CTCSS_FQ config variable.  The thresholds are	speci-
	      fied using the CTCSS_OPEN_THRESH and  CTCSS_CLOSE_THRESH	config
	      variables.  Other	config variables that effect the CTCSS squelch
	      is: CTCSS_MODE, CTCSS_SNR_OFFSET,	CTCSS_BPF_LOW, CTCSS_BPF_HIGH.

	      The SERIAL squelch detector use a	pin in a serial	port to	detect
	      if the squelch is	open. This squelch detector can	be used	if the
	      receiver have an external	hardware indicator of when the squelch
	      is  open.	 Specify which serial port/pin to use with SERIAL_PORT
	      and SERIAL_PIN.

	      The EVDEV	squelch	detector read squelch events from  a  /dev/in-
	      put/eventX  device.  An example where this could be useful is if
	      you have a USB audio device with some buttons  on	 it.  Some  of
	      these  devices  generate key press events, much like a keyboard.
	      Specify which /dev/input device node to use using	the EVDEV_DEV-
	      NAME  config  variable.  Set  which  events that should open and
	      close the	squelch	using the EVDEV_OPEN  and  EVDEV_CLOSE	config
	      variables.

	      The GPIO squelch detector	read a pin on the GPIO Port. Depending
	      on the level of the pin, the squelch is switched.	A HIGH	(3.3V)
	      at  the  pin  set	the squelch to open and	a LOW (GND) level will
	      set the squelch to closed.  Specify which	 squelch  pin  to  use
	      with  the	GPIO_SQL_PIN configuration variable.  On some devices,
	      like the Orange Pi, you also need	to set the GPIO_PATH  configu-
	      ration variable.

	      The SIGLEV squelch detector use signal level measurements	to de-
	      termine if the squelch is	open or	not. Which signal level	detec-
	      tor  to  use is determined by the	setting	of the SIGLEV_DET con-
	      figuration variable. The open and	close thresholds are set using
	      the  SIGLEV_OPEN_THRESH  and  SIGLEV_CLOSE_THRESH	 configuration
	      variables.  If using the NOISE signal level  detector  note  the
	      following. The detector is not perfect (it's affected by speech)
	      so you will also want to setup SQL_HANGTIME to prevent  it  from
	      closing  in  the	middle	of  a  transmission.  A	 value between
	      100-300ms	is probably what you need. If using this squelch  type
	      in  cooperation with a voter, you'll also	probably need to setup
	      SQL_DELAY	to get correct signal level measurements. A  value  of
	      about  40ms  seem	 to  be	OK.  Also, when	using the NOISE	signal
	      level detector the input audio must be unsquelched since silence
	      will be interpreted as a high signal strength.

	      The PTY squelch expects a	very simple protocol over a pseudo-tty
	      device, created by SvxLink at runtime.  An 'O' over this pty de-
	      vice  indicate  an open squelch, a 'Z' is	a closed squelch.  De-
	      fine the slave pty using PTY_PATH	(e.g.  PTY_PATH=/tmp/sql)  and
	      SvxLink will create a link to the	specified path from it's pseu-
	      dotty slave device (/dev/pts/X). This can	be used	by a script to
	      interface	 custom	 devices, modems or other hardware to SvxLink.
	      Look for nhrcx.pl	or trx_pty_ctrl.py for an example.  It is pos-
	      sible to specify the same	PTY for	multiple functions (e.g. DTMF,
	      ptt etc) in both TX and RX configurations. This may be  good  if
	      there is one script handling all functions.

	      The  HIDRAW  squelch supports human interface devices (HID), USB
	      devices like CM108 soundcard  e.g.  used	in  the	 URI  Echolink
	      adapter made by DMK.

       SQL_START_DELAY
	      The  squelch  start delay	is of most use when using VOX squelch.
	      For example, if the transceiver makes a noise when the transmit-
	      ter is turned off, that might trigger the	VOX and	cause an infi-
	      nite loop	of squelch open/close transmitter on/off.  Specify the
	      number  of  milliseconds that the	squelch	should be "deaf" after
	      the transmitter has been turned off.

       SQL_DELAY
	      Specify a	delay in milliseconds that a squelch  open  indication
	      will  be	delayed.   This	odd feature can	be of use when using a
	      fast squelch detector in combination with	the signal  level  de-
	      tector.  A squelch delay will allow the signal level detector to
	      do its work before an indication of squelch open is sent to  the
	      logic  core.  A  delay  might  be	needed when using the voter to
	      choose among multiple receivers. A normal	value could  be	 some-
	      where in between 20-100ms.

       SQL_HANGTIME
	      How  long, in milliseconds, the squelch will stay	open after the
	      detector has indicated that it  is  closed.  This	 configuration
	      variable will affect all squelch detector	types.

       SQL_EXTENDED_HANGTIME
	      At  low  signal  strengths  it can be beneficial to use a	longer
	      squelch hangtime so that it is less likely for  the  squelch  to
	      close.  This configuration variable is unset by default. A value
	      of 1000 milliseconds may be a good value to start	out  with.  To
	      enable the extended squelch hangtime feature, set	up the SQL_EX-
	      TENDED_HANGTIME_THRESH variable.

       SQL_EXTENDED_HANGTIME_THRESH
	      At low signal strengths it can be	beneficial  to	use  a	longer
	      squelch  hangtime	 so  that it is	less likely for	the squelch to
	      close. This configuration	variable is unset by default. When set
	      to a signal level	it will	activate the extended squelch hangtime
	      feature. When the	signal strength	during a transmission fall be-
	      low the set threshold, the extended hangtime will	be used. Start
	      out with a value between 10  to  15.  The	 SQL_EXTENDED_HANGTIME
	      variable	is  used to set	how long the extended squelch hangtime
	      should be. Make sure that	you have calibrated the	 signal	 level
	      detector	before	turning	this feature on. Otherwise it will not
	      work as expected.

       SQL_TIMEOUT
	      Use this configuration variable to set an	upper limit,  in  sec-
	      onds,  for  how  long  the squelch is allowed to be open.	If the
	      timeout value is exceeded	the squelch is forced  to  closed.  If
	      the  squelch  close for real, everything is back to normal. When
	      it opens the next	time a squelch open will be signaled.  For ex-
	      ample, use this feature to make sure that	a faulty receiver can-
	      not block	the system indefinitely.

       VOX_FILTER_DEPTH
	      The number of milliseconds to create  the	 mean  value  over.  A
	      small  value  will  make the vox react quicker (<200) and	larger
	      values will make it a little bit more sluggish. A	small value is
	      often better.

       VOX_THRESH
	      The threshold that the mean value	of the samples must exceed for
	      the squelch to be	considered open. It's hard to say  what	 is  a
	      good  value. Something around 1000 is probably a good value. Set
	      it as low	as possible without getting the	vox to false trigger.

       CTCSS_MODE
	      This configuration variable set the CTCSS	detection method used.
	      These are	the ones to choose from:

	      o	  0  (Default)	Will choose the	detection mode that is the de-
		  fault	in the software. At the	moment this is the  "Estimated
		  SNR" mode.

	      o	  1  (Neighbor bins) This detection mode will use three	narrow
		  frequency bands (~8Hz) to do the detection. One band is cen-
		  tered	 around	the tone to be detected	and then there are one
		  band above and one below the tone. These bands are  used  to
		  estimate  the	 noise	floor.	This is	the detector that have
		  been used in SvxLink for a long time.	It is  however	rather
		  slow	with  its  detection time of about 450ms.  There is no
		  good reason to use this detector anymore but it is  kept  in
		  case the new detector	does not work for some hardware	setup.

	      o	  2  (Estimated	 SNR)  This is a newer detector	implementation
		  which	have some improvements.	The most notable difference is
		  that	it  is	faster.	The mean detection time	will be	around
		  200ms. This is the default detection mode if not  specified.
		  This	detector  will	use  a larger passband to estimate the
		  noise	floor which make it more stable.  The  default	config
		  use  the whole CTCSS passband	but this can be	customized us-
		  ing the CTCSS_BPF_LOW	and CTCSS_BPF_HIGH config variables.

	      o	  3 (Estimated SNR+Phase) This detector	is a bit experimental.
		  It  is  even faster and more narrow than the other detection
		  modes. The mean detection time will be something like	150ms.
		  The  detection  bandwidth  is	 very narrow and very sharp so
		  that no adjacent tones will trigger the detector. The	 price
		  to  pay for these improvements is that is it a bit less sen-
		  sitive.

       CTCSS_FQ
	      If CTCSS (PL,subtone) squelch is used (SQL_DET is	set to CTCSS),
	      this  config variable sets the frequency of the tone to use. The
	      tone frequency ranges from 67.0 to 254.1 Hz. There  actually  is
	      nothing  that  will stop you from	setting	the frequency to some-
	      thing outside this range but there is no guarantee that it  will
	      work.

       CTCSS_OPEN_THRESH
	      If  CTCSS	 (PL,  subtone)	 squelch  is  used  (SQL_DET is	set to
	      CTCSS), this config variable sets	the required tone level	to in-
	      dicate  squelch open. The	value is some kind of estimated	signal
	      to noise dB value. If using CTCSS	mode 2 or 3 it is  helpful  to
	      set  up the CTCSS_SNR_OFFSET config variable. This will make the
	      SNR estimation pretty good. Default threshold is 15dB.

       CTCSS_CLOSE_THRESH
	      If CTCSS (PL, subtone)  squelch  is  used	 (SQL_DET  is  set  to
	      CTCSS), this config variable sets	the required tone level	to in-
	      dicate squelch close. The	value is some kind of estimated	signal
	      to  noise	 dB value. If using CTCSS mode 2 or 3 it is helpful to
	      set up the CTCSS_SNR_OFFSET config variable. This	will make  the
	      SNR estimation pretty good. Default threshold is 9dB.

       CTCSS_SNR_OFFSET
	      This  config  variable is	used when CTCSS_MODE is	set to 0, 2 or
	      3. It will adjust	the estimated SNR value	 so  that  it  becomes
	      very  close  to a	real SNR value.	This value will	have to	be ad-
	      justed if	CTCSS_FQ, CTCSS_MODE, CTCSS_BPF_LOW or	CTCSS_BPF_HIGH
	      changes.	 Use  the siglevdetcal utility to find out what	to set
	      this config variable to.	There is no requirement	 to  set  this
	      config  variable	up. The	downside is that you will then need to
	      experiment    more    with     the     CTCSS_OPEN_THRESH	   and
	      CTCSS_CLOSE_THRESH  config variables to find the correct squelch
	      level.

       CTCSS_BPF_LOW
	      When CTCSS_MODE is set to	0, 2 or	3, this	config	variable  will
	      set  the	low  cutoff frequency for the passband filter. It nor-
	      mally should not have to be adjusted but could improve  the  de-
	      tector  if  some	interference  falls  within the	passband (e.g.
	      mains hum). Note however that the	more narrow you	make the pass-
	      band, the	less stable the	detector will be. You may need to com-
	      pensate by increasing the	open/close thresholds or by setting up
	      SQL_DELAY	and SQL_HANGTIME. Default is 60Hz.

       CTCSS_BPF_HIGH
	      When  CTCSS_MODE	is set to 0, 2 or 3, this config variable will
	      set the high cutoff frequency for	the passband filter.  It  nor-
	      mally  should  not have to be adjusted but could improve the de-
	      tector if	some interference falls	within the passband. Note how-
	      ever that	the more narrow	you make the passband, the less	stable
	      the detector will	be. You	may need to compensate	by  increasing
	      the  open/close  thresholds  or  by  setting  up	SQL_DELAY  and
	      SQL_HANGTIME. Default is 270Hz.

       SERIAL_PORT
	      If SQL_DET is set	to SERIAL,  this  config  variable  determines
	      which serial port	should be used for hardware squelch input (COS
	      -	Carrier	Operated Squelch).  Note: If the same serial  port  is
	      used  for	the PTT, make sure you specify exactly the same	device
	      name. Otherwise the RX and TX will not  be  able	to  share  the
	      port.  Example: SQL_PORT=/dev/ttyu0

       SERIAL_PIN
	      If  SQL_DET  is  set  to SERIAL, this config variable determines
	      which pin	in the serial port that	should be  used	 for  hardware
	      squelch  input  (COS - Carrier Operated Squelch).	It is possible
	      to use the DCD, CTS, DSR or RI pin. If inverted operation	is de-
	      sired, prefix the	pin name with an exclamation mark (!).

	      Example: SQL_PIN=!CTS

       SERIAL_SET_PINS
	      Set  the	specified serial port pins to a	static state. This can
	      be good if using a pin for reference voltage or if a pin have to
	      be  in  a	 certain  state	to not interfere with the operation of
	      some equipment. There are	two pins that are possible to use, RTS
	      and  DTR.	If prefixed with an exclamation	mark (!), the pin will
	      be cleared and if	not it will be set.

	      Example: SERIAL_SET_PINS=RTS!DTR will set	RTS and	clear DTR.

       EVDEV_DEVNAME
	      Specify which /dev/input	device	node  to  use  for  the	 EVDEV
	      squelch detector.	 To find out which device node and event codes
	      to use, install the evtest utility. Find a candidate device node
	      under  /dev/input/ or /dev/input/by-id/ and try the evtest util-
	      ity on it. Press some keys on the	device you want	to read	events
	      from. If you're in luck, events will be printed on the screen.

       EVDEV_OPEN
	      Use  the	evtest	utility, as described above, to	find out type,
	      code and value for the  event  you  want	to  use	 to  open  the
	      squelch.	For  example if	type is	1, code	is 163 and value is 1,
	      set this config variable to 1,163,1.

       EVDEV_CLOSE
	      Use the evtest utility, as described above, to  find  out	 type,
	      code  and	 value	for  the  event	 you  want to use to close the
	      squelch. For example if type is 1, code is 163 and value	is  0,
	      set  this	 config	 variable  to  1,163,0.	 If  you  set the same
	      type,code,value combination for both EVDEV_OPEN and EVDEV_CLOSE,
	      that event will toggle the squelch.

       GPIO_PATH
	      Use  this	configuration variable to set the path to the sys con-
	      trol devices for GPIO.  This normally is /sys/class/gpio but  on
	      some    hardware,	   like	  the	Orange	 Pi,   the   path   is
	      /sys/class/gpio_sw.

       GPIO_SQL_PIN
	      If SQL_DET is set	to GPIO	this configuration variable is used to
	      choose  which GPIO pin to	use for	squelch	input. The most	common
	      name is gpio<number>, like gpio4.	Some  GPIO  drivers  use  more
	      complex  names,  like  gpio33_pe11. If inverted operation	is de-
	      sired, prefix the	pin name with an exclamation mark (!).

	      Example: GPIO_SQL_PIN=!gpio4

       SIGLEV_DET
	      Choose which type	of signal level	detector to use. The available
	      choices are: "NONE", "NOISE", "TONE", "AFSK" or "SIM". Depending
	      on other configuration there may be more choices available.  For
	      example, if a Ddr	receiver is used there will also be a DDR sig-
	      nal level	detector available.  The   signal  level  detector  is
	      only  needed when	using multiple receivers in a voter configura-
	      tion or when using the SIGLEV squelch type.

	      Type NONE	disable	the signal level detector. This	may be used if
	      no signal	level detector is needed.

	      Type  NOISE  use	a  bandpass  filter in the range of 5 -	5.5kHz
	      (CARD_SAMPLE_RATE	>= 16000) or  a	 high-pass  filter  at	3.5kHz
	      (CARD_SAMPLE_RATE	 =  8000)  to  estimate	 the  amount  of noise
	      present on the signal. If	the passband contain a small amount of
	      energy, a	strong signal is assumed. If the passband contain more
	      energy, a	weaker signal is assumed.  The noise detector must  be
	      calibrated  for  the  receiver and audio levels you use. This is
	      done using  the  SIGLEV_SLOPE  and  SIGLEV_OFFSET	 configuration
	      variables. See chapter CALIBRATING THE SIGNAL LEVEL DETECTOR be-
	      low for more information.

	      Type TONE	is not really a	signal level  detector	but  rather  a
	      transport	mechanism for getting signal level measurements	from a
	      remote receiver site, linked in via  RF,	to  the	 main  SvxLink
	      site.  It	is using ten tones, one	for each signal	level step, in
	      the high audio frequency spectrum	(5.5 - 6.4kHz, 100Hz step)  to
	      indicate one of ten signal levels.  Only the receiving part have
	      been implemented in SvxLink at the moment.  On  the  remote  re-
	      ceiver side an Atmel AVR ATmega8 is used to map the signal level
	      voltage to tone frequencies.  Use	the TONE_SIGLEV_MAP configura-
	      tion  variable  to map each tone to a corresponding signal level
	      value in between 0 - 100.

	      Type AFSK	is like	the TONE detector really  a  transport	mecha-
	      nism.  Signal level values are transmitted using Audio Frequency
	      Shift Keying, AFSK, over the receiver uplink channel from	a  re-
	      mote  receiver  site.  AFSK  reception must have been enebled by
	      setting OB_AFSK_ENABLE=1 and also	optionally IB_AFSK_ENABLE=1.

	      Type SIM is a simulated signal level detector that can  be  used
	      to  debug	 problems in the SvxLink software. Use the SIGLEV_MIN,
	      SIGLEV_MAX,    SIGLEV_DEFAULT,	SIGLEV_TOGGLE_INTERVAL	   and
	      SIGLEV_RAND_INTERVAL  configuration  variables  to configure the
	      simulator.

       HID_DEVICE
	      This parameter defines the device	your hidraw  adapter  is  con-
	      nected  to.  This	 port  is  created by the linux/hidraw driver.
	      e.g. HID_DEVICE=/dev/hidraw3

       HID_SQL_PIN
	      Define the pin your hardware squelch (from RX) is	connected  to.
	      Valid values are VOL_UP, VOL_DN, MUTE_PLAY or MUTE_REC.

	      Example: HID_SQL_PIN=VOL_UP

       SIGLEV_SLOPE
	      The  slope  (or  gain) of	the signal level detector. See chapter
	      CALIBRATING THE SIGNAL LEVEL DETECTOR below  for	more  informa-
	      tion.

       SIGLEV_OFFSET
	      The offset of the	signal level detector. See chapter CALIBRATING
	      THE SIGNAL LEVEL DETECTOR	below for more information.

       SIGLEV_BOGUS_THRESH
	      This configuration variable set an upper threshold for the esti-
	      mated  signal  level when	using the noise	signal level detector.
	      If the estimation	goes over the given threshold, a signal	 level
	      of 0 will	be reported. This can be used as a workaround when us-
	      ing a receiver with squelched audio output. When the squelch  is
	      closed, the receiver audio is silent. The	signal level estimator
	      will interpret this as a very strong signal. Setting up the  bo-
	      gus  signal  level threshold will	counteract this	behavior but a
	      better solution is to use	unsquelched audio if possible.

	      By default this feature is disabled. If enabling it, start  with
	      a	value somewhere	around 120.

       TONE_SIGLEV_MAP
	      This configuration variable is used to map tones to signal level
	      values when SIGLEV_DET=TONE. It is a comma separated list	of ten
	      values  in  the 0	- 100 range. The first value map to the	5500Hz
	      tone, the	second to the 5600Hz tone and so on.  The  last	 value
	      map  to the 6400Hz tone.	What levels the	tones should be	mapped
	      to depends on the	tone sender implementation. The	 default  tone
	      map is 10,20,30...,100.

	      The  Atmel  AVR processor	used by	the author have	a reverse map-
	      ping so that the first tone (5500Hz) indicate the	highest	signal
	      strength	and  the last tone (6400Hz) indicate the lowest	signal
	      strength.	It is also not linear since  it's  more	 important  to
	      have  fine  measurement granularity in the lower signal strength
	      range.  This  is	 how   the   mapping   look   for   the	  AVR:
	      100,84,60,50,37,32,28,23,19,8.

       SIGLEV_OPEN_THRESH
	      This is the squelch open threshold for the SIGLEV	squelch	detec-
	      tor.  If using the NOISE signal level  detector,	make  sure  to
	      first calibrate the signal level detector	using the SIGLEV_SLOPE
	      and SIGLEV_OFFSET	configuration variables. The signal level  de-
	      tector  should  normally	be  calibrated	so  that  full	signal
	      strength is 100 and no signal is 0. Depending on your background
	      noise  level a good value	for this configuration variable	is be-
	      tween 5 and 20.

       SIGLEV_CLOSE_THRESH
	      This is the squelch close	threshold for the SIGLEV  squelch  de-
	      tector.	If using the NOISE signal level	detector, make sure to
	      first calibrate the signal level detector	using the SIGLEV_SLOPE
	      and  SIGLEV_OFFSET configuration variables. The signal level de-
	      tector  should  normally	be  calibrated	so  that  full	signal
	      strength is 100 and no signal is 0. Depending on your background
	      noise level a good value for this	configuration variable is  be-
	      tween 1 and 10.

       SIGLEV_MIN
	      The minimum signal level used by SIM signal level	detector.

       SIGLEV_MAX
	      The maximum signal level used by SIM signal level	detector.

       SIGLEV_DEFAULT
	      The  default signal level	set on startup by the SIM signal level
	      detector.

       SIGLEV_TOGGLE_INTERVAL
	      The interval, in milliseconds, that the SIM signal level	detec-
	      tor  will	use to toggle between the maximum and the minimum sig-
	      nal levels.

       SIGLEV_RAND_INTERVAL
	      The interval, in milliseconds, that the SIM signal level	detec-
	      tor  will	 use  between randomizing a new	signal level value. At
	      each interval, the simulator will	randomly  either  increase  or
	      decrease the signal level	with one step.

       DEEMPHASIS
	      Apply a deemphasis filter	on received audio. The deemphasis fil-
	      ter is used when taking audio directly from the detector in  the
	      receiver,	 like  when using a 9k6	packet radio connector.	If not
	      using a deemphasis filter	the high frequencies will be amplified
	      resulting	in a very bright (tinny) sound.

       SQL_TAIL_ELIM
	      Squelch tail elimination is used to remove noise from the	end of
	      a	received transmission. This is of most use when	using CTCSS or
	      SIGLEV squelch with unsquelched input audio. A normal value is a
	      couple of	hundred	milliseconds.  Note that the audio will	be de-
	      layed  by	 the same amount of milliseconds. This does not	matter
	      much for a simplex link but for a	repeater the  delay  might  be
	      annoying	since  you  risk hearing the end of your own transmis-
	      sion.

       PREAMP The incoming signal will be amplified by the specified number of
	      dB.  This	can be used as a last measure if the input audio level
	      can't be set high	enough on the analogue side. A	value  of  6dB
	      will double the signal level. Note that this is a	digital	ampli-
	      fication.	Hence it will reduce the dynamic range of  the	signal
	      so  usage	 should	 be avoided if possible. It's always better to
	      correct the audio	level before sampling it.

       PEAK_METER
	      This is a	help to	adjust the incoming audio level. If enabled it
	      will  output a message when distortion occurs. To	adjust the au-
	      dio level, first open the	squelch. Then increase the audio level
	      until  warning  messages	are printed.  Decrease the audio level
	      until no warning messages	are printed. After the adjustment  has
	      been  done,  the	peak  meter can	be disabled. 0=disabled, 1=en-
	      abled.

       DTMF_DEC_TYPE
	      Specify the DTMF decoder type. Set it to INTERNAL	to use the in-
	      ternal  software DTMF decoder. To	use the	S54S interface featur-
	      ing a hardware DTMF decoder, set it to S54S.  To control it over
	      a	 pseudo	 tty device set	it to PTY.  Setting it to PTY will in-
	      stall the	PTY dtmf decoder. SvxLink creates a symlink linked  to
	      a	 slave	pty device on runtime. The name	has to be defined with
	      DTMF_PTY.	  If  AFSK  reception  is  enabled  using  OB_AFSK_EN-
	      ABLE/IB_AFSK_ENABLE,  remotely  decoded  DTMF  digits may	be re-
	      ceived by	setting	this configuration variable to AFSK.  NONE  or
	      commenting it out	will disable DTMF detection.

       DTMF_MUTING
	      Mute  the	 audio	during the time	when a DTMF digit is being re-
	      ceived. Note that	the audio will be delayed  75ms	 to  give  the
	      DTMF detector time to do its work.  This does not	matter much on
	      a	simplex	link but on a repeater it could	be annoying since  you
	      will hear	the last 75 milliseconds of your own transmission.  To
	      counteract the added delay one can set up	the SQL_TAIL_ELIM con-
	      figuration  variable  to at least	75 milliseconds.  Legal	values
	      for DTMF_MUTING are 0=disabled, 1=enabled.

       DTMF_HANGTIME
	      This configuration variable can be used if the DTMF  decoder  is
	      too  quick  to indicate digit idle. That does not	matter at high
	      signal strengths but for weaker signals and mobile flutter  it's
	      not  good	 at  all.  Each	 DTMF  digit will be detected multiple
	      times.  Using this configuration variable, the time (ms) a  tone
	      must  be missing to be indicated as off can be extended. Setting
	      this value too high will cause the decoder to be a bit  sluggish
	      and it might consider two	digits as one.	The hang time only af-
	      fect consecutive digits of the same value	(e.g. 1	1).  If	a  de-
	      tected  digit  differs from the previously detected digit	(e.g 1
	      2), the hang time	is immediately canceled	and the	detected digit
	      is considered as a new one. A good default value is 50-100ms.

       DTMF_SERIAL
	      When  using  an external hardware	DTMF decoder this config vari-
	      able is used to specify a	serial port (e.g. /dev/ttyu0).

       DTMF_PTY
	      When using the PTY DTMF "decoder"	 this  configuration  variable
	      will  set	 the  path to the PTY slave softlink that the external
	      interface	script use to communicate to SvxLink. Over this	 soft-
	      link  a  very  simple  communication  protocol is	used to	notify
	      SvxLink about received DTMF digits: 0-9, A-F, *, #. "E"  is  the
	      same  as	"*"  and  "F" is the same as "#". Sending a digit tell
	      SvxLink when it starts. To  tell	SvxLink	 that  the  digit  has
	      ended, send a space character.

	      The  PTY DTMF "decoder" can be used by an	external script	to in-
	      terface custom devices, modems or	 other	hardware  to  SvxLink.
	      Look for nhrcx.pl	or trx_pty_ctrl.py for an example.

	      It  is  possible	to specify the same PTY	for multiple functions
	      (e.g. squelch, ptt etc) in both TX and RX	 configurations.  This
	      may be good if there is one script handling all functions.

	      Example: /tmp/rx1_dtmf.

       DTMF_MAX_FWD_TWIST
	      DTMF  use	 two  tones to encode digits 0-9, A-F. These two tones
	      should normally have the sample amplitude. The difference	in am-
	      plitude  is  called twist. Forward twist is when the higher fre-
	      quency tone is lower in amplitude	than the lower frequency tone.
	      According	to the standards, 8dB forward twist should be allowed.
	      Some transmitters	do not correctly modulate the  DTMF  tones  to
	      get  zero	 twist.	 The most common situation is that the forward
	      twist is too large. Increasing this configuration	variable above
	      8dB  might  allow	 DTMF  from these transmitters to be detected.
	      When doing this, the DTMF	detector will  be  more	 sensitive  to
	      noise and	might cause more false triggers.

       DTMF_MAX_REV_TWIST
	      DTMF  use	 two  tones to encode digits 0-9, A-F. These two tones
	      should normally have the sample amplitude. The difference	in am-
	      plitude  is  called  twist. Reverse twist	is when	the lower fre-
	      quency tone is lower in  amplitude  than	the  higher  frequency
	      tone.  According	to  the	standards, 4dB reverse twist should be
	      allowed but SvxLink will allow 6dB by default.  The most	common
	      reason  for getting reverse twist	is a bad de-emphasis filter or
	      that none	at all is used,	like when taking audio	directly  from
	      the  FM  discriminator. Have a look at the DEEMPHASIS configura-
	      tion variable before starting to modify this configuration vari-
	      able.

       DTMF_DEBUG
	      Set  to  1  to continuously print	software DTMF decoder decision
	      parameters. This should only be used for a short while  to  pin-
	      point  problems  with  the DTMF decoding since it	will print one
	      row of analysis parameters 100 times per second.	The  following
	      parameters are printed.

	      o	  pwr  -  The  power  in  the audio signal. Must be over about
		  -50dB.

	      o	  q - Quality. Should be close to 1.00 for a  good  detection.
		  If  the  signal  is  strong but the value is low anyway, the
		  signal probably is distorted for some	reason.	The input  au-
		  dio level may	be too high for	example.

	      o	  twist	 -  The	 amplitude  difference	between	the two	tones.
		  Should be around 0dB,	which means the	tones  should  ideally
		  be  of the same strength. By default,	values between -6dB to
		  +8dB are accepted but	the thresholds can be  set  using  the
		  DTMF_MAX_FWD_TWIST   and   DTMF_MAX_REV_TWIST	 configuration
		  variables.

	      o	  rowq - Quality of the	row (low group)	tone. Should be	 close
		  to one.

	      o	  colq	-  Quality  of the column (high	group) tone. Should be
		  close	to one.

	      o	  digit	- The digit mapped to the two detected tones.

	      o	  row3rd - The	row  tone  relation  to	 its  third  overtone.
		  Should be close to zero. If it's not,	the signal is probably
		  distorted.

	      o	  col3rd - The column tone relation  to	 its  third  overtone.
		  Should be close to zero. If it's not,	the signal is probably
		  distorted.

	      o	  im - The relation of the two tones to	their  intermodulation
		  product.   Should  be	close to zero. If it's not, the	signal
		  is probably distorted.

       1750_MUTING
	      Mute the audio during a call tone	of 1750Hz  is  received.  Note
	      that  the	 audio	will be	delayed	75ms to	give the tone detector
	      time to do its work.  This does not matter  much	on  a  simplex
	      link  but	on a repeater it could be annoying since you will hear
	      the last 75 milliseconds of your own transmission.  To  counter-
	      act  the added delay one can set up the SQL_TAIL_ELIM configura-
	      tion variable to at least	75  milliseconds.   Legal  values  for
	      1750_MUTING are 0=disabled, 1=enabled.

       SEL5_TYPE
	      Define here your selective tone call system. You have the	choice
	      of the following types:  ZVEI1,  ZVEI2,  ZVEI3,  PZVEI,  PDZVEI,
	      DZVEI,  CCITT, EEA, CCIR1, CCIR2,	NATEL, EURO, VDEW, AUTO-A, MO-
	      DAT, PCCIR and EIA. Only one system can  be  used	 at  the  same
	      time.  Please  take  into	consideration that some	Sel5 standards
	      are using	the same or similar tones so it	may have some unwanted
	      effects  if  you define ZVEI1 for	SvxLink	and a (e.g.) ZVEI3 se-
	      quence is	received.

       SEL5_DEC_TYPE
	      At the moment only SEL5_DEC_TYPE=INTERNAL	 is  valid.  Maybe  we
	      have  support for	some external tone detectors later. To disable
	      SEL5 tone	decoding, specify NONE or just comment the  configura-
	      tion variable out.

       RAW_AUDIO_UDP_DEST
	      Setting  this configuration variable makes it possible to	stream
	      the raw audio from the sound device to an	UDP socket. The	sample
	      format  is the one used internally in SvxLink, that is each sam-
	      ple is represented by a 32 bit float.  The sample	 rate  is  the
	      same as the one chosen for the audio device.  The	destination is
	      specified	as ip-address:port.

	      Example: RAW_AUDIO_UDP_DEST=127.0.0.1:10000

       OB_AFSK_ENABLE
	      Set to 1 to enable reception of metadata like signal level  mea-
	      surements,  DTMF digits and tone detections via out-of-band (OB)
	      AFSK. The	out-of-band AFSK is transmitted	above the  voice  band
	      so  that it is possible to transmit AFSK bursts at the same time
	      as someone is speaking. The AFSK bursts are filtered out	before
	      the  audio is handed on to the next stage	so normal users	should
	      never hear the AFSK bursts. The AFSK feature is  typically  used
	      on  a  remote receiver uplink. The protocol used is SvxLink spe-
	      cific. Data is transmitted in 300Bd with a shift of 170Hz	and  a
	      center  frequency	 of 5500Hz. The	RemoteTrx application have the
	      capability to transmit this protocol.

       OB_AFSK_VOICE_GAIN
	      To be able to send both voice and	AFSK at	the same time  it  may
	      be  necessary  to	 lower	the level of the voice audio as	to not
	      overdrive	the transmitter. This is compensated in	the  link  re-
	      ceiver by	amplifying the voice audio back	to its original	level.
	      This configuration variable should thus be set  to  the  negated
	      value of the same	configuration variable in the transmitter sec-
	      tion of the transmitting RemoteTrx. If it's set to -6dB  in  the
	      transmitter configuration	it should be set to 6dB	here.

       IB_AFSK_ENABLE
	      Set to 1 to enable reception of an initial signal	level measure-
	      ment via in-band (IB) AFSK. This is used in cooperation with the
	      out-of-band AFSK feature to quickly transfer a signal level mea-
	      surement to get the squelch opened. The in-band AFSK  is	trans-
	      mitted in	the voice band and can thus use	the higher baudrate of
	      1200Bd. Since it's only transmitted when the squelch  is	closed
	      the  end	user will not hear the AFSK burst. The AFSK feature is
	      typically	used on	a remote receiver uplink. The protocol used is
	      SvxLink  specific. Data is transmitted in	1200Bd with a shift of
	      1000Hz and a center frequency of 1700Hz.	The RemoteTrx applica-
	      tion have	the capability to transmit this	protocol.

       CTRL_PTY
	      Set  this	configuration variable to the path of a	PTY to use for
	      controlling a receivers frequency	and modulation.	 This  can  be
	      used  to	interface  a  receiver	to SvxLink using a translation
	      script, like trx_pty_ctrl.py.  To	 set  the  receive  frequency,
	      SvxLink  will  send  the sequence	"f<frequency>;". The frequency
	      will be in Hz, e.g. f145550000; will be sent to set the receiver
	      to 145.550MHz.

	      To  set  the modulation the command is "m<modulation>;". Look at
	      the documentation	of the MODULATION  configuration  variable  to
	      see  which modulations that are available. To set	"normal" 25kHz
	      channel spaced FM	the command would be mFM;.

	      It is possible to	specify	the same PTY  for  multiple  functions
	      (e.g.  squelch,  ptt etc)	in both	TX and RX configurations. This
	      may be good if there is one script handling all functions.

   Ddr Receiver	Section
       A special kind of local receiver	is the Digital Drop Receiver (DDR). It
       will  use  either the rtl_tcp utility or	a direct USB connection	to in-
       terface to a RTL2832U based DVB-T USB dongle and	use that  as  a	 wide-
       band receiver. These USB	dongles	can be bought cheaply from an Internet
       shop (~$10). The	radio performance may not be great but better than one
       might  think. Usage as a	cheap local coverage receiver or as a link re-
       ceiver may work very well.

       One big advantage of using a wide-band receiver is that it is  possible
       to  monitor more	than one narrow	band channel at	a time.	The only limit
       is the CPU power	and the	bandwidth of the wide-band tuner. You probably
       need a Pentium4 or better to fulfill the	CPU demands.

       Getting	the DVB-T dongle running is out	of scope for this document but
       what you	absolutely need	to do is to find out the  frequency  error  on
       your  specific dongle. When you have figured out	what the frequency er-
       ror is, set up the FQ_CORR configuration	variable in the	wide-band  re-
       ceiver configuration section.

       The  rtl_tcp  utility  is  in a package named similar to	something like
       rtl-sdr.	 When  you  have  the  rtl-sdr	stuff  installed,  just	 start
       rtl_tcp.	No command line	arguments are needed. Then configure a Ddr re-
       ceiver in SvxLink. All configuration variables that are	available  for
       an ordinary local receiver is also available for	a Ddr receiver,	except
       the audio device	related	ones which are	just  ignored.	The  following
       configuration variables are available in	addition to the	ordinary ones.

       FQ     The narrow-band channel frequency	to tune	to.

       MODULATION
	      The modulation used on the channel. Legal	values are: "FM" (two-
	      way radio	frequency modulation), "NBFM"  (two-way	 radio	narrow
	      frequency	 modulation),  "WBFM"  (broadcast  wide-band frequency
	      modulation), "AM"	(two-way radio amplitude  modulation),	"NBAM"
	      (two-way	radio  narrow band amplitude modulation), "USB"	(Upper
	      Sideband), "LSB" (Lower Sideband), "CW" (Continuous  Wave,  e.g.
	      Morse), "WBCW" (CW wide).

       WBRX   The  configuration section for the wide-band receiver to connect
	      this DDR to.  See	"wide-band Receiver Section" below.

       SIGLEV_DET
	      For a Ddr	there also is a	special	signal level  detector	avail-
	      able,  DDR,  that	will measure the RF power before demodulation.
	      This is much more	reliable  than	estimating  the	 signal	 power
	      through  the audio which is normally done	in SvxLink.  The draw-
	      back is that the Ddr signal level	is not	completely  comparable
	      to  the ordinary SvxLink signal level measurements since it have
	      a	larger dynamic range. Set SIGLEV_DET=DDR to activate  the  Ddr
	      signal level detector.

   Wide-band Receiver Section
       A wide-band receiver section is used to configure access	to a wide-band
       receiver	which can be used by a Digital Drop Receiver (DDR),  described
       above, to handle	multiple narrow-band channels using the	same hardware.
       The only	hardware supported at the moment is RTL2832U based  DVB-T  USB
       dongles.	 SvxLink  access  the  dongle  directly	via USB	or through the
       rtl_tcp utility,	which make the dongle available	on a TCP network port.
       The following configuration variables are available:

       TYPE   The  type	 of wide-band receiver used. The only supported	values
	      right now	are "RtlTcp" and "RtlUsb".

       DEV_MATCH
	      When using RtlUsb, this configuration variable is	used to	select
	      the dongle to use	if there are multiple dongles connected	to the
	      computer.	When looking for dongles, SvxLink will	try  to	 match
	      the  string  given  in  this configuration variable in different
	      ways. First, if it's a digit, a match against the	 device	 index
	      is  tried.  The device index is just a number, zero and up, that
	      is given to a dongle when	it's inserted.

	      If the device index does not match, a match against  the	begin-
	      ning, end	or the whole serial number will	be tried.

	      Default: 0 (first	device found)

       HOST   The name of the host that	the rtl_tcp utility is running on (De-
	      fault: localhost).

       PORT   The TCP port that	rtl_tcp	is listening on	(Default: 1234).

       SAMPLE_RATE
	      The sample rate used by the dongle. Legal	values are 960000  and
	      2400000 (Default:	960000).

       FQ_CORR
	      This is probably the most	important configuration	variable. Most
	      dongles are far off in frequency so they need to be  calibrated.
	      Calibrating  the dongle can be done in multiple ways. The	recom-
	      mended way is to use the	devcal	utility	 that  is  distributed
	      along  with  SvxLink.  The calibration procedure is described in
	      the devcal (1) manual page.

	      The end result should be a correction value for how far off  the
	      dongle  is in frequency counted in parts per million (PPM). That
	      is, how many Hz per MHz is the tuner off by. Typical values  are
	      in the range -100	to 100.

       CENTER_FQ
	      The  frequency, in Hz, that the wide-band	tuner should be	placed
	      at. This configuration variable should normally  be  left	 unset
	      since SvxLink will try to	place the wide-band tuner to cover all
	      set up Ddr frequencies. SvxLink will also	try to avoid placing a
	      Ddr  on  the  center  frequency  of the wide-band	spectrum since
	      there is usually some noise there. Only use  this	 configuration
	      variable	if  you	 need  to override the automatic placement for
	      some reason.

       XVRTR_OFFSET
	      If a transverter is used,	this configuration variable can	be set
	      to the frequency offset that the transverter introduce. The fre-
	      quency set here will be added to the  center  frequency  of  the
	      wide-band	receiver.

       GAIN   If unset,	automatic gain is used.	Do not use automatic gain con-
	      trol if using the	DDR signal level detector. That	 may  mess  up
	      the  measurements.  Finding a good gain setting may be hard. Too
	      little and you will not hear the signals you want	to  hear.  Too
	      much  and	 the  tuner will be driven into	distortion. One	way to
	      decide the maximum usable	gain is	 to  use  the  PEAK_METER  ex-
	      plained  below.	When  there are	no distortion warning messages
	      printed or just a	single one now and then	you have found the max
	      gain.  You should	probably back at least one step	down from this
	      value. If	the signals you	want to	receive	are very  strong,  set
	      the gain as low as possible.

	      What  gain values	that are available is tuner dependent. SvxLink
	      will print the available gain values  when  it  establishes  the
	      connection  to the tuner.	Typical	values are in the range	-10 to
	      50dB.

       PEAK_METER
	      If PEAK_METER is set to 1, a warning will	be printed every  time
	      the tuner	is driven into distortion. If it happens too often the
	      gain should be lowered.  At most,	one warning per	second will be
	      printed.

   LocalSim Receiver Section
       A simulated local receiver can be used to debug problems	in the SvxLink
       software.  The only thing that this very	simple simulator  does	is  to
       play a tone. The	generated tone can be controlled using some configura-
       tion variables.

       SIM_WAVEFORM
	      Set the waveform to use; SIN=sine	wave, SQUARE=square wave.

       SIM_TONE_FQ
	      Set the frequency	of the tone in Hz.

       SIM_TONE_PWR
	      Set the tone power in dB.	0dB corresponds	 to  the  power	 in  a
	      full-scale sine wave.

   Voter Section
       Receiver	 type "Voter" is a "receiver" that combines multiple receivers
       and selects one of them to take audio  from  when  the  squelch	opens.
       Which  receiver	to  use	is selected directly after squelch open. It is
       possible	to set up a voting delay which will  make  the	voter  wait  a
       while  before  choosing	which RX to use.  This will give all receivers
       some time to report their signal	strengths.  After the  initial	choice
       have  been made a periodic check	is done	to see if any of the other re-
       ceivers receive a stronger signal.  In the default  configuration  file
       there is	a voter	section	called Voter.

       TYPE   Always "Voter" for a voter.

       RECEIVERS
	      Specify  a  comma	 separated  list  of  receivers	that the voter
	      should use.  Optionally the receiver name	may be followed	 by  a
	      colon  and a squelch delay value.	This can be used to adjust the
	      voting delay for receivers that always are slower	 to  open  for
	      some  reason.  The delay value given will	be subtracted from the
	      voting delay if the receiver is the first	one to open.

	      The usage	of the delay value is best illustrated with  an	 exam-
	      ple.   Let's  say	 we  have three	receivers where	two of the re-
	      ceivers take at most 100ms to report signal level	 and  one  re-
	      ceiver  requires	300ms. We then need to set the VOTING_DELAY to
	      something	like 350ms so as to be sure that all receivers	get  a
	      chance  to  report  their	 signal	level measurement. If only the
	      slow  receiver  opens  there  will   be	a   total   delay   of
	      300+350=650ms.  This  is	unnecessarily long since the other two
	      receivers	should have reported their signal  strength  way  ear-
	      lier.  It's  thus	 safe to shorten the voting delay for the slow
	      receiver,	so we do  this:	 RECEIVERS=FastRx1,FastRx2,SlowRx:200.
	      The  total  squelch open delay will now be 100+350=450ms for the
	      fast receivers and 300+350-200=450ms for the slow	receiver. That
	      is, all receivers	are now	equally	fast.

	      Example: RECEIVERS=Rx1,Rx2:200,Rx3

       VOTING_DELAY
	      Specify the delay	in milliseconds	that the voter will wait after
	      the first	squelch	open detection until the decision of which re-
	      ceiver  to  use is made. This time must be set sufficiently high
	      to allow all receivers to	calculate and report the signal	level.
	      Incoming	audio  and  DTMF  digits  will be buffered for all re-
	      ceivers during the delay time so nothing will be	lost,  but  of
	      course  the  audio will be delayed the specified amount of time.
	      This is most noticeable when using a  repeater  logic.  Use  the
	      BUFFER_LENGTH   configuration  variable  to  adjust  the	buffer
	      length.  The default voting delay	is 0.

       BUFFER_LENGTH
	      Use this configuration variable to adjust	the length of the vot-
	      ing  delay  buffer.  If not specified, the buffer	length will be
	      the same as the voting delay. When using the voter  with	a  re-
	      peater  logic,  try to keep this variable	at 0 to	reduce the la-
	      tency. Only increase it if you feel audio	is lost	in the	begin-
	      ning of transmissions.

       REVOTE_INTERVAL
	      This  is	the interval time in milliseconds with which the voter
	      will check if another receiver is	receiving a  stronger  signal.
	      If  that	is the case, a receiver	switch will be initiated.  De-
	      fault is 1000 milliseconds.

       HYSTERESIS
	      The hysteresis setting will prevent  the	voter  from  switching
	      back  and	 forth	between	two receivers that are equal in	signal
	      strength.	For a switch to	 occur,	 the  other  receivers	signal
	      strength	must  exceed  the current receivers signal strength by
	      the percent specified in this configuration variable. So if  the
	      hysteresis is set	to 50% and the received	signal strength	on the
	      current receiver is 40, a	signal strength	of  40*1.5=60  is  re-
	      quired  on  another  receiver  to	 initiate a switch. At squelch
	      open, if the received signal strength plus hysteresis is	larger
	      than  100,  the  voting delay will be skipped.  The default hys-
	      teresis is 50 percent.

       RX_SWITCH_DELAY
	      When a receiver switch is	initiated by the voter,	it  will  wait
	      the number of milliseconds specified in this configuration vari-
	      able before actually performing the switch. The switch will only
	      occur  if	 the  other receivers signal strength is still higher.
	      Default is 500 milliseconds.

       SQL_CLOSE_REVOTE_DELAY
	      The voter	will wait the number of	milliseconds specified in this
	      config  variable	after a	squelch	close before voting in another
	      receiver.	There are two reasons for using	this delay. The	 first
	      is  to  prevent the voter	from going into	idle state immediately
	      when the squelch close for a fluttery  signal.  If  it  goes  to
	      idle,  the procedure with	voting delay may cause longer dropouts
	      than necessary.  The second reason to use	this  config  variable
	      is  if different receivers have different	hang times (explicitly
	      or implicitly). If both a	slow and fast  receiver	 is  receiving
	      the same signal and the faster is	currently chosen, when the PTT
	      is released the slower receiver will be  voted  before  closing.
	      This  will  cause	 a  double squelch tail	and double roger beep.
	      Default is 500 milliseconds.

       COMMAND_PTY
	      Specify the path to a PTY	that can be used to control the	 voter
	      from the operating system. Available commands:

	      o	  ENABLE rx_name - Enable the given receiver

	      o	  DISABLE rx_name - Disable the	given receiver

	      Commands	can  be	 issued	 using	a simple echo command from the
	      shell. Example: echo "DISABLE Rx1" >/dev/shm/voter_ctrl

   Networked Receiver Section
       A networked receiver section is used to specify the configuration for a
       receiver	 connected through a TCP/IP network. In	the default configura-
       tion file there is a networked receiver	configuration  section	called
       NetRx.  The section name	could be anything. It should match the RX con-
       figuration variable in the logic	core where the receiver	is to be used.
       The available configuration variables are described below. How to use a
       networked receiver is further  described	 in  the  remotetrx(1)	manual
       page.

       TYPE   Always "Net" for a networked receiver.

       HOST   The hostname or IP address of the	remote receiver	host.

       TCP_PORT
	      The TCP port that	RemoteTrx listen on. The default is 5210.

       LOG_DISCONNECTS_ONCE
	      Set this configuration variable to 1 to suppress logging of mul-
	      tiple disconnect messages	in a row, like when there  is  no  Re-
	      moteTrx  running	on the other side.  Thus, failed reconnect at-
	      tempts will not be logged	at all.	This may be of use  if	a  Re-
	      moteTrx  is  missing  for	 a long	time or	if it's	only used from
	      time to time. The	default	is 0 which means  that	all  reconnect
	      attempts will be logged.

       AUTH_KEY
	      This  is	the authentication key (password) to use to connect to
	      the RemoteTrx server. The	same key have to be specified  in  the
	      RemoteTrx	 configuration.	  If  no  key  is specified in the Re-
	      moteTrx config, the login	will be	unauthenticated.  A  good  au-
	      thentication  key	should be 20 characters	long.  If the same Re-
	      moteTrx is used for both RX and TX, the same key must be	speci-
	      fied  in the RX as well as in the	TX configuration section.  The
	      key will never be	transmitted  over  the	network.  A  HMAC-SHA1
	      challenge-response procedure will	be used	for authentication.

       CODEC  The  audio codec to use when transferring	audio from this	remote
	      receiver.	 Available codecs are: RAW (512kbps),  S16  (256kbps),
	      GSM (13.2kbps), SPEEX (8-25kbps),	OPUS (8-64kbps). These are raw
	      bit-rate values. There will be some overhead added  to  this  so
	      the real bit-rates on the	wire are a little bit higher. The OPUS
	      codec is the most	modern one and it also have the	 best  quality
	      for a given bit-rate.

       SPEEX_ENC_FRAMES_PER_PACKET
	      Speex  encoder setting. Each Speex frame contains	20ms audio. If
	      using a low bit-rate configuration, the network overhead will be
	      quite  noticeable	 if  sending each frame	in its own packet. One
	      way to lower the overhead	is to send  multiple  frames  in  each
	      network  packet.	The  drawback  with doing this is that you get
	      more delay. If setting this option  to  something	 like  4  (de-
	      fault), the delay	will be	about 4x20=80ms.

       SPEEX_ENC_QUALITY
	      Speex  encoder setting. Specify the encoder quality using	a num-
	      ber between 0-10.	 Lower values give poorer  quality  and	 lower
	      bit-rates.

       SPEEX_ENC_BITRATE
	      Speex  encoder  setting. Specify the bit-rate to use. Speex will
	      snap to the nearest lower	 possible  bit-rate.  Possible	values
	      range  from  2150	to 24600 bps.  You should probably not specify
	      quality at the same time as bit-rate. Not	sure though...

       SPEEX_ENC_COMPLEXITY
	      Speex encoder setting. The complexity setting (0-10)  tells  the
	      encoder  how  much CPU time it should spend on doing a good job.
	      The difference in	SNR between the	lowest and  highest  value  is
	      about  2dB.  Set	it as high as possible without overloading the
	      CPU on the encoding computer  (check  CPU	 usage	using  command
	      "top").

       SPEEX_ENC_VBR
	      Speex  encoder  setting. Enable (1) or disable (0) variable bit-
	      rate encoding. If	enabled, the encoder will try to keep  a  con-
	      stant quality by increasing the bit-rate when needed.

       SPEEX_ENC_VBR_QUALITY
	      Speex  encoder  setting.	The  quality (0-10) to use in variable
	      bit-rate mode.

       SPEEX_ENC_ABR
	      Speex encoder setting. The average bit-rate encoding will	try to
	      keep  a  target  bit-rate	by continuously	adjusting the quality.
	      This configuration variable specify the target bit-rate and  en-
	      able  ABR. It also need to have VBR enabled so don't force it to
	      off.

       SPEEX_DEC_ENHANCER
	      Speex decoder setting. Enable (1)	or disable (0) the  perceptual
	      enhancer	in  the	 decoder.  Perceptual enhancement is a part of
	      the decoder which, when turned on, attempts to reduce  the  per-
	      ception  of the noise/distortion produced	by the encoding/decod-
	      ing process. In most cases, perceptual  enhancement  brings  the
	      sound  further  from  the	original objectively (e.g. considering
	      only SNR), but in	the end	it still sounds	better (subjective im-
	      provement).

       OPUS_ENC_FRAME_SIZE
	      Opus  encoder  setting. Specify how large, in milliseconds, each
	      audio packet should be. Default: 20ms.

       OPUS_ENC_COMPLEXITY
	      Opus encoder setting. The	complexity setting  (0-10)  tells  the
	      encoder  how  much CPU time it should spend on doing a good job.
	      Set it as	high as	possible without overloading the  CPU  on  the
	      encoding	computer  (check  CPU  usage using command "top"). De-
	      fault: 10.

       OPUS_ENC_BITRATE
	      Opus encoder setting. This is the	bit-rate that the encoder will
	      encode  for.  Rates from about 8000 to 64000 bits	per second are
	      meaningful but the codec can handle from	like  2500  to	512000
	      bps. Default: 20000bps.

       OPUS_ENC_VBR
	      Opus  encoder  setting.  Enable (1) or disable (0) variable bit-
	      rate encoding. If	enabled, the encoder will try to keep  a  con-
	      stant  quality  by  increasing  the bit-rate when	needed and de-
	      crease it	when the quality can be	assured	with a lower bit-rate.
	      The  target average bit-rate is the one set by OPUS_ENC_BITRATE.
	      Default: 1.

   Local Transmitter Section
       A local transmitter section is used to specify the configuration	for  a
       local transmitter. In the default configuration file there is a config-
       uration section called Tx1.  The	section	name  could  be	 anything.  It
       should  match the TX configuration variable in the logic	core where the
       transmitter is to be used. The available	 configuration	variables  are
       described below.

       TYPE   Always "Local" for a local transmitter.

       AUDIO_DEV
	      Specify  the  audio device to use. Normally oss:/dev/dsp.	Have a
	      look at the AUDIO	DEVICE SPECIFICATIONS chapter for more	infor-
	      mation.

       AUDIO_CHANNEL
	      Specify the audio	channel	to use.	SvxLink	can use	the left/right
	      stereo channels as two mono channels. Legal values are 0 or 1.

       AUDIO_DEV_KEEP_OPEN
	      The normal behaviour for SvxLink is to open an audio device when
	      needed  and  close  it when it does not have to be open anymore.
	      This may cause problems in some applications or with some	 sound
	      hardware.	 Set  this  variable to	1 to force SvxLink to keep the
	      audio device open	from application start to exit.

       PTT_TYPE
	      Use this configuration variable to specify which type  of	 hard-
	      ware to use to control the PTT.  Specify "SerialPin" for using a
	      pin in the serial	port, "GPIO" to	use a  pin  in	a  GPIO	 port,
	      "PTY"  if	 you  want  to	use an external	interface script via a
	      pseudo tty port or "Hidraw" to use the  linux/hidraw  driver  to
	      support  hidraw  devices	like CM108 sound card, e.g. URI	device
	      from DMK.

	      Set PTT_TYPE to "Dummy" or "NONE"	to not use any PTT hardware at
	      all. It is an error to not specify PTT_TYPE.

	      Use PTT_PIN to specify the pin to	use for	"SerialPin" or "GPIO".

       PTT_PORT
	      Specify  the  serial  port  that	the  PTT is connected to. E.g.
	      /dev/ttyu0 for COM1.

       PTT_PIN
	      If PTT_TYPE is set to "SerialPin", specify the pin(s) in the se-
	      rial  port that the PTT is connected to. It is possible to spec-
	      ify one or two serial port pins.	Some interface boards  require
	      that  you	specify	two pins since one pin does not	provide	enough
	      drive power to the circuit. A "!"	in front of the	pin name indi-
	      cates  inverted  operation. Some of the possible values are RTS,
	      DTRRTS, !DTR!RTS or even DTR!RTS.

	      If GPIO was specified in PTT_TYPE, set the PTT_PIN config	 vari-
	      able  to	the  pin  name of the GPIO-pin to use. The most	common
	      name is gpio<number>, like gpio3.	 Some GPIO  drivers  use  more
	      complex  pin  names  like	gpio33_pe11.  Have a look at the USING
	      GPIO section for information on how to set up the	operating sys-
	      tem.   Normally, the pin will be active high but if the pin name
	      is prefixed with an exclamation mark it will be active  low  in-
	      stead.  For some hardware	platforms you may need to also set the
	      GPIO_PATH	configuration variable.

       GPIO_PATH
	      Use this configuration variable to set the path to the sys  con-
	      trol  devices for	GPIO.  This normally is	/sys/class/gpio	but on
	      some   hardware,	 like	the   Orange   Pi,   the    path    is
	      /sys/class/gpio_sw.

       PTT_PTY
	      If PTT_TYPE is set to "PTY" this configuration variable will set
	      the path for the PTY slave softlink that is used by the external
	      script to	communicate to SvxLink.

	      SvxLink  sends a 'T' to start transmitting and a 'R' to turn the
	      transmitter off.	This can be used by an external	script to  in-
	      terface  custom  devices,	 modems	 or other hardware to SvxLink.
	      Look for nhrcx.pl	to see an example.

	      It is possible to	specify	the same PTY  for  multiple  functions
	      (e.g.  squelch, DTMF etc)	in both	TX and RX configurations. This
	      may be good if there is one script handling all functions.

       HID_DEVICE
	      Define the device	node where your	hidraw	device	is  accessible
	      at.

	      Example: HID_DEVICE=/dev/hidraw3

       HID_PTT_PIN
	      Define  the  pin your ptt	control	is connected to. Valid parame-
	      ters are are GPIO1,GPIO2,GPIO3,GPIO4. Note that some sound cards
	      like SSS1621 may not support GPIO3 and GPIO4! You	can invert the
	      behavior with a "!" in front of the name.	Only one value is sup-
	      ported.

       SERIAL_SET_PINS
	      Set  the	specified serial port pins to a	static state. This can
	      be good if using a pin for reference voltage or if a pin have to
	      be  in  a	 certain  state	to not interfere with the operation of
	      some equipment. There are	two pins that are possible to use, RTS
	      and  DTR.	If prefixed with an exclamation	mark (!), the pin will
	      be cleared and if	not it will be set. This  configuration	 vari-
	      able can only be used when PTT_TYPE is set to "SerialPin".

	      Example: SERIAL_SET_PINS=RTS!DTR will set	RTS and	clear DTR.

       PTT_HANGTIME
	      Use  this	configuration variable to set a	PTT hangtime. This can
	      be good to have on a transmitter in  combination	with  using  a
	      tone  squelch. When the transmitter is ordered to	stop transmit-
	      ting, the	tone is	immediately turned off,	causing	the squelch to
	      close  on	 the other side. Since the transmitter keeps transmit-
	      ting for a while,	no squelch tail	will be	heard.

	      Another use is on	a remote receiver link transmitter  where  you
	      don't  want the transmitter to turn on and off between transmis-
	      sions or if the squelch close and	open quickly due to for	 exam-
	      ple mobile flutter.

       TIMEOUT
	      This is a	feature	that will prevent the transmitter from getting
	      stuck transmitting.  Specify the number of  seconds  before  the
	      transmitter  is  turned off. Note	that this is a low level secu-
	      rity mechanism that is meant to only kick	in if there is a soft-
	      ware  bug	 in  SvxLink.  Just  so	 that the transmitter will not
	      transmit indefinitely. It	is not meant to	be used	to keep	people
	      from talking too long.

       TX_DELAY
	      The  number of milliseconds (0-1000) to wait after the transmit-
	      ter has been turned on until audio is starting to	 be  transmit-
	      ted.  This can be	used to	compensate for slow TX reaction	or re-
	      mote stations with slow reacting squelches.

       CTCSS_FQ
	      The frequency in Hz of the CTCSS tone to transmit. It is	possi-
	      ble  to  specify	fractions  using  "."  as  decimal comma (e.g.
	      136.5). For the tone to be transmitted the CTCSS_LEVEL  variable
	      must  also  be setup and also the	TX_CTCSS variable in the logic
	      core configuration section.

       CTCSS_LEVEL
	      The level	in percent (0-100) of the CTCSS	tone to	transmit. What
	      level to set is hard to say. The FM modulation swing of the tone
	      should be	in between 500-800 Hz. That is a bit hard  to  measure
	      if  you don't have the right equipment. A	normal FM station have
	      a	maximum	swing of 5kHz so if you	manage to calibrate everything
	      so  that	you  get maximum swing when the	sound card audio is at
	      peak level, the tone level should	be in between 10-16%. However,
	      most  often  the audio settings are configured a bit higher than
	      max since	the audio seldom reaches maximum level.	Then the level
	      of the CTCSS tone	should be reduced. The default in the configu-
	      ration file is 9%. For the tone to be transmitted	 the  CTCSS_FQ
	      variable	must  also  be setup and also the TX_CTCSS variable in
	      the logic	core configuration section.

       PREEMPHASIS
	      Enable this feature if you are modulating	the FM	modulator  di-
	      rectly, like through a 9k6 packet	radio input. If	no preemphasis
	      filter is	applied	to the audio, it will sound very dark when re-
	      ceived.  If  you modulate	the transmitter	through	the microphone
	      input the	radio will apply a preemphasis filter so this  feature
	      should be	disabled. 0=disabled, 1=enabled.

       DTMF_TONE_LENGTH
	      The  duration,  in  milliseconds,	 of DTMF digits	transmitted on
	      this transmitter.	 100ms is the default.

       DTMF_TONE_SPACING
	      The spacing, in milliseconds, between DTMF digits	transmitted on
	      this transmitter.	50ms is	the default.

       DTMF_DIGIT_PWR
	      The  power,  in dB, of DTMF digits transmitted on	this transmit-
	      ter. Zero	dB will	give the same power in the generated signal as
	      there is in a maximum amplitude (full scale) sine	wave. -15dB is
	      the default.

       TONE_SIGLEV_MAP
	      It is possible to	transmit one of	ten tones along	with the  nor-
	      mal  transmission	to indicate a signal strength value to the re-
	      ceiver. This is of most use when using a local transmitter as  a
	      link  transmitter	 in  a	RemoteTrx.  It is not implemented, and
	      probably not useful, in SvxLink Server. Another  requirement  is
	      that  SvxLink  has  been	compiled in 16kHz mode.	Otherwise this
	      feature is disabled.

	      The TONE_SIGLEV_MAP configuration	variable is used to map	 tones
	      to  signal level values. It is a comma separated list of exactly
	      ten values in the	0 - 100	range. The  first  value  map  to  the
	      5500Hz  tone,  the second	to the 5600Hz tone and so on. The last
	      value map	to the 6400Hz tone.  What levels the tones  should  be
	      mapped  to  depends  on  the tone	receiver implementation. Typi-
	      cally, if	 using	a  SvxLink  application	 as  a	receiver,  the
	      TONE_SIGLEV_MAP  should  be the same in the RX configuration for
	      that node.

       TONE_SIGLEV_LEVEL
	      It is possible to	transmit one of	ten tones along	with the  nor-
	      mal  transmission	to indicate a signal strength value to the re-
	      ceiver. This is of most use when using a local transmitter as  a
	      link  transmitter	 in  a	RemoteTrx.  It is not implemented, and
	      probably not useful, in SvxLink Server. Another  requirement  is
	      that  SvxLink  has  been	compiled in 16kHz mode.	Otherwise this
	      feature is disabled.

	      The TONE_SIGLEV_LEVEL configuration variable is used to set  the
	      tone level.  It is a value in the	1-100 range which indicate the
	      output level in percent of the maximum possible level.  The  de-
	      fault is 10.

       MASTER_GAIN
	      This configuration variable can be used to fine tune or increase
	      the audio	gain for all transmitted sound if it's not possible to
	      do  using	the normal sound card hardware gain controls. The gain
	      should be	given in dB and	can be both positive and negative.

       OB_AFSK_ENABLE
	      Set to 1 to enable transmission of metadata  like	 signal	 level
	      measurements,  DTMF  digits  and tone detections via out-of-band
	      (OB) AFSK. The out-of-band AFSK is transmitted above  the	 voice
	      band  so that it is possible to transmit AFSK bursts at the same
	      time as someone is speaking. The AFSK bursts  are	 filtered  out
	      before  the audio	is handed on to	the next stage so normal users
	      should never hear	the AFSK bursts. The AFSK feature is typically
	      used  on	a remote receiver uplink. The protocol used is SvxLink
	      specific.	Data is	transmitted in 300Bd with a shift of 170Hz and
	      a	center frequency of 5500Hz. The	RemoteTrx application have the
	      capability to transmit this protocol.

       OB_AFSK_VOICE_GAIN
	      To be able to send both voice and	AFSK at	the same time  it  may
	      be  necessary  to	 lower	the level of the voice audio as	to not
	      overdrive	the transmitter. This is compensated in	the  link  re-
	      ceiver by	amplifying the voice audio back	to its original	level.
	      This configuration variable should thus be set  to  the  negated
	      value of the same	configuration variable in the receiver section
	      of the receiving node. If	it's set to 6dB	in the	receiver  con-
	      figuration it should be set to -6dB here.

       OB_AFSK_LEVEL
	      The  out-of-band	AFSK modulation	level in dBFS (dB full scale).
	      Default is -6dB.

       OB_AFSK_TX_DELAY
	      The number of milliseconds to send AFSK flag bytes before	 send-
	      ing the actual data when transmitting an out-of-band packet.

       IB_AFSK_ENABLE
	      Set  to 1	to enable transmission of an initial signal level mea-
	      surement via in-band (IB)	AFSK. This is used in cooperation with
	      the  out-of-band AFSK feature to quickly transfer	a signal level
	      measurement to get the  squelch  opened.	The  in-band  AFSK  is
	      transmitted  in  the voice band and can thus use the higher bau-
	      drate of 1200Bd. Since it's only transmitted when	the squelch is
	      closed  the end user will	not hear the AFSK burst. The AFSK fea-
	      ture is typically	used on	a remote receiver uplink. The protocol
	      used  is	SvxLink	specific. Data is transmitted in 1200Bd	with a
	      shift of 1000Hz and a center frequency of	1700Hz.	 The RemoteTrx
	      application have the capability to transmit this protocol.

       IB_AFSK_LEVEL
	      The  in-band  AFSK modulation level in dBFS (dB full scale). De-
	      fault is -6dB.

       IB_AFSK_TX_DELAY
	      The number of milliseconds to send AFSK flag bytes before	 send-
	      ing the actual data when transmitting an in-band packet.

       CTRL_PTY
	      Set  this	configuration variable to the path of a	PTY to use for
	      controlling a transmitters frequency and modulation. This	can be
	      used  to	interface a transmitter	to SvxLink using a translation
	      script, like trx_pty_ctrl.py. To	set  the  transmit  frequency,
	      SvxLink  will  send  the sequence	"F<frequency>;". The frequency
	      will be in Hz, e.g. F145550000; will be sent to set the receiver
	      to 145.550MHz.

	      To  set  the modulation the command is "M<modulation>;". Look at
	      the documentation	of the MODULATION  configuration  variable  to
	      see which	modulations are	available. To set "normal" 25kHz chan-
	      nel spaced FM the	command	would be MFM;.

	      It is possible to	specify	the same PTY  for  multiple  functions
	      (e.g.  squelch,  ptt etc)	in both	TX and RX configurations. This
	      may be good if there is one script handling all functions.

   Networked Transmitter Section
       A networked transmitter section is used to  specify  the	 configuration
       for  a  transmitter  connected through a	TCP/IP network.	In the default
       configuration file there	is a networked transceiver configuration  sec-
       tion called NetTx.  The section name could be anything. It should match
       the TX configuration variable in	the logic core where  the  transmitter
       is  to be used. The available configuration variables are described be-
       low. How	to use a networked transmitter is further described in the re-
       motetrx(1) manual page.

       TYPE   Always "Net" for a networked transmitter.

       HOST   The hostname or IP address of the	remote transmitter host.

       TCP_PORT
	      The TCP port that	RemoteTrx listen on. The default is 5210.

       LOG_DISCONNECTS_ONCE
	      Set this configuration variable to 1 to suppress logging of mul-
	      tiple disconnect messages	in a row, like when there  is  no  Re-
	      moteTrx  running	on the other side.  Thus, failed reconnect at-
	      tempts will not be logged	at all.	This may be of use  if	a  Re-
	      moteTrx  is  missing  for	 a long	time or	if it's	only used from
	      time to time. The	default	is 0 which means  that	all  reconnect
	      attempts will be logged.

       AUTH_KEY
	      This  is	the authentication key (password) to use to connect to
	      the RemoteTrx server. The	same key have to be specified  in  the
	      RemoteTrx	 configuration.	  If  no  key  is specified in the Re-
	      moteTrx config, the login	will be	unauthenticated.  A  good  au-
	      thentication  key	should be 20 characters	long.  If the same Re-
	      moteTrx is used for both RX and TX, the same key must be	speci-
	      fied  in the RX as well as in the	TX configuration section.  The
	      key will never be	transmitted  over  the	network.  A  HMAC-SHA1
	      challenge-response procedure will	be used	for authentication.

       CODEC  The  audio  codec	 to use	when transferring audio	to this	remote
	      transmitter.   Available	codecs	 are:	RAW   (512kbps),   S16
	      (256kbps),  GSM  (13.2kbps),  SPEEX (8-25kbps), OPUS (8-64kbps).
	      These are	raw bit-rate values. There will	be some	overhead added
	      to  this	so  the	 real  bit-rates  on the wire are a little bit
	      higher. The OPUS codec is	the most modern	one and	it  also  have
	      the  best	 quality  for  a  given	bit-rate. There	also is	a NULL
	      codec that will just throw away samples which  can  be  used  in
	      special  situations when the audio is sent through another audio
	      path.

       SPEEX_ENC_FRAMES_PER_PACKET
	      Speex encoder setting. Each Speex	frame contains 20ms audio.  If
	      using a low bit-rate configuration, the network overhead will be
	      quite noticeable if sending each frame in	its  own  packet.  One
	      way  to  lower  the  overhead is to send multiple	frames in each
	      network packet. The drawback with	doing this  is	that  you  get
	      more  delay.  If	setting	 this  option to something like	4 (de-
	      fault), the delay	will be	about 4x20=80ms.

       SPEEX_ENC_QUALITY
	      Speex encoder setting. Specify the encoder quality using a  num-
	      ber  between  0-10.   Lower values give poorer quality and lower
	      bit-rates.

       SPEEX_ENC_BITRATE
	      Speex encoder setting. Specify the bit-rate to use.  Speex  will
	      snap  to	the  nearest  lower possible bit-rate. Possible	values
	      range from 2150 to 24600 bps.  You should	probably  not  specify
	      quality at the same time as bit-rate. Not	sure though...

       SPEEX_ENC_COMPLEXITY
	      Speex  encoder  setting. The complexity setting (0-10) tells the
	      encoder how much CPU time	it should spend	on doing a  good  job.
	      The  difference  in  SNR between the lowest and highest value is
	      about 2dB. Set it	as high	as possible  without  overloading  the
	      CPU  on  the  encoding  computer	(check CPU usage using command
	      "top").

       SPEEX_ENC_VBR
	      Speex encoder setting. Enable (1)	or disable (0)	variable  bit-
	      rate  encoding.  If enabled, the encoder will try	to keep	a con-
	      stant quality by increasing the bit-rate when needed.

       SPEEX_ENC_VBR_QUALITY
	      Speex encoder setting. The quality (0-10)	 to  use  in  variable
	      bit-rate mode.

       SPEEX_ENC_ABR
	      Speex encoder setting. The average bit-rate encoding will	try to
	      keep a target bit-rate by	continuously  adjusting	 the  quality.
	      This  configuration variable specify the target bit-rate and en-
	      able ABR.	It also	need to	have VBR enabled so don't force	it  to
	      off.

       SPEEX_DEC_ENHANCER
	      Speex  decoder setting. Enable (1) or disable (0)	the perceptual
	      enhancer in the decoder.	Perceptual enhancement is  a  part  of
	      the  decoder  which, when	turned on, attempts to reduce the per-
	      ception of the noise/distortion produced by the  encoding/decod-
	      ing  process.  In	 most cases, perceptual	enhancement brings the
	      sound further from the original  objectively  (e.g.  considering
	      only SNR), but in	the end	it still sounds	better (subjective im-
	      provement).

       OPUS_ENC_FRAME_SIZE
	      Opus encoder setting. Specify how	large, in  milliseconds,  each
	      audio packet should be. Default: 20ms.

       OPUS_ENC_COMPLEXITY
	      Opus  encoder  setting.  The complexity setting (0-10) tells the
	      encoder how much CPU time	it should spend	on doing a  good  job.
	      Set  it  as  high	as possible without overloading	the CPU	on the
	      encoding computer	(check CPU usage  using	 command  "top").  De-
	      fault: 10.

       OPUS_ENC_BITRATE
	      Opus encoder setting. This is the	bit-rate that the encoder will
	      encode for.  Rates from about 8000 to 64000 bits per second  are
	      meaningful  but  the  codec  can handle from like	2500 to	512000
	      bps. Default: 20000bps.

       OPUS_ENC_VBR
	      Opus encoder setting. Enable (1) or disable  (0)	variable  bit-
	      rate  encoding.  If enabled, the encoder will try	to keep	a con-
	      stant quality by increasing the bit-rate	when  needed  and  de-
	      crease it	when the quality can be	assured	with a lower bit-rate.
	      The target average bit-rate is the one set by  OPUS_ENC_BITRATE.
	      Default: 1.

   Multi Transmitter Section
       A  multi	transmitter section is used if one wants to transmit on	multi-
       ple transmitters	simultaneously.	The name of the	section	 can  be  any-
       thing.  Just  point  it out from	another	transmitter specification like
       the TX variable in a Logic core configuration.

       TYPE   Always "Multi" for a multi transmitter section.

       TRANSMITTERS
	      A	comma separated	list of	transmitters.

   Module Section
       A module	section	contain	the configuration for a	 specific  module.  It
       have some general configuration variables and some module specific con-
       figuration variables. The general configuration	variables  are	listed
       below.

       NAME   The  name	of the module. This name must match the	namespace used
	      in the TCL event handling	script.	If not set, NAME will  be  set
	      to the section name.

       PLUGIN_NAME
	      The  base	 name of the plugin. For example if this configuration
	      variable is set to Foo, the core will look for a	plugin	called
	      ModuleFoo.so.  If	 not  set, PLUGIN_NAME will be set to the same
	      value as NAME.

       ID     Specify the module identification	number.	 This  is  the	number
	      used to access the module	from the radio interface.

       TIMEOUT
	      Specify  the timeout time, in seconds, after which a module will
	      be automatically deactivated if there has	been no	activity.

       Module specific configuration variables are described in	the  man  page
       for  that module. The documentation for the Parrot module can for exam-
       ple be found in the ModuleParrot.conf(5)	manual page.

   LocationInfo
       STATUS_SERVER_LIST
	      Enter a space separated list of  EchoLink	 status	 servers  that
	      should  be  used to send node status beacons. Your node informa-
	      tion can be  found  on  http://www.echolink.org/links.jsp.   The
	      format  is  host:port. Host - hostname or	IP address, port - UDP
	      port.  Don't change the default unless you know what you are do-
	      ing.  If	you  don't  want to update the EchoLink	status server,
	      comment out this configuration variable.

	      Example:
	      STATUS_SERVER_LIST=aprs.echolink.org:5199

       APRS_SERVER_LIST
	      This configuration variable specifies connection parameters  for
	      connecting  to an	APRS server network using the TCP protocol. In
	      this case, the  positioning  information	is  forwarded  to  the
	      worldwide	APRS network. Have a look at http://aprs.fi/.

	      To  choose a suitable APRS server	from the so called tier	2 net-
	      work, have a look	at http://www.aprs2.net/. Either choose	a spe-
	      cific  server or one of the regional addresses. The regional ad-
	      dresses bundle all APRS servers within a region so that a	random
	      tier  2  server  is chosen within	the region. There are five re-
	      gions defined: noam.aprs2.net - North America, euro.aprs2.net  -
	      Europe,  asia.aprs2.net  -  Asia,	soam.aprs2.net - South America
	      and Africa, aunz.aprs2.net - Australia  and  New	Zealand.   The
	      format  is  a  space separated list of host:port entries.	Host -
	      hostname or IP address, port - TCP port.

	      Example:
	      APRS_SERVER_LIST=euro.aprs2.net:14580

       LON_POSITION
	      The longitude of the station position, entered  as  "degrees.ar-
	      cminutes.arcseconds"

	      Example:
	      LON_POSITION=09.02.20E

       LAT_POSITION
	      The  latitude  of	 the station position, entered as "degrees.ar-
	      cminutes.arcseconds"

	      Example:
	      LAT_POSITION=51.02.22N

       CALLSIGN
	      Enter your callsign for the APRS network with a prefix that  in-
	      dicates the type of station, (ER-	for repeaters, EL- for links).

	      Examples:
	      CALLSIGN=EL-DL1ABC    # callsign for a link
	      CALLSIGN=ER-DB0ABC    # callsign for a repeater

       FREQUENCY
	      The tx-frequency of the link/repeater in MHz. For	repeaters, in-
	      formation	about the RX/TX	shift  in  the	COMMENT	 configuration
	      variable may be useful.

	      Example:
	      FREQUENCY=430.050	    # tx-frequency is 430.050 MHz

       TX_POWER
	      The power	of your	transmitter in watts.

	      Example:
	      TX_POWER=10	    # tx output	is 10 watts

       ANTENNA_GAIN
	      The gain of your antenna in dBd.

	      Example:
	      ANTENNA_GAIN=5	    # antenna gain is 5	dBd

       ANTENNA_HEIGHT
	      The height of the	link-/repeater antenna in meters or feet above
	      the terrain, not sealevel.

	      Example:
	      ANTENNA_HEIGHT=10m    # 10 meters	above the ground
	      ANTENNA_HEIGHT=90	    # 90 feet

       ANTENNA_DIR
	      Main beam	direction of the antenna in degrees. If	an omni	direc-
	      tion antenna is used, specify -1 as the direction.

	      Example:
	      ANTENNA_DIR=-1	    # an omni directional antenna is used
	      ANTENNA_DIR=128	    # main beam	direction is 128 degrees

       PATH   The PATH variable	controls the way of forwarding your beacon in-
	      side the APRS network if it is gated by a	local APRS digipeater.
	      In  some	cases it has to	be changed according to	local require-
	      ments. Please contact your local APRS sysop for further informa-
	      tion.  Changes should be made only according to the NEWn-N para-
	      digm. Leave this variable	untouched if you  are  unsure  of  its
	      setting.	 No spaces or control characters are allowed. PATH has
	      no influence on the propagation on non-RF	networks.

	      Examples:
	      PATH=WIDE1-1
	      PATH=WIDE1-1,WIDE2-2

       BEACON_INTERVAL
	      The interval, in minutes,	with which beacons will	be sent	to the
	      APRS  network.   A  good	value is 10 minutes. If	your beacon is
	      gated via	RF, please increase the	interval a  bit	 to  keep  the
	      APRS traffic on RF produced by the APRS RF gate as low as	possi-
	      ble. Intervals shorter than 10 minutes will be changed to	10.

	      Example:
	      BEACON_INTERVAL=30    # APRS-beacons will	be sent	every 30  min-
	      utes.

       TONE   The CTCSS	sub-audible tone that is to be used for	operation over
	      your link	or repeater. If	you don't use tone control set	it  to
	      0.

	      Examples:
	      TONE=136	    # we are using a CTCSS-tone	of 136.5 Hz
	      TONE=0	    # we don't use CTCSS sub-audible or	call tones
	      TONE=1750	    # the link/repeater	use a tone burst of 1750 Hz

       STATISTICS_INTERVAL
	      Defines  the  interval  in  minutes in that an aprs statistic is
	      sent into	the aprs network. Range: 5-60, default is 10 minutes

       COMMENT
	      Specify a	short comment here, maybe a link to  your  website  or
	      information  that	 could	be  interesting	for others. The	length
	      should not exceed	255 characters and may not have	control	 char-
	      acters  like  "Carriage Return" (\r) or "Line Feed" (\n) inside.
	      Make your	comment	as short as you	can to give users with a small
	      display (TH-D7) the chance to display the	full comment text.

	      Example:
	      COMMENT=[svx] Running SvxLink by SM0SVX

       PTY_PATH
	      Specify  a  path to a communications PTY that can	be used	by ex-
	      ternal applications to inject APRS packets into the APRS-IS net-
	      work.

AUDIO DEVICE SPECIFICATIONS
       The AUDIO_DEV configuration variables specify which audio device	to use
       for a receiver or transmitter. SvxLink support a	 number	 of  different
       audio  input  and output	devices. The format of the configuration vari-
       able is "type:dev_spec".	There are three	different types	of  audio  de-
       vices supported,	"alsa",	"oss" and "udp".

       The   "alsa"   type  will  use  the  specified  Alsa  device.  Example:
       "oss:/dev/dsp". Describing the format of	Alsa device names  is  outside
       the scope for this document.

       The  "oss"  type	 will  use  the	 specified  OSS	 audio device. Example
       "oss:/dev/dsp".	OSS is the old sound system used by Linux. Alsa	should
       be used when possible.

       The  "udp" type is not really an	audio device but instead will read and
       write audio from/to a UDP socket. This can be used to interface SvxLink
       to  all	sorts  of  audio  sources/sinks	capable	of streaming raw audio
       through UDP. One	example	usage is to interface SvxLink with GNU	Radio.
       Example:	 "udp:127.0.0.1:10000".	 Note  however that the	only supported
       format is raw 16	bit signed samples, two	interleved channels.  Sampling
       frequency  can  be chosen using the CARD_SAMPLE_RATE config variable as
       usual.

USING GPIO
       GPIO (General Purpose IO) is used to access hardware pins that are made
       available  for  example on an embedded system. Before starting to use a
       pin in SvxLink some setup need to be done in the	operating system. With
       the  standard  distribution  of SvxLink there is	a pair of scripts that
       help with setting up and	taking down the	GPIO  pins.  The  scripts  are
       named  svxlink_gpio_up  and  svxlink_gpio_down. The configuration file,
       which can be found among	the other SvxLink configuration	 files	(typi-
       cally in	/etc/svxlink), is called gpio.conf.

CALIBRATING THE	SIGNAL LEVEL DETECTOR
       The signal level	detector is used when using multiple receivers or when
       using the SIGLEV	squelch. The signal level is used by a voter to	choose
       the  receiver  with the highest signal strength.	The choice is made di-
       rectly after squelch open. For the voter	to make	a correct choice,  the
       signal level detector must be calibrated	on each	receiver.

       To  use	the  noise  signal level detector, first set SIGLEV_DET=NOISE.
       There are two configuration variables that is used to calibrate the de-
       tector.	 They  are  SIGLEV_SLOPE and SIGLEV_OFFSET in a	local receiver
       section.	The slope is the gain of the detector and the offset  is  used
       to  adjust  the detector	so that	when there is no input signal, the de-
       tector will return 0. The goal is to adjust the detector	so  that  when
       no  signal  is  received, a value of 0 is produced and when full	signal
       strength	is received, a value of	100 is produced. It will never be  ex-
       akt but that does not matter.

       The  calibration	is normally done by using the siglevdetcal(1) applica-
       tion. To	be able	to do a	correct	calibration, it	must  be  possible  to
       open  the  squelch  so  that  only noise	is received. The antenna cable
       should be disconnected or a dummy load should be	used.  WARNING:	Before
       starting	the siglevdetcal application, pull the PTT cable since the PTT
       might get triggered during the calibration procedure.

       The siglevdetcal	utility	will also measure the CTCSS tone SNR offset so
       that  the  CTCSS_SNR_OFFSET  config  variable can be set	up to a	proper
       value.

       If the siglevdetcal application cannot be used  for  some  reason,  the
       manual procedure	below might be used. This procedure will only work for
       a receiver with unsquelched audio.  Note: To  calibrate	a  remote  re-
       ceiver  it  must	 be  connected	to  the	SvxLink	server.	 Otherwise the
       squelch will not	open.

	      1	  Connect a dummy load or  disconnect  the  antenna  from  the
		  transceiver.	If  you	 disconnect  the antenna, make sure to
		  also disconnect the PTT.

	      2	  Set SIGLEV_SLOPE=1 and SIGLEV_OFFSET=0 and restart SvxLink.

	      3	  Open the squelch so that there is  only  noise  coming  into
		  SvxLink.

	      4	  Use a	second transceiver to make a short, unmodulated	trans-
		  mission. Release the PTT when	the "Squelch OPEN" message  is
		  printed. Repeat this for about five times.

	      5	  Calculate  the  mean diff (open level	- close	level) and the
		  mean lower (squelch close) value. Make sure to use at	 least
		  four significant digits in your calculations.

	      6	  SIGLEV_SLOPE = 100 / (mean diff)

	      7	  SIGLEV_OFFSET	= - (mean lower) * SIGLEV_SLOPE

	      8	  After	  changing  SIGLEV_SLOPE  and  SIGLEV_OFFSET,  restart
		  SvxLink and check to see that	the squelch open value is  now
		  around 100 and the squelch close value is around 0.

STATE PTY FORMAT
       The format of the output	from the state PTY is:

	   <timestamp> <context>:<event	name> <event data>

       where the different parts mean:

	   timestamp = <seconds	since 1	jan 1970>.<milliseconds>
	   context = Name of context
	   event_name =	Name of	event
	   event data =	Event specific data

       The following specific events exist.

       Voter:sql_state
	      Report  the state	of all squelches for all receivers. The	format
	      of the event specific data is:

		  <rx name><state><siglev> [<rx_name><state><siglev> ...]

	      where the	different parts	mean:

		  rx_name = Configuration file section name for	receiver
		  state	= _ (sql closed), : (sql open),	* (sql open and	rx se-
		  lected)
		  siglev = The measured	signal level

FILES
       /etc/svxlink/svxlink.conf (or deprecated	/etc/svxlink.conf)
	      The system wide configuration file.

       ~/.svxlink/svxlink.conf
	      Per user configuration file.

       /etc/svxlink/svxlink.d/*
	      Additional configuration files. Typically	one configuration file
	      per module.

AUTHOR
       Tobias Blomberg (SM0SVX)	<sm0svx	at users dot sourceforge dot net>

SEE ALSO
       svxlink(1), remotetrx(1), siglevdetcal(1), devcal(1)

Linux				 JANUARI 2018		       SVXLINK.CONF(5)

NAME | DESCRIPTION | FILE FORMAT | CONFIGURATION VARIABLES | AUDIO DEVICE SPECIFICATIONS | USING GPIO | CALIBRATING THE SIGNAL LEVEL DETECTOR | STATE PTY FORMAT | FILES | AUTHOR | SEE ALSO

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