Echolink - Server
The SvxLink Server is a general purpose voice services system, developed by
Tobias Blomberg, by SM0SVX which when connected to a transceiver, can act as both
an advanced repeater system and can also operate on a simplex channel. One could
call it a radio operating system since it sits between the hardware (transceiver)
and the applications (modules) and handle basic system services as well as input
These are my note from my experiences installing SVXLink on a Raspberry Pi 4
Model B Rev 1.2 with 4Gb RAM running Buster Raspbian GNU/Linux 10
Echolink Nodes in Queensland
|VK4DAK-R|| SE QLD Linked Repeater Net||69580
|VK4JRC-R|| Central Queensland||9003
|VK4PQ-R|| Townsville [0/20]||956580
|VK4RAI-R|| The Knobby Ipswich||158872
|VK4RAR-R|| Rockhampton QLD||108959
|VK4RBA-R|| Brisbane QLD QG62nk||575182
|VK4RBN-R|| Brisbane, Australia||888046
|VK4RCQ-R|| Biloela ||781664
|VK4RDB-R|| Redlands Coast, Qld||474766
|VK4RGC-R|| Goldcoast, Australia||66702
|VK4RHB-R|| Booral, Fraser Coast [Svx]||527138
|VK4RNL-R|| Craignish Fraser coast||281814
|VK4WIS-R|| Sunshine Coast||316084
EchoLink Link Status
This page provides for extensive searches of Echolink Nodes. It also provides an export facility to Googlr Maps.
EchoLink Link Status
Echolink Callsign Registration and Validation
All access to the Echolink "network" is controlled by a validation database.
You are required to provide proof of license. Several way are offered to validate.
The following screen allows for amateur radio operators to validate their callsigns:
Results of my searches:
|Callsign||Status||Date Registered (UTC)
|VK4PK ||Already validated ||22-Jul-2017
|VK4PK-L ||Already validated ||5-Aug-2020
|VK4RDB ||Already validated ||5-May-2020
|VK4RDB-L ||Already validated ||28-Mar-2020
|VK4RDB-R ||Already validated ||20-Jan-2019
|VK4RBA-L ||Already validated ||18-Jul-2012
Callsign suffix meaning. Note this is only a conventions and not a fixed rule. Some
clubs that have two Echolink Nodes will use "-L" for one and "-R" for the other.
- -R indicates that you have connected EchoLink to a rig tuned to the frequency pair of a local repeater
(or connected directly to a repeater)
- -L indicates it is tuned to a simplex frequency. Commonly used as a private node.
Prepare Rpi of Build
Remove unused apps from Raspbian:
Install the Candidate
Download the sound bites required by svxlink. Check these are the latest releases:
Configuration of SVXLink
Determine the Sound cards and their devices:
S\Determine the USB to Serial Device:
SVXLink Build from Source
This is NOT the prefered method of installing SVXLink:
Radio - Tait T22020 with T1000 UIS Interface Card
A Tait T2020 with a T2000-UIS interface card was available for use. See the Tait radio page here,
Radio-Transceivers/Tait-Radios/Tait-Radios.html#T2000-UIS for more details on this model Tait radio
|LK1||2-3||LINE OUT Flat / De-emphasised||1-2 Flat / 2-3 De-emphasised
|LK2||IN||MIC AUDIO to LINE OUT||IN = YES / OUT = NO
|LK3||OUT||BEEP to LINE OUT||IN = YES / OUT = NO
|LK4||OUT||LINE IN to LINE OUT Side Tone||IN = YES / OUT = NO
|LK5||1-2||GATE OUT Source ||1-2 BUSY + RX GATE
2-3 BUSY ONLY
2-4 TRUNKED BUSY
|LK6||2-3||LINE IN Flat / Pre- emphasised||1-2 Flat / 2-3 Pre-emphasised
|LK7||IN||LINE IN to Volume & Speaker||IN = YES / OUT = NO
|LK8||IN||LINE IN Flat / Pre- emphasised||IN= Pre-emphasised / OUT = Flat
|LK9||IN||LINE IN 1 600 Terminated ||IN = YES / OUT = NO
|LK10||IN||LINE IN 2 600 Terminated ||IN = YES / OUT = NO
|LK11||OUT OUT||LINE OUT, LINE IN, GATE OUT and PTT IN Control ||OUT = NONE
1-2 AUX SW
2-3 CALL SW
|LK12||OUT||RX/TX Disabling ||IN = YES / OUT = NO
|LK13||OUT||RX Disable ||IN = TX ONLY/ OUT = NO
|LK14||OUT||GATE OUT Phase||OUT = Active Lo / IN = Active Hi
|LK15||OUT||PTT IN Phase||OUT = Active Lo / IN = Active Hi
|LK16||2-3||GATE OUT Relay Phase||1-2 N.C. / 2-3 N.O.
|LK17||OUT||GATE OUT Common to Ground ||IN = GROUNDED / OUT = NOT
|LK18||1-2||I/O Signals matrix line 11 - Volts Source||1-2 +13.8V SW / 2-3 +13.8V UNSW
or OUT = NONE
|LK19||IN||OPTO Coupler Option||IN = Yes / OUT = NO
|LK20||20||TX Tail Timer||IN = Yes / OUT = NO
|LK21||2-3||External Line Source||1-2 /Emrgncy / 2-3 RX/TX Disabling
|LK22|| ** Not Found||LINE OUT 1 output impedance||IN = Very Low / OUT = 600 OHMS
Interface Cable Construction
Cable Made For This Application:
|DB9-F Pin No|
|Colour||Function||To DB9-M Pin No|
Tait T2020-T2000-UIS S21 DB9F Default Pin Out:
|DB9 ||Description||I/O ||Tait Terminology|
|Pin 1||Discriminator Audio||Out ||LINE OUT 1|
|Pin 2||Radio Busy Indicator||Out ||/GATE OUT 1|
|Pin 4||PTT||In||/PTT IN 1|
|Pin 5||Transmit Audio||In||LINE IN 1|
|Pin 6||No Connect||LINE IN 2|
|Pin 7||No Connect||/PTT IN 2|
|Pin 8||Data Mute||In||/GATE OUT 2|
|Pin 9||Power (Switched)||Out||LINE OUT 2|
Audio Connection and Consideratios
Speaker/ Line Out/ Audio Out - with respect to the sound card:
|Audio||Pin on Radio's DB9|
Mic/ Line in/ Audio In - with respect to the sound card:
|Audio||Pin on Radio's DB9|
Tait Signal Matrix setting
I/O Signal Matrix to DB9 Pinouts
This is the standard layout and as set up in the Radio used in this project.
Tait 2020 Configuration Steps- **EDIT THESE
Step to configure the Tait Radio for SVXlink Server operation.
- Program the T2020 as required, i.e. Tx/Rx frequencies, etc.
- Confirm the T2020 is fully functional (i.e. test Tx/Rx and adjust if required)
- If no CTCSS is required, adjust microphone deviation for 5Khz (on a 25Khz channel) or if
using CTCSS, 4.5Khz (on a 25Khz channel)
- Adjust sub audio deviation (if used) for 500Hz (on a 25Khz channel)
- If fitted remove R513 (0 ohm resistor) on Logic PCB linking options connector S14 Pin 5
(PTT-TO-OPT) and S14 pin 6 (PTT-FRM-OPT)
- On the UIT board, modify the I/O signals and I/O Pins matrix (changes are highlighted) as
follows. RSSI Output on Pin 7 is optional.
- Modify the Link Settings as set out above.
- Connect / fit the A2000-UIT to the T2000 series II transceiver.
Configuration of the VK4RBA-R Echolink Server
Leigh VK4LAH did an excellent job building and testing this svxlink Echolink server
for the Brisbane Amateur Radio Club based at Roachdale, Brisbane. Futher testing
is being conduced and some reconfiguration and fine tuning is anticitated.
Notes on this configuration:
Hardware employed on this site is a Raspberry Pi 3B, USB2 C-Media sound card,
and a prolific USB to serial cable. The radio transceiver is a Tait T202 with a T2000 UIS
interface card. There is a short RF link to the VK4RBA
repeater station. In this configuration the Server is operating in simplex mode.
Serial pinouts in use are:
Some issues controlling the with the serial outputWhen RTS is pulled low, the radio will transmit with the setting PTT_PIN=!RTS as the radio is using DTR as the reference.
At this stage the gate signal (pin 2)is not being actuated by the Serial Interface.
It was attempted to use DCD to ground. This didn’t work because the A2000 UIS
card needs a reference and it is suggestion to use the RTS or DTR signal. This
interferes with the PTT function, so VOX was used.
The [Rx1] stanza of svxlink.conf:
The [Tx1] stanza of svxlink.conf:
The IP_ALLOW is used to
let clients on the local network to setup an EchoLink (voice) connection
without being authenticated. Use this to run Qtel, connecting to your own
The SVXLink relied on the work done by CQiNet in decipering the Echolink Protocol
EchoLib classes documentation:
This is better resource:
This is a quick instruction on how to install svxlink from source code. An easier
way is to use pre-compiled packages already available in the latest Raspbian release.
Instruction on how to install svxlink from source code:
These instructions explain how to install SvxLink on a Raspberry Pi, with pre-compiled packages from the official Raspbian software repository.
Instruction on how to install svxlink from the official Raspbian software repository:
Glenn Lyons VK4PK
Ver:gnl20200806 - pre published v0.9