I’ve recently been acquiring equipment and testing an Echolink relay to a local repeater. Overall building the relay wasn’t difficult but I did learn several things about transferring radio audio to a computer and vise versa.
- Audio going out to the repeater needs to be no more that 8kHz and mono.
Most of the time when dealing with audio from a computer going out to some other device the computer can handle converting most audio levels down to whatever is needed for the output device. This is not the case with Echolink. Echolink needs a clean 8kHz sample-rate or bad things start to happen. The software will also not even attempt to convert a stereo signal into a mono output, instead you will only get a badly splattered left-channel audio stream.
- Knobs are TOUCHY!
The adjustments on the Signalink USB aren’t that bad unless you use the jumpers to amplify the adjustments. For this setup I didn’t need to amplify anything and left the 3 extra jumpers off. The radio’s volume knob has so far been the largest issue with it’s sensitivity making it hard to adjust the RX levels of Echolink going out to the repeater. This still needs more adjusting so I’m just waiting until I can catch several different users connected and rag-chewing so I can get a sense of the average volume level I need to send out to the repeater.
- The Echolink software is a memory hog.
I almost didn’t mention this but thought it may be worth noting just in case someone may find this while trying to setup an Echolink relay. The first computer I used for the relay was an i3 laptop with 4gb of RAM. The relay would run good for around 8 hours then start struggling until and eventual crash due to the computer being out of memory. Nothing else caused this issue other than the Echolink program and nothing else but system tasks were running in the background. I have since moved the relay to a much better computer with 8gb of RAM and have not seen memory usage go over 40% yet. I believe Echolink’s overhead may just require more memory than they claim.
- Antenna Separation.
I have a small house on a small lot so my antennas are relatively close to each other. I will be relocating the 3 element yagi that is being used for the relay link to another location as soon as weather permits due to interference from my base VHF and HF antennas. It isn’t bad interference but enough that it needs to be corrected for stability on the Echolink relay.
The relay is running with a Yaesu FT-1900R using a mere 5 watts through a 3 element yagi mounted around 20 feet above ground level. I was very surprised to find I didn’t need much power when using the yagi. Future plans include relocating the antenna as mentioned above, swapping the Yaesu out for a commercial radio like an older Motorola, and building a temperature and/or transmit controlled cooling system to provide additional cooling for heavy transmit sessions. For now I’m very happy with the audio quality and just need to do more audio level adjustments. I’m hoping this will provide a way for more local operators to get into the repeater and participate in nets and activities if their locations doesn’t permit working the repeater.