Msg dialog box (center) shows syntax for sending aprs email. IT WORKS! You must first enter APRS password into settings.

JS8call screen capture

Jordan Sherer ,KN4CRD , js8call presentation.

Download link

Like some, the more I read about this area of ham radio and the more confused I became. So many modes! Even hardware software /hardware setup is not clear.

I will start with a specific setup and work backwards to the finer points and theory.

First do not get the audio interface confused with CAT (computer aided tuning). I use a signalink usb,by  Tigertronics in Oregon for audio. This unit has its own VOX for the radio for generating ptt signal  to the radio. You will need acc cable specific to radio used.

Note the word ‘CODEC’ in audio input/output selection. This screenshot is from raspberry pi desktop

There are only 4 signals passed to radio.


2-tx audio

3-rx audio


Also there is a dip header inside to adapt to specific radio.

When this properly installed, that’s it! No more hardware is needed, but it is nice to have  CAT control by purchasing a cable for your radio.

Remember that all digital com. Is upper sideband only!  Actual tx frequency is the dial plus offset indicated in the software. Some of my favorite digital software is.


JS8call-This is one of the most exciting digimode innovations that have ever come along .Allows weak signal texting(chat) with forward error correction, auto relay and one-way email capability.  All without internet can be equivalent of a HF network eventually relaying messages around the world.



Before operation you will need to will put callsign and audio com port info into  settings rx knob need to be adjusted . Tx is adjusted by tapping tune button in sw ,and gradually increasing level until desired power output power level is reached.

All filtering and audio signal processing is done digitally, radio agc-off and internalfilters are opend or deselected. For some modes , accurate time (+_ 1sec) is necessary for decoding . Internet time sever ,, works. Also, most importantly, ONLY USE UPPER SIDEBAND, no matter what band your on.

It is highly recommended to download manuals and read them!


Gary ae7ov