Aug 15 2021

Guide to using FT4 on satellites

Setup for FT4 on the RS-44 satelliteAMSAT-SM have published a guide to using the popular digital mode FT4 via the amateur radio satellites using SDR-Console software, a SDR receiver and the Icom IC-705 as the transmitter.  We have also had information from Jef ON8NT of the setup that he and Thierry ON2ACO used.

The AMSAT-SM guide covers:

• Step 1 – Setup SDR-Console and IC-705 with correct frequency

• Step 2 – Config WSJT-X

• Step 3 – Start Satellite External Radio in SDR-Console

• Step 4 – Select correct RX frequency in SDR-Console

• Step 5 – Find yourself on the satellite transponder

• Step 6 – Start calling CQ

• How to use a 2nd instance of WSJT-X for RX of your own FT4 signal

Read the guide at https://www.amsat.se/2021/08/15/ft4-via-satellite-with-sdr-console-and-ic-705/

This is a short video of FT-4 communication via satellite AO-73 with SDR-Console V3.1 and Icom IC-705. It is a part of a guide that will be published later on AMSAT-SM web https://www.amsat.se/

In the first part you will see the first screen with SDR-Console with Airspy Mini as receiver, audio is piped to WSJT-X. You will also see SDR-Console handle the TX Doppler correction for the IC-705 via “External radio”.

In the second part you will see the second screen with WSJT-X connected to IC-705. The output was only one (1) to two (2) watts! You can see that WSJT-X is reading the Doppler corrected frequency. You will also see SDR-Console satellite tracking and PstRotator controlling the SPID RAS rotor.

Watch FT4 via AO-73 with SDR-Console and Icom IC-705

Thierry ON2ACO and Jef ON8NT use the ICOM IC-9700 for FT4 on the satellites.

They used the video from NU1U on YouTube which gives a good step by step ‘how-to’.

Watch IC-9700 using SatPC32 and WSJT-X

Instead of SatPC32 they used the S.A.T. controller from http://csntechnologies.net/sat

For configuring the RX instance from WSJT-X, also the article from GM4FVM on using multiple instance was very helpful in setting up the soundcard properly in WSJT-X !
See https://gm4fvm.blogspot.com/2021/02/multiple-instances-of-wsjt-x-using-more.html