SDR and software

WSJT-X Full Duplex FT4 test with IC-9700 via RS-44

The latest version of WSJT-X Improved, from v2.7.1, it is possible to use full duplex, that is listening and decoding at the same time you are transmitting. For satellite operators, mainly QO-100, you can now have full duplex control over your transmission avoiding drifting of your FTx signal.

I did a test with FT4 over RS-44 as I will try to describe here in this post. I’m using Icom IC-9700 and PstRotator for doppler control but the concept is the same if you are using other rigs and doppler control software.

First download WSJT-X Improved, use version from v2.7.1.

To be able to use doppler control from PstRotator and at the same time control PTT from WSJT-X use Omnirig (setup not described in this post).

For IC-9700 you must set up the USB soundcard in Windows to use both channels (“Kanal 2” in swedish means “2 channels”):

In WSJT-X use the USB left channel from the IC-9700 – left channel is the main band audio.

Set up for Full Duplex Mode in WSJT-X:

Below is an animated GIF when using FT4 via RS-44. Transmitting power is at 0% (zero) so very little uplink power is needed. You see that after every TX sequence WSJT-X is decoding my signal:

And below you see the WSJT-X spectrum as an animated GIF. What you see is my transmitted FT4 signal received in full duplex.


The Full Duplex version of WSJT-X improved is working perfect for FT4 via satellite!

SDR and software

Nooelec Ham It Down 3GHz downconverter

Nooelec, manufacturer of LNAs and SDR equipment, releases a new downconverter. It is designed to convert signals from the 1.55 GHz to 3.1 GHz range into the frequency range of software-defined radio devices like RTL-SDRs.

Initial price is set to around 90 US$ and it makes it an interesting product for S-band RX if you have a SDR since before.

Nooelec product page

Also there is a first review on Youtube from dereksgc

SDR and software

Greencube Terminal by OZ9AAR

Greencube Terminal by @CarstenGrn1 Carsten Grøn / OZ9AAR is a packet terminal software for the Greencube IO-117 satellite. This software adds a couple of interesting features compared to the original terminal by Andy, UZ7HO.

Some of the feature are:

  • Logging to several logging software
  • Local ADIF search of worked stations
  • Integrated tracking of your own station and all active stations on the satellite
  • A smart way of list stations who are calling you
  • And many others

I highly recommend this software for working IO-117. It is updated often and full info can be found at this page.

Ham Satellite news SDR and software

Working GreenCube digipeater guide by FG8OJ

@FG8OJ has made an excellent guide of working GreenCube digipeater with IC-9700 and supporting software. I will not write a new guide as Burts guide fully covers everything.

Valid exchange messages for a QSO should be:

You can look at FT8 needed exchange : 2 exchanges from each side:

A:R + Report

B:R + Report

Beginners and operation SDR and software

Guide to AX.25 via OPUSAT-II

OPUSAT-II, or Hirogari satellite, has the possibility to send, store and receive short AX.25 messages. This is a simple guide how to set up a Windows system to send and receive via OPUSAT-II.

  1. Download Soundmodem from
  2. To be able to key your radio, download from the same page and unzip these files to the same folder as Soundmodem
  3. If you use IC-705, download and replace the CAT.DLL file from
  4. Start Soundmodem and set up the ptt for your radio:
  5. Setup the audio input and output to your radio in Soundmodem under Devices menu.
  6. Download MessageBox software from and unzip
  7. Start MessageBox. It should connect to soundmodem.
  8. When OPUSAT-II is in range, transmit via MessageBox (Send) at 436.500 MHz FM and receive at 145.900 MHz. If you are lucky, your AX.25 is stored in OPUSAT-II:

SDR and software

VFO control for SDR Console Satellite External Radio

In SDR Console v3 it is possible to control an external radio for transmitting (TX) in the satellite mode – this is called External Radio control. To change frequency you can click on the digits in the control window with the mouse pointer or change with the arrow keys, but it is not possible to use any other shortcut keys or VFO knobs.

This solutions adds a AutoHotKey script for remapping and controlling both RX and TX VFO and a software remote VFO with the help of Unified Remote software. You can use these independent – but best is together. If you only use the AutoHotKey script then you can toggle between the RX VFO and External Radio TX VFO and control with the arrow keys. If you only use the Unified Remote you can control the RX VFO but not switch to the External Radio TX VFO.

Files and instructions can be found at Lars Thunberg SM0TGU GitHub.

Short animated GIF from adjustning the RX VFOs and satellite external radio TX VFO in SDR Console