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.
Summary:
The Full Duplex version of WSJT-X improved is working perfect for FT4 via satellite!
4 replies on “WSJT-X Full Duplex FT4 test with IC-9700 via RS-44”
Hello i am SV1CEV Vagelis from Greece
i have the same equipment, and this time try connect to rs-44 via FT4 mode
maybe by see you on this satellite
Thank you very match for this best report
73s
Please contact me for sked if you would.
73 de Lars SM0TGU
Lars – I set up like this and definitely receive the downlink because I made 2 contacts ( single instance of WSJT). However I don’t see my transmit on the left side – I use an arrow 2, dual band yagi – it the TX overloading the RX ?
Should not be a problem with the IC-9700. Very hard for me to know what the problem can be.