Gpredict 2.2.1 & IC-9100

Gpredict 2.2.1 interface set up as Duplex TRX, Sub up, Main down. IC-9100 in Satellite mode. Sometimes it works correctly if I set the main & sub dial correctly from the Gpredict radio control downlink & uplink window. Depends on the satellite. Sometimes if I go to [TRACK] it selects the inverse of what it should be almost as if the Transponder data was reversed. If I disengage and swap main and sub on the radio and re engage, it immediately reverses the VFOs again. So I can’t use it.
To update the TX (sub) VFO Gpredict swaps VFOs every “cycle” time but it sounds like 3 very quick swaps rather than just one. Gpredict works as expected on my FT-817 & IC-706.
From my my googling, I gather this is a well known problem but I haven’t found a reason or solution yet. I am still experimenting to see if I can find exactly what is happening when and where.
Your input is welcome.
Thanks, Bob vk2byf

Hi Bob,

Yes, we are aware of problems with this radio, but I haven’t had a chance to look into it and I do not have the radio anyway. There is an open issue on github, see

According to the information there, I have a patch in my mailbox that should fix it (at least conceptually), so if you are interested we can try to test it. I am very busy though, so it will probably progress slowly.


Hopefully something similar will work for the new IC-9700 when that is released.

I had vaguely considered building something in python to present the radios two VFOs as two separate Hamlib-compatible servers. to avoid issues with GPredict, but it would of course be nice if it works out-of-the-box :slight_smile:

1 Like

Is it already implemented in HAMLib? Is a spec available? If you could provide a link to the protocol spec I could at least throw an eye on it.

I think the IC-9700 CIV spec has only been released in Japanese so far (see here: ). Definitely no Hamlib support yet.

If it’s anything like the IC7600 vs IC-7610, then the protocol will be very similar to the IC-910H.

1 Like

what could possibly go wrong… :smile:

1 Like

They’ll get there eventually! I don’t think the IC-9700 has been released in english-speaking countries yet.

1 Like

I’m happy to try your patch and provide feedback. I understand work must come first. It’s what pays the bills. I’m no programmer so please keep it simple. When you have time, no hurry.

Some additional 9700 documents have been released on the Icom Japanese website, in English (Just read about it on the AMSAT mailing list and QRZ sat forums). Hopefully there will be information of value there.


1 Like

The CI-V Spec is here:

The manuals are here:

1 Like

This link no longer works and I couldn’t find any other link on their website. The other two are still fine, though.