Using a 4m transverter with Smart SDR/6600

John G3WGV

6600 + SmartSDR 3.4.21, Windows 10, Homebrew logging software and controller both via API

I'm having weird problems with getting SmartSDR and/or my logging/control software to correctly change band to 4m. I've correctly set up 4m and 2m transverters in Radio setup | XVTR. Both have a 28MHz IF.

I have various ways to QSY to a new band. I can do it through my homebrew logging software or my homebrew controller, both of which use the Flex API or, of course, I can do it via the SmartSDR Band menu. Any of these work fine when QSYing to any HF band or to 2m via the transverter. If I QSY using my logging program (by far the most usual method) then the logger also sends the necessary commands via the API to set the PTT and antenna ports appropriately. That too works fine on HF and on 2m.

However, when I try to QSY to 4m strange things happen! Often nothing happens at all. The 6600 just stays where it was. Sometimes it QSYs to 6m and then tells me that I am out of band! Eventually, some arbitrary combination of band change requests via the logger, controller or SmartSDR gets me onto 4m.

In due course I want to go somewhere else, let's say 20m. The frequency change usually happens OK but the PTT line stays on RCA TX3 (the 4m PPT line) and the antenna port selection remains set to XVRTB for 4m, even though I sent the correct API commands to revert to Ant1 and RCA TX1.

I'm starting to conclude that there is a bug in the way that SmartSDR handles transverters, perhaps specifically 4m transverters, although I can't really see why it should be so specific. I feel that I need to refine the problem definition before raising a ticket! Has anyone else seen this rather odd behaviour?

Thanks and 73,

John, G3WGV