ka9q-radio w/ rx888 and frequency converter

[Glenn Elmore]

 How do I configure a ka9q-radio with an RX888+converter (frequency
offset) to be able to select 2m WSPR from WD?

First glance shows AirSpy .conf but nothing with external freq
conversion HW. Maybe I haven't looked far enough yet...

[Phil Karn]

Right now the rx888 only supports direct sampling at baseband. It has a
tuner, but we haven't finished support for it yet.

I could add a config option that would accept a LO frequency for an
external converter and make frequency calculations. I do have such an
option for the Airspy, I could model it on that.

[glenn.e...@gmail.com]

For best performance I think neither direct sampling nor the on-board tuner will be optimum, certainly not for demanding modes like FST4W at microwave. It's in these cases that an external downconverter is probably the choice.  So I guess I'd be happy with the entered-LO/calculation solution that essentially creates a good receiver.  But, OTOH, I'm probably in the minority so it may not be worth spending your time on when there are other more important things.

I'm asking because I wanted to use it with an external converter to examine sub-Hz phenomena at VHF when everything is referenced to a good local standard, e.g. looking at aircraft scatter Doppler shift on VHF or UHF WSPR.