Alan, just a guess here as I have nil experience with QDXs IQ mode.
?My guess though is that IQ samples that have not benefitted from the superhet conversion to 12 KHz IF that? the QDX internal SDR performs are being sent to your SDR software and that SDR software is responsible for nulling the DC spike. The superhet conversion would moot the issue.
This would be a great place for Hans or someone else with deeper knowledge to chime in.
On Sun, Oct 22, 2023, 7:37 AM Alan G4ZFQ <alan4alan@...> wrote:
On 22/10/2023 09:43, John Z wrote:
> from what you described I think you are seeing the annoying DC offset at
> the center frequency that is common to SDRs and quadrature sampling
> detectors.
John,
Yes, sorry some devices do have a big DC spike. I'd have expected the
QDX spike to be small but I guess it is not.
