Hmm, would have to steal a signal generator from work, but can probably also use the TX of my KX3 as well [note to self: need a signal generator for the home lab some day].? I did some testing with the KX3 at zero power output into a dummy load which still produced more than enough signal (Said dummy load is also an attenuator and I've got an SMA output on it), but I never probed the I/Q signals at the PCM1804 (But it gets picked up by the audio of the QMX quite well) as I was at first thinking it was the mixer IC's or something further up the chain.? I'll see if I can get a good signal into the RX_IN node at the BPF and go from there up to ~500mV at the PCM1804, those levels should easily be handled by the entire RX chain.
