Did some measurements on receiving on harmonics of the LO
It seems the receiver is rather sensitive on harmonics of the LO. More like between -3dB and -6dB on first harmonic instead of -9dB
I also measured what the receiver does on harmonics of the antenna signal. Testing with a rather clean sinus input there is a signal at 3rd harmonic at about -35dB. Mirror rejection completely fails on these harmonics. Still need to verify if the input sinus is clean enough
If all these measurements are correct (not sure) it is terribly clear why you need a good BPF with direct conversion
--
Erik@Home
