Search found 2 matches

by oh1nd
Thu Jun 29, 2017 7:46 pm
Forum: SDRplay related
Topic: RSP2 LO 3rd harmonic spurious response only -20dBC
Replies: 17
Views: 46699

Re: RSP2 LO 3rd harmonic spurious response only -20dBC

It looks like the IQ mixers are not analog multipliers like in old Motorola MC1496 circuit but instead IQ mixers are working in switched mode. So the LO is like a square wave. The spectrum of that includes odd harmonics and the only way to get rid of spurious conversion products is to filter input s...
by oh1nd
Wed Jun 28, 2017 8:08 am
Forum: SDRplay related
Topic: RSP2 LO 3rd harmonic spurious response only -20dBC
Replies: 17
Views: 46699

RSP2 LO 3rd harmonic spurious response only -20dBC

This is incredible poor result. I heard stations that for sure are not on 1.8 or 3.5MHz band. This did not depend on signal levels and therefore is not an overloading or nonlinearity issue. So I did search frequencies that produre spurious responses. I used a professional HP signal generator and fou...