RE: [Discuss-gnuradio] Quadrature demodulator update

[Philip Mackenzie]

Dave,

>       Not so clear to me.  If I understand you correctly the IF sampling
>clock is getting into the front end of the receiver ?

Yes thats exactly whats happening.

>       A spectrum analyzer might and might not help locate the
>problem, but look up material on shielding, grounding, interference
>control and EMC testing and remediation (VDE and FCC A and B).

I did try a spectrum analyser a while ago. I can't remember the exact
numbers but the peaks did show up right across the band (up past 2GHz) and
were very strong, so strong in fact that I figured it was more than
shielding, etc. Maybe I was wrong but I assumed that since the mini-circuits
amplifier comes in a shielded metal enclosure that I wouldn't need to mount
it in a another shielded box. All the interconnects are BNC 50ohm coax.

Anyway, I'm sure a combination of both impedance matching and shielding, etc
will fix it. Since no-one has reported any similar problems using the
microtune front-end I can only assume that 4020 card is not to blame.

Thanks for all the replies,

Philip.