On Tue, 27 Jun 2006 21:37:44 +0100, john wilkinson
wrote:

Hi,
If I feed my second mixer into a spectrum analyser, and inject a 44.545MHz
LO, with no power to the first IF stage, I see spurs at about 48-50KHz
intervals on the mixer output, from 0 to the 455KHz normal output freq.

The mixer is an SBL-1.

Any ideas as to where these are comming from?

Best regards,
John

You have spurs on one or both of the inputs to the SBL1. Passive
doide mixers will not generate spurs like that though they may pass
them through if the sources are dirty.

Also the IF could also be oscillating and your see ing that
contribution. If its the 100db IF duscussed before, thats a lot of
gain and I'd hope its bypassed and shielded very well.

Allison