These traces speak for themselves!
Suddenly we have a useful measuring machine. The missing gain is back! The wild wiggles are gone. Forgive the strange screen reflections of a finger shadow trying to take a photo! At the time, I was just a tad distracted (delighted?) with what was happening.
At the other end of the range with a 0dBm signal! Here the centre frequency is 1500MHz.
Not bad for something lashed up from bits to hand. And it came with a learning experience that is hard to find in other ways. This calls for one of those "raised arm and smack the pal's hand" celebratory gestures (USA culture spread far!), but lacking anyone nearby, I am pleased to share it with you folk.
Go Back to "How We Finally Got it Right"
Page 1 Special Mixer Mess (description of the problem)
Page 2 - Spectrum Analyser Mixer Dissection - Taking things apart
Page 3 - Spectrum Analyser Mixer Dissection - A closer look
Page 4 - Spectrum Analyser Mixer Dissection - Oh Yes - it is still full of surprises!
Page 5 - Spectrum Analyser Mixer Dissection - How it ended up
How We Finally Got it Right (and all the secrets too!)
The Result - Performance Traces
Some (not so good) Traces
Author : Graham Seale