....ah... the smell of success.... followed by disappointment... nothing beats the thrill of trying to find the problem without success guaranties!
I was building an expansion band module (for the band module expander...confusing hum?),
basically a blank band module that will allow me access from outside the radio bandpass and VFO signals
Then I was injecting an external VFO signal and noticed some instability in frequency using the 40m band.
(On the left using the Si570 as external VFO)
After debugging a little bit I discovered the culprit...
Have a nice weekend!