[R-1051] R-1051C problem - radio seems to be possessed...

[David Ross]

Has anyone seem this problem before?

Intermittent problems with USB & LSB & FSK & ISB mode reception, but AM 
& CW modes work with no problems.

Problems with various modes come and go, but AM & CW modes never fail. 
Either a mode works or it doesn't work, there is no in-between.

At first it seemed like neither product detector was working.  All 
voltages on both USB & LSB modules are OK and switch normally.  500KC 
injection voltages to both modules seems OK at 400mV P-P.  Swapping 
modules makes no difference.

Sitting on the bench seems to have helped the radio -  early symptoms 
were that only AM & CW modes functioned.  Lately the symptoms are that 
all modes work except for ISB.

When a mode is working, it works fine with good sensitivity and a good 
clean sound.

Any guidance here?  My ignorance is complete...

thank you
Dave Ross    N7EPI