Hello Chuck,
Following your post I went through the schematics and could retrace the RX signal flow (on paper).
So I now got a better understanding of the RX signal path.
Before I treat the switch with contact cleaner I will measure continuity between the antenna input and the IF-Trap which seems to be located on trimmer Board A.
Out of interest:
Could you shed some light on where the 'marker signal' is fed into the circuitry?
73, from the UK
