Ah... here we have a? sticking point - I do not have an oscilloscope and only a fairly basic home made RF probe for my digital meter.? Although I understand the various circuit diagrams and the function of the components - and have repaired lots of old <thermionic tube> gear in the past - I don't think I would know what I was looking for here - that is unless my RF probe and Digital meter will show increase or absence of a signal.? I haver just made an extender board for the PB2154 so I can see what I might be doing(!) and will? see what I can do over the next day or so.
Alistair GM4ENF