G'day all, the whole fault finding process is too involved to go into, but the other day I found that a critical short RG213 patchcord was braid intermittent at one end of the PL259 plug.
It had been like that for quite a few years, causing some weird and wonderful symptoms and faults!
Needless to say my whole HF Ham station is now working a lot better including much improved transmit reports. That faulty patchcord was apparently contributing very significant loss 'on transmit'.
Regards, Felix (vk4fuq) aka catman.