[EdHolland]

Backwards and forwards yesterday. In my kit of spares, I found one IF filter that would fit the first 455 kHz stage as a direct replacement. This was tried and made no difference whatsoever. In touching up the alignment, it was possible to get the S meter to be peaked at the exact carrier frequency, which had previously been slightly off. However the "tuned for best sound" point is still askew when using the AM wide filter. So I'm back to the opinion that the wider of the two filters in the 2nd IF stage is off centre. The narrow filter, also used for SSB, is in fine condition.

A determined search has found the required part - even these 80's & '90s parts are becoming quite scarce. I have 12 kHz bandwidth filters that could work, but they are not the correct pin-out.

/Ed