Re: "Fuzzy" FM
OK, so I've changed capacitors.
A handful of caps that looked a bit like the Hunts Mouldseal types (but wasn't) was replaced.
No change.
A couple of other caps, including the discriminator cap, was also replaced with the
same result.
I then did an IF realignment as per Paul Stennings excellent instructions, it worked great and
brought a bit more sensitivity and with that a few more stations but the distortion remains.
I then tried swapping the full set of valves, no change.
Tape input is clean and nice.
AM likewise.
FM is distorted on all stations and at all volumes.
Tuning seems fine with the best sound reproduction at the well defined peak of the signal, also confirmed by the magic eye.
HT voltages are generally a little low so I think, I will concentrate on the (metal) rectifier next.
If that does not cure the poor thing, I think the two discriminator diodes will be next. I suppose that eventual differencies
in leakage etc. would play a role and those OA 79 could easily have passed their sell-by date.
Please chime in with any and all ideas, you may sit with.
Martin
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