[EdHolland]

I think the circuit location of the mystery cap is traced. If my electrical sleuthing is correct, it is in place of a 5600 mmF (pF) cap (C25). This is switched into the oscillator circuit on some wavebands. One end permanently on the hot end of the main variable capacitor (C26), which is in circuit all the time, except when the bandswitch is at the preset position, and the other end at another wafer switch terminal.

Quite a "bold" move to replace 5600 pf with 0.1 uf! Given that I'm not sure the exact task of this cap just yet (but it is probably bypass duty) I wonder the effect this has on the circuit.

Do my esteemed forum members have suggestions for a suitable cap to use in this location? The one very grainy under-chassis picture I can find HERE suggests a paper cap in what appears to be the same location, but it's hard to see exactly... Bandswitch is near the top of the image, and the cap is tucked in to the right of the rear wafer, below the mounting posts.

Thanks

Ed