Re: RCA AR88D Comms Receiver.
The AR88D local oscillator is a 6J5 and uses a number of high value resistors which means capacitor leakage will have to be zero.
In case any are bad If you haven't done so fit new resistors at R4, R11 and R14 then new capacitors at C13 (=82pF) and C14 (220pF) and C53 (=6.8pF)
Different examples of the 6J5 metal/glass have varying stray capacitances which may also come into play.
Also check all the ground connections around the 6J5 in case one has oxidised and you're inadvertently adding a section of chassis or resistance into the oscillator circuit.
That range of RF voltages looks to be too great to me. Remember a scope probe may be not all it seems to be in terms of bandwidth.
Allan G3PIY
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