1Ж42А. As a mixer/Frequency changer????

[Murphyv310]

Thanks very much Michael.
I have ordered them from a UK seller and they should be here Wednesday or Thursday.
I've now got a Pye B16T to restore and that'll take up my time for a good few weeks. I want to try another idea later with the radio using a 1N4148 with some forward bias. I agree that these valves have very high input impedance so any damping massively reduces performance.