Over the years I have repaired some Rogers and De Forest chassis that have a component installed in the RF circuit per the attached photo – it seems to be a capacitor by referencing the schematic, but the ones I have seen have had no measurable capacitance and infinite resistance (and the radios still work ok).
Thanks guys – I thought that’s what it was but did not have a components list to check against. Julian – I am using a Sencore LC meter that can measure down to 1pf, so I reckon the capacitor has failed.