[Beardyman]

Yes it does but I've been going through the photos I took before any work was carried out & the original resistor was a 500K across pins 2 & 6. I've also been looking through various other schematics of radios that use the FC4 (theres a fair few!) & the highest value I've found in those was 100K in an EKCO set. Unlike the valve museum datasheet the Defiant has that 500K across 2 & 6 but also a 250R with 0.1uf in parallel to chassis from pin 6 (k). I don't have enough knowledge of valves to unpick the designers thoughts on this one but the radio now works as it should. I'm sure there are other members who may shed some light on this toothsome feature.