Have finished recapping the set, I get sound from the gram input but some static from the radio, before I get to that I need to figure out the tone control. It appears to operate in reverse, I only replaced the capacitor connected to the centre lug, so I haven't reversed the connections. When the tone control is turned to bass, it generates a low tone in the speaker, if halfway or fully to treble the tone isn't apparent, did these sets have a reversed tone control or is something else going on?

Thanks
Darrin

Tone generated with tone turned down:

https://drive.google.com/file/d/1PNUWaZqlpmQ-C6Hlhd0gyZxy2b6c4Cov/view?usp=drivesdk

Perhaps some kind of feedback issue involving the tone control. Try checking all of the conections in that part of the circuit and clean the audio valve connections.

Thanks STC830, will recheck. Turns out the radio works fine, just somebody who will remain nameless didn't know how to correctly operate the set. The other issue is that the dial lamp voltages are around 29V (AC), the have a 220ohm resister across the lamp fittings that get quite warm, both lamps have blown and I'm not sure what the voltage there should be.

I'm not sure what the voltage there should be.

I don't have that schematic in front of me, but the usual practice was to run the dial lamps from the valve heater supply, be that 6.3 volts or 12.6 volts.

The existing (blown) bulbs should have the voltage printed on them.

Thanks gtc, I found out they rated at 19v and can be replaced with 1447bulbs.

The lamps are in series with the magic eye heater and the rectifier, the lamps have bypass resisters, which get quite warm without the lamps.

OK, so that's an AC/DC set and the voltages across components depend on where components sit in the series chain given a constant current (such as 300mA).

I'm not sure why there is a resistor in parallel (whether by design or fitted afterwards) but, without one resistor in a parallel pair, then the other one carries all of the current and the power dissipated in that remaining resistance is therefore increased by a power of two. Power = current squared times resistance.

There is rhyme & reason for those parallel resistors across the heaters. I repaired an STC 236, 32 V lighting set and that had 40 Ohm resistors across several valves one of which had fried. That may have been the result of an open heater? However, they are meant to be there as the heaters were in series.