My latest addition - Radialva Groom

[Geaney]

Hi John,

As you have already checked R6 through R14 and replaced those resistors out of tolerance, the only other thing connected across that part of the circuit is the field coil (marked EXC on the diagram) with a specified resistance of 3000 ohms.

This set is quite unusual in having the field coil connected in 'parallel' instead of series with the heater/dial bulbs supply. Because of this it will have an effect on the negative bias arrangement. Check its resistance, hopefully it will be fine and the problem located elsewhere.

Regards,

Thanks Robert, the field coil measures 3,200 Ohms which I assume is close enough. I guess I should be thankful that it's not the coil though I'm now running out of places to look.

Cheers, John