Dumont RA-103

[Davala]

Originally Posted by Tom9589

Check the voltage on Pin 9 of the CRT while you vary the brightness control. If it doesn't vary, you might have a heater-to-cathode short in the CRT. An isolation transformer (looks like a CRT brightener) can cure that problem.

I thought that I might have a heater to cathode short as well. I'll have the chassis up on the bench(desk) later today but I think the voltage did vary last I checked. The brightness range does change from bright to very bright!

Thanks!
Matt Davala