Dumont RA-103 Project Redux

[Chris K]

Great. I will try that this evening. Not to dismiss Tom’s suggestion but disconnecting B+ leads in bulk sounds too daunting for me right now. Both original resistor cans are in circuit and in use. I’ll take a comprehensive look and document it then post.

[Electronic M]

Originally Posted by Chris K

Great. I will try that this evening. Not to dismiss Tom’s suggestion but disconnecting B+ leads in bulk sounds too daunting for me right now. Both original resistor cans are in circuit and in use. I’ll take a comprehensive look and document it then post.

On most other sets I'd say have more faith in yourself. Dumonts with those harnesses usually aren't fun sets to trace leads on....Says a guy who made one good harness out of 2 half mouse eaten ones (it took a day and was a huge PITA, but I did it).

[Chris K]

Yeah it's a spider web, a mouse trap and hedge maze held together with hundreds of 1948 style zip ties...these annoying wax covered string knots. I had a thought. The main distribution switch for the B+ appears to be the selector switch on the front for phono, FM Tel and Tel without pilot light (why?). Do you think it would be helpful to power it up with phono selected and see if it shorts when the relay closes? Do the same perhaps with the FM position selected? Could this approach eliminate some sections as the source of the problem?

I relocated the new focus rheostat in the original position and hooked it up. I don't need new problems that I might make from running new wires etc...

The original canned resistors seem to be OK. The only terminal that has continuity with the chassis is the one that is connected to ground.