[R-390] Dial Light Wires Fried

[Bob kb8tq]

Hi

Is it common on an R390 or a R390A? It’s not anything I have seen on either radio.

Best guess:

Filament windings put out a lot of current. The chassis wires are rarely rated to handle
the max output of the transformer. How much current is that? The fuse will eventually 
blow at some power level. A military grade transformer probably can deliver all that power
to the filament winding

Pilot light wiring runs around on the front panel. It’s the least protected part of the radio.
Having this or that “wander in” and create a short is a very real possibility. 

Does this ever happen in the real world? Yes indeed it does. Back in my early years
fiddling around on various radios, I did it at least once. 

Bob

> On Feb 11, 2026, at 7:36 AM, Tom via R-390 <r-390 at mailman.qth.net> wrote:
> 
> Is it "common" for the wires to the dial lights to be fried on an R390? I've
> had three in here the last few months and each one has had the wires fried.
> 
> 
> 
> Tom
> 
> W3TA
> 
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