[Elecraft] RS 22-507 Power Supply

[Augie Hansen]

David Cutter wrote:
> It sounds like a malfunction in the start-up circuit.  How is the psu 
> switched off?   My guess is it is not an isolating switch on the 
> supply input, but some low power circuit that sends a signal to the 
> start-up circuit.  This is not an area to be tackled lightly, as it is 
> at mains potential.  Over here that can be lethal, but still be 
> careful how you investigate.

Thanks for the advice, David.

I'll trace out the circuit when I finish my current project (time is 
tight right now) and do some troubleshooting. Having learned electronics 
as a kid back in the tube/valve era (radio and TV broadcast in the late 
1950s and 1960s), I tend to be wary around AC and high-voltage circuits. 
I worked as a transmitter engineer one summer between semesters at 
WEAN/WPJB-FM in Providence, RI. The chief engineer impressed the 
importance of caution around such circuits by showing me a picture of a 
"fried" engineer who had gotten across the HV in the 5KW AM walk-in 
transmitter at the site several years earlier. That made a lasting 
impression on me for sure.

Cheers,
Gus Hansen
KB0YH