Please reply off the list. This is the only place I know that has some electronics type people that can answer a question about an Astron RS-20A I picked up.
The PS regulates but has no high current draw because the equalizing resistors coming off the emitter of the pass transistors are fried. Now, what Astron did is put in a small wire about 30 gauge (hard to tell) from the emitter outputs of the pass transistors to the SCR crowbar circuit. These small "hair like" wires are fried in two...thus no AMPs out. They are about an inch or inch and a half long. The unit does regulate. The schematic calls for .1 ohm - 10 Watts resistors as equalizing resistors from the pass transistors.
In my opinion this is a hair brain (but cheap) way of getting .1 ohm except when you draw to much current they become fusable links.
Oh yea, there was a 15 amp fuse in the AC side....wonder why the PS is Kaput? It calls for a 5 amp fuse on the AC side.
So, now....how to repair? Replace the small strands with similar wire (this stuff is about the size of a human hair)...or get some "Dale" .1 ohm 10 watt resistors. I have some 1.5 ohm 25 watt resistors in the junk box...I would think that would work since they are just equalizing resistors and I might have to drive the pass transistors a little harder for the 723. There is a long way from .1 ohm to 1.5 ohms.
So, any geniuses out there who have fixed these things before?
Please reply off list so I don't get my kiester in a jam with the Elecraft boys...
Lee Buller
K0WA
In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense devine?
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