I still have, and use, an "antique", Big, Honkin' 50 amp 12/6V battery charger -- and it uses selenium rectifiers. It's out in the bitterly cold, dark, detached garage ATM -- or I would quote from it's metal name tag. A hand-me-down from my father ... and maybe even, his father.
In the past I was able to start my old, dilapidated, hardly-any- compression Jeep with no onboard battery!
Still have the charger -- not the Jeep. :-)
Jonesy
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Marvin L Jones | Marvin | W3DHJ.net | linux
38.238N 104.547W | @ jonz.net | Jonesy | FreeBSD
forward/back resistance with a basic ohm meter should be around 100:1 or better as I recall, and you might have to use a resistance bridge of some kind (or other measuring circuit) with a voltage potential of several volts for the higher voltage selenium rectifiers.
Selenium rectifiers might have a voltage drop of several volts during normal operation. So maybe a test circuit would work better...
You could drive normal AC power through it, into a (safe) resistive load (no capacitors), and then look at the downstream waveform on an o-scope. It should be half wave AC at a reasonable peak voltage, into a reasonable resistive load (let's say a 10k or 20k several-watt resistor).
I assume it's for a radio that runs on 110V [or maybe 220/240V for EU and AU radios]. So you'll see a half-wave 50/60 cycle waveform that peaks at around 1.4 times the input voltage.
If you look at it with an o-scope and see too much on the negative cycle, you'll know it's bad. Otherwise it should be ok to use it as long as the resulting output voltage is correct.
--
(aka 'Bombastic Bob' in case you wondered)
'Feeling with my fingers, and thinking with my brain' - me
right they'll probably short out when they fail and blow the filter caps.
You could try a resistive load (10k-20k, several watt resistor) and disconnect it from the filter capacitors when you do it. Then look at the waveform. (I suggested this in a different post already, just summarizing)
--
(aka 'Bombastic Bob' in case you wondered)
'Feeling with my fingers, and thinking with my brain' - me
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