You Know You Are Old When

[CalG]

I still have a lot of selenium rectifiers. All different sizes, some full wave, assorted voltage and current ratings.

Last week end, I halped a friend repair his standby generator set. An old "power company" Onan with a nice diesel engine.
It was only putting out 70 volts per leg.

It's a transformer regulated device, and a look at the schematic showed that the most likely, or at least the lowest hanging fruit would be the bridge rectifier that supplies the exciter. Sure enough, replacing that device brought the output to just under 250V leg to leg.
My friend was amazed that I happened to have such a component "just kicking around" in my shop. ;-)

 

[Fuddyduddy1952]

It's been over 50 years since I had some Electronics Engineering but from memory () I seem to remember the forward voltage drop for germanium was about 0.3V, silicon about 0.65V, and selenium about 1 volt per stack. So I would replace a defective selenium with silicon for many reasons.