Selenium rectifiers in Zenith radios

[Findm-Keepm]

Originally Posted by transmaster

One thing people in the Electronic world over look are the ammeters used in commercial heavy equipment world. There you can get meters of 500 amps, or more. should you wish they are designed to a 100% duty cycle they have heavy duty shunts they read from. I know truck drivers who are hamradio operators they use heavy duty ammeters to monitor the power consumption, and charge state of the batteries used to power the 1500 watt ( or more ) HF amps they use in their mobile HF. setups.

Most of the stuff I do is low current, and the plethora of 50mV/full scale ammeters makes it easy to make your own shunts. A .05 ohm resistor is a natural 1A shunt, plenty for measuring my sub-1A needs. I have a shunt set as well, but have never used above the 5A shunt - the 50, 100 and 300A are all pristine. I smoked the 1A shunt, and replaced it with a .05 ohm, 50 Watt, 1 percent aluminum encased wirewound power resistor. Werks for me!

Cheers,