Draloric Polywatt Resistors with screw terminals:
I found them in an abandoned Lab in the University-Hospital where I work.
Never seen resistors like that before… the one in the housing is a potentiometer.
I found them in an abandoned Lab in the University-Hospital where I work.
Never seen resistors like that before… the one in the housing is a potentiometer.
They are ~1 century years old, used in wireless (TSF) sets. I have a few of them in my attic (but I am not going to use them any time soon: they had pretty awful performance compared to present day carbon film resistors). One exception though: I also had a full glass resistor (probably semiconducting), swiss made, a filament of glass inside an evacuated enveloppe. It must have cost an arm and a leg at the time, and was probably vastly superior.
The standard resistors like yours were probably deemed excellent at the time, considering the performance of valves, interstage transformers and capacitors
The standard resistors like yours were probably deemed excellent at the time, considering the performance of valves, interstage transformers and capacitors
Compare and contrast with today's 01005 size surface mounted resistors. 🙂
Those resistors are cool, though. They should go in a museum.
Tom
Those resistors are cool, though. They should go in a museum.
Tom
TSF is the acronym for Téléphonie Sans Fil.
It comprised everything from galena to TRF, "reflex" types and regenerative ones.
After the superhet became commonplace, the TSF stuck: in the sixties, my grandfather still used the term for transistor radios.
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Thank you.
This is the one I was referring to..
https://en.wikipedia.org/wiki/Tuned_radio_frequency_receiver
This is the one I was referring to..
https://en.wikipedia.org/wiki/Tuned_radio_frequency_receiver