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Author Topic: A Chance Crystal Radio Project  (Read 68 times)

Offline vu2nan

  • Warrant Officer Class One
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  • Nandu - VU2NAN since 1977.
    • Amateur Radio VU2NAN - Nandu
A Chance Crystal Radio Project
« on: August 19, 2019, 16:26:18 UTC »
A vintage unmarked inductor/transformer had been lying neglected in my junkbox for decades and I had to resurrect it.

Resistance checks showed that 2 windings, with a tap each, are terminated in its 6 pins. One measured 70 Ω with a 5 Ω tap and the other less than 1 Ω. A threaded core, with a movement of 5 mm is situated at the top of the unit.

The 70 Ω winding appeared to be suitable for a crystal radio. It was wired up as per the schematic shown below.

More details at