[ARC5] [Milsurplus] Audio Impedance Matching on USAAF aircraft

[hwhall@aol.com]

Cerussite need not be the euhedral clear or white crystals one can buy as specimens in a rock shop. Cerussite is a weathering or alteration byproduct of galena & can therefore appear as thin surface coatings. I have a suspicion the cerussite detectors of old might've been just that - thinly altered galena whose surface scrapings could chemically analyze as cerussite. Thus, baldfaced dishonesty may not have been at play. Or maybe not *completely* (giving a nod to "marketing").

Wayne
WB4OGM

On Thursday, January 1, 2026 at 09:54:42 AM MST, Al Klase <ark at ar88.net> wrote: 

Silicon Carbide was know as carborundum.  It was not near as good a detector as galena, but was far more stable.
Marconi America provided both in their marine receivers such as the 101, but claimed their galena was cerussite, a total lie.
See:  https://skywaves.ar88.net/xtal/Cerusite/
A 2000 Ohm (DC) headset was appropriate for either.

73,
AL