"Uncle Peter" wrote in message
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"Ken G." wrote in message
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Goofy style here . never seen one till this



Looks like a variable inductor tuned by a brass vane.


Variable tapped coil, rather than tuned. I've built crystal sets when I was
a kid that used a very crude form of this, with a fixed cap across it made
from wax paper and aluminum foil, and a slider made of brass that was
screwed onto a board and just scraped across the coil's windings to tune the
stations.