[Milsurplus] Mechanical Modulator

[J Forster]

See my earlier post about electrometers. The time varying capacitance makes a
very small AC current in the presence of a DC or electrostatic field. That AC
current can then be amplified, detected, and measured.

Best,.
-John

=============

WB6BLV (DM06) wrote:

> The 'wobulator' I mentioned is not connected mechanically to any other
> parts... it is nothing more than a variable capacitor driven by a voice coil
> (as in a pm speaker); the voice coil displaces one of two plates (or one set
> of two sets of plates in larger units) of the internal capacitor.  Audio fed
> to the voice coil causes the capacitance of the wobulator to vary at the
> frequency of that audio.  Being a mechanical device, the band of frequencies
> to which the voice coil can respond is limited to the low audio spectrum.
> Not bad for '30s amd early '40s technology, though, huh?
>
> Anybody know of wobulators being used in anything besides the APN-1??
>
> John
> WB6BLV at inreach.com
>
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