found what I believe are a few vrc drum pickup heads too bad photos don't post here interested parties,can email

[Ed Sharpe]

not these heads.....

Sent from AOL Mobile Mail

On Saturday, May 12, 2018 Chuck Guzis via cctalk <cctalk at classiccmp.org> wrote:
My guess was MADRE or NRL:

https://www.wikiwand.com/en/Over-the-horizon_radar

The timing would be right. Acoustic delay lines served the same
purpose, but you couldn't have a mercury delay line in an airplane,
practically speaking.

--Chuck