[BC] Audio "proofs"

[Dana Puopolo]

After Clarence died, my friend Al Carp's fiancee (now wife) Linda replaced
him, but by then demand was falling off thanks to low cost frequency counters.
After a few years they pulled the plug and razed the one room penthouse.

-D

From: RichardBJohnson at comcast.net

I do! Every station for which I worked would contract Cambridge Crystals for
their monthly frequency measurement --even WCHA in Chambersburg, PA! I visited
him once and he showed me how he would zero-beat a signal with a local
generator, and with an interpolation oscillator, measure the local generator's
frequency to within one-tenth of a cycle (in those days, before Hz).