ddwyer wrote:

In article , Mike Coslo
writes


H. Peter Friedrichs wrote:



Michael,

I'm interested in "extreme" homebrew for its own sake. I simply like it.

http://www.mindspring.com/~pfriedr/b...ry/gallery.htm
http://www.mindspring.com/~pfriedr/b...ry/gallery.htm


Very enjoyable Site, Peter!


- Mike KB3EIA -



I was in the Xtal business for 20 years so can answer individual
questions.
WWII and before Xtals were flat plates and vibrated to the edges in "air
gap" holders.
after 1950s centre plated crystals were ideally dead at the edges.
If you want to lap frequencies up a VCO tuned comms receiver can pick up
the broad band noise generated and centered on the crystal frequency.
Above assume shear mode AT type or Z cut plates.



The Crystal grinding shop in the Washington DC Navy Yard (1947) had a
National HRO receiver
connected to the rough grinding machine. They picked up the noise to
tell how near to the finished
frequency they were. They then went to hand grinding to finish.

I have a chunk of Quartz from that shop.

Bill K7NOM