"robert casey" wrote in message
ink.net...
Many years ago my father (now a silent key) built a crystal tester that
pretty much worked with any crystal you stuck into it. Low frequency,
high frequency, name it. It also had a meter that indicated "crystal
activity" and also had an adjustment (think it was a pot) for IIRC "bias".
Also an output jack to feed say a frequency counter.


Bob

A simple Pierce or a Colpitts osc. would do the trick. The oscillator
will only work in the fundamental mode. I suspect they
built a simple oscillator, and probably added a germanium
diode (detector) on the output to drive a meter to indicate
the relative "activity" of the crystal under test. I checked
my Bill Orr handbooks and didn't find anything similar.

Pete k1zjh