"Ken Scharf" wrote in message
. ..
Just got the lot of 400+ crystals I won on ebay.
Turns out they are NOT HC49/u rocks, but HC6/U!
Isn't it ture that the larger crystals are better
for use in filters than the smaller one's (higher
Q, less loss, etc?)

While Q comes with cubic feet (of space around inductors and capacitors) it
isn't the only factor when it comes to crystals. There, it's mostly surface
finish, cut and the amount of plateback used to place them on frequency. You
can have Q of several hundred K in the small HC-49, and less than 50K in the
larger holders. (Crystal itself may be larger or smaller, doesn't HAVE to go
with the can).

Have to measure a representative sample to determine the average, I haven't
seen a crystal made in recent years with really high Q. Quality control
folks have learned how to take all the quality out and make them cheaper.

After WW2, some manufacturers bought up all the FT-243 crystals they could
find. Chopped the wafers into tiny pieces and made really good crystals for
many years.

W4ZCB