John Larkin wrote:
This is a quartz crystal made for us by Lap-Tech in Canada. It's glass
sealed with vacuum inside, for high Q and low ageing. It's a 40 MHz
overtone AT cut, for oven use. The manufacturer writes the
turning-point (zero TC) temperature on the base of each individual
unit; you can barely see the '61' on this one.

John




Nice closeups! Thanks.

Ed