Old crystals

 At one time, back about 1987, I was busy building both QRP transistor rigs and replicas of vintage home brew projects. 

I often operated a Viking Adventurer as my transmitter. It was crystal controlled and had 50 watts input to the final tube. 

As my receiver at the time I had an old BC-342, an old Army receiver from the WWII era. I added a digital frequency counter to the BC-342.  It was made of 7400 series TTL logic a set of binary thumbwheel switches that I used to subtract the IF frequency from the oscillator frequency to get the actual receive frequency.   I designed that counter myself and spent four or five days at the kitchen table wire wrapping the circuit board.  

Anyway,  recently came across a handful of FT-243 crystals that I had ordered to use with my Viking Adventurer and with my experimental transmitters.  I ordered them from an outfit called CW Quartz Crystals in Marshfield, Missouri, in 1987.  So they are 35 years old.  The adhesive on all the labels had dried out and the frequency labels had all fallen to the bottom of the bin.  I had to spend a couple of hours with a signal generator and an o-scope, finding each crystal's resonant frequency and then reattaching the appropriate label.  

I was working on 80 meters and 40 meters and also experimenting with 30 meters, which explains the frequencies used.  There is only on 40 meter crystal left.  I must have lost the rest of the 40 meter crystals here and there as I moved around in the '90s.