[TenTec] 20 MHz reference oscillator crystals - Also a note to whoever keeps the repair archive

[MadScientist1948]

For those who keep track of this sort of thing, I had purchased an Omni 6 with what appeared to be a CPU problem (gobbledegook on the display).

I was prepared to acquire yet another parts set…

What made me think it was worth tinkering with was the fact that the problem was thermal, with a time constant roughly that of the crystal oven.

I had some spare ovens so no worries there but this was certainly not the root cause of the problem.

I found that the 20 MHz reference went away as the oven heated up. 

I injected 20 MHz from my signal generator and all was well.

I found a bag of proper 20 MHz crystals on the auction site. They are perfect as a mechanical fit and they went into the circuit perfectly and I was able to calibrate dead-on to 20 MHz.

The radio now works perfectly.

Now I am left with a bag of about 39 of these crystals. If anyone needs one, drop me a line.

$10 shipped in CONUSA.

Gary

W0DVN