[R-390] R-390 Digest, Vol 98, Issue 2

[chuck.rippel at cox.net]

There are 2 crystals in that oven, most likely the 200KC calibrator 
crystal has failed.  That problem is fairly common.

While you are in the RF deck, check ALL the 2.2k (Red-Red-Red) resistor 
and REPLACE C-327 with a 100pf, 1KV ceramic cap.  Its across the primary 
of T-207 and can be easily seen.  Another very high failure item.

Chuck Rippel


On Mon, Jun 4, 2012 at 12:03 PM, r-390-request at mailman.qth.net wrote:

> As I stated before, I think I cooked my crystal calibrator crystal 
> plug-in unit whilst following the alignment procedures laid down in 
> the Y2K R-390A manual. The instructions said to inject a signal into 
> E210. and zero beat the signal by rocking the sig gen in. I was unable 
> to hear any signal to zero beat and afterwords my Crystal calibrator 
> wandered and sounded garbled.
>
> I switched out the plug-in crystal unit and the problem was solved.
>
> Thinking I may have done something wrong in the procedure, I carefully 
> read the procedure and repeated the procedure. I still could hear no 
> signal to zero beat to. I didn't increase the sig gen gain this time 
> and discontinued the procedure.
>