[Milsurplus] Prc-6 frequency stability

[Bruce Gentry]

If all the components in the oscillator circuit are good, I will make an 
educated guess  the crystal is bad.  If the quartz is contaminated it 
can be extremely unstable or stop oscillating altogether and act as a 
capacitor. The oscillator could then free run anywhere the oscillator 
coil tuning takes it and drifts to.  A good crystal in the PRC-6 should 
be within  a few hundred cycles of it's labeled frequency. Almost all 
PRC-6 crystals are soldered closed, you can heat the can and it will 
come off.  As long as the conductive plating and leads to the quartz 
slab in good shape, and it isn't chipped or broken,a careful wash with 
warm water and detergent followed by a rinse with distilled water 
usually  gets an old crystal up to par.  Clean out the can as well,  
make sure the slab and leads can't touch the can, and resolder 
carefully. You should not need to use much solder to re-seal it. I have 
had very good luck with this. 

      Bruce Gentry KA2IVY

Robert Newberry wrote:
> I have a prc-6 that no matter how many times I bring it on freq it likes to
> drift. Today testing it I had it drift up to 51.16. Also it would drift
> down to 51.1. Also radio is rocked for 51.000. I know these were used with
> radios that had front ends that were "50 wide" but it seems like it drifts
> quite a bit. Is this normal?
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