[Milsurplus] BC-342 Xtal IS bad!

[Barry Hauser]

Hi Phil

I know that crystals can go bad, all right, but usually it's the leads
inside the case or the junction between the leads and the crystal itself.
Somehow I don't think it's possible to solder onto quartz ;-) -- unless the
quartz is coated with a bit of silver or something.

Maybe it's possible that the quartz itself is just worn out, I suppose.
Could be all that vibration eventually scrambles the molecules.  That would
be a heck of a re-alignment job.

Seriously, though, you might check how the leads are connected to the xtal.
Maybe if they were re-freshed using some of that conductive glue or liquid
solder or whatever they're using on surface mount components these days.

Failing that - or another 470 kHz crystal, has anyone ever converted these
312/342's to 455?  Is there too little over-range in the rest of the IF
circuitry?

Barry

----- Original Message ----- 
From: "Philip Atchley" <beaconeer at elite.net>
To: <milsurplus at mailman.qth.net>
Sent: Thursday, May 27, 2004 5:18 PM
Subject: [Milsurplus] BC-342 Xtal IS bad!


> Hi All,
>
> This morning I pulled the Xtal out of the Xtal filter and took it down to
> the TV shop where I do stereo repairs on a part time basis.
>
> I fired up the "vintage" B& K audio generator and RCA scope and checked
the
> Xtal for activity per the procedure that a couple folks here told me (and
> which I think I once did many, many years ago).
>
> Anyway, the upshot is that the Xtal IS bad as I couldn't observe any
> resonance peak at all.
>
> I'm going to try one LAST resort.  I already dis-assembled and cleaned it.
> I'm going to try that ONE MORE TIME since it's out of the receiver right
> now.  "Maybe" that will accomplish something.
>
> 73 from the "Beaconeers Lair".
> Phil, KO6BB
>
> DX begins at the noise floor!
> Merced, Central California
> 37.18N  120.29W  CM97sh
>
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