[NJARC] HQ170

[Don Ehrlich]

Al,

Why do you call a fine old radio like the HQ170 junk?

The history of bad capacitors associated with IF transformers (and
other coils) is true of almost all boatanchor receivers that used
silver mica capacitors in those tuned stages where stability was
important.  The silver in the dielectric eventually 'migrated' out to
the surface of the dielectric, forming tendrils that shorted the
capacitor.  That is no longer a problem with modern silver micas,
however.

Alignment is a complex process but the instructions in the manual are
very clear.  With patience anyone with a generator and a set of those
little plastic hex alignment tools can do it.  A scope is not even
necessary, the S-meter is adequate for indication.  I have aligned my
HQ170AC and HQ180 several times and both are extremely sensitive.

Don K7FJ

----- Original Message ----- 
From: "Al Klase" <skywaves at webex.net>
To: "New Jersey Antique Radio Club" <njarc at mailman.qth.net>
Sent: Friday, August 06, 2004 11:32 AM
Subject: Re: [NJARC] HQ170


> StephenTetorka at cs.com wrote:
>   > It will be a nice challenge for me to try to
> align...I've got a gen. & scope.
> >
> > Any suggestions on how to start?
>
> Hi Steve,
>
> DON'T EVEN TRY TO ALIGN JUNK!
>
> It's unlikely that the radio would be a deaf as you describe
> on, all bands, due to aged alignment.  Unless, of course,
> some "unqualified" individual had tried to align his way out
> of trouble.
>
> I'd take the signal generator, start at, say, the last IF
> grid, and work my way back to the antenna terminals looking
> for a really dead stage.  I'd then try to tune up that
> stage, after I determined it had a good tube in the socket
> with the right voltages it's pins.
>
> As I recall, there is some history of bad IF transformers
> (shorted caps inside) in these sets.
>
> 73,
> Al
>
> Al Klase - N3FRQ
> skywaves at webex.net
> Flemington, NJ 08822
> Web Page:  http://www.webex.net/~skywaves/home.htm
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