[Hallicrafters]V7,#8-Help with SX-42

[Phil Barnes-Roberts AD6PQ]

At 04:00 AM 8/9/04 -0400, hallicrafters-request at mailman.qth.net juggled the 
keys to produce...
>From: Edward B Richards <zuu6k at juno.com>
>Precedence: list
>Subject: Re: [Hallicrafters] Help with SX-42
>Cc: hallicrafters at mailman.qth.net
>Date: Sun, 8 Aug 2004 20:33:21 -0700
>To: barry_hauser at juno.com
>Message-ID: <20040808.212631.-558423.5.zuu6k at juno.com>
>Content-Type: text/plain
>MIME-Version: 1.0
>Message: 10
>
>Thanks, Barry;
>
>That is EXACTLY my problem. Same wafer. I have it isolated so I know it
>is leakage across the insulation. Lots of good tips. Thanks again.
>
>73, Ed Richards K6UUZ

Lots of good help to be had on this reflector.  Remember in 
troubleshooting, try the cheap/easy things first.  Maybe in this case, some 
contact cleaner flushing, and toothbrush work, to try to remove any gunk 
that can be taken off that way, before disemboweling the bandswitch.  I was 
going to say, pull one end of any interstage capacitors off the switch, but 
sounds like you did.  A leaky cap could have been it.

If it comes to that, there may be usable switch wafers still available out 
there, either through parts distributors, or someplace like Antique 
Electronic Supply.  The Web, and Google, can be your friend.  Good hunting, 
and good luck!  Let us know how it's going.


>On Montml>Aug 2004 03:24:12 GMT "Barry H" <barry_hauser at juno.com> writes:
> >
> > Hi Ed
> >
> > Have you seen all the info at
> > http://www.antiqueradio.org/halli07.htm ?
> >
> > Scroll way down the page and there's the account of A. B. Bonds
> > about this or very similar situation.
> >
> > A bad cap may have caused arcing and the wafer or rotore may be
> > carbonized.  If so, you may be able to scrape away enough of the
> > char to remove the short -- or "accidental resistor."  If you can
> > see the blackened area -- with a flashlight, you may be able to
> > scrape it with an Xacto knife or similar tool.
> >
> > Another thing they say is that the dirt buildup can cause shorting
> > and arcing on that bandswitch.  The carbon track might be on/around
> > the rotor, or it might be on one place on the wafer and the shorting
> > action is occurring through the wiper(s).
> >

-
73, Phil Barnes-Roberts AD6PQ  DM04we | Mailto:AD6PQ at arrl dot net
Bio and address at http://www.qrz.com/callsign/ad6pq  626-791-0851h
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