Fw: [R-390] R-390A trouble (I FOUND THE PROBLEM)

[Jim Temple]

After wiggling almost all the leads to confirm security, I discovered the
following.....

Pin 5 of V201/6DC6, from the underside, seemed to be in place and secure.
Upon wiggling, it seemed loose, so I gently tugged on the pin lead and it
came out of the socket from below the plastic.  It was broken between the
socket pin and where it emerges from the socket mold on the bottom.

Apparently, there was enough contact to do the initial alignment, and after
a couple of hours burn in, it insulated itself, creating the below symptoms.

What was maddening was that the break was within the plastic mold of pin 5,
which took a tug to break it from the plastic.  Three components are
attached.  Later I will summarize what was affected and the fix.

WOW......this is one for the books.

I think I will go for replacement, but if there is an easy fix, I will
consider it.

Well, thats it.  Thanks for the support and help with this problem.  After I
complete the repair, I will post a summary of the symptoms and fix.  So long
for now.

Regards,

Jim
73, KF4ICZ

----- Original Message -----
From: "Jim Temple" <jetemp@insightbb.com>
To: <r-390@mailman.qth.net>
Sent: Thursday, March 28, 2002 10:56 PM
Subject: Re: [R-390] R-390A trouble


> OK, I replaced C227 .047.  The old one measured .075 when out of circuit.
I
> have a picked-over RF parts deck that happend to have this cap.  It
measured
> .04745, so hopefully this is the problem.
>
> HOWEVER, I am going to clean, inspect, wiggle, tap, eyeball, and generally
> give it the twice over before reinstalling in the morning.  I'm winding
down
> for the night.
>
> Will report back after reinstallation of the RF deck in the morning.
>
> Thanks for the great support and suggestions.  Good night.
>
> Regards,
>
> Jim
> 73, KF4ICZ
>
> ----- Original Message -----
> From: "Barry Hauser" <barry@hausernet.com>
> To: <bill@iaxs.net>; "Jim Temple" <jetemp@insightbb.com>;
> <r-390@mailman.qth.net>
> Sent: Thursday, March 28, 2002 9:55 PM
> Subject: Re: [R-390] R-390A trouble
>
>
> > > Barry, I think you've got it.
> > >
> > > But I thought of another thing to try. Because the set is
> > > oscillating within itself, something common to the IF and
> > > RF decks is carrying energy between them.
> > <snipped>
> >
> > Got what?  I dunno, but, hey, Bill, I think YOU"RE onto something.  Jim
> > should check out all those jumpers with the mini-BNC's -- maybe one of
'em
> > was swapped with that Skyhighgain cable Norman told us about.
> >
> > Seriously, tho' -- wasn't that another thing that could cause weird
> > problems -- bad mini-coax?
> >
> > When the rational, logical, informed, incisive, deductive approach fails
> ...
> > Well, let's consider ALL the clues ...
> >
> > Squeal -- loud disturbing noise, alarm, or (sl.) to give information, to
> > "rat" on.
> > Happens over 3 MC's, that could be written as >3.  Looks like a bird,
> don't
> > it?
> > Motorboating, boats, water, ocean -- could be a seagull, or maybe
> > "putt-putt" = golf
> > Then there's the thing about cats.  Wait a minute!  A bird that looks
like
> a
> > rat is a bat -- but then what's golf got to do with it?  This is going
> > nowhere -- might mean something to a witch.  Is Les around?
> >
> > Forget all that -- pull the RF deck and check it out.  Could be an
> > "underneath-ARGHHH-do-I-hafta?" problem.  Give it the close eyeball
> > inspection.  By all means CLEAN the bandswitch -- twice. (unless I
missed
> > something and you did that already)
> >
> > Nobody seems to be focused on the >3 thing.  Why would this problem kick
> in
> > there?  What is different circuitry-wise about 0-1-2-3 vs 4+?  I guess
one
> > thing might be a rotor section or two on the bandswitch, no?  Maybe not.
> > Any particular reason a bad cap would cause the squeal and motorboating
to
> > start at 4 MC's?
> >
> > Great, now I'm gonna be up all night 'cause of somebody else's radio.
> >
> > Barry
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
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> >
>