Fw: [R-390] R-390A trouble (BIG CORRECTION)

Thu, 28 Mar 2002 14:33:00 -0800

Jim,

I bet you have as many winning lottery tickets as I have.

I do not know if your that kind of guy, but,
now would be a good time to grab a  beer and
ask your self what it was that caused the spirits of
creation to visit you this way.

Pull the tube off the RF deck and start them back in
third mixer
PTO,
second mixer
5654 6ak5 on the crystal deck
first mixer and 17MHz osc it is not because it does it over 8.
6DC6.

Once you find the stage and the signal level to inject to get the
problem to putt, putt your only close. You still will have to find
the problem under the deck.

Pull all those tubes up and clean the socket pins.
De oxit if you can, use what you got.
work the tubes in and out 4 or 5 times.
If you just got a pin with crude or oxide, you mite as well
just short gun it and get over it.
As it putts on more than one band, 2-3, 4-7, 8-16 you
know it is not in the cans and slugs on the top side or there
trimmer cap in the top of the cans.

Roger.

                    "Jim Temple"                                                                                       
                    <jetemp@insightbb        To:     <[email protected]>                                           
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                    Sent by:                 Subject:     Fw: [R-390] R-390A trouble (BIG CORRECTION)                  
                    r-390-admin@mailm                                                                                  
                    an.qth.net                                                                                         

                    03/28/02 02:01 PM                                                                                  

Ooops.......

I meant IF deck,  not RF deck.  Sorry for the mixup.

So I substituted a working IF deck for my IF deck and the symptoms are
exactly the same.

Yikes, sorry.

Jim

----- Original Message -----
From: "Jim Temple" <[email protected]>
To: <[email protected]>
Sent: Thursday, March 28, 2002 3:46 PM
Subject: Fw: [R-390] R-390A trouble

> Hi Roger and list,
>
> OK, I have a friend who inherited a R-390A from his father.  I picked up
his
> RF deck, and upon installation in my receiver, the symptoms are exactly
the
> same as with the original symptoms below.  Now what??
>
> Jim
>
> ----- Original Message -----
> From: "Jim Temple" <[email protected]>
> To: <[email protected]>
> Sent: Thursday, March 28, 2002 3:15 PM
> Subject: Re: [R-390] R-390A trouble
>
>
> > Hi Roger and list,
> >
> > OK, here is what I found.  (Narrowing down the sypmtoms).
> >
> > 1.  In AGC position.
> >     a.  RF gain at 5.  AGC voltage essentially 0.  Little rushing
sound.
> > Receiver apparently stable.
> >     b.  As RF gain is increased, background/rushing noise slowly
increases
> > to a level that seems normal and strong.  Noise sounds normal and
stable.
> > TO A POINT.
> >     c.  As RF gain increases toward 9, the AGC voltage abruptly
increases
> > and the audio breaks into the putt, putt/screeching sound.  The AGC
> voltage
> > will continue to increase to about 7-8 volts, and the putt,
> putt/screeching
> > continues as long as there is AGC voltage.
> >     d.  The carrier level remains essentially 0, until the putt, putt
> > begins, then the carrier lever meter shows a smooth increase to 100.
> >
> > 2.  In MGC position.
> >     a.  Symptoms are the same until the point that the background noise
> > becomes strong (about 9 on the RF gain), then the receiver abruptly
blocks
> > as if from a strong signal.  The carrier level meter will JUMP to 100.
> >
> > 3.  An observation is that the problem occurrs at the same position of
the
> > RF gain control, whether the function switch is AGC or MGC.  The only
> > difference is that the receiver putt, putts in AGC and blocks in MGC.
> Both
> > increase the carrier level to 100 (slowly in AGC, abruptly in MGC.
> >
> > I hope my observations are clear, if not please ask to clarify.
Thanks,
> > guys.
> >
> > Jim
> > 73, KF4ICZ
> >
> > ----- Original Message -----
> > From: "Roger L Ruszkowski" <[email protected]>
> > To: <[email protected]>
> > Sent: Thursday, March 28, 2002 1:09 PM
> > Subject: Re: [R-390] R-390A trouble
> >
> >
> > >>
> > >> Hi Roger and list,
> > >>
> > >> OK, I want to fix this receiver. Here goes. Jim 73, KF4ICZ
> > >
> > > Jim, your on it now. Roger.
> > >
> > > The question please.
> > >
> > >
> > > Does this putt, putt occur when in the MGC function?
> > >
> > > If no, then its most likely an IF deck AGC voltage generation problem
> and
> > > not the RF deck at all. If yes, then it is not and AGC problem at all
> and
> > > we are looking for a bad CAP.
> > >
> > > Roger.
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > R-390 mailing list
> > > [email protected]
> > > http://mailman.qth.net/mailman/listinfo/r-390
> > >
> >
>

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