[R-390] Silver solder

Mon, 24 Jun 2002 20:37:38 -0400

Hmmmm..... maybe I should consider touching up all joints.  Good post Dan.

Scott

----- Original Message -----
From: "Dan Martin" <[email protected]>
To: "Jim Temple" <[email protected]>; <[email protected]>
Sent: Monday, June 24, 2002 6:32 PM
Subject: Re: [R-390] Silver solder

> ----- Original Message -----
> From: "Jim Temple" <[email protected]>
> To: <[email protected]>
> Sent: Monday, June 24, 2002 10:05 AM
> Subject: Re: [R-390] Silver solder
>
>
> > Also, take the time to re solder joints that look suspicious.  Grounding
> > points and deterioriated solder joints are the cause of almost all
faults
> in
> > this radio, in my experience.
> >
> > Jim
>
> You know, you can >read< something over and over and intrinsically accept
it
> as valid but it's not until it happens to you, in your own experience,
that
> you really believe it. I'd known of Jim's admonition above on deteriorated
> solder joints for years and always kept a low level look-out for them. It
> wasn't until I began to experience a rash of odd problems with my '67 EAC
> recently that I finally experienced it first-hand. To make a long story
> short, an assortment of .5-8 mHz peculiarities, including obvious AGC and
> sensitivity issues got me to take out the rf deck. I had no AGC at the
grid
> of the first mixer and got infinite from the grid pin to ground. Ah. Open
> resistor, I thought. R208, 231 or 232 have gone open. Nope. Checking each
> one individually showed they were fine. Finally, after repetitive checks
> over and over, I had continuity all through the AGC line ... except at one
> terminal joining two resistors together - R231 and 232, as I recall. It
was
> fine in and fine out, but open at the solder junction. Laid a soldering
iron
> on it and added a touch of solder and - perfect! All was well. Funny thing
> is, this was my personal 390A of several years, in immaculate condition
and
> gone over both by me and Chuck. The solder joint just opened one day.
Like -
> that!
>
> It >does< happen! I always understood it. Now I believe it!
>
> Dan
> WB4GRA
>
> _______________________________________________
> R-390 mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/r-390