[R-390] Metal strips on inside of 390A's side panels?

[Tim Shoppa]

"Barry" <N4BUQ at aol.com> wrote:
> Those strips are spot-welded, not glued, to the side panels.  It is a clever
> way to gain extra support for the main shelf.  The weight rests on these
> instead of relying on the shear strength of those little #6-32 screws.  All
> the screws do is keep the center shelf tight against the side panels while
> the spot-welded strips take the weight.  Also, it helps keep the center
> panel at precisely the right height so that the controls will be centered as
> closely as possible.
>
> Barry - N4BUQ

Thanks Barry. On my yellow striper the welds had undone themselves
(what would undo spotwelds?) at a couple
of welds. For now some super-glue seems to be holding them in place,
although I'm dubious of super-glue providing enough strength to keep
the main deck plate supported, that sounds like a job for JB Weld :-).

Project for 2005: manufacture an entire R-390A entirely out of JB Weld!

Maybe the strip is a different alloy than the aluminum side plate,
and temperature differentials did the work of detaching them?

And another chemical testimonial: Goof-off is good at removing spray
paint from the back and side panels. Takes several applications followed
by scraping but it does work (and the original legends are still at
least mostly there.) It also removed dymo label remains nearly instantly.

Also went into both my RF decks and replaced a bunch of out-of-tolerance 1/2W
carbon comp resistors. Lots of 10K's were at 20K+, many 2.2K's at 6 or 7 K,
a 1M at 2M, etc. The worst of them had signs of charring (past abuse?)
I know I'm a heretic for it, but most of them got replaced by 1W metal
films (yeah, yeah, tell me all about their self-inductance...)

Why so many charred out-of-tolerance resistors on my RF decks? One
was a Stewart-Warner yellow-striper, the other is a Stewart-Warner that
has been very gingerly treated over the years. Incidentally, the serial
numbers on my two RF decks: #625 and #626! Twin brothers, separated
at birth, one treated royally, the other abandoned at SJC, and finally
reunited on my bench!

Tim.