[R-390] The saga cont pt 6 pleasant surprise

Sat Sep 11 17:27:05 EDT 2010

To be quite honest, I'm not sure if therer are any "Black Beauties Of Death"
in this radio; all the caps under the IF deck, for example are either yellow
AVX film caps or light green silver micas with the value stamped in plain
text [not the old dot code SM's], or brown tubulars.  I'm guessing it's a
very late IF deck being as it looks like the filter trimmer access holes on
the side were punched at time of manufacture and the markings by them are
silk screened.  There are some brown tubulars under the IF deck, bypass caps
mostly, but not a black one to be seen.

Mygawd, I hope I don't have to replace every one of those brown tubular
jobs...that would be a hell of a job.  I figured if the filter killer C553
and the 8uF 'rotter' on the audio board were replaced, that got the
immediate 'wolf off the door'.

Although come to think of it there are 2 other caps in the audio/limiter
circuit Chuck Rippel recommends shotgunning, aren't there?

And I DO have a couple virgin octal plugs to build new filter caps on,
although the old ones aren't leaking and there's no hum to speak of...

Has anyone put together a comprehensive list of all the caps in the radio
that should be replaced if one is going to go over-the-top?  If it's every
non-silver-mica/non-ceramic-disc in the radio, frankly, I dread getting into
it to THAT extent...but if that's what has to be done...at that point it
ain't fun anymore...

73 de KA9EGW

-----Original Message-----
From: Craig C Heaton [mailto:wd8kdg at att.net]
Sent: Saturday, September 11, 2010 4:04 PM
To: ka9egw at britewerkz.com; r-390 at mailman.qth.net
Subject: RE: [R-390] The saga cont pt 6 pleasant surprise

BBOD's????

73's
Craig

-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net]
On Behalf Of ka9egw at britewerkz.com
Sent: Saturday, September 11, 2010 1:25 PM
To: r-390 at mailman.qth.net
Subject: [R-390] The saga cont pt 6 pleasant surprise

So after pulling the IF deck and looking at C553...it's already a 630V part,
so I figured I'd button her back up...but while I was in there I took a look
at the two resistors in question, R546 & R547; I sez "they're easy to get
to, what the heck" and added the 2 diodes in for the rest of the SSB AGC
mod.

And the band went out.  But on the couple SSB stations I can find, couple
guys working the Ohio Parks On The Air contest around 7205, all is good
indeed.  I'll see how she does after the sun goes around and 75 opens up...

Let's see, I did the whole geartrain cleaning and alignment, did the Rippel
audio mod, replaced the self-destructing 8uF cap on the audio board, checked
the filter-killer cap C553, added the 47pF and the 2 diodes for the SSB mod,
verified the presence of all 8 mechanical filter trimmers...I'm thinking a
full alignment is about all that's left.

Anyone else see anything else critical that I'm overlooking?

73 de KA9EGW

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