[R-390] New Project (More Questions)

[Craig C. Heaton]

Hi Joe,

1. 3223's I don't think so, stick with 5814's. Collins had good reasons
using the tubes chosen.

2. So far, I've only had experience with BBOD's and Vitamin Q's. BBOD were
old, worn out, they served their country well. Orange Drops were the
replacement for the BBOD's. Most of the Vitamin Q's were good, not all.
Orange Drops used there too. The set was a Motorola 56 vintage.

3. If your set still has BBOD's, next recap, the realign IF and RF sections.

4. Could be old caps (BBOD's), needing alignment. With a receiver worthy of
going back on line at a listening post, I would expect: with switch on MGC,
with the IF output connected to a scope, RF gain full clockwise, with a
strong signal; you should see and hear overload.

You are getting there, don't stop now. After a couple days of recapping,
several tries of realignment, it will all come together. The R-390/A will
become a working receiver.

Then you will want a excellent receiving R-390/A. That's flowertimes's
story, I've saved his notes.

wd8kdg
Craig

-----Original Message-----
From: r-390-bounces at mailman.qth.net
[mailto:r-390-bounces at mailman.qth.net]On Behalf Of Carole White-Connor
Sent: Saturday, February 24, 2007 6:36 PM
To: r-390 at mailman.qth.net
Subject: Re: [R-390] New Project (More Questions)


Today, I redid the filter caps, replaced the "exploding" cap and adjusted
the IF
gain. The set is performing nicely, but I have a few more questions:

1. The AF deck had two 3223 tubes in place of the 5814As. Is that an
acceptable
substitute? I replaced them with NOS 5814s.

2. Some of the caps are Westcaps. Are these like the usually reliable
Vitamin Qs or
like the unreliable brown/black beauties?

3. The two bands that are relatively weak are 2-3 mhz and 3-4 mhz. Any ideas
on
where I should look for the problem?

4. WHen I switch from AGC to MGC, I don't get the jump in signal strength I
expect.
It doesn't overload on MGC, even on relatively strong stations. Is that
normal? If
not, what should I be looking at?

Again, thanks for all your help. There is nothing better than advice from
guys who
have been under the hood of these sets.

Joe Connor

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