[R-390] Where to find the Tube list for my R-390/URR

[Barry Hauser]

Hi Ron:

I assume you're asking about the NON-A which is the original,
non-cost-reduced model, AKA " a man's radio", etc.

While most of the information was declassified some time ago, the tube list
itself, remains TOP SECRET and remains on a need-to-know basis.

However, you can look in the parts lists or, after signing the proper
authorization forms,  take the top and bottom covers off and look inside.
(If you have one of these radios, you are required to look
inside --frequently.)  Y'see, they printed the tube numbers right by the
sockets they go into.  See, that's why they kept it Top Secret.  They
figured if you didn't have an R-390, AKA NON-A, you don't need to know, but
if you have one, you can just look inside, so then you don't need it anyway.
And -- if you've managed to get hold of the manuals and can't find the tubes
in them, you probably don't represent a serious security risk. It's a DC
bureaucratic spook thing.

So much for the tomfoolery, or, in this case, barryfoolery, perhaps.  I
think someone has a tube compliment list on a web page somewhere.  One must
visit is Dave Medley's web pages -- http://www.davemed.com/

Here's another must-see http://www.r-390a.net/Pearls/edited-R-390-non-A.pdf

This one includes tube layouts of the top and bottom
http://asa.npoint.net/35720-3.pdf

To my knowledge, there were no changes in the tube lineup for the R-390
(non-A) and it was also the same for the R-391 -- the autotune version,
which is electronically identical.  Some previous owner may have made
subtitutions, I suppose.  You might find that the two 26Z5W's have been
replaced by silicon diodes and/or the 3TF7 ballast tube has been subbed out
with a resistor or something or other.

It's a good idea to pull all the tubes and check them on a tester.  While
the final test is performance in the receiver, it's best not to use the
receiver to test for shorted tubes which can cause collateral damage.  At
the same time, you can check what tubes are actually in the sockets, and
clean the pins and socket contacts with DeOxit.  You should also check the
mechanical alignment/synchronization.  But here's the most important issue
of all:  Does it have the "green gear" or was it purloined by an enemy agent
posing as a tech pretending to be forgetful?  This will either be up high on
the front of the RF deck hanging on a screw a bit toward the left or hidden
down below as if it's part of the gearworks, but not meshing with any other
gear (if it's in the proper storage position.)  If you do not have the green
gear, you should now be obsessed with acquring one.  This is a tradition.

We'll expect a complete report.

Barry




----- Original Message -----
From: "Ron H" <rnharsh@attbi.com>
To: <R-390@mailman.qth.net>
Sent: Sunday, June 08, 2003 4:36 PM
Subject: [R-390] Where to find the Tube list for my R-390/URR


I am now the proud owner of a new/old R-390/URR and have downloaded hundreds
of megabytes of manuals but haven't been able to find a list of the tubes
used. Is this because there were many variations? I would have thought that
since all of the particular model were manufactured to a milspec the tube
compliment would have been the same.

K3PID - Ron