[R-390] R-390 Mechanical Alignment

[Robert P. Meadows]

I probably have an original manual around here somewhere, plus three or four R390 in various states.  One is my first one that went away and came back, over a period of about 35 years.
Robert
W4RRD

-----Original Message-----
From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> On Behalf Of Jacques Fortin
Sent: Monday, February 22, 2021 2:22 PM
To: Robert P Meadows <rpmeadow at bellsouth.net>
Cc: R-390 at mailman.qth.net
Subject: Re: [R-390] R-390 Mechanical Alignment

Hello Tom,

If ever you can find the Collins R-390 1953 manual (on line or in paper) please tell me.
I once searched it on the web, but never been able to found it.
However, I had an original copy in hand in 1983 and "photocopied" it.
I found my R-390 in a local "army surplus" store in 1982.
I used it as-is at the time, but it was left is storage from 1985 to 2018 !
I then began to restore it.
Final alignment and modifications were performed last December !

For the "proof-in-the-pudding": when the KC display shows "000" the PTO runs at 3.455 MHz, so the 2nd IF have to be tuned at 3.000 MHz to provide a 455 kHz IF.
So the tuning slugs have to be OUT of the coils.
At "999" the PTO runs at 2.454 MHz and the 2nd IF at 2.001 MHz so the slugs have to be IN the coils.
This matches the position of the 2nd IF cams in the pictures for the "000" position, contradicting the text.

73, Jacques, VE2JFE in Montreal