[R-390] R-390 Green Gear

[Jacques Fortin]

Barry, which manual did you have in hand to check the cams alignment ?
The two last manuals (The TM11-856 and the TM11-5820-357-35) are in error
relating to the correct initial cams positions.
The first Collins manual (1953) is however correct.
I already posted about this: the TM11-856 became correct only if the
corrections listed in the C4 changes document are applied, but the same
error was repeated in the TM11-5820-357-35 without the C4 correction
applied.

If the proper initial positioning procedure of the cams is applied, there
will be no other problems encountered during the RF + IFs alignments.
Leave the green gear in place: the positions of all cams should check
correct if the initial positioning is done, BUT ONLY IF it was OK before you
installed it !

Be aware also that the initial position of the cams and MC and KC tuning
shafts is completely different than the R-390A ones.

73, Jacques, VE2JFE in Montreal

-----Message d'origine-----
De : r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> De la
part de Barry
Envoyé : 26 août 2024 11:20
À : R-390 Mailing List <r-390 at mailman.qth.net>
Objet : [R-390] R-390 Green Gear

I've restarted working on the R-390.  Hopefully I'll have the knobs
repainted successfully soon but, in the meantime, I'm going back to the rest
of the radio.

When I started the front panel restoration project, in anticipation of
removing the RF deck for cleaning, I installed the Green Gear in the
position where it engages the gears (as opposed to where it's normally held
for safe-keeping).  In the interim, I'd forgotten I had moved it and have
rotated both the KC and MC shafts.  Now I'm not sure what that might have
done to the gear/cam alignments.  I thought that with the gear installed
that way, it would lock any movement on those shafts but apparently that's
not true.

If I remove that gear now without placing the KC and MC gearing back to the
positions where they were when I installed the Green Gear, does that leave
the cams improperly aligned?  If not, I can realign them but was hoping to
avoid that if it isn't necessary.

Thanks,
Barry - N4BUQ
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:R-390 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html