[R-390] Removing Megacycle Change shaft

[rochep at comcast.net]

Actually I think I just need to get to the gearbox disassembly to the point of Steps/Pictures 12-16 in Chapter 10 in the manual. Once I get the gear off the MHZ shaft I am good.

From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on behalf of rochep--- via R-390 <r-390 at mailman.qth.net>
Date: Tuesday, June 16, 2026 at 11:40 AM
To: Jacques Fortin <jacques.f at videotron.ca>; 'Jordan Arndt' <Outposter30 at shaw.ca>; r-390 at mailman.qth.net <r-390 at mailman.qth.net>
Subject: Re: [R-390] Removing Megacycle Change shaft

I agree, taking out the gearbox is what I am looking at. Got alot more to learn before getting at this, I assume the entire RF deck and gearbox comes out together. Lots of YouTube videos to follow. Thank you all!

Paul

From: Jacques Fortin <jacques.f at videotron.ca>
Date: Tuesday, June 16, 2026 at 11:21 AM
To: 'Jordan Arndt' <Outposter30 at shaw.ca>; 'PAUL ROCHE' <rochep at comcast.net>; r-390 at mailman.qth.net <r-390 at mailman.qth.net>
Subject: RE: [R-390] Removing Megacycle Change shaft

Hi Jordan,
Not sure about this clamp ID, but it must have a 13/32" hole to fit the gear
part that it have to hold to the shaft.
See attached picture.
The ultimate problem that Paul is facing will be to remove the broken clamp
there without damaging anything else around.
Using a two-part clamp is a good idea, medium hard to machine, but there can
be other hidden mechanical damages in his set.
We never know what happened to these radios before.
To maintain (or restore) those requires both electrical and mechanical
skills.

IMHO, Paul should attempt a gearbox disassembly, cleaning and reassembly
(Y2K-R3a manual Chapter 10).
At least, he will be able to catch any other marginal mechanical flaw within
during the process.
This is one of the worst case I seen so far: a clamp broken at the worst
possible place, but.. any other broken clamp within the gearbox will require
disassembly, anyways.

There is other "stupid" damages I was able to see in my "spare" EAC RF deck
yesterday night: some of the clamp screws heads are "eaten" internally, most
probably because someone tried to use Allen bits instead of Bristol ones on
those.
That one will be due for a complete overhaul, I believe: it is completely
gummed up, also.

PAUL: just a comment...
The answers you provided came to me OK directly to my email address, but the
same text did not "passed" thru the forum: the postings came to me "empty".
I cannot tell why, but have a check...

73, Jacques, VE2JFE in Montreal
______________________________________________________________
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