[R-390] Zero Adjust Clutch Repair

[chuck.rippel at cox.net]

In reading the thread, I haven't really gotten my mind around exactly 
what is broken/not working with the clutch.

Generally, I find that at one time, the clutch was oiled and that oil 
had hardened.  You can turn the "ZERO ADJUST" knob all the way in but 
the clutch plates do not disengage and no adjustment can be made.  Is 
that what we're talking about ?

If so, 80% of the time I find that the radio can be put on its side, the 
"ZERO ADJUST" cranked in and a few generous squirts of WD-40 sprayed 
into the gaps in the clutch plates.  Sometimes, a very small screwdriver 
needs to be worked in between the plates to open a gap.  Once that's 
done, with the Zero Adjust still fully engaged, rock the KC Change knob 
back and forth and try to break the clutch loose.  Once its loose, give 
the plates another shot of WD40 while rocking the KC Change knob back 
and forth.  The idea is to soften and flush out some of the hardened 
lubricant.

If not, the clutch can be taken apart but its no picnic.  There is a "C" 
clip that needs removed then the clutch discs, springs and plates need 
to be individually cleaned.  Do NOT oil them !!  Getting it back 
together is also a chore.

--
No  trees were killed to deliver this message.  However, a large number 
of electrons were terribly inconvenienced.

Chuck Rippel



>
> Message: 2
> Date: Sat, 16 Mar 2013 16:38:49 -0400
> From: Bob Young <bobyoung53 at hotmail.com>
> To: "r-390 at mailman.qth.net" <r-390 at mailman.qth.net>
> Subject: Re: [R-390] Zero adjust on R-390 receiver
> Message-ID: <SNT136-W3953A23CBE155668D2BCD5CCEE0 at phx.gbl>
> Content-Type: text/plain; charset="Windows-1252"
>
> OK I have it upside down on the floor and one side of the clutch goes 
> in farther than the other side, something is binding it or or it 
> appears that way. Hard to tell with the front plate on. If I put a 
> very thin screwdriver in there that part of the clutch will open more 
> but then the other side binds against the mating surface. I think I'm 
> goping to have to take it apart to really see what's going on. The 
> three little rods seem to be ok and not binding.
>
> Bob
> KB1OKL