[R-390] Megacycle Change Stuck R-390

[Alex Hopper]

Thank you both! Is adjusting the 10-turn stop something that would require
removal of the crystal oscillator or RF modules?
-Alex

On Thu, May 1, 2025 at 10:53 AM Barry <n4buq at knology.net> wrote:

> Hi Alex,
>
> There are a series of "wings" on the shaft that determine where the stop
> point should be at both ends of rotation (I think those limit the shaft to
> just a tad over 10 turns end-to-end).  If all of those are completely
> stopped against each other, then that would cause this and the solution
> would be to loosen the clamp and adjust those stopping points.  If the stop
> point is reached but those "wings" can still be rotated slightly with your
> fingers (be aware there is power near that point so best to unplug the
> radio to try this), then something else might be a problem but I think the
> 10-turn stop is the problem.
>
> Good luck,
> Barry - N4BUQ
>
> > Hi All,
> >
> > I have an R-390 that has recently been restored.  It is performing very
> > well, with one exception...
> >
> > Last night I attempted to tune up through all of the megahertz bands all
> > the way to 32 MgHz for the first time.  I got to '30' on the megacycle
> > change knob, and the knob wouldn't rotate any further to 31.  I could get
> > it to go slightly towards 31, but it was obviously stuck and I didn't
> want
> > to attempt to jam it.
> >
> > What would potentially be the cause for this being stuck?
> >
> > Thanks,
> > -Alex
> > ______________________________________________________________
> > 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
>