According to Frank, it's the outside set of dots, which may be your problem. Also, it may help for you to try to tune a middle note on the key board (A, or C) by ear, or to a tuner first so you are in the ballpark first. Is it a CMC board or an SMS? There can be a few reasons for drift.
-Jack
--- On Thu, 6/26/08, john barrick <astroboy@cinci.rr.com> wrote:
> From: john barrick <astroboy@cinci.rr.com>
> Subject: Re: [newmellotrongroup] tuning
> To: newmellotrongroup@yahoogroups.com
> Date: Thursday, June 26, 2008, 7:58 PM
> OK - I'm in the states with 60 HZ. I'm using a
> little fluorescent shop
> light. It appears to be the inner ring of dots that works
> for 60.
> Here's the problem. The only time I can get the dots
> stationary, the
> motor appears to be running at half speed. It'll sit
> still a while and
> then they'll begin a slow creep, then they'll sit
> still again. I
> thought the tach head was in the loop to provide feedback
> to the speed
> control so that everything would remain constant under
> varying loads.
> Would this not also keep the speed constant also if
> you're receiving
> power fluctuations? I got my power supply back from Jerry
> Korb at the
> beginning of May (I was lucky to have him take the project
> on before the
> situation with his mother developed) and it's go brand
> new huge caps
> that are beyond spec - so I doubt the problem is there.
> Should I look
> at the tach head?
>
>
> Bruce Daily wrote:
> >
> > Yep. Either an AC-driven fluorescent bulb, or
> AC-driven neon bulb
> > would be ideal. The question is whether one set of
> dots is for 60 Hz,
> > and the other set is for 50 Hz. I'll have to test
> it, I guess.
> >
> >
> >
> > -Bruce D.
> >
> >
> >
> >
> >
> > --- On ∗Thu, 6/26/08, lsf5275@aol.com
> /<lsf5275@aol.com>/∗ wrote:
> >
> > From: lsf5275@aol.com <lsf5275@aol.com>
> > Subject: Re: [newmellotrongroup] tuning
> > To: newmellotrongroup@yahoogroups.com
> > Date: Thursday, June 26, 2008, 8:20 AM
> >
> > In a message dated 6/26/2008 7:04:10 A.M. Eastern
> Daylight Time,
> > e4103s@yahoo. com writes:
> >
> > Yes, U.S. power (assuming you are in the the
> States) runs at
> > 60 cycles, so if you shut out all the lights
> in the room and
> > plug in a small lamp and shine it on the
> flywheel while you
> > turn the tuning pot, it should line things up
> at 440. Keep in
> > mind, incandescent strobing is pretty quick
> and the dots on
> > the flywheel are pretty far apart so you may
> need to adjust
> > your eyes to see it. Pretty brilliant of them
> to consider
> > this, although with the CMC-10's that were
> in many of these
> > things, I'm sure they needed all the help
> they could get until
> > the SMS's were made.
> > -Jack
> >
> >
> > Any florescent light makes it easy.
> >
> > Frank
> >
> >
> >
> >
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