The Mellotron Group

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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