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Hi Shai,

I apologise in advance if this is over your head, but it's how I'd tackle it. Maybe you've used an oscilloscope before.
 
I used to calibrate video recorders headwheel and capstan motors speeds with a calibrated oscilloscope, factory alignment tape and a factory manual. 
The scope was a 2 or 4 channel Tektronics model with a built in frequency counter and integral on screen reading voltmeter and setting up the operating parameters was absolutely essential to insure tape interchangeability. Especially when the machines had been in constant use for 15 years and component values had drifted somewhat.
 If your capstan motor uses pulse width drive, this scope would make setting the speed a snap as you would only have to measure the duty cycle and compare it to the figure given in the service manual or against a known good machine. If it's DC any good Digital Voltmeter could be used if you know the correct voltage.    

If you are interested, I will find the model number for you.

Best,
Bob Hodge
   


-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Steven Smolian
Sent: Friday, January 28, 2011 4:29 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Test tones circa 1978

There used to be a guy on eBay selling dubs of test tapes.

Steve Smolian

----- Original Message ----- 
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, January 28, 2011 3:41 PM
Subject: Re: [ARSCLIST] Test tones circa 1978


> Hi, Shai,
> 
> You can trust the MRL flutter tapes, not the normal calibration tapes.
> 
> I think Jay says that some place in the literature.
> 
> There are better ways to calibrate speed involving long-term
> 
> Cheers,
> 
> Richard
> 
> On 2011-01-28 3:11 PM, Shai Drori wrote:
>> If I can't trust an MRL test tape for speed accuracy then what options 
>> do I have? This is a hot issue for me now since I need to calibrate 
>> all machines for speed as well.
>> Shai
>>
>> On 27/01/2011 23:38, Richard L. Hess wrote:
>>> Hi, Jim,
>>>
>>> One thing that I used to do for quick testing was using a Sound 
>>> Technology 1710A leave it punched on 20 Hz then just go up the scale 
>>> 20-200-2000-20000 Hz, but that was more for testing than slate tones.
>>>
>>> I made a function generator that was nominally 10-100 per band but 
>>> had a modification switch to go from 10-200 so I could sweep 1K-20K 
>>> for recorder alignment without range switching.
>>>
>>> I would never trust "alignment" tones at the front of the tape for 
>>> speed setting. In fact, you can't even trust an MRL calibration tape 
>>> for that, other than the flutter test tapes, and that's not as 
>>> accurate as you need for setting speed precisely on a recorder (which 
>>> should be done with a large-diameter TAPE tachometer. This is a whole 
>>> large issue, actually.
>>>
>>> Then, what Tom said, often times the tones were spliced on from a 
>>> different session.
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>> On 2011-01-27 1:40 PM, Jim Sam wrote:
>>>> All,
>>>>
>>>> Does anyone know how much test tone generators varied circa 1978?
>>>>
>>>> I know not to expect digital accuracy.  For example, I would not
>>>> expect a 10.00 kHz tone, but how much leeway was there?  +/- 0.25kHz,
>>>> +/-0.5 kHz, +/-1.0 kHz, etc.?
>>>>
>>>> Thanks,
>>>> Jim
>>>>
>>>
>>
> 
> -- 
> Richard L. Hess                   email: [log in to unmask]
> Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
> http://www.richardhess.com/tape/contact.htm
> Quality tape transfers -- even from hard-to-play tapes.