Re: Adjust CP4 Clock Frequency


Roland Christen
 

1100 mount diameter is 175mm, yielding an error of more than 1/2 mm (.022inch) which you will definitely see with the tape lined up.


-----Original Message-----
From: Craig Young <craig.young.m8@...>
To: main@ap-gto.groups.io
Sent: Tue, May 5, 2020 5:31 pm
Subject: Re: [ap-gto] Adjust CP4 Clock Frequency

I'm not sure the test will be accurate enough.  If the diameter of the circle the tape is on is say 150mm then the circumference is about 471 mm (c = pi * diam).  If the clock error is 0.001 then the error after 24 hours would be 471mm * 0.001 = 0.47mm .. not sure if I can accurately see that.  On the other hand, the number of encoder pulses for a period of time should be known very accurately .. without revealing the confidential information, how about a test in APCC where you set the time and the software reports the number of pulses recorded.  Seems like that is a basic test and could be added to the AE tab to check calibration, tracking rate, etc.  That would be far more accurate than cutting a piece of tape.

Craig

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