[time-nuts] [Fwd: Re: What is the best counter for a Time Nuts?]
XDE-L2G3 at myamail.com
Tue Oct 14 03:09:03 UTC 2008
hasweb at has.org.nz wrote:
>Mike Monett wrote:
>> > So, assuming my known timebase is "bang on", I know the frequency
>> > of the unknown 10 MHz source to an accuracy of roughly 3e-10 or 3
>> > parts in 10 billion.
>> > To get a more precise measurement of the frequency difference
>> > between the two 10 MHz clocks, I supply the known 10 MHz clock to
>> > the Channel A input of an HP 3575A Gain-Phase meter and the
>> > unknown 10 MHz clock to the channel B input of the Gain-Phase
>> > meter.
>> Another very difficult instrument to find any data on. The best I
>> could find shows it has an accuracy of ± 0.5 degree and resolution
>> of 0.1 degree.
>Try the agilent website for the manuals not yet readily available
>For directions visit:
>There is a 3575A manual for downloading at the Agilent ftp link.
>If you read it you will find that the specified error with 10MHz
>inputs is much larger: 10-20 degrees or so.
There is nothing in the hparchive site, and I don't have the Agilent ftp
Could you give a direct link to the 3575A manual?
The basic principle is sound. It should be very easy to make a simple PWM
circuit to measure phase accurately at 10MHz. You mentioned the same thing
earlier. Why not post the schematic so we can take a look?
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