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:
www.hparchive.com http://www.hparchive.com
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.
Bruce
There is nothing in the hparchive site, and I don't have the Agilent ftp
site url.
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?
Mike Monett
hasweb@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:
>www.hparchive.com <http://www.hparchive.com>
>
>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.
>
>Bruce
There is nothing in the hparchive site, and I don't have the Agilent ftp
site url.
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?
Mike Monett
