Tom Van Baak [EMAIL PROTECTED] wrote:
Now I am confused. I thought it used the internal crystal clock
for the timing, and selected which pulse to output for the 1PPS,
and this is what causes the sawtooth. If so, the timing is
determined by the crystal.
Correct. For
Mike,
So where did the 1ns granularity come in?
For example, Motorola receivers output the sawtooth correction as
an 8-bit signed binary field in the @@En/Hn TRAIM message. The
range of said byte is -128 to +127; the scale, the granularity, the
units of that field are 1 ns. Make sense now?
On 10/13/08 8:54 PM, Mike Monett [EMAIL PROTECTED] wrote:
Mike,
So where did the 1ns granularity come in?
For example, Motorola receivers output the sawtooth correction as
an 8-bit signed binary field in the @@En/Hn TRAIM message. The
range of said byte is -128 to +127; the
Mike,
Comments below...
I have to learn more about how you do your measurements. A 53132A is
way out of my price range at the moment. But I do have a 53310A
which should give comparable results.
Yes, if you can get a clean series of 1PPS sub-ns time interval
measurements over GPIB
Tom Van Baak [EMAIL PROTECTED] wrote:
Mike,
Comments below.
I have to learn more about how you do your measurements. A 53132A
is way out of my price range at the moment. But I do have a
53310A which should give comparable results.
Yes, if you can get a clean series
Now I am confused. I thought it used the internal crystal clock for
the timing, and selected which pulse to output for the 1PPS, and
this is what causes the sawtooth. If so, the timing is determined by
the crystal.
Correct. For example, if the xtal were 20.00 MHz then the hardware
Mike Monett wrote:
Bruce Griffiths [EMAIL PROTECTED] wrote:
Mike
They actually use an augmented form of GPS common view for which
the GPS PPS signal and its timing variations are largely common to
both locations and thus largely cancel when comparing the
The single-shot is supposed to eliminate the 1PPS jitter? So it must
be triggered on the 1PPS, and the variable delay gives an average of
half the clock period?
Yes, right.
Note another equivalent technique is to use two serial ports;
one for the receiver (record sawtooth corrections) and
Bruce Griffiths [EMAIL PROTECTED] wrote:
Mike
They actually use an augmented form of GPS common view for which
the GPS PPS signal and its timing variations are largely common to
both locations and thus largely cancel when comparing the
frequencies at the customer
Hi Mike,
Rick's CNSC02-O1 implementation has been discussed here
a number of times over the years (google the archives). It uses
a programmable digital delay line to compensate for the receiver
reported quantization error on each pending 1 pps.
Here's a quick plot of an M12+ receiver without
Mike Monett wrote:
For more detail see:
http://tf.nist.gov/timefreq/service/fms.htm
Thanks very much for the link. It is curious they don't seem to
spend much effort on correcting the user's frequency errors. They
just want to report how much they are off.
Why is
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Testing frequency using NTP Bruce GPS ps
Mike Monett wrote:
For more detail see:
http://tf.nist.gov/timefreq/service/fms.htm
Thanks very much for the link. It is curious they
don't seem
Tom Van Baak [EMAIL PROTECTED] wrote:
Hi Mike,
Hi Tom,
I want to thank you for the very nice reply you gave to my email a
while ago. Unfortunately, I am still learning about precision
frequency references, and I don't have enough knowledge yet to give
you an intelligent
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