The counter is in TIME MODE. And simple calculation could transform it
to frequency as necessary. For example:
1/(350.50824*10^-9)
2852999.97512184021693755330
OR
1/0.0000003505082409000000
2852999.96779619226350692058
Which is pretty close to my DDS VFO freq. value [2853000]
I switch counter to TIME MODE, because ADEV1 utility using times, not
frequency:
Here is from documentation:
"Adev1 works on everything from pendulum clocks to hydrogen masers. The
only restrictions are that the data must be phase (time interval) rather
than frequency; the data must be sequential (no gaps); and the data
should be free from glitches or outliers."
I am using 10 second intervals for the measurement. DDS VFO clocked by
Trimble TB and its using AD9852 chip.
Regards,
V.P.
On 2015-05-03 10:01, Bob Camp wrote:
Hi
Either the output data is with the counter set to time mode (and
it’s in 100’s of ns) or you have it
set to frequency mode and have a very stable system.
Bob
On May 2, 2015, at 9:53 PM, d0ct0r <t...@patoka.org> wrote:
Hello,
I would like to create some charts for ADEV for following setup:
HP5386A counter connected to External REF. (OCXO). The input of
counter connected to my DDS VFO. The frequency on VFO is 2853000 Hz.
Here is what I got from counter via GPIB:
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082409E-7
S +3.505082408E-7
S +3.505082409E-7
S +3.505082408E-7
S +3.505082408E-7
S +3.505082408E-7
I converted it to following form:
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082408000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
0.0000003505082409000000
Then I tried to use ADEV by tvb (long life to Tom!). See attached file
1b.bmp
And I tried to create the charts for the collected data. See attached
file 1a.bmp.
But it seems I am doing something wrong. Any advises will be greatly
appreciated. Thanks !
--
WBW,
V.P.<1a.png><1b.png>_______________________________________________
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--
WBW,
V.P.
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