I believe that the maximum frequency difference between the PFA's two
inputs in 200 Hz (not kHz or MHz), so the two signals you are comparing
must be very close in frequency.
Dave - WA8YWQ
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On 2023-08-04 13:25, W0LEV wrote:
So if I have a GPS reference of a couple of parts in 10^13, that will be my
accuracy, and only at 10 MHz output from my GPS "clock"? With the 10 MHz
reference from GPS, will it measure ADEV on other non-10 MHz frequencies
(I'm thinking of DTV unmodulated carriers and HF signals off the
ionosphere)?
In the past for DTV carriers, I've dumped my 10 MHz GPS referenced output
into a comb generator and picked the tine which is closest to the DTV
carrier. That is selected on the a spectrum analyzer which is then zeroed
to the tine. Then I measure the frequency of the DTV carrier. The
measurement is "sort'a" referenced to the 10 MHz GPS derived output through
the comb generator. Not perfect, but it gets me down to 0.001 Hz.
Dave - W?LEV
Dave - W?LEV
On Fri, Aug 4, 2023 at 7:36?PM Erik Kaashoek <erik@...> wrote:
On Fri, Aug 4, 2023 at 10:56 AM, W0LEV wrote:
To what is this new PFA referenced? I have a piece of HP equipment that
offers Allen Variance measurements, but the reference is internal, not GPS.
The tinyPFA can measure the phase difference of two 10MHz signals with
1e-13 accuracy in one second
Its accuracy and resolution is better than any of the big timer/counters
but less then the phasestation devices.
It's sole purpose it to measure frequency stability or ADEV of one source
against another source
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*Dave - W?LEV*
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Dave - W?LEV
