|
Fully configured tinyPFA for sale at Eleshop.
--
For more info on the tinyPFA go to
Erik, PD0EK
|
Erik,
Delivered within 24 hours!
Everything seems to be there for the experimenter without doing any software manipulation.
I didn't realize it had its own 'PFA-markings' on the nanoVNA.
Now, 'real' experimenting can start.
Jan ON4MMW
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Show quoted text
-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Erik Kaashoek Sent: Wednesday, August 2, 2023 1:59 PM To: [email protected]Subject: [nanovna-users] TinyPFA Fully configured tinyPFA for sale at Eleshop. -- For more info on the tinyPFA go to Erik, PD0EK
|
Please forgive me for not being familiar with all the "new" acronyms
infiltering our standard english language. Although PFA is undoubtedly an
RF acronym, I am unfamiliar with its meaning? "Pretty Fast Analyzer"? ?
Dave - W?LEV
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Show quoted text
On Fri, Aug 4, 2023 at 2:49?PM Jan Boutsen <jan.boutsen@...> wrote: Erik,
Delivered within 24 hours!
Everything seems to be there for the experimenter without doing any
software manipulation.
I didn't realize it had its own 'PFA-markings' on the nanoVNA.
Now, 'real' experimenting can start.
Jan ON4MMW
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Erik
Kaashoek
Sent: Wednesday, August 2, 2023 1:59 PM
To: [email protected]
Subject: [nanovna-users] TinyPFA
Fully configured tinyPFA for sale at Eleshop.
--
For more info on the tinyPFA go to
Erik, PD0EK
-- *Dave - W?LEV*
--
Dave - W?LEV
|
On 8/4/23 10:35 AM, W0LEV wrote: Please forgive me for not being familiar with all the "new" acronyms
infiltering our standard english language. Although PFA is undoubtedly an
RF acronym, I am unfamiliar with its meaning? "Pretty Fast Analyzer"? ?
Dave - W?LEV
Phase/Frequency Analyzer - a box that measures the Allan Deviation and Phase Noise of a source. On Fri, Aug 4, 2023 at 2:49?PM Jan Boutsen <jan.boutsen@...> wrote:
Erik,
Delivered within 24 hours!
Everything seems to be there for the experimenter without doing any
software manipulation.
I didn't realize it had its own 'PFA-markings' on the nanoVNA.
Now, 'real' experimenting can start.
Jan ON4MMW
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Erik
Kaashoek
Sent: Wednesday, August 2, 2023 1:59 PM
To: [email protected]
Subject: [nanovna-users] TinyPFA
Fully configured tinyPFA for sale at Eleshop.
--
For more info on the tinyPFA go to
Erik, PD0EK
|
Thanks, Jim! I was embarrassed to ask, but....
Having worked on the GPS (rubidium) clocks in the formative days of the
birds, I am all too familiar with Allen Variance (most of which I've
forgotten).
But, doing Doppler from WWV to look at the ionosphere, I have learned that
precision time keeping and frequency references is addicting. Who needs
drugs for addiction to something - precision frequency references?!
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.
Dave - W?LEV
toggle quoted message
Show quoted text
On Fri, Aug 4, 2023 at 5:46?PM Jim Lux <jimlux@...> wrote: On 8/4/23 10:35 AM, W0LEV wrote:
Please forgive me for not being familiar with all the "new" acronyms
infiltering our standard english language. Although PFA is undoubtedly an
RF acronym, I am unfamiliar with its meaning? "Pretty Fast Analyzer"? ?
Dave - W?LEV
Phase/Frequency Analyzer - a box that measures the Allan Deviation and
Phase Noise of a source.
On Fri, Aug 4, 2023 at 2:49?PM Jan Boutsen <jan.boutsen@...> wrote:
Erik,
Delivered within 24 hours!
Everything seems to be there for the experimenter without doing any
software manipulation.
I didn't realize it had its own 'PFA-markings' on the nanoVNA.
Now, 'real' experimenting can start.
Jan ON4MMW
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Erik
Kaashoek
Sent: Wednesday, August 2, 2023 1:59 PM
To: [email protected]
Subject: [nanovna-users] TinyPFA
Fully configured tinyPFA for sale at Eleshop.
--
For more info on the tinyPFA go to
Erik, PD0EK
-- *Dave - W?LEV*
--
Dave - W?LEV
|
On 8/4/23 10:56 AM, W0LEV wrote: Thanks, Jim! I was embarrassed to ask, but....
Having worked on the GPS (rubidium) clocks in the formative days of the
birds, I am all too familiar with Allen Variance (most of which I've
forgotten).
But, doing Doppler from WWV to look at the ionosphere, I have learned that
precision time keeping and frequency references is addicting. Who needs
drugs for addiction to something - precision frequency references?!
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.
Dave - W?LEV It has two inputs, so you (by calculation) beat one input against the other, using the internal clock. If you want to get into this kind of measurement (which is, as you say, addictive) the TAPR TICC is a useful piece of gear: it measures the time of zero crossing with fraction of a ns accuracy - useful for, say, 1pps ticks. And, of course, the time-nuts mailing list. Erik is on the time-nuts list, and there's been some discussion of the TinyPFA there. On Fri, Aug 4, 2023 at 5:46?PM Jim Lux <jimlux@...> wrote:
On 8/4/23 10:35 AM, W0LEV wrote:
Please forgive me for not being familiar with all the "new" acronyms
infiltering our standard english language. Although PFA is undoubtedly an
RF acronym, I am unfamiliar with its meaning? "Pretty Fast Analyzer"? ?
Dave - W?LEV
Phase/Frequency Analyzer - a box that measures the Allan Deviation and
Phase Noise of a source.
On Fri, Aug 4, 2023 at 2:49?PM Jan Boutsen <jan.boutsen@...> wrote:
Erik,
Delivered within 24 hours!
Everything seems to be there for the experimenter without doing any
software manipulation.
I didn't realize it had its own 'PFA-markings' on the nanoVNA.
Now, 'real' experimenting can start.
Jan ON4MMW
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
Erik
Kaashoek
Sent: Wednesday, August 2, 2023 1:59 PM
To: [email protected]
Subject: [nanovna-users] TinyPFA
Fully configured tinyPFA for sale at Eleshop.
--
For more info on the tinyPFA go to
Erik, PD0EK
|
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 -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
|
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
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Show quoted text
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
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK
-- *Dave - W?LEV*
--
Dave - W?LEV
|
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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Show quoted text
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
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK -- *Dave - W?LEV*
--
Dave - W?LEV
|
Thanks, David, for answering my question. So the reference must be quite
close to the measured frequency. Won't work with my 10 MHz GPS reference.
Of course, I have several signal generators, but none as good as the GPS
referenced 10 MHz.
Dave - W?LEV
toggle quoted message
Show quoted text
On Fri, Aug 4, 2023 at 8:45?PM David McQuate <mcquate@...> wrote: 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
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
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK --
*Dave - W?LEV*
--
Dave - W?LEV
-- *Dave - W?LEV*
--
Dave - W?LEV
|
On 8/4/23 2:42 PM, W0LEV wrote: Thanks, David, for answering my question. So the reference must be quite
close to the measured frequency. Won't work with my 10 MHz GPS reference.
Of course, I have several signal generators, but none as good as the GPS
referenced 10 MHz. You might wait for Erik to weigh in. I don't know that it wouldn't work with appropriately harmonically related frequencies. I suppose it sets the receive LO, and the back end only has a few kHz BW. But if you had a 10 MHz and a 20 MHz, it might work, since you'd be beating the 2nd harmonic of the LO for the 20, and the first harmonic for the 10. But this is also why you see a lot of folks rigging up various and sundry programmable dividers to get it down to 1 pps, which you can compare with TAPR TICC or similar - For ADEV, anyway. And tons of emails over the years on the time-nuts list about how to make this or that measurement, where you don't want the measurement system to degrade the measurement (after all, that divider isn't noise free!) - you know, when you're comparing your cryogenic sapphire resonator against your active hydrogen maser in the garage. Dave - W?LEV
On Fri, Aug 4, 2023 at 8:45?PM David McQuate <mcquate@...> wrote:
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
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
--
NanoVNA Wiki: /g/nanovna-users/wiki/home
NanoVNA Files: /g/nanovna-users/files
Erik, PD0EK --
*Dave - W?LEV*
--
Dave - W?LEV
|
It depends on the accuracy you need For 1e-13 accuracy the two input frequencies (could be harmonics) have to be within 0.5 Hz of each other. If 1e-10 is sufficient accuracy you can first calibrate the internal TCXO of the tinyPFA with a GPSDO or other reference and than measure a source at any frequency between 100kHz and 300 MHz against the calibrated internal TCXO. It should even be possible to measure at a harmonic of this range. -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
|
If you take a VCO under test and phase lock it to an appropriate XO and use that XO to input to the PFA. Can you obtain close in PN as well via the Allen variance close in and then from a time jitter the PN at some offset, say 1 kHz?
I have a test for far offsets but limited on close in PN.
Alan
|
|
|
Excellent, thanks.
This quote in the document, refers to the internal reference limits?
The phase noise of the internal reference (TCXO) is limited but eliminated when using
an external reference
-60dBc @ 0.1 Hz offset
-80dBc @ 1 Hz offset
|
Yes, these are the internal reference limits, only relevant when you measure against the internal reference For phase noise measurements you should always use an external reference -- NanoVNA Wiki: /g/nanovna-users/wiki/homeNanoVNA Files: /g/nanovna-users/filesErik, PD0EK
|
