Re: [time-nuts] Anybody have suggestions for time related science fairprojects?

[Bill Hawkins]

Well, how about the frequency drift between a pendulum, a tuning fork,
and a crystal.
Atomic standards could be added depending on availability.

Bill Hawkins


-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal
Murray
Sent: Thursday, May 10, 2018 11:56 PM
To: time-nuts@febo.com
Cc: Hal Murray
Subject: [time-nuts] Anybody have suggestions for time related science
fairprojects?


A few months ago, I was a judge for the county level middle school
science fair.  (I'm not very good at what they wanted, but that's a
different
problem.)

What sort of interesting time related experiments can a middle school
geek do?

Borrowing serious gear may not be off scale as long as a youngster can
run it.

-

An alternat meaning to the "nut" part of time-nuts:  ")
  https://www.snopes.com/fact-check/schools-removing-analog-clocks/


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Re: [time-nuts] Anybody have suggestions for time related science fairprojects?

[Bill Hawkins]

Um, time dilation by altitude if you have access to a mile high change.
Or subjective time dilation when a person is prevented from doing a task
on time.

Bill Hawkins 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal
Murray
Sent: Thursday, May 10, 2018 11:56 PM
To: time-nuts@febo.com
Cc: Hal Murray
Subject: [time-nuts] Anybody have suggestions for time related science
fairprojects?


A few months ago, I was a judge for the county level middle school
science fair.  (I'm not very good at what they wanted, but that's a
different
problem.)

What sort of interesting time related experiments can a middle school
geek do?

Borrowing serious gear may not be off scale as long as a youngster can
run it.

-

An alternat meaning to the "nut" part of time-nuts:  ")
  https://www.snopes.com/fact-check/schools-removing-analog-clocks/


--
These are my opinions.  I hate spam.



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[time-nuts] Anybody have suggestions for time related science fair projects?

[Hal Murray]

A few months ago, I was a judge for the county level middle school science 
fair.  (I'm not very good at what they wanted, but that's a different 
problem.)

What sort of interesting time related experiments can a middle school geek do?

Borrowing serious gear may not be off scale as long as a youngster can run it.

-

An alternat meaning to the "nut" part of time-nuts:  ")
  https://www.snopes.com/fact-check/schools-removing-analog-clocks/


-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] nuts about position (cheap receiver)

[Peter Monta]

>
>
> Results from the Z12 in L1/L2 mode were... iffy...  then the receiver died.
>

The teqc tool from UNAVCO can help with diagnosing iffy data.  Can you put
your RINEX somewhere?  With the antenna in an unobstructed area my Z12
routinely gives 1 cm-ish horizonal, few-cm 3D, using OPUS-S or OPUS-RS.

Conceivably there's some reference-clock problem with your Z12 that's
trashing the phase observables.  As another check, let the unit cool to
room temp, then power up and see if it tracks.
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Re: [time-nuts] Ashtech Z12 question.

[Peter Monta]

> Well, my Z12 stopped tracking sats yesterday.   It passes all self-tests.
>  I then replaced the memory backup batteries... it fixed the bootup error
> problem, but still won't track sats.
>

Rats.  Is the antenna known to be good?  Is the Z12 providing bias on the
antenna cable?  Did the Z12 stop tracking right in the middle of the
session with no nearby events or configuration changes?  If you can
manually inject DC to the antenna with a bias tee, verify the presence of
signal with another receiver, then feed the signal to the Z12 (or use a
splitter to feed both receivers), that might be worth trying.
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[time-nuts] nuts about position (cheap receiver)

[Mark Sims]

I have Lady Heather's RINEX writer working fairly well.  Handles GPS and 
GLONASS (should also do Galileo when the M8T comes in from Germany... was "in 
stock" but it took them over a week to ship it).

I just did a run on the Furuno GT-8736.  It only outputs pseudoranges.  A 2.5 
hour run @ 1Hz had error ellipses around 0.4 meters lat/lon  1 meter altitude.. 
 similar to a Ublox-5T with pseudoranges and carrier phase.  The LEA-5T with 17 
hours of 1Hz data were .17 /.15 /.4 meters... not too shabby for a $25 receiver.

The NVS-08 with 3 hours of 1Hz GPS/GLONASS data was 0.63/0.59/1.5m (without 
GLONASS data being processed).   Once CSRS-PPP had GLONASS orbit data 
available, they automatically re-ran it and the error ellipses improved to 
.57/.56/1.4m

A 19 hour/1Hz run on a NVS-08 receiver was 0.175 meters lat/lon .455 meters 
altitude.  

Results from the Z12 in L1/L2 mode were... iffy...  then the receiver died.
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[time-nuts] Ashtech Z12 question.

[Mark Sims]

Well, my Z12 stopped tracking sats yesterday.   It passes all self-tests.   I 
then replaced the memory backup batteries... it fixed the bootup error problem, 
but still won't track sats.
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Re: [time-nuts] Question about frequency counter testing

[Bob kb8tq]

Hi

> On May 10, 2018, at 1:44 PM, Oleg Skydan  wrote:
> 
> Bob, thanks for clarification!
> 
> From: "Bob kb8tq" 
>> If you collect data over the entire second and average that down for a 
>> single point, then no, your ADEV will not be correct.
> 
> That probably explains why I got so nice (and suspicious) plots :)
> 
>> There are a number of papers on this. What ADEV wants to see is a single 
>> phase “sample” at one second spacing.
> 
> After I read your answer I remembered some nice papers from prof. Rubiola, me 
> bad - I was able to answer my question by myself. When we take a single phase 
> "sample" at start and at end time of the "each tau" it is equivalent to 
> summing all timestamps intervals I collect during that "tau", but by doing LR 
> processing I calculate *weighted* sum, so the results will differ. So, it 
> appears "ADEV" calculations is PDEV (parabolic) in reality, because of the 
> current firmware processing.
> 
> I made a test with two plots for illustration - one is the classical ADEV 
> (with 2.5ns time resolution), the second one with LR processed data (5e6 
> timestamps per second). Both plots are made from the same data. It is obvious 
> the classical ADEV is limited by the counter resolution in the left part of 
> the plot. It is interesting is it possible to use the 498 extra points 
> per each second to improve counter resolution in ADEV measurements without 
> affecting ADEV?

The most accurate answer is always “that depends”. The simple answer is no. If 
you take a look at some of the papers from 
the 90’s you can find suggestions on doing filtering on the first point in the 
series. The gotcha is that it does impact the first
point. The claim is that if you do it right, it does not impact the rest of the 
points in the series. 

Bob


> 
> Thanks!
> Oleg UR3IQO 
> <Снимок экрана (1151).png>___
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Re: [time-nuts] Question about frequency counter testing

[Oleg Skydan]

Bob, thanks for clarification!

From: "Bob kb8tq" 
If you collect data over the entire second and average that down for a 
single point, then no, your ADEV will not be correct.


That probably explains why I got so nice (and suspicious) plots :)

There are a number of papers on this. What ADEV wants to see is a single 
phase “sample” at one second spacing.


After I read your answer I remembered some nice papers from prof. Rubiola, 
me bad - I was able to answer my question by myself. When we take a single 
phase "sample" at start and at end time of the "each tau" it is equivalent 
to summing all timestamps intervals I collect during that "tau", but by 
doing LR processing I calculate *weighted* sum, so the results will differ. 
So, it appears "ADEV" calculations is PDEV (parabolic) in reality, because 
of the current firmware processing.


I made a test with two plots for illustration - one is the classical ADEV 
(with 2.5ns time resolution), the second one with LR processed data (5e6 
timestamps per second). Both plots are made from the same data. It is 
obvious the classical ADEV is limited by the counter resolution in the left 
part of the plot. It is interesting is it possible to use the 498 extra 
points per each second to improve counter resolution in ADEV measurements 
without affecting ADEV?


Thanks!
Oleg UR3IQO 
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Re: [time-nuts] Question about frequency counter testing

[Bob kb8tq]

Hi

More or less: 

ADEV takes the *difference* between phase samples and then does a standard
deviation on them. RMS of the phase samples makes a lot of sense and it was
used back in the late 50’s / early 60’s. The gotcha turns out to be that it is 
an 
ill behaved measure. The more data you take, the bigger the number you get. 
( = it does not converge ). That problem is what lead NBS to dig into a better 
measure. The result was ADEV.

The point about averaging vs decimation relates to what you do to the data 
*before*
you ever compute the ADEV. If you have 0.1 second samples, you have to do 
something
to get to a tau of 1 second or 10 seconds or … The process you use to get the 
data
to the proper interval turns out to matter quite a bit. 

Bob

> On May 10, 2018, at 12:17 PM, Dana Whitlow  wrote:
> 
> I'm a bit fuzzy, then, on the definition of ADEV.  I was under the
> impression that one measured a series of
> "phase samples" at the desired spacing, then took the RMS value of that
> series, not just a single sample,
> as the ADEV value.
> 
> Can anybody say which it is?   The RMS approach seems to make better sense
> as it provides some measure
> of defense against taking a sample that happens to be an outlier, yet
> avoids the flaw of tending to average
> the reported ADEV towards zero.
> 
> Dana   (K8YUM)
> 
> 
> On Thu, May 10, 2018 at 9:21 AM, Bob kb8tq  wrote:
> 
>> Hi
>> 
>> If you collect data over the entire second and average that down for a
>> single point, then no, your ADEV will not be correct.
>> There are a number of papers on this. What ADEV wants to see is a single
>> phase “sample” at one second spacing. This is
>> also at the root of how you get 10 second ADEV. You don’t average the ten
>> 1 second data points. You throw nine data points
>> away and use one of them ( = you decimate the data ).
>> 
>> What happens if you ignore this? Your curve looks “to good”. The resultant
>> curve is *below* the real curve when plotted.
>> 
>> A quick way to demonstrate this is to do ADEV with averaged vs decimated
>> data ….
>> 
>> Bob
>> 
>>> On May 10, 2018, at 4:46 AM, Oleg Skydan  wrote:
>>> 
>>> Hi
>>> 
>>> I have got a pair of not so bad OCXOs (Morion GK85). I did some
>> measurements, the results may be interested to others (sorry if not), so I
>> decided to post them.
>>> 
>>> I ran a set of 5minutes long counter runs (two OCXOs were measured
>> against each other), each point is 1sec gate frequency measurement with
>> different number of timestamps used in LR calculation (from 10 till 5e6).
>> The counter provides continuous counting. As you can see I reach the HW
>> limitations at 5..6e-12 ADEV (1s tau) with only 1e5 timestamps. The results
>> looks reasonable, the theory predicts 27ps equivalent resolution with 1e5
>> timestamps, also the sqrt(N) law is clearly seen on the plots. I do not
>> know what is the limiting factor, if it is OCXOs or some counter HW.
>>> 
>>> I know there are HW problems, some of them were identified during this
>> experiment. They were expectable, cause HW is still just an ugly
>> construction made from the boards left in the "radio junk box" from the
>> other projects/experiments. I am going to move to the well designed PCB
>> with some improvements in HW (and more or less "normal" analog frontend
>> with good comparator, ADCMP604 or something similar, for the "low
>> frequency" input). But I want to finish my initial tests, it should help
>> with the HW design.
>>> 
>>> Now I have some questions. As you know I am experimenting with the
>> counter that uses LR calculations to improve its resolution. The LR data
>> for each measurement is collected during the gate time only, also
>> measurements are continuous. Will the ADEV be calculated correctly from
>> such measurements? I understand that any averaging for the time window
>> larger then single measurement time will spoil the ADEV plot. Also I
>> understand that using LR can result in incorrect frequency estimate for the
>> signal with large drift (should not be a problem for the discussed
>> measurements, at least for the numbers we are talking about).
>>> 
>>> Does the ADEV plots I got looks reasonable for the used "mid range"
>> OCXOs (see the second plot for the long run test)?
>>> 
>>> BTW, I see I can interface GPS module to my counter without additional
>> HW (except the module itself, do not worry it will not be another DIY
>> GPSDO, probably :-) ). I will try to do it. The initial idea is not try to
>> lock the reference OCXO to GPS, instead I will just measure GPS against REF
>> and will make corrections using pure math in SW. I see some advantages with
>> such design - no hi resolution DAC, reference for DAC, no loop, no
>> additional hardware at all - only the GPS module and software :) (it is in
>> the spirit of this project)... Of cause I will not have reference signal
>> that can be used outside the counter, I think I can live with 

Re: [time-nuts] Question about frequency counter testing

[Dana Whitlow]

I'm a bit fuzzy, then, on the definition of ADEV.  I was under the
impression that one measured a series of
"phase samples" at the desired spacing, then took the RMS value of that
series, not just a single sample,
as the ADEV value.

Can anybody say which it is?   The RMS approach seems to make better sense
as it provides some measure
of defense against taking a sample that happens to be an outlier, yet
avoids the flaw of tending to average
the reported ADEV towards zero.

Dana   (K8YUM)


On Thu, May 10, 2018 at 9:21 AM, Bob kb8tq  wrote:

> Hi
>
> If you collect data over the entire second and average that down for a
> single point, then no, your ADEV will not be correct.
> There are a number of papers on this. What ADEV wants to see is a single
> phase “sample” at one second spacing. This is
> also at the root of how you get 10 second ADEV. You don’t average the ten
> 1 second data points. You throw nine data points
> away and use one of them ( = you decimate the data ).
>
> What happens if you ignore this? Your curve looks “to good”. The resultant
> curve is *below* the real curve when plotted.
>
> A quick way to demonstrate this is to do ADEV with averaged vs decimated
> data ….
>
> Bob
>
> > On May 10, 2018, at 4:46 AM, Oleg Skydan  wrote:
> >
> > Hi
> >
> > I have got a pair of not so bad OCXOs (Morion GK85). I did some
> measurements, the results may be interested to others (sorry if not), so I
> decided to post them.
> >
> > I ran a set of 5minutes long counter runs (two OCXOs were measured
> against each other), each point is 1sec gate frequency measurement with
> different number of timestamps used in LR calculation (from 10 till 5e6).
> The counter provides continuous counting. As you can see I reach the HW
> limitations at 5..6e-12 ADEV (1s tau) with only 1e5 timestamps. The results
> looks reasonable, the theory predicts 27ps equivalent resolution with 1e5
> timestamps, also the sqrt(N) law is clearly seen on the plots. I do not
> know what is the limiting factor, if it is OCXOs or some counter HW.
> >
> > I know there are HW problems, some of them were identified during this
> experiment. They were expectable, cause HW is still just an ugly
> construction made from the boards left in the "radio junk box" from the
> other projects/experiments. I am going to move to the well designed PCB
> with some improvements in HW (and more or less "normal" analog frontend
> with good comparator, ADCMP604 or something similar, for the "low
> frequency" input). But I want to finish my initial tests, it should help
> with the HW design.
> >
> > Now I have some questions. As you know I am experimenting with the
> counter that uses LR calculations to improve its resolution. The LR data
> for each measurement is collected during the gate time only, also
> measurements are continuous. Will the ADEV be calculated correctly from
> such measurements? I understand that any averaging for the time window
> larger then single measurement time will spoil the ADEV plot. Also I
> understand that using LR can result in incorrect frequency estimate for the
> signal with large drift (should not be a problem for the discussed
> measurements, at least for the numbers we are talking about).
> >
> > Does the ADEV plots I got looks reasonable for the used "mid range"
> OCXOs (see the second plot for the long run test)?
> >
> > BTW, I see I can interface GPS module to my counter without additional
> HW (except the module itself, do not worry it will not be another DIY
> GPSDO, probably :-) ). I will try to do it. The initial idea is not try to
> lock the reference OCXO to GPS, instead I will just measure GPS against REF
> and will make corrections using pure math in SW. I see some advantages with
> such design - no hi resolution DAC, reference for DAC, no loop, no
> additional hardware at all - only the GPS module and software :) (it is in
> the spirit of this project)... Of cause I will not have reference signal
> that can be used outside the counter, I think I can live with it. It worth
> to do some experiments.
> >
> > Best!
> > Oleg UR3IQO
> > <Снимок экрана (1148).png><Снимок экрана (1150).png><Снимок экрана
> (1149).png>___
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> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
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[time-nuts] how long dues this rubidium standard last for

[cdelect]

Paul,

I agree with Bob, the small telecom ones to include the Efratom ones have
a lifetime that is just a guess at this point.

A brand new PRS10 with a warranty and the original owner repair discount
would be a good bet, they do however have lamp assy problems unless that
has been redesigned.

The HP5065A however has no significant failure modes, and I have worked
on and seen good performance out of 40 Year old units!

As discussed here before 5065A performance leaves the others "in the
dust".

The filter (either Edmund or Thor labs sell them) will run about
$170-$200 however you cannot guarantee a performance increase with every
5065A as there are other parameters that must be met.

The main problem is finding one that is affordable!

Due to it's excellent short term stability (<1.5X10-13th at 100 Sec) it's
in high demand and prices have been increasing as the available ones get
snapped up!

As Bob noted a last production serial number (prefix 2816A) recently went
for $4000.00

Mid vintage ones can run $2000.00

If you don't need the 5065A performance then just buy a telecom one
whenever your current one dies!

Cheers,

Corby

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Re: [time-nuts] Question about frequency counter testing

[Bob kb8tq]

Hi

If you collect data over the entire second and average that down for a single 
point, then no, your ADEV will not be correct. 
There are a number of papers on this. What ADEV wants to see is a single phase 
“sample” at one second spacing. This is
also at the root of how you get 10 second ADEV. You don’t average the ten 1 
second data points. You throw nine data points
away and use one of them ( = you decimate the data ). 

What happens if you ignore this? Your curve looks “to good”. The resultant 
curve is *below* the real curve when plotted. 

A quick way to demonstrate this is to do ADEV with averaged vs decimated data ….

Bob

> On May 10, 2018, at 4:46 AM, Oleg Skydan  wrote:
> 
> Hi
> 
> I have got a pair of not so bad OCXOs (Morion GK85). I did some measurements, 
> the results may be interested to others (sorry if not), so I decided to post 
> them.
> 
> I ran a set of 5minutes long counter runs (two OCXOs were measured against 
> each other), each point is 1sec gate frequency measurement with different 
> number of timestamps used in LR calculation (from 10 till 5e6). The counter 
> provides continuous counting. As you can see I reach the HW limitations at 
> 5..6e-12 ADEV (1s tau) with only 1e5 timestamps. The results looks 
> reasonable, the theory predicts 27ps equivalent resolution with 1e5 
> timestamps, also the sqrt(N) law is clearly seen on the plots. I do not know 
> what is the limiting factor, if it is OCXOs or some counter HW.
> 
> I know there are HW problems, some of them were identified during this 
> experiment. They were expectable, cause HW is still just an ugly construction 
> made from the boards left in the "radio junk box" from the other 
> projects/experiments. I am going to move to the well designed PCB with some 
> improvements in HW (and more or less "normal" analog frontend with good 
> comparator, ADCMP604 or something similar, for the "low frequency" input). 
> But I want to finish my initial tests, it should help with the HW design.
> 
> Now I have some questions. As you know I am experimenting with the counter 
> that uses LR calculations to improve its resolution. The LR data for each 
> measurement is collected during the gate time only, also measurements are 
> continuous. Will the ADEV be calculated correctly from such measurements? I 
> understand that any averaging for the time window larger then single 
> measurement time will spoil the ADEV plot. Also I understand that using LR 
> can result in incorrect frequency estimate for the signal with large drift 
> (should not be a problem for the discussed measurements, at least for the 
> numbers we are talking about).
> 
> Does the ADEV plots I got looks reasonable for the used "mid range" OCXOs 
> (see the second plot for the long run test)?
> 
> BTW, I see I can interface GPS module to my counter without additional HW 
> (except the module itself, do not worry it will not be another DIY GPSDO, 
> probably :-) ). I will try to do it. The initial idea is not try to lock the 
> reference OCXO to GPS, instead I will just measure GPS against REF and will 
> make corrections using pure math in SW. I see some advantages with such 
> design - no hi resolution DAC, reference for DAC, no loop, no additional 
> hardware at all - only the GPS module and software :) (it is in the spirit of 
> this project)... Of cause I will not have reference signal that can be used 
> outside the counter, I think I can live with it. It worth to do some 
> experiments.
> 
> Best!
> Oleg UR3IQO 
> <Снимок экрана (1148).png><Снимок экрана (1150).png><Снимок экрана 
> (1149).png>___
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Re: [time-nuts] HP 5372A

[Don Murray via time-nuts]

Hi Magnus...
 
 
Appreciate any help!
 
I participate in the ARRL Frequency Measuring Test,
and I would like to automate the measuring process.
 
I have two frequencies, A and B...
 
A is a GPS locked HP 3336B set to 455,000.000 Hz
 
I use the 3336B instead of the 455,000Hz BFO
signal from my GPS locked Racal receiver so
that I can measure AM stations without the
annoying beat note.  ;-)
 
B is an IF signal which should appear between
455,000.000Hz and 455,001.000 Hz
 
I would like the 5372A to calculate the B minus A
delta, over a manually started and automatically
stopped measurement period of 110 seconds.
 
I would like a delta resolution of 0.001Hz to be
developed by the box.
 
Now, there will be doppler.  I want the box
to analyze and give me a best statistical guess
for the B minus A delta.
 
BTW the B minus A delta will be added to the
frequency of my Racal receiver to give me the
best "guess" as to the correct frequency of the
target signal.
 
The Racal reads out to the Hz, and I am able to
accurately determine if the Racal is tuned above
or below the "target" frequency.
 
I will be tuned below the "target" and within
1 Hz of the "target."
 
I assume I will be in the one frequency mode.
 
Can the box give me the desired resolution?
 
What sampling period would be the best to use?
 
What statistical result would I use as my delta?
 
Appreciate your help.  My head is spinning whenever I
get into the operating manual!
 
TNX...
 
 
73
Don
W4WJ
 
In a message dated 5/10/2018 2:19:49 AM Central Standard Time, 
mag...@rubidium.dyndns.org writes:

 
 Hi,

What issues do you have?

Cheers,
Magnus

On 05/08/2018 02:32 AM, Don Murray via time-nuts wrote:
> Hello Time Nuts...
> 
> 
>  
> Who is the resident expert on the HP5372A?
>  
> I have some operational questions.  ;-)
>  
> email off list please.  w4wj at aol.com
>  
> TNX all...
>  
> 73
> Don
> W4WJ
>  
>  
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Re: [time-nuts] Question about frequency counter testing

[Oleg Skydan]

Hi

I have got a pair of not so bad OCXOs (Morion GK85). I did some 
measurements, the results may be interested to others (sorry if not), so I 
decided to post them.


I ran a set of 5minutes long counter runs (two OCXOs were measured against 
each other), each point is 1sec gate frequency measurement with different 
number of timestamps used in LR calculation (from 10 till 5e6). The counter 
provides continuous counting. As you can see I reach the HW limitations at 
5..6e-12 ADEV (1s tau) with only 1e5 timestamps. The results looks 
reasonable, the theory predicts 27ps equivalent resolution with 1e5 
timestamps, also the sqrt(N) law is clearly seen on the plots. I do not know 
what is the limiting factor, if it is OCXOs or some counter HW.


I know there are HW problems, some of them were identified during this 
experiment. They were expectable, cause HW is still just an ugly 
construction made from the boards left in the "radio junk box" from the 
other projects/experiments. I am going to move to the well designed PCB with 
some improvements in HW (and more or less "normal" analog frontend with good 
comparator, ADCMP604 or something similar, for the "low frequency" input). 
But I want to finish my initial tests, it should help with the HW design.


Now I have some questions. As you know I am experimenting with the counter 
that uses LR calculations to improve its resolution. The LR data for each 
measurement is collected during the gate time only, also measurements are 
continuous. Will the ADEV be calculated correctly from such measurements? I 
understand that any averaging for the time window larger then single 
measurement time will spoil the ADEV plot. Also I understand that using LR 
can result in incorrect frequency estimate for the signal with large drift 
(should not be a problem for the discussed measurements, at least for the 
numbers we are talking about).


Does the ADEV plots I got looks reasonable for the used "mid range" OCXOs 
(see the second plot for the long run test)?


BTW, I see I can interface GPS module to my counter without additional HW 
(except the module itself, do not worry it will not be another DIY GPSDO, 
probably :-) ). I will try to do it. The initial idea is not try to lock the 
reference OCXO to GPS, instead I will just measure GPS against REF and will 
make corrections using pure math in SW. I see some advantages with such 
design - no hi resolution DAC, reference for DAC, no loop, no additional 
hardware at all - only the GPS module and software :) (it is in the spirit 
of this project)... Of cause I will not have reference signal that can be 
used outside the counter, I think I can live with it. It worth to do some 
experiments.


Best!
Oleg UR3IQO 
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Re: [time-nuts] HP 5372A

[Magnus Danielson]

Hi,

What issues do you have?

Cheers,
Magnus

On 05/08/2018 02:32 AM, Don Murray via time-nuts wrote:
> Hello Time Nuts...
> 
> 
>  
> Who is the resident expert on the HP5372A?
>  
> I have some operational questions.  ;-)
>  
> email off list please.  w4wj at aol.com
>  
> TNX all...
>  
> 73
> Don
> W4WJ
>  
>  
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