EK
Erik Kaashoek
Tue, Nov 9, 2021 5:26 PM
As far as I understood the ADEV at a Tau of 1 second is a statement
about the amount of variation to be expected over a one second interval.
It would be nice if we would be able to measure a frequency in an
infinite short interval but any frequency measurement takes time.
What if the frequency counter does a complete measurement of a frequency
source every second and all the variation within that second is hidden
because of the "integration" that happens over the second?
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on
many measurements done during one second but they can not provide
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second still
valid for determining the ADEV at the Tau of one second of a frequency
source?
Or should there be a correction factor depending on the method used in
the frequency counter?
I tried to read some scientific studies on this subject but I am not
smart enough to understand.
Hope one of you can provide some information.
Erik.
As far as I understood the ADEV at a Tau of 1 second is a statement
about the amount of variation to be expected over a one second interval.
It would be nice if we would be able to measure a frequency in an
infinite short interval but any frequency measurement takes time.
What if the frequency counter does a complete measurement of a frequency
source every second and all the variation within that second is hidden
because of the "integration" that happens over the second?
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on
many measurements done during one second but they can not provide
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second still
valid for determining the ADEV at the Tau of one second of a frequency
source?
Or should there be a correction factor depending on the method used in
the frequency counter?
I tried to read some scientific studies on this subject but I am not
smart enough to understand.
Hope one of you can provide some information.
Erik.
BK
Bob kb8tq
Tue, Nov 9, 2021 9:21 PM
Hi
The simple answer is that there are no shortcuts allowed if you are after a proper
ADEV. You take the (single) phase samples at the specified tau and push them into
the math. Anything else you do, will reduce the noise and thus compromise the noise
measuring properties of the approach.
Bob
On Nov 9, 2021, at 12:26 PM, Erik Kaashoek erik@kaashoek.com wrote:
As far as I understood the ADEV at a Tau of 1 second is a statement about the amount of variation to be expected over a one second interval.
It would be nice if we would be able to measure a frequency in an infinite short interval but any frequency measurement takes time.
What if the frequency counter does a complete measurement of a frequency source every second and all the variation within that second is hidden because of the "integration" that happens over the second?
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on many measurements done during one second but they can not provide information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second still valid for determining the ADEV at the Tau of one second of a frequency source?
Or should there be a correction factor depending on the method used in the frequency counter?
I tried to read some scientific studies on this subject but I am not smart enough to understand.
Hope one of you can provide some information.
Erik.
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.
Hi
The simple answer is that there are no shortcuts allowed if you are after a proper
ADEV. You take the (single) phase samples at the specified tau and push them into
the math. Anything else you do, will reduce the noise and thus compromise the noise
measuring properties of the approach.
Bob
> On Nov 9, 2021, at 12:26 PM, Erik Kaashoek <erik@kaashoek.com> wrote:
>
> As far as I understood the ADEV at a Tau of 1 second is a statement about the amount of variation to be expected over a one second interval.
> It would be nice if we would be able to measure a frequency in an infinite short interval but any frequency measurement takes time.
> What if the frequency counter does a complete measurement of a frequency source every second and all the variation within that second is hidden because of the "integration" that happens over the second?
> This is specially the case with continuous time-stamping counters.
> They can provide a precise number by applying statistical methods on many measurements done during one second but they can not provide information exactly at the end of a second.
> Is this kind of statistical measurement over a period of a second still valid for determining the ADEV at the Tau of one second of a frequency source?
> Or should there be a correction factor depending on the method used in the frequency counter?
> I tried to read some scientific studies on this subject but I am not smart enough to understand.
> Hope one of you can provide some information.
> Erik.
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
BK
Bob kb8tq
Tue, Nov 9, 2021 10:10 PM
On Nov 9, 2021, at 12:26 PM, Erik Kaashoek erik@kaashoek.com wrote:
As far as I understood the ADEV at a Tau of 1 second is a statement about the amount of variation to be expected over a one second interval.
It would be nice if we would be able to measure a frequency in an infinite short interval but any frequency measurement takes time.
What if the frequency counter does a complete measurement of a frequency source every second and all the variation within that second is hidden because of the "integration" that happens over the second?
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on many measurements done during one second but they can not provide information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second still valid for determining the ADEV at the Tau of one second of a frequency source?
Or should there be a correction factor depending on the method used in the frequency counter?
I tried to read some scientific studies on this subject but I am not smart enough to understand.
Hope one of you can provide some information.
Erik.
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.
> On Nov 9, 2021, at 12:26 PM, Erik Kaashoek <erik@kaashoek.com> wrote:
>
> As far as I understood the ADEV at a Tau of 1 second is a statement about the amount of variation to be expected over a one second interval.
> It would be nice if we would be able to measure a frequency in an infinite short interval but any frequency measurement takes time.
> What if the frequency counter does a complete measurement of a frequency source every second and all the variation within that second is hidden because of the "integration" that happens over the second?
> This is specially the case with continuous time-stamping counters.
> They can provide a precise number by applying statistical methods on many measurements done during one second but they can not provide information exactly at the end of a second.
> Is this kind of statistical measurement over a period of a second still valid for determining the ADEV at the Tau of one second of a frequency source?
> Or should there be a correction factor depending on the method used in the frequency counter?
> I tried to read some scientific studies on this subject but I am not smart enough to understand.
> Hope one of you can provide some information.
> Erik.
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
MD
Magnus Danielson
Tue, Nov 9, 2021 10:29 PM
Hi Erik,
On 2021-11-09 18:26, Erik Kaashoek wrote:
As far as I understood the ADEV at a Tau of 1 second is a statement
about the amount of variation to be expected over a one second interval.
Rather, the variation of readings of a frequency estimation done over a
span over 1 second.
It would be nice if we would be able to measure a frequency in an
infinite short interval but any frequency measurement takes time.
Turn out that basic white noise and systematic noise will limit our
frequency resolution to form a 1/tau limit slope, so infinite short
interval will bury it well into that noise whatever we do.
What if the frequency counter does a complete measurement of a
frequency source every second and all the variation within that second
is hidden because of the "integration" that happens over the second?
That is what happens, but that is not what the ADEV is about, it's about
the variations of these measures as we look for a bunch of them. So if
we now have say 1000 of these frequency estimates, how much variations
in these can be contributed to the random noise of the source, and to
analyse that, we need at least a tool like ADEV since standard deviation
will not even converge for white and flicker phase noise modulation.
What ADEV actually aims to do is to provide a low-frequency spectroscopy
method at a time when time-interval counters was about the only tool at
hand, and even those where very rare. We now have a much wider palette
of tools, but ADEV is relevant for how we measure frequency stability
and a few other applications.
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on
many measurements done during one second but they can not provide
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second
still valid for determining the ADEV at the Tau of one second of a
frequency source?
Not for ADEV, but if you use averaging counter you get the result of
MDEV and for linear regression / least square counter you get the
response of PDEV. That is the result of various statistical measures and
then applying the ADEV processing on these frequency estimates. The
upcoming IEEE Std 1139 revision, which is in approval process now
include language to reflect that.
Or should there be a correction factor depending on the method used in
the frequency counter?
Yes, you then need to use the appropriate bias function for ADEV/MDEV
and ADEV/PDEV to convert between these scales. Knowing the response of
ADEV, MDEV and PDEV for a particular noise-type which is dominant at the
tau of interest, you can readily convert between them by forming the
bias functions.
You may find NIST SP-1065 a useful and handy tool, even if it does not
cover the more recent work such as PDEV.
https://www.nist.gov/publications/handbook-frequency-stability-analysis
I tried to read some scientific studies on this subject but I am not
smart enough to understand.
Hope one of you can provide some information.
It is scattered over a large number of articles, and quite a lot of
folks get confused. Hopefully the updated IEEE Std 1139 will be of aid
to you. It also has lots of useful references.
Cheers,
Magnus
Hi Erik,
On 2021-11-09 18:26, Erik Kaashoek wrote:
> As far as I understood the ADEV at a Tau of 1 second is a statement
> about the amount of variation to be expected over a one second interval.
Rather, the variation of readings of a frequency estimation done over a
span over 1 second.
> It would be nice if we would be able to measure a frequency in an
> infinite short interval but any frequency measurement takes time.
Turn out that basic white noise and systematic noise will limit our
frequency resolution to form a 1/tau limit slope, so infinite short
interval will bury it well into that noise whatever we do.
> What if the frequency counter does a complete measurement of a
> frequency source every second and all the variation within that second
> is hidden because of the "integration" that happens over the second?
That is what happens, but that is not what the ADEV is about, it's about
the variations of these measures as we look for a bunch of them. So if
we now have say 1000 of these frequency estimates, how much variations
in these can be contributed to the random noise of the source, and to
analyse that, we need at least a tool like ADEV since standard deviation
will not even converge for white and flicker phase noise modulation.
What ADEV actually aims to do is to provide a low-frequency spectroscopy
method at a time when time-interval counters was about the only tool at
hand, and even those where very rare. We now have a much wider palette
of tools, but ADEV is relevant for how we measure frequency stability
and a few other applications.
> This is specially the case with continuous time-stamping counters.
> They can provide a precise number by applying statistical methods on
> many measurements done during one second but they can not provide
> information exactly at the end of a second.
> Is this kind of statistical measurement over a period of a second
> still valid for determining the ADEV at the Tau of one second of a
> frequency source?
Not for ADEV, but if you use averaging counter you get the result of
MDEV and for linear regression / least square counter you get the
response of PDEV. That is the result of various statistical measures and
then applying the ADEV processing on these frequency estimates. The
upcoming IEEE Std 1139 revision, which is in approval process now
include language to reflect that.
> Or should there be a correction factor depending on the method used in
> the frequency counter?
Yes, you then need to use the appropriate bias function for ADEV/MDEV
and ADEV/PDEV to convert between these scales. Knowing the response of
ADEV, MDEV and PDEV for a particular noise-type which is dominant at the
tau of interest, you can readily convert between them by forming the
bias functions.
You may find NIST SP-1065 a useful and handy tool, even if it does not
cover the more recent work such as PDEV.
https://www.nist.gov/publications/handbook-frequency-stability-analysis
> I tried to read some scientific studies on this subject but I am not
> smart enough to understand.
> Hope one of you can provide some information.
It is scattered over a large number of articles, and quite a lot of
folks get confused. Hopefully the updated IEEE Std 1139 will be of aid
to you. It also has lots of useful references.
Cheers,
Magnus
R(
Richard (Rick) Karlquist
Wed, Nov 10, 2021 12:53 AM
Let me just mention that when I worked at the HP Santa Clara
Division counters section, they came out with a "feature"
that they called "continuous count". However, it was limited
to something like 3 MHz. So a 100 MHz counter would only
continuously count signals below 3 MHz.
So you need to verify for what bandwidth your specific counter
model is truly doing continuous count.
Rick N6RK
On 11/9/2021 2:29 PM, Magnus Danielson via time-nuts wrote:
Hi Erik,
On 2021-11-09 18:26, Erik Kaashoek wrote:
As far as I understood the ADEV at a Tau of 1 second is a statement
about the amount of variation to be expected over a one second interval.
Rather, the variation of readings of a frequency estimation done over a
span over 1 second.
It would be nice if we would be able to measure a frequency in an
infinite short interval but any frequency measurement takes time.
Turn out that basic white noise and systematic noise will limit our
frequency resolution to form a 1/tau limit slope, so infinite short
interval will bury it well into that noise whatever we do.
What if the frequency counter does a complete measurement of a
frequency source every second and all the variation within that second
is hidden because of the "integration" that happens over the second?
That is what happens, but that is not what the ADEV is about, it's about
the variations of these measures as we look for a bunch of them. So if
we now have say 1000 of these frequency estimates, how much variations
in these can be contributed to the random noise of the source, and to
analyse that, we need at least a tool like ADEV since standard deviation
will not even converge for white and flicker phase noise modulation.
What ADEV actually aims to do is to provide a low-frequency spectroscopy
method at a time when time-interval counters was about the only tool at
hand, and even those where very rare. We now have a much wider palette
of tools, but ADEV is relevant for how we measure frequency stability
and a few other applications.
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on
many measurements done during one second but they can not provide
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second
still valid for determining the ADEV at the Tau of one second of a
frequency source?
Not for ADEV, but if you use averaging counter you get the result of
MDEV and for linear regression / least square counter you get the
response of PDEV. That is the result of various statistical measures and
then applying the ADEV processing on these frequency estimates. The
upcoming IEEE Std 1139 revision, which is in approval process now
include language to reflect that.
Or should there be a correction factor depending on the method used in
the frequency counter?
Yes, you then need to use the appropriate bias function for ADEV/MDEV
and ADEV/PDEV to convert between these scales. Knowing the response of
ADEV, MDEV and PDEV for a particular noise-type which is dominant at the
tau of interest, you can readily convert between them by forming the
bias functions.
You may find NIST SP-1065 a useful and handy tool, even if it does not
cover the more recent work such as PDEV.
https://www.nist.gov/publications/handbook-frequency-stability-analysis
I tried to read some scientific studies on this subject but I am not
smart enough to understand.
Hope one of you can provide some information.
It is scattered over a large number of articles, and quite a lot of
folks get confused. Hopefully the updated IEEE Std 1139 will be of aid
to you. It also has lots of useful references.
Cheers,
Magnus
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.
Let me just mention that when I worked at the HP Santa Clara
Division counters section, they came out with a "feature"
that they called "continuous count". However, it was limited
to something like 3 MHz. So a 100 MHz counter would only
continuously count signals below 3 MHz.
So you need to verify for what bandwidth your specific counter
model is truly doing continuous count.
Rick N6RK
On 11/9/2021 2:29 PM, Magnus Danielson via time-nuts wrote:
> Hi Erik,
>
> On 2021-11-09 18:26, Erik Kaashoek wrote:
>> As far as I understood the ADEV at a Tau of 1 second is a statement
>> about the amount of variation to be expected over a one second interval.
> Rather, the variation of readings of a frequency estimation done over a
> span over 1 second.
>> It would be nice if we would be able to measure a frequency in an
>> infinite short interval but any frequency measurement takes time.
> Turn out that basic white noise and systematic noise will limit our
> frequency resolution to form a 1/tau limit slope, so infinite short
> interval will bury it well into that noise whatever we do.
>> What if the frequency counter does a complete measurement of a
>> frequency source every second and all the variation within that second
>> is hidden because of the "integration" that happens over the second?
>
> That is what happens, but that is not what the ADEV is about, it's about
> the variations of these measures as we look for a bunch of them. So if
> we now have say 1000 of these frequency estimates, how much variations
> in these can be contributed to the random noise of the source, and to
> analyse that, we need at least a tool like ADEV since standard deviation
> will not even converge for white and flicker phase noise modulation.
>
> What ADEV actually aims to do is to provide a low-frequency spectroscopy
> method at a time when time-interval counters was about the only tool at
> hand, and even those where very rare. We now have a much wider palette
> of tools, but ADEV is relevant for how we measure frequency stability
> and a few other applications.
>
>> This is specially the case with continuous time-stamping counters.
>> They can provide a precise number by applying statistical methods on
>> many measurements done during one second but they can not provide
>> information exactly at the end of a second.
>> Is this kind of statistical measurement over a period of a second
>> still valid for determining the ADEV at the Tau of one second of a
>> frequency source?
> Not for ADEV, but if you use averaging counter you get the result of
> MDEV and for linear regression / least square counter you get the
> response of PDEV. That is the result of various statistical measures and
> then applying the ADEV processing on these frequency estimates. The
> upcoming IEEE Std 1139 revision, which is in approval process now
> include language to reflect that.
>> Or should there be a correction factor depending on the method used in
>> the frequency counter?
>
> Yes, you then need to use the appropriate bias function for ADEV/MDEV
> and ADEV/PDEV to convert between these scales. Knowing the response of
> ADEV, MDEV and PDEV for a particular noise-type which is dominant at the
> tau of interest, you can readily convert between them by forming the
> bias functions.
>
> You may find NIST SP-1065 a useful and handy tool, even if it does not
> cover the more recent work such as PDEV.
>
> https://www.nist.gov/publications/handbook-frequency-stability-analysis
>
>> I tried to read some scientific studies on this subject but I am not
>> smart enough to understand.
>> Hope one of you can provide some information.
>
> It is scattered over a large number of articles, and quite a lot of
> folks get confused. Hopefully the updated IEEE Std 1139 will be of aid
> to you. It also has lots of useful references.
>
> Cheers,
> Magnus
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
> send an email to time-nuts-leave@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
>
MD
Magnus Danielson
Wed, Nov 10, 2021 8:10 AM
Rick,
"continuous count" as in counting/time-stamping each individual cycle
forms a sample-rate limit. However, this is not what is meant with
continuous conting today, as that is that you have a continuous
time-stamping for some time-base. In that some number of counted cycle
(+/- 1) occurs between each time-stamp. Unless one attempts to use
time-base very near the maximum sample rate per second, it cease to be a
practical concern as one does not want to miss samples.
I have a counter that can time-stamp at 10 MSa/s and 13.333 MSa/s
depending on mode. I extremely rarely use that even close to the
extreme, as continuous counting I normally need is maybe up to 100 Sa/s.
Cheers,
Magnus
On 2021-11-10 01:53, Richard (Rick) Karlquist wrote:
Let me just mention that when I worked at the HP Santa Clara
Division counters section, they came out with a "feature"
that they called "continuous count". However, it was limited
to something like 3 MHz. So a 100 MHz counter would only
continuously count signals below 3 MHz.
So you need to verify for what bandwidth your specific counter
model is truly doing continuous count.
Rick N6RK
On 11/9/2021 2:29 PM, Magnus Danielson via time-nuts wrote:
Hi Erik,
On 2021-11-09 18:26, Erik Kaashoek wrote:
As far as I understood the ADEV at a Tau of 1 second is a statement
about the amount of variation to be expected over a one second
interval.
Rather, the variation of readings of a frequency estimation done over
a span over 1 second.
It would be nice if we would be able to measure a frequency in an
infinite short interval but any frequency measurement takes time.
Turn out that basic white noise and systematic noise will limit our
frequency resolution to form a 1/tau limit slope, so infinite short
interval will bury it well into that noise whatever we do.
What if the frequency counter does a complete measurement of a
frequency source every second and all the variation within that
second is hidden because of the "integration" that happens over the
second?
That is what happens, but that is not what the ADEV is about, it's
about the variations of these measures as we look for a bunch of
them. So if we now have say 1000 of these frequency estimates, how
much variations in these can be contributed to the random noise of
the source, and to analyse that, we need at least a tool like ADEV
since standard deviation will not even converge for white and flicker
phase noise modulation.
What ADEV actually aims to do is to provide a low-frequency
spectroscopy method at a time when time-interval counters was about
the only tool at hand, and even those where very rare. We now have a
much wider palette of tools, but ADEV is relevant for how we measure
frequency stability and a few other applications.
This is specially the case with continuous time-stamping counters.
They can provide a precise number by applying statistical methods on
many measurements done during one second but they can not provide
information exactly at the end of a second.
Is this kind of statistical measurement over a period of a second
still valid for determining the ADEV at the Tau of one second of a
frequency source?
Not for ADEV, but if you use averaging counter you get the result of
MDEV and for linear regression / least square counter you get the
response of PDEV. That is the result of various statistical measures
and then applying the ADEV processing on these frequency estimates.
The upcoming IEEE Std 1139 revision, which is in approval process now
include language to reflect that.
Or should there be a correction factor depending on the method used
in the frequency counter?
Yes, you then need to use the appropriate bias function for ADEV/MDEV
and ADEV/PDEV to convert between these scales. Knowing the response
of ADEV, MDEV and PDEV for a particular noise-type which is dominant
at the tau of interest, you can readily convert between them by
forming the bias functions.
You may find NIST SP-1065 a useful and handy tool, even if it does
not cover the more recent work such as PDEV.
https://www.nist.gov/publications/handbook-frequency-stability-analysis
I tried to read some scientific studies on this subject but I am not
smart enough to understand.
Hope one of you can provide some information.
It is scattered over a large number of articles, and quite a lot of
folks get confused. Hopefully the updated IEEE Std 1139 will be of
aid to you. It also has lots of useful references.
Cheers,
Magnus
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.
Rick,
"continuous count" as in counting/time-stamping each individual cycle
forms a sample-rate limit. However, this is not what is meant with
continuous conting today, as that is that you have a continuous
time-stamping for some time-base. In that some number of counted cycle
(+/- 1) occurs between each time-stamp. Unless one attempts to use
time-base very near the maximum sample rate per second, it cease to be a
practical concern as one does not want to miss samples.
I have a counter that can time-stamp at 10 MSa/s and 13.333 MSa/s
depending on mode. I extremely rarely use that even close to the
extreme, as continuous counting I normally need is maybe up to 100 Sa/s.
Cheers,
Magnus
On 2021-11-10 01:53, Richard (Rick) Karlquist wrote:
> Let me just mention that when I worked at the HP Santa Clara
> Division counters section, they came out with a "feature"
> that they called "continuous count". However, it was limited
> to something like 3 MHz. So a 100 MHz counter would only
> continuously count signals below 3 MHz.
>
> So you need to verify for what bandwidth your specific counter
> model is truly doing continuous count.
>
> Rick N6RK
>
> On 11/9/2021 2:29 PM, Magnus Danielson via time-nuts wrote:
>> Hi Erik,
>>
>> On 2021-11-09 18:26, Erik Kaashoek wrote:
>>> As far as I understood the ADEV at a Tau of 1 second is a statement
>>> about the amount of variation to be expected over a one second
>>> interval.
>> Rather, the variation of readings of a frequency estimation done over
>> a span over 1 second.
>>> It would be nice if we would be able to measure a frequency in an
>>> infinite short interval but any frequency measurement takes time.
>> Turn out that basic white noise and systematic noise will limit our
>> frequency resolution to form a 1/tau limit slope, so infinite short
>> interval will bury it well into that noise whatever we do.
>>> What if the frequency counter does a complete measurement of a
>>> frequency source every second and all the variation within that
>>> second is hidden because of the "integration" that happens over the
>>> second?
>>
>> That is what happens, but that is not what the ADEV is about, it's
>> about the variations of these measures as we look for a bunch of
>> them. So if we now have say 1000 of these frequency estimates, how
>> much variations in these can be contributed to the random noise of
>> the source, and to analyse that, we need at least a tool like ADEV
>> since standard deviation will not even converge for white and flicker
>> phase noise modulation.
>>
>> What ADEV actually aims to do is to provide a low-frequency
>> spectroscopy method at a time when time-interval counters was about
>> the only tool at hand, and even those where very rare. We now have a
>> much wider palette of tools, but ADEV is relevant for how we measure
>> frequency stability and a few other applications.
>>
>>> This is specially the case with continuous time-stamping counters.
>>> They can provide a precise number by applying statistical methods on
>>> many measurements done during one second but they can not provide
>>> information exactly at the end of a second.
>>> Is this kind of statistical measurement over a period of a second
>>> still valid for determining the ADEV at the Tau of one second of a
>>> frequency source?
>> Not for ADEV, but if you use averaging counter you get the result of
>> MDEV and for linear regression / least square counter you get the
>> response of PDEV. That is the result of various statistical measures
>> and then applying the ADEV processing on these frequency estimates.
>> The upcoming IEEE Std 1139 revision, which is in approval process now
>> include language to reflect that.
>>> Or should there be a correction factor depending on the method used
>>> in the frequency counter?
>>
>> Yes, you then need to use the appropriate bias function for ADEV/MDEV
>> and ADEV/PDEV to convert between these scales. Knowing the response
>> of ADEV, MDEV and PDEV for a particular noise-type which is dominant
>> at the tau of interest, you can readily convert between them by
>> forming the bias functions.
>>
>> You may find NIST SP-1065 a useful and handy tool, even if it does
>> not cover the more recent work such as PDEV.
>>
>> https://www.nist.gov/publications/handbook-frequency-stability-analysis
>>
>>> I tried to read some scientific studies on this subject but I am not
>>> smart enough to understand.
>>> Hope one of you can provide some information.
>>
>> It is scattered over a large number of articles, and quite a lot of
>> folks get confused. Hopefully the updated IEEE Std 1139 will be of
>> aid to you. It also has lots of useful references.
>>
>> Cheers,
>> Magnus
>> _______________________________________________
>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
>> send an email to time-nuts-leave@lists.febo.com
>> To unsubscribe, go to and follow the instructions there.
>>
R(
Richard (Rick) Karlquist
Wed, Nov 10, 2021 10:40 PM
I am looking for help choosing a potting compound that
has the following properties:
- Good for 5,000VAC @ 1 MHz
- Low RF losses.
- Low permittivity is preferred
- Low tempco of permittivity is a want.
- Something I can implement in my home shop
without access to a vacuum pump etc. is a want.
Thanks in advance
Rick Karlquist N6RK
I am looking for help choosing a potting compound that
has the following properties:
1. Good for 5,000VAC @ 1 MHz
2. Low RF losses.
3. Low permittivity is preferred
4. Low tempco of permittivity is a want.
5. Something I can implement in my home shop
without access to a vacuum pump etc. is a want.
Thanks in advance
Rick Karlquist N6RK
LJ
Lux, Jim
Thu, Nov 11, 2021 12:32 AM
On 11/10/21 2:40 PM, Richard (Rick) Karlquist wrote:
I am looking for help choosing a potting compound that
has the following properties:
1. Good for 5,000VAC @ 1 MHz
2. Low RF losses.
3. Low permittivity is preferred
4. Low tempco of permittivity is a want.
5. Something I can implement in my home shop
without access to a vacuum pump etc. is a want.
What about curing? Is temperature cure (put it in an oven) ok? or do you
need room temp cure?
Silicones are usually pretty good, RF wise. But you need to check the
filler and exact composition.
I found a two component silicone that has epsilon 2.5 used for RF
potting, 15kV/mm breakdown.
https://vitrochem.com/wordpress/wp-content/uploads/2020/10/Two-Component-Condensation-Silicone.pdf
they say nothing about the dissipation.
Aha. RTV12 from Momentive - clear - epsilon 3.0, tan d (at 1kHz) is
0.001, 400 V/mil - This stuff is pretty common, but I can't find any
higher frequency permittivity info, which is odd. Someone somewhere
probably built something and measured it.
Diallyl Pthalate is what they use in connectors - it's a thermosetting
resin with good electrical properties.
https://www.cosmicplastics.com/products/dap/
Picking the first one in the list 224 DAP - 360 V/mil, so for your 5kV,
you'd need ~14 mils. (most plastics are in this range)
Epsilon is kind of high 3.5, tan D is 0.01? Is that good enough for you
dissipation wise? There's lots of kinds with various fillers.
A common way to reduce epsilon and tan d is to mix in microspheres.
Some epoxies are also good. Rogers not only makes laminates for
circuitboards they also produce the epoxy from which they are made
We use tons of arathane and solithane at JPL (both are urethanes), but I
don't know if we pot RF circuits in araldite. Huntsman makes the
"ara???" materials
https://huntsman-pimcore.equisolve-dev.com/Documents/US_2019_High_Performance_Components_Selector_Guide.pdf
one thing is that we store this stuff at -80C, but I don't know if
that's after mixing or if it's shipped that way (in dry ice).
masterbond.com -> give them a call or email
EP110F80-1 is a 2 part epoxy with e=2.69@1MHz, so it's probably
reasonably low loss.
On 11/10/21 2:40 PM, Richard (Rick) Karlquist wrote:
> I am looking for help choosing a potting compound that
> has the following properties:
>
> 1. Good for 5,000VAC @ 1 MHz
> 2. Low RF losses.
> 3. Low permittivity is preferred
> 4. Low tempco of permittivity is a want.
> 5. Something I can implement in my home shop
> without access to a vacuum pump etc. is a want.
What about curing? Is temperature cure (put it in an oven) ok? or do you
need room temp cure?
Silicones are usually pretty good, RF wise. But you need to check the
filler and exact composition.
I found a two component silicone that has epsilon 2.5 used for RF
potting, 15kV/mm breakdown.
https://vitrochem.com/wordpress/wp-content/uploads/2020/10/Two-Component-Condensation-Silicone.pdf
they say nothing about the dissipation.
Aha. RTV12 from Momentive - clear - epsilon 3.0, tan d (at 1kHz) is
0.001, 400 V/mil - This stuff is pretty common, but I can't find any
higher frequency permittivity info, which is odd. Someone somewhere
probably built something and measured it.
Diallyl Pthalate is what they use in connectors - it's a thermosetting
resin with good electrical properties.
https://www.cosmicplastics.com/products/dap/
Picking the first one in the list 224 DAP - 360 V/mil, so for your 5kV,
you'd need ~14 mils. (most plastics are in this range)
Epsilon is kind of high 3.5, tan D is 0.01? Is that good enough for you
dissipation wise? There's lots of kinds with various fillers.
A common way to reduce epsilon and tan d is to mix in microspheres.
Some epoxies are also good. Rogers not only makes laminates for
circuitboards they also produce the epoxy from which they are made
We use tons of arathane and solithane at JPL (both are urethanes), but I
don't know if we pot RF circuits in araldite. Huntsman makes the
"ara???" materials
https://huntsman-pimcore.equisolve-dev.com/Documents/US_2019_High_Performance_Components_Selector_Guide.pdf
one thing is that we store this stuff at -80C, but I don't know if
that's after mixing or if it's shipped that way (in dry ice).
masterbond.com -> give them a call or email
EP110F80-1 is a 2 part epoxy with e=2.69@1MHz, so it's probably
reasonably low loss.
BC
Brooke Clarke
Thu, Nov 11, 2021 12:37 AM
Hi Jim:
Be careful with RTVs. Some out gas acid that attacks metal, even gold plated metal. Guess how I know that.
--
Have Fun,
Brooke Clarke
https://www.PRC68.com
axioms:
- The extent to which you can fix or improve something will be limited by how well you understand how it works.
- Everybody, with no exceptions, holds false beliefs.
-------- Original Message --------
On 11/10/21 2:40 PM, Richard (Rick) Karlquist wrote:
I am looking for help choosing a potting compound that
has the following properties:
1. Good for 5,000VAC @ 1 MHz
2. Low RF losses.
3. Low permittivity is preferred
4. Low tempco of permittivity is a want.
5. Something I can implement in my home shop
without access to a vacuum pump etc. is a want.
What about curing? Is temperature cure (put it in an oven) ok? or do you need room temp cure?
Silicones are usually pretty good, RF wise. But you need to check the filler and exact composition.
I found a two component silicone that has epsilon 2.5 used for RF potting, 15kV/mm breakdown.
https://vitrochem.com/wordpress/wp-content/uploads/2020/10/Two-Component-Condensation-Silicone.pdf
they say nothing about the dissipation.
Aha. RTV12 from Momentive - clear - epsilon 3.0, tan d (at 1kHz) is 0.001, 400 V/mil - This stuff is pretty common,
but I can't find any higher frequency permittivity info, which is odd. Someone somewhere probably built something and
measured it.
Diallyl Pthalate is what they use in connectors - it's a thermosetting resin with good electrical properties.
https://www.cosmicplastics.com/products/dap/
Picking the first one in the list 224 DAP - 360 V/mil, so for your 5kV, you'd need ~14 mils. (most plastics are in
this range)
Epsilon is kind of high 3.5, tan D is 0.01? Is that good enough for you dissipation wise? There's lots of kinds with
various fillers.
A common way to reduce epsilon and tan d is to mix in microspheres.
Some epoxies are also good. Rogers not only makes laminates for circuitboards they also produce the epoxy from which
they are made
We use tons of arathane and solithane at JPL (both are urethanes), but I don't know if we pot RF circuits in araldite.
Huntsman makes the "ara???" materials
https://huntsman-pimcore.equisolve-dev.com/Documents/US_2019_High_Performance_Components_Selector_Guide.pdf
one thing is that we store this stuff at -80C, but I don't know if that's after mixing or if it's shipped that way (in
dry ice).
masterbond.com -> give them a call or email
EP110F80-1 is a 2 part epoxy with e=2.69@1MHz, so it's probably reasonably low loss.
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.
Hi Jim:
Be careful with RTVs. Some out gas acid that attacks metal, even gold plated metal. Guess how I know that.
--
Have Fun,
Brooke Clarke
https://www.PRC68.com
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
-------- Original Message --------
> On 11/10/21 2:40 PM, Richard (Rick) Karlquist wrote:
>> I am looking for help choosing a potting compound that
>> has the following properties:
>>
>> 1. Good for 5,000VAC @ 1 MHz
>> 2. Low RF losses.
>> 3. Low permittivity is preferred
>> 4. Low tempco of permittivity is a want.
>> 5. Something I can implement in my home shop
>> without access to a vacuum pump etc. is a want.
>
> What about curing? Is temperature cure (put it in an oven) ok? or do you need room temp cure?
>
>
> Silicones are usually pretty good, RF wise. But you need to check the filler and exact composition.
>
> I found a two component silicone that has epsilon 2.5 used for RF potting, 15kV/mm breakdown.
>
> https://vitrochem.com/wordpress/wp-content/uploads/2020/10/Two-Component-Condensation-Silicone.pdf
>
> they say nothing about the dissipation.
>
>
> Aha. RTV12 from Momentive - clear - epsilon 3.0, tan d (at 1kHz) is 0.001, 400 V/mil - This stuff is pretty common,
> but I can't find any higher frequency permittivity info, which is odd. Someone somewhere probably built something and
> measured it.
>
>
> Diallyl Pthalate is what they use in connectors - it's a thermosetting resin with good electrical properties.
>
> https://www.cosmicplastics.com/products/dap/
>
> Picking the first one in the list 224 DAP - 360 V/mil, so for your 5kV, you'd need ~14 mils. (most plastics are in
> this range)
>
> Epsilon is kind of high 3.5, tan D is 0.01? Is that good enough for you dissipation wise? There's lots of kinds with
> various fillers.
>
> A common way to reduce epsilon and tan d is to mix in microspheres.
>
>
> Some epoxies are also good. Rogers not only makes laminates for circuitboards they also produce the epoxy from which
> they are made
>
>
> We use tons of arathane and solithane at JPL (both are urethanes), but I don't know if we pot RF circuits in araldite.
> Huntsman makes the "ara???" materials
>
> https://huntsman-pimcore.equisolve-dev.com/Documents/US_2019_High_Performance_Components_Selector_Guide.pdf
>
> one thing is that we store this stuff at -80C, but I don't know if that's after mixing or if it's shipped that way (in
> dry ice).
>
> masterbond.com -> give them a call or email
>
> EP110F80-1 is a 2 part epoxy with e=2.69@1MHz, so it's probably reasonably low loss.
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
LJ
Lux, Jim
Thu, Nov 11, 2021 12:38 AM
On 11/10/21 4:37 PM, Brooke Clarke via time-nuts wrote:
Hi Jim:
Be careful with RTVs. Some out gas acid that attacks metal, even gold
plated metal. Guess how I know that.
Oh yes.. one definitely needs to read the data sheets.. RTV12 is 2
part. Most 2 part RTVs don't use acid. And the one part that cure in
an oven at 70C, likewise.
On 11/10/21 4:37 PM, Brooke Clarke via time-nuts wrote:
> Hi Jim:
>
> Be careful with RTVs. Some out gas acid that attacks metal, even gold
> plated metal. Guess how I know that.
>
Oh yes.. one definitely needs to read the data sheets.. RTV12 is 2
part. Most 2 part RTVs don't use acid. And the one part that cure in
an oven at 70C, likewise.
