Short term 10MHz source
Lady Heather has a TICC tuning feature (&a keyboard command) that sets the channel offset, etc values. You connect a 1PPS input to both channels via matched cables and a "T" adapter. Heather calculates and sets various parameters.
And as far as decimating the TICC output values in firmware... please don't. Let the user decimate the values if they want to.
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes, where
one in ten was taken. Now OK, you can argue this until the cows come home,
but the result is that the meaning isn't crystal clear, and particularly on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
Truncate, to me at least, means to shorten : ie to remove some precision by
rounding off lower bits.
I agree that the source of the word 'decimate' is unclear, but I think,
within the field of DSP, it has a reasonably precise definition whether or
not that corresponds with wider usage or derivation.
On Thu, Jan 10, 2019 at 12:02 PM Peter Vince petervince1952@gmail.com
wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes, where
one in ten was taken. Now OK, you can argue this until the cows come home,
but the result is that the meaning isn't crystal clear, and particularly on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
I was moved to check on the terms "decimate" and "downsample" to see what
their
relative meanings are, and was disappointed to see that they are virtually
the same.
Perhaps Tom would be willing to discuss this point and suggest meanings to
be used
in this group.
Dana
On Thu, Jan 10, 2019 at 6:13 AM Adrian Godwin artgodwin@gmail.com wrote:
Truncate, to me at least, means to shorten : ie to remove some precision by
rounding off lower bits.
I agree that the source of the word 'decimate' is unclear, but I think,
within the field of DSP, it has a reasonably precise definition whether or
not that corresponds with wider usage or derivation.
On Thu, Jan 10, 2019 at 12:02 PM Peter Vince petervince1952@gmail.com
wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and particularly
on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
time-nuts mailing list -- time-nuts@lists.febo.com
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and follow the instructions there.
And just to clarify the subject matter -- the TICC data output contains 12 decimal places, i.e., 1 ps precision. The actual resolution is about 55 ps, so the last digit is pure noise, and the penultimate digit should really be either 5 or 0.
To eliminate the distraction of the noise, It's under consideration to zero the last decimal place, and maybe to round to 50 ps. I think the last digit is a no-brainer, but am more hesitant about the rounding.
Coming soon to a git near you...
On Jan 10, 2019, 7:13 AM, at 7:13 AM, Adrian Godwin artgodwin@gmail.com wrote:
Truncate, to me at least, means to shorten : ie to remove some
precision by
rounding off lower bits.
I agree that the source of the word 'decimate' is unclear, but I think,
within the field of DSP, it has a reasonably precise definition whether
or
not that corresponds with wider usage or derivation.
On Thu, Jan 10, 2019 at 12:02 PM Peter Vince petervince1952@gmail.com
wrote:
In his comment below, Mark has used the word "decimate". There is
much
debate about what this word means (presently, and/or in the past),
but
common explanations refer back to Roman times when they apparently
killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and
particularly on
a technical forum where precision is paramount, and the entire reason
we
are here, I believe accuracy and clarity of expression is also
important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware...
please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
Peter,
While the word derives back to the Roman times, today it is a technical
term for data-reduction being used in professional literature, so it's
meaning has already been established.
For instance, in modern phase-noise measurement setups the sample-rate
is around 100 MS/s, and that sample-rate of multiple ADCs with
relatively high amounts of bits is way to high to hand over to software,
so it is decimated down in steps in FPGA before handing over to
software. Decimation is the term used in that context.
Cheers,
Magnus
On 2019-01-10 13:01, Peter Vince wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes, where
one in ten was taken. Now OK, you can argue this until the cows come home,
but the result is that the meaning isn't crystal clear, and particularly on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Thank you for your reply Magnus. Could you please clarify then exactly
what "decimate" means in this context. Is it "truncation", i.e.
eliminating or ignoring the last few digits, be they decimal or binary?
And/or is there some rounding involved?
Peter
On Thu, 10 Jan 2019 at 13:01, Magnus Danielson magnus@rubidium.se wrote:
Peter,
While the word derives back to the Roman times, today it is a technical
term for data-reduction being used in professional literature, so it's
meaning has already been established.
For instance, in modern phase-noise measurement setups the sample-rate
is around 100 MS/s, and that sample-rate of multiple ADCs with
relatively high amounts of bits is way to high to hand over to software,
so it is decimated down in steps in FPGA before handing over to
software. Decimation is the term used in that context.
Cheers,
Magnus
On 2019-01-10 13:01, Peter Vince wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and particularly
on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
In digital filtering, decimation is a reduction of sample rate,
truncation is a reduction of precision. Interpolation can refer to
either of the opposite processes. The terms downsampling and upsampling
can be used to avoid confusion with regards to sample rate. I am trying
to come up with an adequate term for improving precision. Averaging is
one form, but not inclusive.
David N1HAC
On 1/10/19 7:59 AM, Magnus Danielson wrote:
Peter,
While the word derives back to the Roman times, today it is a
technical term for data-reduction being used in professional
literature, so it's meaning has already been established.
For instance, in modern phase-noise measurement setups the sample-rate
is around 100 MS/s, and that sample-rate of multiple ADCs with
relatively high amounts of bits is way to high to hand over to
software, so it is decimated down in steps in FPGA before handing over
to software. Decimation is the term used in that context.
Cheers,
Magnus
On 2019-01-10 13:01, Peter Vince wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently
killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and
particularly on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also
important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
Peter,
No, it's not truncation per se.
Let's say you have 100 samples. With a 10-to-1 decimation you reduce
them into 10 samples in whatever method maintaining the core value
(phase for instance). As you do that, you get more and more bits as
these is combined. For larger decimation ratios (often hierarchially)
you end up having so many bits that eventually you also truncate the
lower parts, but that is something you would try to avoid when you can.
I hope that clarifies it for you.
I am in a meeting now, so that is why I am brief.
Cheers,
Magnus - at IFCS2019 JTPC working for Group 2
On 2019-01-10 14:12, Peter Vince wrote:
Thank you for your reply Magnus. Could you please clarify then exactly
what "decimate" means in this context. Is it "truncation", i.e.
eliminating or ignoring the last few digits, be they decimal or binary?
And/or is there some rounding involved?
Peter
On Thu, 10 Jan 2019 at 13:01, Magnus Danielson magnus@rubidium.se wrote:
Peter,
While the word derives back to the Roman times, today it is a technical
term for data-reduction being used in professional literature, so it's
meaning has already been established.
For instance, in modern phase-noise measurement setups the sample-rate
is around 100 MS/s, and that sample-rate of multiple ADCs with
relatively high amounts of bits is way to high to hand over to software,
so it is decimated down in steps in FPGA before handing over to
software. Decimation is the term used in that context.
Cheers,
Magnus
On 2019-01-10 13:01, Peter Vince wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and particularly
on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
This is not misuse. Everyone in signal processing knows what decimation
means in this context.
I pulled out one of my older signal processing books - Gold and Rader,
"Digital Processing Of Signals", 1969 - and Decimation is used in several
places exactly as we use it today.
I looked in some of my non-digital signal processing and older books, like
MIT Rad Lab series, and don't see the term used, but I know that I heard
old-timers using decimation used in automatic analog signal processing
especially with regard to "zooming out" on a spectrum analyzer or
pinball-style pulse-height analyzer (often the knobs gave you only factors
of ten).
Tim N3QE
On Thu, Jan 10, 2019 at 7:02 AM Peter Vince petervince1952@gmail.com
wrote:
In his comment below, Mark has used the word "decimate". There is much
debate about what this word means (presently, and/or in the past), but
common explanations refer back to Roman times when they apparently killed
one person in ten as a punishment, and similarly "tithes" - or taxes, where
one in ten was taken. Now OK, you can argue this until the cows come home,
but the result is that the meaning isn't crystal clear, and particularly on
a technical forum where precision is paramount, and the entire reason we
are here, I believe accuracy and clarity of expression is also important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware... please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Hi
Pretty much every DVM out there spits out more digits than make sense accuracy wise. It
certainly makes sense to note in the doc’s what the accuracy / resolution of the device is.
Keeping the extra digit does not cost anything in this case. It might come in useful if somebody
spent the time to work out how to phase modulate the reference to “fill in the gaps”. As
Magnus has noted in the past, HP did this on real world counters once upon a time….
Bob
On Jan 10, 2019, at 7:54 AM, John Ackermann. N8UR jra@febo.com wrote:
And just to clarify the subject matter -- the TICC data output contains 12 decimal places, i.e., 1 ps precision. The actual resolution is about 55 ps, so the last digit is pure noise, and the penultimate digit should really be either 5 or 0.
To eliminate the distraction of the noise, It's under consideration to zero the last decimal place, and maybe to round to 50 ps. I think the last digit is a no-brainer, but am more hesitant about the rounding.
Coming soon to a git near you...
On Jan 10, 2019, 7:13 AM, at 7:13 AM, Adrian Godwin artgodwin@gmail.com wrote:
Truncate, to me at least, means to shorten : ie to remove some
precision by
rounding off lower bits.
I agree that the source of the word 'decimate' is unclear, but I think,
within the field of DSP, it has a reasonably precise definition whether
or
not that corresponds with wider usage or derivation.
On Thu, Jan 10, 2019 at 12:02 PM Peter Vince petervince1952@gmail.com
wrote:
In his comment below, Mark has used the word "decimate". There is
much
debate about what this word means (presently, and/or in the past),
but
common explanations refer back to Roman times when they apparently
killed
one person in ten as a punishment, and similarly "tithes" - or taxes,
where
one in ten was taken. Now OK, you can argue this until the cows come
home,
but the result is that the meaning isn't crystal clear, and
particularly on
a technical forum where precision is paramount, and the entire reason
we
are here, I believe accuracy and clarity of expression is also
important.
In this instance, I believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com wrote:
...
And as far as decimating the TICC output values in firmware...
please
don't. Let the user decimate the values if they want to.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
Thank you all!
Peter
There is a reason dictionaries supply multiple definitions to words
and it's not surprising that some engineer or scientist chose the
most common meaning of decimate in coining the name decimation
filter. I must admit it bugs me as well when the decimate is
equated with slaughter.
The meaning of words can evolve over time.
Washington DC had (has?) a radio station called WGAY back in the
seventies. The the meaning of the word gay evolved since those call
letters were first assigned. Interestingly the station formats
evolved with the word.
http://beautifulmusicradio.blogspot.com/2013/01/wgay-and-wqmr-washingtons-quality-music.html
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out
the Websters Unabridged Dictionary, and forced me to read the
definition of the word philistine in front of the group.
Fortunately, there were many entries under the word and I chose "a
native of Philistia" to read out loud. The moral is words can have
many meanings and, more importantly, don't make fun of Einstein
around German Physicists.
Bob Martin
On 1/10/2019 6:58 AM, Tim Shoppa wrote:
This is not misuse. Everyone in signal processing knows what
decimation means in this context.
I pulled out one of my older signal processing books - Gold and
Rader, "Digital Processing Of Signals", 1969 - and Decimation is
used in several places exactly as we use it today.
I looked in some of my non-digital signal processing and older
books, like MIT Rad Lab series, and don't see the term used, but
I know that I heard old-timers using decimation used in automatic
analog signal processing especially with regard to "zooming out"
on a spectrum analyzer or pinball-style pulse-height analyzer
(often the knobs gave you only factors of ten).
Tim N3QE
On Thu, Jan 10, 2019 at 7:02 AM Peter Vince
petervince1952@gmail.com wrote:
In his comment below, Mark has used the word "decimate". There
is much debate about what this word means (presently, and/or in
the past), but common explanations refer back to Roman times
when they apparently killed one person in ten as a punishment,
and similarly "tithes" - or taxes, where one in ten was taken.
Now OK, you can argue this until the cows come home, but the
result is that the meaning isn't crystal clear, and
particularly on a technical forum where precision is paramount,
and the entire reason we are here, I believe accuracy and
clarity of expression is also important. In this instance, I
believe "truncate" would be a better word.
</rant> :-)
Regards,
Peter Vince
On Wed, 9 Jan 2019 at 23:56, Mark Sims holrum@hotmail.com
wrote:
... And as far as decimating the TICC output values in
firmware... please
don't. Let the user decimate the values if they want to.
_______________________________________________ time-nuts
mailing list -- time-nuts@lists.febo.com To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________ time-nuts mailing
list -- time-nuts@lists.febo.com To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Am 10.01.19 um 17:33 schrieb Bob Martin:
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out the
Websters Unabridged Dictionary, and forced me to read the definition
of the word philistine in front of the group. Fortunately, there were
many entries under the word and I chose "a native of Philistia" to
read out loud. The moral is words can have many meanings and, more
importantly, don't make fun of Einstein
around German Physicists.
I wonder if Howard even understood the intended pun.
Stein means stone, nothing else. I have seen/heard it used in the
sense of a "mug for beer" only by Americans. The closest
German word would be Steinkrug, but only if you want to
emphasize that the Krug is made of ceramics and not of glass.
Decimation apart of the Roman sense for me is only throwing away samples,
and the need for filtering goes with it even without explicitly saying.
Cheers, Gerhard
In his comment below, Mark has used the word "decimate".
I contacted Mark about this as soon as he posted yesterday. It turns out he did not mean decimate. It's just the word he accidentally chose. He was offering an opinion on precision or resolution; not decimation.
Decimation involves a reduction in the number of samples; a lowering of the sample rate.
The discussion is about improving TICC resolution. You might think "the more digits the better". If 10 is good, turn it up to 11, or 12, or maybe even 15 (as a Bob special). But it turns out it's more complicated than that in the case of the TICC. More digits isn't always better. I'll explain in detail later.
Meanwhile, don't let this decimate thread go too far. It's not what Mark meant. Treat it more like a typo than a manifesto.
/tvb
I'm confused...
I see two separate cases here:
Case A: you simply throw away samples, keeping only every nth sample,
without
regard for the frequency content of the original signal.
Case B: you first perform appropriate anti-aliasing filtering on the
original signal, and
only then throw away all but every nth sample>
Which casee are we talking about when we use the word "decimate"? And
then what
is the correct terminology for the other case? Inquiring minds really
want to know...
Dana
On Thu, Jan 10, 2019 at 11:49 AM Gerhard Hoffmann dk4xp@arcor.de wrote:
Am 10.01.19 um 17:33 schrieb Bob Martin:
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out the
Websters Unabridged Dictionary, and forced me to read the definition
of the word philistine in front of the group. Fortunately, there were
many entries under the word and I chose "a native of Philistia" to
read out loud. The moral is words can have many meanings and, more
importantly, don't make fun of Einstein
around German Physicists.
I wonder if Howard even understood the intended pun.
Stein means stone, nothing else. I have seen/heard it used in the
sense of a "mug for beer" only by Americans. The closest
German word would be Steinkrug, but only if you want to
emphasize that the Krug is made of ceramics and not of glass.
Decimation apart of the Roman sense for me is only throwing away samples,
and the need for filtering goes with it even without explicitly saying.
Cheers, Gerhard
time-nuts mailing list -- time-nuts@lists.febo.com
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and follow the instructions there.
Dana,
Case B is what is typically what is intended. Exactly what manifests the
processing varies.
Cheers,
Magnus
On 2019-01-10 19:24, Dana Whitlow wrote:
I'm confused...
I see two separate cases here:
Case A: you simply throw away samples, keeping only every nth sample,
without
regard for the frequency content of the original signal.
Case B: you first perform appropriate anti-aliasing filtering on the
original signal, and
only then throw away all but every nth sample>
Which casee are we talking about when we use the word "decimate"? And
then what
is the correct terminology for the other case? Inquiring minds really
want to know...
Dana
On Thu, Jan 10, 2019 at 11:49 AM Gerhard Hoffmann dk4xp@arcor.de wrote:
Am 10.01.19 um 17:33 schrieb Bob Martin:
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out the
Websters Unabridged Dictionary, and forced me to read the definition
of the word philistine in front of the group. Fortunately, there were
many entries under the word and I chose "a native of Philistia" to
read out loud. The moral is words can have many meanings and, more
importantly, don't make fun of Einstein
around German Physicists.
I wonder if Howard even understood the intended pun.
Stein means stone, nothing else. I have seen/heard it used in the
sense of a "mug for beer" only by Americans. The closest
German word would be Steinkrug, but only if you want to
emphasize that the Krug is made of ceramics and not of glass.
Decimation apart of the Roman sense for me is only throwing away samples,
and the need for filtering goes with it even without explicitly saying.
Cheers, Gerhard
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Hi
In the case of most typical downconversion setups, the samples are tossed out
by the filter. If you put 1,000 samples into a CIC decimator and it is a 1000:1 device,
only one sample comes out. I signal processing it is called a decimator none the less.
Bob
On Jan 10, 2019, at 1:24 PM, Dana Whitlow k8yumdoober@gmail.com wrote:
I'm confused...
I see two separate cases here:
Case A: you simply throw away samples, keeping only every nth sample,
without
regard for the frequency content of the original signal.
Case B: you first perform appropriate anti-aliasing filtering on the
original signal, and
only then throw away all but every nth sample>
Which casee are we talking about when we use the word "decimate"? And
then what
is the correct terminology for the other case? Inquiring minds really
want to know...
Dana
On Thu, Jan 10, 2019 at 11:49 AM Gerhard Hoffmann dk4xp@arcor.de wrote:
Am 10.01.19 um 17:33 schrieb Bob Martin:
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out the
Websters Unabridged Dictionary, and forced me to read the definition
of the word philistine in front of the group. Fortunately, there were
many entries under the word and I chose "a native of Philistia" to
read out loud. The moral is words can have many meanings and, more
importantly, don't make fun of Einstein
around German Physicists.
I wonder if Howard even understood the intended pun.
Stein means stone, nothing else. I have seen/heard it used in the
sense of a "mug for beer" only by Americans. The closest
German word would be Steinkrug, but only if you want to
emphasize that the Krug is made of ceramics and not of glass.
Decimation apart of the Roman sense for me is only throwing away samples,
and the need for filtering goes with it even without explicitly saying.
Cheers, Gerhard
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Hi
Separate reply because it is a very different case:
If you are doing ADEV for longer tau, you do indeed use case A. You simply throw
away 9 out of 10 samples when going from 1 second tau to 10 seconds. There are
a number of papers out there on just why this is the correct thing to do in this case.
Bob
On Jan 10, 2019, at 1:24 PM, Dana Whitlow k8yumdoober@gmail.com wrote:
I'm confused...
I see two separate cases here:
Case A: you simply throw away samples, keeping only every nth sample,
without
regard for the frequency content of the original signal.
Case B: you first perform appropriate anti-aliasing filtering on the
original signal, and
only then throw away all but every nth sample>
Which casee are we talking about when we use the word "decimate"? And
then what
is the correct terminology for the other case? Inquiring minds really
want to know...
Dana
On Thu, Jan 10, 2019 at 11:49 AM Gerhard Hoffmann dk4xp@arcor.de wrote:
Am 10.01.19 um 17:33 schrieb Bob Martin:
Back in those same seventies, I was working for an army lab (Harry
Diamond Labs) as a summer student. I saw a picture in a lab supply
catalog of a (ein) stein of beer. I tore it out and taped it over a
picture off Albert Einstein that a German physicist, Howard Brandt,
had on the wall over his desk. This was a bad idea. Howard was so
incensed that he called the whole department together, hauled out the
Websters Unabridged Dictionary, and forced me to read the definition
of the word philistine in front of the group. Fortunately, there were
many entries under the word and I chose "a native of Philistia" to
read out loud. The moral is words can have many meanings and, more
importantly, don't make fun of Einstein
around German Physicists.
I wonder if Howard even understood the intended pun.
Stein means stone, nothing else. I have seen/heard it used in the
sense of a "mug for beer" only by Americans. The closest
German word would be Steinkrug, but only if you want to
emphasize that the Krug is made of ceramics and not of glass.
Decimation apart of the Roman sense for me is only throwing away samples,
and the need for filtering goes with it even without explicitly saying.
Cheers, Gerhard
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.