[time-nuts] LEA-6T effect of position hold

[Ole Petter Ronningen]

Hi, all

The subject of position hold mode in GPS receivers pops up every now and
then. Here is a plot that may be of interest to some. Nothing new, but I
thought it a nice visualisation of the difference between position hold and
"not position hold".

I was measuring EFOS 3 against the PPS of a U-blox LEA-6T to get a coarse
indication of the frequency. I have not got around to mounting permanent
antennas in my new lab, so this was a bare board with a patch-antenna on my
desk - no great precision needed nor expected. I fired up the receiver and
made the measurements while it was still surveying - about half way through
it switched to position hold mode. The position is reported with a standard
deviation of 15 meters, so not a great fix. However, I thought the phase
plot was interesting.

Thinking about a GPSDO, it is easy to see the difference between using the
first half of the plot to discipline an oscillator versus the second half.

In case the attachment does not make it though, it is also here:
http://www.efos3.com/images/AHM%20v%20PPS%20pos%20hold.PNG

Ole
[image: Inline image 1]
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Re: [time-nuts] Autodesk Eagle -- maybe they're listening

[Graham / KE9H]

Mike:

You can get Eagle 7.7 at:
ftp://ftp.cadsoft.de/eagle/program/7.7/

Somehow, that ftp server is still up and serving downloads.

--- Graham

==

On Mon, Jan 23, 2017 at 6:56 PM, Mike Suhar  wrote:

> Many companies are trying to jump on the subscription band wagon.  It is a
> way to keep a steady flow of income.  Unfortunately,  hobbyists are left
> out in the cold.   I have version 7.5 with the hobbyist license.  I just
> tried to get 7.7 but the download pulls in version 8.0.  I did not install
> it.
>
> If you are not using the software on a regular basis I assume  you could
> go  with the monthly subscription for a month then drop it.  Pick up again
> a few months later when you start another project and need more than the
> freeware capabilities.
>
> Looks like they have a student version but the way I read it you have to
> actually be a student enrolled in an education institution.  I assume they
> require some form of proof.
>
> Mike
> W8RKO
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John
> Ackermann N8UR
> Sent: Monday, January 23, 2017 17:14
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Autodesk Eagle -- maybe they're listening
>
> Autodesk just sent a follow-up to my "new price model unacceptable"
> complaint a few days ago.  It looks like they are going to upgrade the
> "Standard" subscription ($100/year) to support 4 layer boards up to 160
> cm2, which I think matches the current standard version capabilities.
> Here's a thread from the Autodesk forum:
>
> http://forums.autodesk.com/t5/eagle-forum/a-path-forward-
> for-the-make-license-a-step-up-for-standard/td-p/6823182
>
> This is effective with the next release, which is supposed to be out in a
> couple of weeks.  (In the meantime, I've made sure to download every flavor
> of installer for version 7.7.0, just in case...)
>
>
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Re: [time-nuts] Autodesk Eagle -- maybe they're listening

[jimlux]

On 1/23/17 4:56 PM, Mike Suhar wrote:


Looks like they have a student version but the way I read it you have to 
actually be a student enrolled in an education institution.  I assume they 
require some form of proof.



The usual hack for that is to enroll in a single class at the local 
community college, which you don't need to pass, just enroll, so you get 
the student ID.




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Re: [time-nuts] Thermal effects on cables

[Scott Stobbe]

A google search for digiwave turned up cheap coax at walmart. I don't know
how well copper clad steel holds up in the kHz, low MHz.

On Mon, Jan 23, 2017 at 5:01 PM, Bob Camp  wrote:

> Hi
>
> Back a long time ago the people I was working with spent time looking
> at the impedance of a variety of coax cables. The data they came up
> with on some varieties of cable would suggest that cable is not an outlier…
>
> Bob
>
>
> > On Jan 23, 2017, at 3:08 PM, jimlux  wrote:
> >
> > On 1/23/17 9:16 AM, Bob Camp wrote:
> >> Hi
> >>
> >> Nothing is ever simple if you dig deep enough:
> >>
> >> http://www.jensign.com/RG58U/
> >>
> >> http://www.cliftonlaboratories.com/the_curious_case_of.htm
> >>
> >
> > here's my guess on the curious case cable: it was mismarked by accident
> at the factory (e.g. 93 ohm coax, marked as 50 because someone forgot to
> push the button on the marking machine), and dumped in the scrap bin, and
> then sold by someone who bought the surplus and just read the markings.
> >
> > Or, even sold as a whole spool, likely at a discount, to a
> "knowledgeable buyer" who was willing to take it, mismarkings and all.
> >
> >
> >
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Re: [time-nuts] Autodesk Eagle -- maybe they're listening

[Jim Pruitt]

Mike,  you are correct about Autodesk products being free to
students/faculty/and staff with proof of status.  A college/university
email would do that.

I retired from a medium size state university here in late spring.  My job
there was to purchase, set up, install/administer software and hardware,
and maintain some application servers including ones for Autodesk,
Solidworks, Matlab, and Oracle Primavera.  I had 2 Autocad labs consisting
of about 25 stations each.  We used Autodesk products because they were
free to universities as long as it was in a teaching capacity.  For that
reason facilities management could not use the educational version.
Autodesk and the cad labs took up over 75% of my time so 2 labs kept me
busy and I had 10 other pc labs to maintain on campus.  I assume that
because the product was free to us we were on the bottom of the food chain
as I ran into a bug with their product that cause our students to have to
sit for 20 minutes before the license server would issue them a license.
Keep in mind that classes only lasted 50 minutes!  Even though I hired a
third party VAR (value added reseller) for cad tech support.  Education was
all on their own so even my VAR could not help me resolve the problem.
They did manage to give me one name at Autodesk that I could contact and
push them from inside.  If it had not been for that I feel they never would
have taken the problem seriously.  Even at that it took 2 months to get it
figured out.  They did not fix the problem til the following year when a
new version was released.  Prior to the product being offered free I could
contact Autodesk and get support when needed.

In short,  Autodesk products are free to students and staff/faculty when
used for educational purposes.  I had to resort to forums and other avenues
to get tech support.

Good luck.

Jim Pruitt


On Mon, Jan 23, 2017 at 4:56 PM, Mike Suhar  wrote:

> Many companies are trying to jump on the subscription band wagon.  It is a
> way to keep a steady flow of income.  Unfortunately,  hobbyists are left
> out in the cold.   I have version 7.5 with the hobbyist license.  I just
> tried to get 7.7 but the download pulls in version 8.0.  I did not install
> it.
>
> If you are not using the software on a regular basis I assume  you could
> go  with the monthly subscription for a month then drop it.  Pick up again
> a few months later when you start another project and need more than the
> freeware capabilities.
>
> Looks like they have a student version but the way I read it you have to
> actually be a student enrolled in an education institution.  I assume they
> require some form of proof.
>
> Mike
> W8RKO
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John
> Ackermann N8UR
> Sent: Monday, January 23, 2017 17:14
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Autodesk Eagle -- maybe they're listening
>
> Autodesk just sent a follow-up to my "new price model unacceptable"
> complaint a few days ago.  It looks like they are going to upgrade the
> "Standard" subscription ($100/year) to support 4 layer boards up to 160
> cm2, which I think matches the current standard version capabilities.
> Here's a thread from the Autodesk forum:
>
> http://forums.autodesk.com/t5/eagle-forum/a-path-forward-
> for-the-make-license-a-step-up-for-standard/td-p/6823182
>
> This is effective with the next release, which is supposed to be out in a
> couple of weeks.  (In the meantime, I've made sure to download every flavor
> of installer for version 7.7.0, just in case...)
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>
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Re: [time-nuts] Autodesk Eagle -- maybe they're listening

[Mike Suhar]

Many companies are trying to jump on the subscription band wagon.  It is a way 
to keep a steady flow of income.  Unfortunately,  hobbyists are left out in the 
cold.   I have version 7.5 with the hobbyist license.  I just tried to get 7.7 
but the download pulls in version 8.0.  I did not install it.  

If you are not using the software on a regular basis I assume  you could go  
with the monthly subscription for a month then drop it.  Pick up again a few 
months later when you start another project and need more than the freeware 
capabilities.  

Looks like they have a student version but the way I read it you have to 
actually be a student enrolled in an education institution.  I assume they 
require some form of proof.  

Mike
W8RKO

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann 
N8UR
Sent: Monday, January 23, 2017 17:14
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Autodesk Eagle -- maybe they're listening

Autodesk just sent a follow-up to my "new price model unacceptable" 
complaint a few days ago.  It looks like they are going to upgrade the 
"Standard" subscription ($100/year) to support 4 layer boards up to 160 cm2, 
which I think matches the current standard version capabilities. 
Here's a thread from the Autodesk forum:

http://forums.autodesk.com/t5/eagle-forum/a-path-forward-for-the-make-license-a-step-up-for-standard/td-p/6823182

This is effective with the next release, which is supposed to be out in a 
couple of weeks.  (In the meantime, I've made sure to download every flavor of 
installer for version 7.7.0, just in case...)


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Re: [time-nuts] Autodesk Eagle -- maybe they're listening

[Graham / KE9H]

Hi John:

It is still an effective tripling or quadrupling of the cost.

I purchased a "non profit" license several years ago for $129.  "Non
commercial, 4 layers, up to 160 sq cm., all functionality enabled."
They converted this to a "standard" license over time.
A license was good for the life of a major version, such as 5 or 6.
When 7 came out, I had to buy a new license for 7, but it was at the
existing customer upgrade price, which was $69.

So $129 initially, then $69 every two or three years or so, as new major
versions came out.
Now they want $100 per year.

--- Graham

On Mon, Jan 23, 2017 at 4:14 PM, John Ackermann N8UR  wrote:

> Autodesk just sent a follow-up to my "new price model unacceptable"
> complaint a few days ago.  It looks like they are going to upgrade the
> "Standard" subscription ($100/year) to support 4 layer boards up to 160
> cm2, which I think matches the current standard version capabilities.
> Here's a thread from the Autodesk forum:
>
> http://forums.autodesk.com/t5/eagle-forum/a-path-forward-for
> -the-make-license-a-step-up-for-standard/td-p/6823182
>
> This is effective with the next release, which is supposed to be out in a
> couple of weeks.  (In the meantime, I've made sure to download every flavor
> of installer for version 7.7.0, just in case...)
>
>
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Re: [time-nuts] Li-ion Battreries

[Brooke Clarke]

Hi Mark:

I agree.
The Vietnam era PRC-25 radio had a solid metal battery box that was water tight and used a BA-4386 battery with 
Magnesium chemistry.

http://www.prc68.com/I/PRC25.shtml#DCP
The problem was that as a normal part of its operation the battery releases hydrogen gas.  I know someone who has a scar 
on his head because when he opened the battery box the pressure shot it into his face.  No chemical explosion, just gas 
pressure.


The more modern radios that use the BA-5590 (BA is military speak for primary) Li-SO4 battery where the sulfur is 
compressed to make it a liquid have been known to explode if you try to charge them. This has resulted in a requirement 
for all battery boxes/spaces to allow for one cell to "vent" and not cause a problem.  This is even more important with 
the current BB-2590 (secondary/rechargeable) battery made up of a couple dozen 18650 Li cells.

http://www.prc68.com/I/BA5590.shtml#BB-2590Inside

PS This "5590" family of batteries are all form-fit-function interchangeable and are made up of two "12 Volt" batteries 
in one 5.0 x 4.4 x 2.45" box.  It's the standard battery in the military for non vehicle applications that need vehicle 
compatibility (ie either 12 or 24 volts).  The radio or host device can wire its plug so the battery appears as either a 
12 or 24 volt battery.  While the long in the tooth BA-5590 can only supply a couple of amps (internal fuse) the newer 
BB-2590 can supply maybe 35 Amps for a short time, I think to start a motor.


Rather that buying raw 18650 cells and connecting them getting a BB-2590 may be a better option.  There are numerous 
military chargers that can charge them as well as hobby grade chargers that work with Li cells.


There are some very low cost battery capacity testers on eBay:
http://www.prc68.com/I/BatTst.shtml#Resistor - good for 18650 cell testing

http://www.prc68.com/I/BatTst.shtml#EL - good for BB-2590 testing

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.

 Original Message 

They can be if you store them in something like an ammo box.   If they "go off" 
in the sealed box the pressure builds,  the reaction rate increases exponentially,  and 
voila... shrapnel time.   There's a video out there showing the results.

Most people recommend storing them in nomex/kevlar "cell bags".   I keep mine, 
bagged,  in an unused/unplugged oven!  If one goes off,  hopefully the flames won't 
spread to the rest of the property and the hinged oven door allows pressure to escape.

Hobby RC packs are one of the most dangerous type of rechargeable lithium cells out 
there... even from "reputable" sources and brands.   A local hobby shop twice 
had  brand new name brand packs sitting on the shelf go off.  A friend of mine had the 
same thing happen carrying a just purchased pack home in his car.




They aren't bombs, guys.  Use sensible precautions and get on with it

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Re: [time-nuts] Thermal effects on cables

[Bob Camp]

Hi

Back a long time ago the people I was working with spent time looking
at the impedance of a variety of coax cables. The data they came up
with on some varieties of cable would suggest that cable is not an outlier…

Bob


> On Jan 23, 2017, at 3:08 PM, jimlux  wrote:
> 
> On 1/23/17 9:16 AM, Bob Camp wrote:
>> Hi
>> 
>> Nothing is ever simple if you dig deep enough:
>> 
>> http://www.jensign.com/RG58U/
>> 
>> http://www.cliftonlaboratories.com/the_curious_case_of.htm
>> 
> 
> here's my guess on the curious case cable: it was mismarked by accident at 
> the factory (e.g. 93 ohm coax, marked as 50 because someone forgot to push 
> the button on the marking machine), and dumped in the scrap bin, and then 
> sold by someone who bought the surplus and just read the markings.
> 
> Or, even sold as a whole spool, likely at a discount, to a "knowledgeable 
> buyer" who was willing to take it, mismarkings and all.
> 
> 
> 
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[time-nuts] Autodesk Eagle -- maybe they're listening

[John Ackermann N8UR]

Autodesk just sent a follow-up to my "new price model unacceptable" 
complaint a few days ago.  It looks like they are going to upgrade the 
"Standard" subscription ($100/year) to support 4 layer boards up to 160 
cm2, which I think matches the current standard version capabilities. 
Here's a thread from the Autodesk forum:


http://forums.autodesk.com/t5/eagle-forum/a-path-forward-for-the-make-license-a-step-up-for-standard/td-p/6823182

This is effective with the next release, which is supposed to be out in 
a couple of weeks.  (In the meantime, I've made sure to download every 
flavor of installer for version 7.7.0, just in case...)



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Re: [time-nuts] Thermal effects on cables

[jimlux]

On 1/23/17 9:16 AM, Bob Camp wrote:

Hi

Nothing is ever simple if you dig deep enough:

http://www.jensign.com/RG58U/

http://www.cliftonlaboratories.com/the_curious_case_of.htm



here's my guess on the curious case cable: it was mismarked by accident 
at the factory (e.g. 93 ohm coax, marked as 50 because someone forgot to 
push the button on the marking machine), and dumped in the scrap bin, 
and then sold by someone who bought the surplus and just read the markings.


Or, even sold as a whole spool, likely at a discount, to a 
"knowledgeable buyer" who was willing to take it, mismarkings and all.




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Re: [time-nuts] purpose of time of day display units

[George Atkinson]

They also help weigh the rack down :-)
I took this photo before I saw the thread.

Robert G8RPi.


> On 23 January 2017 at 12:14 Bob Camp  wrote:
> 
> 
> Hi
> 
> Trying to troubleshoot those racks *without* being able to see the timing is
> harder than if you can. This gizmo should trigger at the top of the minute. 
> Did it trigger? That’s much easier to catch if you can see the minute
> transition. 
> If the rack goes down, it needs to be back up fast…..
> 
> Bob
> 
> 
> > On Jan 23, 2017, at 2:36 AM, Robert Atkinson via time-nuts
> >  wrote:
> > 
> > One must remember the original use of these displays was displaying IRIG
> > time either distributed from a master clock, locally generated or from a
> > recording (tape) They long predate GPS. There are more sophisticated units
> > that include controls for the tape recorder so you could auto search to a
> > certain time. Multiple displays could be used for locally generated time,
> > time received from a remote site by fixed line or radio and time from data
> > or video recorders.I have a number of them and one sits above my GPStar as
> > the LCD on the GPStar is hard to read from across the workshop and it lets
> > me have time available while showing timing or satellite  status on the GPS.
> > Just picked up 3 more (RAPCO 104 anyone have a manual for these) at the
> > weekend.
> > Robert G8RPI.
> > 
> >  From: Bob Bownes 
> > To: Discussion of precise time and frequency measurement
> >  
> > Sent: Sunday, 22 January 2017, 18:33
> > Subject: Re: [time-nuts] purpose of time of day display units
> > 
> > 
> > #5) Everyone likes blinkenlights. 
> > 
> 
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Re: [time-nuts] Thermal effects on cables

[jimlux]

On 1/23/17 7:13 AM, REEVES Paul wrote:

Hi David,

Surely the impedance of the cable is only affected by the ratio of the inner 
conductor and outer conductor diameters modified by the internal dielectric 
constant, nothing to do with the frequency of operation. You might well have 
problems converting the larger diameters down to a suitable size for the 
connectors at the higher frequencies though
I thought that the HP cabling for the 8510 series VNAs was air spaced but I 
might well be wrong - I just tried not to damage them :-)
Regards,



I think the large outer diameter is essentially a soft armoring, which 
limits the bend radius, which in turn limits the deformation of the 
outer conductor and dielectric.


VNA test port cables also have very good shielding effectiveness as well 
as stable propagation properties.


The underlying cable would have to be fairly small diameter, because 
otherwise you'd get moding problems at high frequencies.  At 60 GHz, the 
cable really has to be smaller than a few mm diameter.



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Re: [time-nuts] Thermal effects on cables

[Attila Kinali]

On Mon, 23 Jan 2017 15:13:39 +
REEVES Paul  wrote:

> Surely the impedance of the cable is only affected by the ratio
> of the inner conductor and outer conductor diameters modified by
> the internal dielectric constant, nothing to do with the frequency of
> operation. You might well have problems converting the larger diameters
> down to a suitable size for the connectors at the higher frequencies
> though

If you are only looking at the impedance, then yes. But once you get
to high frequencies, you get also multi-mode behaviour of the coax cables
and connectors, which leads to dispersion. That's why people hardly use
N connectors for GHz frequencies, even though the connector itself would
allow it. For VNAs where even small phase shifts/instabilities due to
multi-mode behaviour/dispersion are a no go, the connectors are usually
3.5mm (basically a precise version of the SMA), 2.9mm, 2,4mm etc 
and go down to even 1.0mm which can be spec'ed up to 110GHz.

BTW: the 3.5mm connector is one that you will find on many instruments
that go beyond 1-2GHz. Unfortunately it looks exactly the same as an
SMA connector and will mate with one. Even more unfortunately, mating
it with an SMA connector will scar the connector and most likely move
it out of spec (ie degrade it to a simple SMA connector). If it's just
an adapter, you've only lost a bit of money (in the order of a few €100).
If it was the connector of your VNA/oscilloscope/..., you might need to
send it in for an expensive repair.

Attila Kinali

-- 
You know, the very powerful and the very stupid have one thing in common.
They don't alters their views to fit the facts, they alter the facts to
fit the views, which can be uncomfortable if you happen to be one of the
facts that needs altering.  -- The Doctor
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Re: [time-nuts] Thunderbolt Harmonics

[Götz Romahn]

hello to all,
to put things right into perspective please note that the famous OCXO 
hp10811 is "only" specified with harmonics <25 dB (see page 11 of manual 
https://www.febo.com/pages/hp10811/HP10811AB-Manual.pdf).

This device is but still often felt to be useful.
Goetz


Am 22.01.2017 um 09:21 schrieb Rhys D:

Bill,

No offence taken at all. On the contrary, I really appreciate a great deal
the effort you have gone to straightening out my misconceptions and
blunders!

This forum is such a great learning opportunity. I usually work with
digital systems, so my RF and analog knowledge is sketchy at best. Half the
reason I bought a spectrum analyser is to have an excuse to learn a bit
about RF in a hands on way.

It's funny you mentioned the overly precise numbers. After I wrote them I
thought, well that's ridiculous, but I left them as is. That'll teach me!

Cheers,

Rhys



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Re: [time-nuts] Thermal effects on cables

[Bob Camp]

Hi

Nothing is ever simple if you dig deep enough:

http://www.jensign.com/RG58U/

http://www.cliftonlaboratories.com/the_curious_case_of.htm

Bob

> On Jan 23, 2017, at 10:13 AM, REEVES Paul  
> wrote:
> 
> Hi David,
> 
> Surely the impedance of the cable is only affected by the ratio of the inner 
> conductor and outer conductor diameters modified by the internal dielectric 
> constant, nothing to do with the frequency of operation. You might well have 
> problems converting the larger diameters down to a suitable size for the 
> connectors at the higher frequencies though
> I thought that the HP cabling for the 8510 series VNAs was air spaced but I 
> might well be wrong - I just tried not to damage them :-)
> Regards,
> 
> Paul Reeves
> 
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David 
> Kirkby (Kirkby Microwave Ltd)
> Sent: 23 January 2017 13:26
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Thermal effects on cables
> 
> On 13 January 2017 at 06:52, Ole Petter Ronningen 
> wrote:
> 
>> Hi, all
>> 
>> The question of phase shifts in cables pops up every now and then on 
>> this list - I stumbled across a good table of measured phase shifts 
>> with temperature in different cable types in this paper:
>> http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_
>> PresentationWSchaefer.pdf
>> that I though would be of interest to others.
>> 
>> 
> I've like to know how VNA cables compare. They are expensive enough - a 
> couple of cables around 600 mm long (24") for my VNA are over $5000. They are 
> much larger diameter than normal cables, but much more flexible too.
> The construction is obviously very different. Since mine are designed for use 
> to 26.5 GHz, the internal diameter of the outer conductor can be no more than 
> a couple of mm, yet the overall cable has a diameter of about 15 mm.
> 
> Dave
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Re: [time-nuts] Thermal effects on cables

[Tim Shoppa]

Dave, the typical spec sheet for VNA cables have a very restricted "lab
temperature" range specified. For example 23C +/- 5C.

There's a very nice graph showing effect of flexure on phase stability in
Fig 2 of this spec sheet:
https://www.gore.com/sites/g/files/ypyipe116/files/2016-07/GMCA-0224-DAT-US-MAY16_e.pdf

Funny how people always want to put the words "dielectric" and "constant"
right next to each other but we know it isn't constant :-)

Tim N3QE

On Mon, Jan 23, 2017 at 8:26 AM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:

> On 13 January 2017 at 06:52, Ole Petter Ronningen 
> wrote:
>
> > Hi, all
> >
> > The question of phase shifts in cables pops up every now and then on this
> > list - I stumbled across a good table of measured phase shifts with
> > temperature in different cable types in this paper:
> > http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_
> > PresentationWSchaefer.pdf
> > that I though would be of interest to others.
> >
> >
> I've like to know how VNA cables compare. They are expensive enough - a
> couple of cables around 600 mm long (24") for my VNA are over $5000. They
> are much larger diameter than normal cables, but much more flexible too.
> The construction is obviously very different. Since mine are designed for
> use to 26.5 GHz, the internal diameter of the outer conductor can be no
> more than a couple of mm, yet the overall cable has a diameter of about 15
> mm.
>
> Dave
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[time-nuts] Subject: Re: Allan Variance with an HP53132a counter

[clemgill]

‌Hi 
Magnus,

Thanks for your enlightening reply.
I am indeed looking at a possible process to correct the DeltaDEV bias to 
provide something approaching the traditional ADEV.
Could you please send me a link to your paper on Omega counters ?

Indeed the "Australian" paper shows significant skew in White phase and Flicker 
phase noise regions but much less in the other noise regions, which shoudl be 
correctable when one identifies the shape of the responses.

Another paper from E. Rubiola ("On the measurement of frequency ans of its 
sample variance with high-resolution counters") introduces the point that the 
average on m contiguous Delta measures converges to a Pi estimate (AVAR) for 
large value of m. However this seems to be challenged by the "Australian" paper 
pointing at a significant side effect (sensitivity surge) around N times the 
reciprocal of gate time (N = number of samples).

Best,
Gilles.

Message: 11
Date: Sun, 22 Jan 2017 20:34:32 +0100
From: Magnus Danielson
To: time-nuts@febo.com
Cc: mag...@rubidium.se
Subject: Re: [time-nuts] Allan Variance with an HP53132a counter
Message-ID:
Content-Type: text/plain; charset=utf-8; format=flowed

Hi,

There is two types of errors done when using this type of counters,

First, the delta-estimator of frequency filtering will skew the Allan
deviation, mostly in the white phase noise region but the effect wears
of at the length of the averaging windown of the counter. Correct
interleave factor and processing lets the prefiltering be extended into
modified Allan deviation.

Second, the moving average is a form of interleaved estimation producing
a higher reading rate than the length of the avereage, giving a improved
response compared to traditional non-interleaved behavior. However,
processing such values as non-interleaved values will skew the Allan
deviation response. Correctly handle it as interleaved values removes
this bias effect.

You can do the same with Omega counters, considering you do things
properly for PDEV. I've got a paper to complete on that topic.

Cheers,
Magnus


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Re: [time-nuts] Li-ion Batteries

[ziggy9+time-nuts]

Balancing series packs is indeed important. This is why laptop batteries have 
all those pins on their connectors, and why hobby type batteries have balance 
charge connectors. Although they are different chemistries (laptop and 
16450/18650 batteries are typically Li-Ion while hobby type batteries are 
typically Li-Poly) they both have this requirement. And each chemistry has it’s 
own charge/discharge requirements. Note that within Li-Ion there are still 
different chemistries that again have their own requirements, which are 
different from LiFE which are different from A123. Be careful making blanket 
statements.

At the risk of violating my own comment above, if you are discharging to 2.5V 
*under load*, then that could be OK depending on the specific battery. If you 
are measuring 2.5V with *no load*, then that is over discharged for pretty much 
any chemistry. And there is really nothing to be gained by discharging to this 
level. 3V is considered to be a safe low level cutoff for most cases, and below 
about 3.2V there is little capacity remaining anyway. 

Over discharge and over charge both wind up plating metallic Lithium on the 
electrodes. Doing both is asking for trouble. Trickle charging a Li battery is 
also bad news as it over charges and again starts to plate out Lithium. 

Yes, you can use a power supply to charge Li batteries. But you must be using a 
current limited supply, and voltage regulated. 4.2V at say .5 to 1C should be 
fine as long as you are there to babysit. But if you forget and leave it go 
then you will be trickle charging. Do that for too long it may become a 
problem. You simply cannot treat Li batteries/cells as you did anything else.

Proper multi-chemistry Li chargers are not hard to find, nor are they horribly 
expensive. Please use one. (And not the cheapest one you can get from 
Hobby-King or eBay.)

References? Please see:
>

NFPA: 
>
Sony: 
>
Panasonic: >


Datasheets:
Different chemistry/application:
Li/SOCl2: 
>

vs:

Li-MnO2: 
>

vs:

>
>

Paul

> On Jan 23, 2017, at 6:47 AM, Bert Kehren via time-nuts  
> wrote:
> 
> The biggest mistake you can make if you plan to use them in series not to  
> equalize them before use. They come in different state of charge. Maybe 
> close if  from the same lot but not close enough and I do not count on the 
> equalizer. I  start with a discharge to 2.5 V and charge two at a time in 
> Parallel with a  holder that I modified. Set a power supply to 4.2 V 
> precisely and 
> charge all  batteries for that particular application with that setting.
> Bert Kehren
> 
> 

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Re: [time-nuts] Thermal effects on cables

[REEVES Paul]

Hi David,

Surely the impedance of the cable is only affected by the ratio of the inner 
conductor and outer conductor diameters modified by the internal dielectric 
constant, nothing to do with the frequency of operation. You might well have 
problems converting the larger diameters down to a suitable size for the 
connectors at the higher frequencies though
I thought that the HP cabling for the 8510 series VNAs was air spaced but I 
might well be wrong - I just tried not to damage them :-)
Regards,

Paul Reeves

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David 
Kirkby (Kirkby Microwave Ltd)
Sent: 23 January 2017 13:26
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thermal effects on cables

On 13 January 2017 at 06:52, Ole Petter Ronningen 
wrote:

> Hi, all
>
> The question of phase shifts in cables pops up every now and then on 
> this list - I stumbled across a good table of measured phase shifts 
> with temperature in different cable types in this paper:
> http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_
> PresentationWSchaefer.pdf
> that I though would be of interest to others.
>
>
I've like to know how VNA cables compare. They are expensive enough - a couple 
of cables around 600 mm long (24") for my VNA are over $5000. They are much 
larger diameter than normal cables, but much more flexible too.
The construction is obviously very different. Since mine are designed for use 
to 26.5 GHz, the internal diameter of the outer conductor can be no more than a 
couple of mm, yet the overall cable has a diameter of about 15 mm.

Dave
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Re: [time-nuts] Li-ion Batteries

[Bert Kehren via time-nuts]

The biggest mistake you can make if you plan to use them in series not to  
equalize them before use. They come in different state of charge. Maybe 
close if  from the same lot but not close enough and I do not count on the 
equalizer. I  start with a discharge to 2.5 V and charge two at a time in 
Parallel with a  holder that I modified. Set a power supply to 4.2 V precisely 
and 
charge all  batteries for that particular application with that setting.
Bert Kehren
 
 
In a message dated 1/23/2017 4:12:08 A.M. Eastern Standard Time,  
hol...@hotmail.com writes:

I built  a switched capacitor balancer.  It takes some time to balance a 
wildly  out-of-balance pack but does a great job of maintaining balance during 
 charging and discharge.  I run the balancer during pack charging and  
discharging.  I tried it charging an 8S LiFePO4 pack with 7 fully charged  
cells 
and one fully discharged cell and it worked fine... no cells were  
over-volted during charging.

It does not waste energy/generate heat  like a resistive balancer.   An 
inductive balancer can handle higher  balance currents for very high capacity 
packs, but is also quite a bit more  complicated to do correctly.  Also built 
a processor-per-cell BMS using  ATTINY-85's.   I've used both on  4S32P / 
8S16P A123 packs and  ICR 18650 packs.

Those A123 cells can dump 200A (each!) into a short  circuit... you REALLY 
don't want to short a 32P A123 pack...  They are  also rather tolerant of 
abuse.  A friend made a video of charging one at  a 100C rate and it survived 
without exploding/melting.  I once bought  some that had been sitting fully 
charged for over 4 years and when tested  still retained over 80% of the 
charge.  A couple of charge/discharge  cycles and they performed like new.  I 
keep  4S1P packs in my cars  for jump starting.   There is a video of a guy 
in Canada staring his  car over 10 times in sub-zero weather using one.  The 
cells are 26650  size... are about the size of a D  cell.




> The BMS doesn't balance the  charge after charging (which consumes time & 
 energy
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Re: [time-nuts] Thermal effects on cables

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 13 January 2017 at 06:52, Ole Petter Ronningen 
wrote:

> Hi, all
>
> The question of phase shifts in cables pops up every now and then on this
> list - I stumbled across a good table of measured phase shifts with
> temperature in different cable types in this paper:
> http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_
> PresentationWSchaefer.pdf
> that I though would be of interest to others.
>
>
I've like to know how VNA cables compare. They are expensive enough - a
couple of cables around 600 mm long (24") for my VNA are over $5000. They
are much larger diameter than normal cables, but much more flexible too.
The construction is obviously very different. Since mine are designed for
use to 26.5 GHz, the internal diameter of the outer conductor can be no
more than a couple of mm, yet the overall cable has a diameter of about 15
mm.

Dave
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Re: [time-nuts] purpose of time of day display units

[Bob Camp]

Hi

Trying to troubleshoot those racks *without* being able to see the timing is
harder than if you can. This gizmo should trigger at the top of the minute. 
Did it trigger? That’s much easier to catch if you can see the minute 
transition. 
If the rack goes down, it needs to be back up fast…..

Bob


> On Jan 23, 2017, at 2:36 AM, Robert Atkinson via time-nuts 
>  wrote:
> 
> One must remember the original use of these displays was displaying IRIG time 
> either distributed from a master clock, locally generated or from a recording 
> (tape) They long predate GPS. There are more sophisticated units that include 
> controls for the tape recorder so you could auto search to a certain time. 
> Multiple displays could be used for locally generated time, time received 
> from a remote site by fixed line or radio and time from data or video 
> recorders.I have a number of them and one sits above my GPStar as the LCD on 
> the GPStar is hard to read from across the workshop and it lets me have time 
> available while showing timing or satellite  status on the GPS. Just picked 
> up 3 more (RAPCO 104 anyone have a manual for these) at the weekend.
> Robert G8RPI.
> 
>  From: Bob Bownes 
> To: Discussion of precise time and frequency measurement  
> Sent: Sunday, 22 January 2017, 18:33
> Subject: Re: [time-nuts] purpose of time of day display units
> 
> 
> #5) Everyone likes blinkenlights. 
> 

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Re: [time-nuts] purpose of time of day display units

[Tim Shoppa]

http://www.washingtonpost.com/lifestyle/style/for-public-clocks-a-time-warp/2011/10/25/gIQAXOZ5jM_story.html

"If the clocks are right — on churches and in classrooms, on stores and in
bars — they tell us that things are in order. They tell us that people
are paying attention. If a clock is wrong, maybe everything else is,
too."


On Sun, Jan 22, 2017 at 1:31 AM, Ruslan Nabioullin 
wrote:

> Hi, looking at pictures of various time metrology equipment setups for
> best practices and inspiration, I have commonly seen time of day display
> unit(s) installed in racks containing processing or time transfer
> equipment, e.g., http://www.xyht.com/wp-content/uploads/2015/05/Powers_
> Master_Clock.jpg. All that these units do is merely display the time of
> day and sometimes the date, typically by means of seven segment LED
> displays, of the time code inputted to them (typically IRIG-B, I'm
> guessing).  Any ideas why such a unit is necessary when one can simply look
> at the time displayed by timing receivers and time code generators (and
> even some standards), and the interface of some fusor, defined in this
> context as a system which performs timing data fusion (by implementing a
> paper clock or a more primitive algorithm) and timekeeping, either by means
> of a direct shell, or via something like NTP?
>
> Thanks in advance,
> Ruslan
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Re: [time-nuts] Manual and Software for R (Meinberg) ED170MP GPS Receiver?

[Martin Burnicki]

Dave,

Dave Hallidy wrote:
> All-
> 
> I just acquired a Rohde & Schwarz (actually a Meinberg) ED170MP GPS Receiver
> (and antenna) and I'd like to get it going.
> 
> Can someone here point me to the manual and any software for it?

Please contact techsupp...@meinberg.de for help. I'm sure our support
guys can help you.

Martin (working @Meinberg)

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Re: [time-nuts] Thermal effects on cables

[Attila Kinali]

On Fri, 13 Jan 2017 07:52:18 +0100
Ole Petter Ronningen  wrote:

> The question of phase shifts in cables pops up every now and then on this
> list - I stumbled across a good table of measured phase shifts with
> temperature in different cable types in this paper:
> http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_PresentationWSchaefer.pdf
> that I though would be of interest to others.

I would like to add here a couple of more references:

"Phaste stability of typical navy radio frequency coaxial cables",
by Rodriguez, 1965
http://www.dtic.mil/dtic/tr/fulltext/u2/628682.pdf

"Current Innovations In Phase Stable Coaxial Cable Design"
by Times Microwave Systems
https://www.timesmicrowave.com/downloads/tech/phasearticle.pdf

"Understanding Phase versus Temperature Behavior - The Teflon Knee",
by Micro Coax
http://www.micro-coax.com/wp-content/themes/micro_coax/includes/pdf/applications_notes/13-MIC-0012.Phase_vs_Temp_Behavior_FINAL.pdf

"Temperature Stability of Coaxial Cables",
by Czuba and Sikora, 2011
http://przyrbwn.icm.edu.pl/APP/PDF/119/a119z4p17.pdf

"Phase stable RF-cable for space applications"
by Karstensen et al. 2013
Poster: 
https://www.ethz.ch/content/dam/ethz/special-interest/mavt/design-materials-fabrication/composite-materials-dam/Research/Posters/067.pdf
Paper: https://escies.org/download/webDocumentFile?id=60894


Attila Kinali
-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
 -- Miss Matheson, The Diamond Age, Neil Stephenson
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Re: [time-nuts] Li-ion Battreries

[Chris Albertson]

No way will an ammo box explode and send shrapnel flying.  Even if filled
with machine gun bullets and tossed in a fire.  The rubber gasket fails and
the pressure escapes.  A slow burning object like a battery will never
cause steel to fragment.   If someone made a video it was faked

The purpose of the box is that first it offers mechanical protection in
storage and transport and second it is a heat sink.  If a few hundred watts
of energy is put into a small part of the box, the heat conducts to a
larger area and you have a lower temperature.

The box is designed to store ammo in a combat area, the box will not
explode if something inside of it catches fire.  The gasket would fail
first or it not the wire bail holding the lid would fail under minimal
pressure.   The lid opens LONG before the steel can bursts

If I wanted to make a dramatic video, I'd fill the entire box with gun
powder.  The lid would fly open and burning powder would to ejected into
the air and it would LOOK like an explosion

On Sun, Jan 22, 2017 at 6:25 PM, Mark Sims  wrote:

> They can be if you store them in something like an ammo box.   If they "go
> off" in the sealed box the pressure builds,  the reaction rate increases
> exponentially,  and voila... shrapnel time.   There's a video out there
> showing the results.
>
> Most people recommend storing them in nomex/kevlar "cell bags".   I keep
> mine, bagged,  in an unused/unplugged oven!  If one goes off,  hopefully
> the flames won't spread to the rest of the property and the hinged oven
> door allows pressure to escape.
>
> Hobby RC packs are one of the most dangerous type of rechargeable lithium
> cells out there... even from "reputable" sources and brands.   A local
> hobby shop twice had  brand new name brand packs sitting on the shelf go
> off.  A friend of mine had the same thing happen carrying a just purchased
> pack home in his car.
>
> 
>
> > They aren't bombs, guys.  Use sensible precautions and get on with it
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>



-- 

Chris Albertson
Redondo Beach, California
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[time-nuts] Li-ion Batteries

[Mark Sims]

I built a switched capacitor balancer.  It takes some time to balance a wildly 
out-of-balance pack but does a great job of maintaining balance during charging 
and discharge.  I run the balancer during pack charging and discharging.  I 
tried it charging an 8S LiFePO4 pack with 7 fully charged cells and one fully 
discharged cell and it worked fine... no cells were over-volted during charging.

It does not waste energy/generate heat like a resistive balancer.   An 
inductive balancer can handle higher balance currents for very high capacity 
packs, but is also quite a bit more complicated to do correctly.  Also built a 
processor-per-cell BMS using ATTINY-85's.   I've used both on  4S32P / 8S16P 
A123 packs and ICR 18650 packs.

Those A123 cells can dump 200A (each!) into a short circuit... you REALLY don't 
want to short a 32P A123 pack...  They are also rather tolerant of abuse.  A 
friend made a video of charging one at a 100C rate and it survived without 
exploding/melting.  I once bought some that had been sitting fully charged for 
over 4 years and when tested still retained over 80% of the charge.  A couple 
of charge/discharge cycles and they performed like new.  I keep  4S1P packs in 
my cars for jump starting.   There is a video of a guy in Canada staring his 
car over 10 times in sub-zero weather using one.  The cells are 26650 size... 
are about the size of a D cell.




> The BMS doesn't balance the charge after charging (which consumes time & 
> energy
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Re: [time-nuts] purpose of time of day display units

[Robert Atkinson via time-nuts]

One must remember the original use of these displays was displaying IRIG time 
either distributed from a master clock, locally generated or from a recording 
(tape) They long predate GPS. There are more sophisticated units that include 
controls for the tape recorder so you could auto search to a certain time. 
Multiple displays could be used for locally generated time, time received from 
a remote site by fixed line or radio and time from data or video recorders.I 
have a number of them and one sits above my GPStar as the LCD on the GPStar is 
hard to read from across the workshop and it lets me have time available while 
showing timing or satellite  status on the GPS. Just picked up 3 more (RAPCO 
104 anyone have a manual for these) at the weekend.
Robert G8RPI.

  From: Bob Bownes 
 To: Discussion of precise time and frequency measurement  
 Sent: Sunday, 22 January 2017, 18:33
 Subject: Re: [time-nuts] purpose of time of day display units
   

#5) Everyone likes blinkenlights. 



> On Jan 22, 2017, at 08:55, jimlux  wrote:
> 
>> On 1/21/17 10:31 PM, Ruslan Nabioullin wrote:
>> Hi, looking at pictures of various time metrology equipment setups for
>> best practices and inspiration, I have commonly seen time of day display
>> unit(s) installed in racks containing processing or time transfer
>> equipment, e.g.,
>> http://www.xyht.com/wp-content/uploads/2015/05/Powers_Master_Clock.jpg.
>> All that these units do is merely display the time of day and sometimes
>> the date, typically by means of seven segment LED displays, of the time
>> code inputted to them (typically IRIG-B, I'm guessing).
> 
> There's a few reasons I can think of:
> 1) the display is also a distribution amplifier of some sort - one time 
> source going into rack, distributed to things in the rack (or the next rack)
> 
> 2) as phk commented, it lets you know that your time code isn't broken (i.e. 
> someone got in behind the rack and disconnected the wrong cable)
> 
> 3) It's a crude visual check - your eye/brain is pretty good at catching a 
> change in the pattern of blinky lights.  IN this situation, you'd expect all 
> the displays to change simultaneously.
> 
> 4) the equipment configuration "just growed" from a collection of smaller 
> ones, each with its own display.
> 
> We put displays like this in all of our ground support equipment (GSE) racks 
> when doing spacecraft or subsystem tests, mostly for reason #2 and #4.
> 
> You might have a GSE rack or two in the lab when you're building up the 
> subsystem.  Someone else's subsystem has their rack, also with a timecode 
> display.  When you bring the two subsystems together for integration, you 
> bring the racks with them, and it's not worth it to reconfigure.
> 
> 
> 
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