[time-nuts] Odetics CommSync GPS Rollover Problem

[Rob Kimberley via time-nuts]

Happy to report that problem now resolved by replacing one of the Motorola
Oncore modules with a later version. 

Have just ordered another for the secondary channel.

Rob

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[time-nuts] Odetics Telecom CommSync - GPS Rollover Problem.

[Rob Kimberley via time-nuts]

I wonder if Tom Van Baak can help me on this one. 

 

Recently powered mine up for the first time in a few years. Although the
unit survived the original GPS Rollover, it obviously can't cope with the
subsequent one, and is currently showing June 01, 1998 as I type this..

 

Tom, as you bought one of these off me, do you know of any updated firmware?

 

Thanks and kind regards

Rob K

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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

[Rob Kimberley]

Hi Martin,

Thanks for this.

Rob

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Martin Burnicki
Sent: 11 October 2017 18:17
To: time-nuts@febo.com
Subject: Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather 
GPS time

Hi Rob,

Rob Kimberley wrote:> I'm using the Meinberg NTP Distribution here with their 
NTP Monitor prog on Win10-64, and two GPS NTP servers.> > Config
settings: -> >server 192.168.1.120 iburst minpoll 4 maxpoll 5>
server 192.168.1.121 iburst minpoll 4 maxpoll 5> > Consistent sub millisecond 
results. I've also found that Win10 actually performs way better than Win7.
This is because with Windows 8 and newer there is a new API call to read the 
system time with 100 ns resolution. The older API provides only 1 ms resolution.

ntpd uses the new API, if available.

Martin
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

[Rob Kimberley]

I'm using the Meinberg NTP Distribution here with their NTP Monitor prog on 
Win10-64, and two GPS NTP servers.

Config settings: -

   server 192.168.1.120 iburst minpoll 4 maxpoll 5
   server 192.168.1.121 iburst minpoll 4 maxpoll 5

Consistent sub millisecond results. I've also found that Win10 actually 
performs way better than Win7.

Rob

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike Cook
Sent: 11 October 2017 16:26
To: Chris Wilson; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather 
GPS time

I have Win7-64 and my LH and system time are the same (with a very short delta 
of < 0.2s probably due to their respective window update time).
I use the Meinberg disturb of NTP. My client’s offset from the paris 
observatory is less than a millisec.

Maybe you should check your NTP status and see what offset you get from a known 
good source with ntpdate -b -d .




> Le 11 oct. 2017 à 13:29, Chris Wilson  a écrit :
> 
> 
> 
>  11/10/2017 12:24
> 
> Probably   a   simple  answer,  but I am curious as to why my PC clock
> which  is set by NTP on Windows 7 64 bit OS is ahead of Lady Heather's 
> time,  locked  to  a  Trimble  Thunderbolt  by  about  half  a  second
> (guesstimate..)  I  caught  a screen shot of the discrepancy just now, 
> it's at http://www.gatesgarth.com/time.jpg
> 
> I use NTP for low signal WSPR transmissions and a second out isn't the 
> end  of  the  world,  if  indeed  something  IS out. More academic 
> than problematic, thanks
> 
> -- 
>   Best Regards,
>   Chris Wilson.
> mailto: ch...@chriswilson.tv
> 
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"The power of accurate observation is commonly called cynicism by those who 
have not got it. » George Bernard Shaw

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Re: [time-nuts] Weird GPSDO behavior

[Rob Kimberley]

I'd go with a power surge as it's so regular at 8AM.
Rob

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Skip Withrow
Sent: 28 September 2017 21:18
To: time-nuts
Subject: [time-nuts] Weird GPSDO behavior

Hello Time-Nuts,

I have a NTGS50AA GPSDO (close cousin to the NTBW50AA and Thunderbolt) with the 
OCXO removed and a SRS PRS-10 rubidium oscillator in its place.  I have been 
running Lady Heather 5.0 and have changed the damping, gain, and time constant 
to give me a 20,000 second time constant with a damping of .6.  I have attached 
a Lady Heather screen shot of the weird behavior.  You can see that my GPS 
antenna is in a very none ideal location (window on the west side of the 
building).

Once per day (about 8am) something disturbs the system.  So, the GPSDO spends 
much of its time recovering and never gives me anywhere near the performance 
that this system is capable of.  I would think that it is not the PRS-10 as it 
has no knowledge of time.  I would also think that it is not the GPS system or 
receiver, since the GPS constellation repeats twice per day.

Kind of the two things that I am left with are a glitch by the power company 
every morning (there is some large industrial machinery across the street (but 
then I would kind of expect glitches at 8am and 5pm), and perhaps Lady Heather 
doing something funny.  This system has been running for quite some time, I 
have not tried restarting Lady Heather yet.

Anybody seen anything like this, or have any good ideas?

Thanks in advance,
Skip Withrow 

https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon";
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Re: [time-nuts] Need Time Help

[Rob Kimberley]

Suggest you try the following which I use on Win10 with great success

https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable

and

https://www.meinbergglobal.com/english/sw/ntp-server-monitor.htm

Rob K



-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of dl...@yahoo.de 
via time-nuts
Sent: 04 October 2016 07:57
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Need Time Help

Hello Larry,
for Windows i know only one piece of software that is able to set the system 
clock within a few milliseconds.  Dimension4. 
http://www.thinkman.com/dimension4/features.htm

Since I have not yet even measured it i can not tell if it meets your 
specifications.

Maybe you give it a try. 

Chris
DL3HC

- Nachricht beantworten -
Von: "Larry Hower" 
An: 
Betreff: [time-nuts] Need Time Help
Datum: Di., Okt. 4, 2016 06:41

Hello to the List:

After a long and bitter struggle with XP and WIN 10, I am writing to ask for 
some help in solving some problems we have been having in our attempt to 
establish a very accurate time reference for use in EME activities.

We are hoping to achieve less than 5ms deviation, although anything below 15ms 
will be adequate for now.

Specifically, we want to use a universal reference that will enable amateur 
radio operators in different parts of the world to start and stop their 
transmissions within a few milliseconds of a specific time. For example, I 
transmit at 12:00:00 for 1.75 minutes and “Joe” listens. Then “Joe”
transmits at 12:02:00 for 1.75 minutes. Repeat until QSO happens.

We are using WSJT-X software. We use standard receivers plus we have tried a 
few SDRs.

Sorry for the oversimplified example but I want to make sure we are all on the 
same page.

As background:

1. We are using desktops and laptops in separate locations running XP or Win 10.

2. We have used MS clock tools, including use of Boulder time servers, tried 
both host name and IP address, without reaching the goal.

3. We have set up some Serial GPS units with PPS and some USB GPS receivers (no 
PPS) and can get to about 0.2 sec but it is not trusted or close enough.

4. We have set up a network time server with similar results.

5. Deviation is measured using WSJT-X

-

*Standard Receivers*

ICOMs (910/9100 and others – non-SDR). Locked to 10MHz external osc reference. 
We have frequency accuracy of 1 to 2 Hertz at 10GHz.


*SDRs*

We believe that SDR processing can insert a delay of varying length, depending 
on the software, bandwidth, etc. Our SDR tests seem to have a delay of as much 
as 0.5 sec. And with sometimes variable results. We will see how SDRs can be 
used after we resolve the current issues.


*Some time related hardware details*

*1. Global Star 4 USB and Serial Connections*

http://usglobalsat.com/p-688-bu-353-s4.aspx#images/product/large/688.jpg

We have 4 of these. Two are older models with serial connections. We have 
serial ports on some computers (XP and a new high-end laptop running WIN
10) so we are able to activate the PPS option. Two of the GStar are newer 
models with USB connections which are not able to use the PPS option.

We have tried NEMATime and NEMATime 2 software on this hardware without 
reaching our goal of <15ms. Range of deviation is from 0.0 to about 0.3 sec. 
Drifts.  Deviation is measured using WSJT-X.


*2. TimeNet NTP Device*

http://www.veracityglobal.com/products/networked-video-integ
ration-devices/timenet.aspx

We have one of these TimNet units and it has been set up at 2 different 
locations on differing computers according to user instructions. We are using 
the TimNet software as DL'd recently from their web site. We get GPS “lock” and 
Time “lock” shown in the user panel but we do not have faith that this is 
carried into the system clock. Occasionally the "lock"
indicators go blank but the time seems to be updated when the software is 
strted again (the updated is operation is show at the correct time.  We think 
the app needs some work. Deviation is measured using WSJT-X.  See later details.


*Setup*

The G Star units have been installed at 2 separate locations, tested using 
WSJT-X QRA 64 and WSPR-2 signals on 10.137MHz.

Similar tests with a TimeNet unit at one end and G Stars at the other end.

G Star units were installed on the XP laptops with the PPS option enabled and 
running WSJT-X. These XP units seem to have their time “in sync”. See following.


*WSJT-X*

We are not sure what, if any, internal delays there are attributable to this 
software. We have been using the same version/build at both ends for the tests. 
The software displays in 0.1 sec increments but will show 0.0sec when things 
appear to be working well. We do not know the actual level of precision of the 
WSJT-X software time measurements. I undersand that WSJT-X “reads” the system 
clock at the start of a period (TX or RX) and displays what it finds as the 
time deviation from the local system clo

Re: [time-nuts] End of Loran-C in Europe confirmed.

[Rob Kimberley]

Sad news..

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning 
Kamp
Sent: 17 December 2015 10:51
To: time-nuts@febo.com
Subject: [time-nuts] End of Loran-C in Europe confirmed.

I've spent some time tracking this down, but it looks like all Loran-C in 
Europe shuts down on new-years eve.

The only station I have not found official confirmation for is Sylt, but 
France, Norway, Denmark and UK have all officially announced shut-down of their 
stations.

It seems that they have also agreed to not dismantle anything until
2017 "In case something political happens".

Poul-Henning

PS: I havn't checked recently if the Russian Chayka still transmits, they've 
never been usable for me because the 8000µs GRI gets trashed by any [V]LF 
transmitter on a integral kHz frequency, which is pretty much all of them.

PPS: During my research I noticed that the guy who comes closest to being the 
inventor of Loran-[ABCF] and OMEGA, John *Alvin* Pierce, doesn't even have a 
Wikipedia page.

Somebody with more time than me should rectify that.

Here, in his own words, is the story of how US military saw the light in 
radio-navigation:

http://phk.freebsd.dk/misc/jack_pierce.html#spring

The full memoir is 1st. class nerd-reading.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] Datum PRS-45A

[Rob Kimberley]

>From my memory of these units while selling Austron products, they had FTS 
>tubes and the command set should be the same.




Sent from Samsung tablet

 Original message 
From: W2HX  
Date:04/02/2015  04:18  (GMT+00:00) 
To: "Discussion of precise time and frequency measurement (time-nuts@febo.com)" 
 
Subject: [time-nuts] Datum PRS-45A 

Hello all,

I recently acquired a very nice PRS-45A for a very good price (<$500).  I wired 
up a -48V supply and within 30 minutes it was locked! I am very happy about 
that. Now I am trying to communicate with it so I can read parameters such as 
the hours on the tube, etc.

I do have the monitor.exe program, but unfortunately, I do not have easy access 
to a PC serial port. I do have access to my 24-port console server that I use 
for my GPSDOs and other serial devices. This gives me telnet access to those 
devices.

In the time-nuts archives, I read that there may be some similarities to the 
FTS-4065C in terms of controlling it. I have that manual, and it describes some 
commands that can be issued directly to the device without using the 
monitor.exe program. At the moment, I cannot get any communication going with 
the PRS. I tested my cable and it is fine. But I don't know a lot of things

a)  Default baud rate (It may be 2400 baud as the FTS manual seems to 
indicate)

b)  Number of bits

c)   Parity setting

d)  DTE/DCE

Etc.  I was hoping, can anyone tell me if the PRS should echo back characters 
to me even if I haven't sent a well-formed command? According to the FTS 
manual, these commands involve control characters as well as a 5 digit serial 
number. Being unsure if I am a) sending the right control characters, b) if it 
is correct to use the last 5 digits of my 10 digit serial number c) if the PRS 
commands are even the same as the FTS commands - I sure would love see an echo 
of a  character or something to indicate that the communication 
parameters are correct and all I have to worry about is forming the correct 
command.

Any ideas greatly appreciated. If I can establish any basic communication with 
it, then I can investigate a serial port to telnet stub driver that could 
present a COM port to the monitor program and maybe I could get it working this 
way.  I should mention, that even if I had access to a real serial port, it is 
my long term intention to use the console server ultimately.
Thanks for the time and bandwidth

73 Eugene W2HX

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[time-nuts] Datum 9150-5106 Manual

[Rob Kimberley]

Hi,

I'm looking for the manual for a Datum 9150-5106 Airborne Time Code
Generator.

Unfortunately I got rid of all my Datum manuals some time back. Hope someone
can help.

Many thanks

Rob 



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[time-nuts] R.I.N. Journals

[Rob Kimberley]

I have a box plus of Royal Institute of Navigation Journals going back
several years.

Free to a good home - UK  - collection only.

DE6 2AF post code.

Cheers

Rob Kimberley



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Re: [time-nuts] Examples of leap-seconds in local timezones

[Rob Kimberley]

Magnus,

(Going from memory here...) I seem to remember that NPL in UK used to add
0.1 second to each of the first 10 seconds after the hour. If this wrong, I
hope someone picks up on it!
Cheers
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Magnus Danielson
Sent: 22 January 2014 19:53
To: time-nuts@febo.com
Subject: [time-nuts] Examples of leap-seconds in local timezones

Fellow time-nuts,

In a discussion it again re-occurred that we needed examples of how
leap-seconds is indeed is inserted into the local timezones at the UTC
midnight.

I think I recall that the Tokyo stock exchange was closed during the
leap-second for instance. Stuff like that.

Cheers,
Magnus
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Re: [time-nuts] REQ: Manuals and Schematics for the Austron 2010B

[Rob Kimberley]

Hi John,

This is an old analogue design, but have used and sold them in the past. A
bit of a bugger to set up, but they work well.
Good luck!
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John C. Westmoreland, P.E.
Sent: 31 December 2013 00:14
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] REQ: Manuals and Schematics for the Austron 2010B

Hello time-nuts,

Another request -
does someone in the group have the manuals and schematics for the Austron
2010B - disciplined frequency standard?

Thanks and Happy New Year!
John Westmoreland
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Re: [time-nuts] Austron

[Rob Kimberley]

John, I worked for Austron between 1985 and 1989 running their European sales 
and support. Not sure how much I can help you. I live in the UK. Please email 
me off list as a first pass. 
Rob Kimberley


Regards
Rob Kimberley 

Sent from Samsung Mobile

 Original message 
From: "John C. Westmoreland, P.E."  
Date:  
To: Discussion of precise time and frequency measurement  
Subject: Re: [time-nuts] Austron 
 
Hello Thomas,

Yes - I was aware of that.  And there is another company in there too I
think - EndRun Technologies.  Someone from that company told me about
Austron.

I am hoping someone on this list was employed by or worked for Austron.

Thanks,
John Westmoreland


On Thu, Dec 26, 2013 at 10:41 PM, Tom Knox  wrote:

> Austron was purchased by Datum which was then purchased by Symmetricom,
> which was recently sold to Microsemi.
>
> Thomas Knox
>
>
>
> > From: j...@westmorelandengineering.com
> > Date: Thu, 26 Dec 2013 17:42:21 -0800
> > To: time-nuts@febo.com
> > Subject: [time-nuts] Austron
> >
> > Hello Time-Nuts!
> >
> > I hope everyone is enjoying their Holiday Season!
> >
> > I have a question - I have been doing a little research lately on the
> > company that used to be in Austin, TX - Austron - they seemed to have
> filed
> > quite a few patents in areas of interest to our group.
> >
> > Here's one just as an example:
> >
> https://www.google.com/patents/US5220333?pg=PA1&dq=assignee:++austron&hl=en&sa=X&ei=tdq8UoL_EqbQ2wXy14DwCA&ved=0CDcQ6AEwAA
> >
> > Are there any former Austron people on this list?  If so, I would like to
> > have a brief phone conversation with you if that is OK.  Just general
> > questions - nothing personal of course.
> >
> > E-Mail could work but could be quicker just to have a brief phone call.
>  I
> > have Skype also if that
> > is easier.
> >
> > Thanks and Happy Holidays!
> > John Westmoreland
> > ___
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>
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Re: [time-nuts] GPS timing antenna 5 meter BNC Plug with cable

[Rob Kimberley]

Chinese email address on web site.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 05 December 2013 05:56
To: Time-nuts mailing list
Subject: [time-nuts] GPS timing antenna 5 meter BNC Plug with cable

Anyone know whether these antennas are any good?  Anyone used one?  I wonder
where they are made?

 
http://www.rfsupplier.com/timing-antenna-meter-plug-with-rg58-coax-cable-p-2
344.html

Looks like it has no filter, and some of the spelling is dubious!

Thanks,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk 

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Re: [time-nuts] Using a UBlox NEO-6 GPS module for calibrating a PIC microprocessor based timer.

[Rob Kimberley]

Good to hear you're still in the T&F biz Mike!!
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mike Garvey
Sent: 01 December 2013 14:46
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Using a UBlox NEO-6 GPS module for calibrating a
PIC microprocessor based timer.

Luke,
Seems that you might indeed become a time nut, though most of those on the
list are focused on atomic clock topics and the time precision that atomic
clocks provide.
That said, sounds like you have a good start.  While I have not used the GPS
module you mention, GPS timing sources typically show timing accuracies of
20 to 100 ns.  The short term noise arises from the signal-to-noise of the
"as received" signals, so the 99% accuracy of 60 ns likely means that you
can assume that all of the pulses are within +/-100 ns.  The time noise is
"white" for GPS signals.  Note also that this is time accuracy, not
frequency accuracy.  Frequency accuracy is maintained by GPS Ground Control
Segment with reference to the US Naval Observatory Time Scale.
At the risk of unraveling your existing measurement architecture, you might
consider measuring the clock phase (pendulum passing) with respect to the
GPS pulse.  This would be a time interval measurement with an accurate (GPS)
reference pulse and a time interval based upon your TCXO.  This reduces the
burden of calibrating the TCXO and will eliminate concerns about the
frequency accuracy and stability of the TCXO.  For example, if your TCXO is
off frequency by 1 ppm, you would get a non-cumulative error of 1 ppm in the
time interval measurement rather than a 1 ppm error in the clock rate.  The
1 ppm TCXO error drops out of the solution for rate of the clock; only
changes in the TCXO frequency enter and they are typically much smaller.

Hope this is useful; others on the list will likely have other input.
Mike

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Luke Mester
Sent: Sunday, December 01, 2013 2:54 AM
To: time-nuts@febo.com
Subject: [time-nuts] Using a UBlox NEO-6 GPS module for calibrating a PIC
microprocessor based timer.

One of my hobbies is collecting and repairing mechanical clocks. I was
looking at buying one of the specialized electronic timers used to measure
the performance of mechanical clocks. I really couldn't justify the cost
just for hobby use.

Since I have electronics and programming skills I decided to build my own
timer using a PIC chip. This became a much bigger project than I expected!

I have my clock timer running and have most of the software features that I
need working. I then realized that I need some way to calibrate it and
verify it's accuracy.

I didn't have any source of accurate time available.  After searching the
internet and finding this mailing list I decided to try a GPS module. I
bought a $20 module from DX.com. It has a built in antenna, voltage
regulator, serial interface and most important, a 1 PPS output.The GPS is a
UBlox NEO-6M. After reading the specs on this module I see that they claim a
99% accuracy of <60ns for the time pulse signal. What does this mean?
What about the other 1%? How much variation can the time pulse have? If it's
really 60ns it's much better than I need.

I'm hoping that some of the time experts on this mailing list can give me
some idea what to expect from this GPS module. Also, if there are any
settings that I should change to get better timing performance. There are a
huge number of settings available when I run it's configuration program. I
have no idea what most of them do.

I'm using one of the hardware timers on the PIC chip to measure the time
interval. The PIC is running with a 100ns (10MHz) instruction cycle. The
timer will provide 100ns resolution. I'm getting occasional variations of
about a microsecond. Because I'm using interrupt driven code to capture the
timer value there will be some unavoidable jitter in the timing. I was
expecting about 4 or 5 cycles (400ns - 500ns) but I'm getting more than
twice that. Is it safe to assume that these are due to problems in my
hardware or software? Is this from variations in the GPS PPS output? Maybe
I'm just not interpreting the data correctly.

Below are links to some data plots:

Four plots are shown. The first two are the Rate and Beat error that my
timer reports while monitoring the GPS PPS signal. Rate is normally the
average of two beats ( two time interval samples). If a clock is not in beat
(the tick and tock take different amounts of time) the displayed rate would
jump back and forth. Averaging two beats eliminates this jump. I have
disabled this average in my code so that the rate is now showing each beat
and not the average of two. I turned it off because I expect that this
averaging could hide possible problems with my timer.  Beat error is the
difference between the two beats. This shows the rate change for

Re: [time-nuts] Problem with site?

[Rob Kimberley]

Thanks Alan,

Unusually quiet!!

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Alan Melia
Sent: 22 October 2013 13:45
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Problem with site?

My last message arrived at 0559 this morning 22nd Oct Alan G3NYK

- Original Message -
From: "Rob Kimberley" 
To: "'Discussion of precise time and frequency measurement'" 

Sent: Tuesday, October 22, 2013 12:52 PM
Subject: [time-nuts] Problem with site?


> Just a test to see if this site is working, as had no posts since Sunday.
>
> Cheers
>
> Rob Kimberley
>
>
>
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[time-nuts] Problem with site?

[Rob Kimberley]

Just a test to see if this site is working, as had no posts since Sunday.

Cheers

Rob Kimberley
 


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Re: [time-nuts] refclock -> NTP server settings/tuning?

[Rob Kimberley]

I've found that setting Minpoll and Maxpoll to 5 gives me best results.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Anders Wallin
Sent: 29 September 2013 13:11
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] refclock -> NTP server settings/tuning?

Thanks for all replies,

I can try changing maxpoll to a larger value and see if the trace is
smoother.

The refclock driver is a userspace C-program (daemon) that essentially does:
while(1) {
gettimeofday(&tv,NULL) // system time, for NTP  receiveTimeStamp
get_wr_time(&wr_tv); // WR time, for NTP clockTimeStamp
// write tv and wr_tv to shared memory where NTP expects to see them
sleep(8);
}

This may be the cause of a constant negative offset I see, since one
time-stamp is always read before the other. Perhaps this could be improved
by reading system time both before and after get_wr_time() and reporting the
average of the two readings as receiveTimeStamp? Or measure the offset and
put it as a "time1" offset-value in ntp.conf If the driver was written as a
kernel module, would that run with higher priority and less variable delay?

I use the same piece of code to log how well system time tracks WR-time.
Here I sometimes see sudden spikes of 100s of microseconds. Could this be
caused by the OS context switching in the middle of my program between the
two timestamp-reading functions? Again, would this improve if the
time-logger was written as a kernel module, or is there some other way of
coding it that avoids context switches and keeps the two time-stamp reading
functions "atomic"?

Standard Ubuntu nowadays has a pre-packaged "lowlatency" kernel which I
think is RT-Preempt with some modifications. But I assume both the
refclock-driver and the logger would need a re-write to take advantage of
the RT-kernel. Does anyone have experienced with that?

thanks,
Anders
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Re: [time-nuts] Case for Rb Standard?

[Rob Kimberley]

Bob,

Should work OK if it's a metal case and fan is good. You need a decent also
heat sink as they run pretty hot. 

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bob Stewart
Sent: 27 September 2013 04:03
To: Time Nuts
Subject: [time-nuts] Case for Rb Standard?

I've had the Rb on the shelf for a few days next to a few old 3.5" disk
drives, and it suddenly struck me that they're about the same size. 
External drive cases and PSUs are "cheap as chips", as they say, so I was
wondering how many people are using an external drive case to hold their Rb
standard?  Any brand favorites?

Bob - AE6RV
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Re: [time-nuts] Space mission comes to an end because of a "computer time tagging" problem

[Rob Kimberley]

David,

The satellite has probably got a Rb as its clock (hopefully more than one).
All I can imagine is that there has been a major clock failure of some sort,
and everything is in free run and unable to sync up with ground.

Thoughts?

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 20 September 2013 17:51
To: Time-nuts mailing list
Subject: [time-nuts] Space mission comes to an end becuase of a "computer
time tagging" problem

NASA's Deep Space Comet Hunter Mission Comes to an end

The news release includes this paragraph:
"After losing contact with the spacecraft last month, mission
controllers spent several weeks trying to uplink commands to reactivate its
onboard systems.  Although the exact cause of the loss is not known,
analysis has uncovered a potential problem with computer time tagging that
could have led to loss of control for Deep Impact's orientation.  That would
then affect the positioning of its radio antennas, making communication
difficult, as well as its solar arrays, which would in turn prevent the
spacecraft from getting power and allow cold temperatures to ruin onboard
equipment, essentially freezing its battery and propulsion systems."

Knowing the membership of this group, does anyone have more insight into
what the "computer time tagging" problem might be?

Thanks,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk 

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Re: [time-nuts] FCC politics vs their engineers...

[Rob Kimberley]

I remember a story told to me many years ago, about a discussion between an
American Astronaut and a Russian Cosmonaut. 

It goes along something like this...

Astronaut to Cosmonaut:  " I wouldn't be happy sitting on the top of that
low technology rocket"

Cosmonaut to Astronaut: "I would rather that than sit at the top of a pile
of low bids"

Rob K



-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. Forster
Sent: 17 September 2013 19:19
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FCC politics vs their engineers...

"It is hard to imagine a more stupid or more dangerous way of making
decisions than by putting those decisions in the hands of people who pay no
price for being wrong." - Thomas Sowell

YMMV,

-John

===



> Was it not always so?? Remember the politicians pay the bills not the 
> engineers!
> Alan
> G3NYK
>
> - Original Message -
> From: "Eric Williams" 
> To: "Discussion of precise time and frequency measurement"
> 
> Sent: Tuesday, September 17, 2013 7:04 PM
> Subject: Re: [time-nuts] FCC politics vs their engineers...
>
>
>> "He tells me with some bitterness that politics triumphed over all of 
>> the objections of the engineering staff to LS and that this is not 
>> the first time that this has happened."
>>
>> That's how we ended up with Challenger and Columbia.
>>
>>
>> On Tue, Sep 17, 2013 at 6:46 AM, Michael Baker 
>> wrote:
>>
>>> Time-Nutters--
>>>
>>> Jim wrote:
>>> snip
>>> > That's why the FCC granted a "conditional" waiver of the rules.  
>>> > It was politically expedient, and I would imagine that the 
>>> > engineers at the FCC thought "there's no way they'll be able to 
>>> > demonstrate no interference"
>>>
>>> Charles wrote:
>>> snip
>>> > The Commission not only thought LS would demonstrate 
>>> > non-interference, it put its thumb on the scale until the public 
>>> > outcry became too loud to ignore (the GPS interests took forever 
>>> > to wake up -- that didn't happen until all of the comment periods 
>>> > were long closed).  It just didn't matter what the staff engineers 
>>> > thought -- which is business  as usual at the FCC.
>>> --**--
>>>
>>> A friend of mine was one of the FCC lead supervisory engineers that 
>>> was involved in the LS fiasco.  He tells me that there were 
>>> technical reports, evaluation summaries and strong opinions offered 
>>> by the engineering staff that provided a number of reasons why the 
>>> LS project should be denied.  He tells me that most of these 
>>> engineering studies got buried and ignored.
>>> He tells me with some bitterness that politics triumphed over all of 
>>> the objections of the engineering staff to LS and that this is not 
>>> the first time that this has happened.
>>>
>>> Mike Baker
>>> Gainesville, FL  USA
>>>
>>> __**_
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
>>> https://www.febo.com/cgi-bin/** 
>>> mailman/listinfo/time-nuts>> info/time-nuts>
>>> and follow the instructions there.
>>>
>> ___
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>
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>


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Re: [time-nuts] New NTBW50AA

[Rob Kimberley]

Do you have any idea how much the antenna will move in a strong wind? It
really needs to be in a secure rigid position for optimum timing
performance. Sorry if this has been covered before but just picked up the
thread.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of quartz55
Sent: 14 September 2013 18:26
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] New NTBW50AA

Here's a better view of the antenna looking due south.
http://i251.photobucket.com/albums/gg287/DogTi/abovebeamssouth_zpsd8fb78ca.j
pg

Dave
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Re: [time-nuts] 9390-55108 IRIG

[Rob Kimberley]

It was originally designed to put on magnetic tape for time tagging
telemetry data from the White Sands missile testing base. It can be used for
a number of applications where you need to send time via coax cable to other
devices i.e. time displays, synchronising other timing devices.

Google IRIG-B and get the history.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Al Wolfe
Sent: 09 August 2013 18:38
To: time-nuts@febo.com
Subject: Re: [time-nuts] 9390-55108 IRIG

The TrueTime GPS receiver and frequency standard I have puts out IRIG-B
as well as 4 each 10 Mhz. signals. What in practical terms is the IRIG-B
(AM, not DC) good for?

Al, K9SI


> The DC code was usually TTL compatible PWM and the IRIG-B would be 3V 
> pk-pk AM. Marker 8 cycles, "1" 5 cycles and "0" 2 cycles wide. Spaces 
> 1V pk-pk.


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Re: [time-nuts] 9390-55108 IRIG

[Rob Kimberley]

Good luck!
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 13:42
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 9390-55108 IRIG

Rob, that's it - IRIG-B.
Then I must look at the O/S / sound driver/codec.
ALSA has replaced OSS which the driver was written to use.
There is ALSA OSS emulation, which I am using.
That is perhaps, the problem.
I just have to find an older distribution that uses OSS and install it.
Thanks for your Help!

--marki

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob Kimberley
Sent: Friday, 9 August 2013 10:32 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 9390-55108 IRIG

<https://www.google.co.uk/search?q=IRIG+B&oe=utf-8&rls=org.mozilla:en-GB:off
icial&client=firefox-a&channel=np&gws_rd=cr&um=1&ie=UTF-8&hl=en&tbm=isch&sou
rce=og&sa=N&tab=wi&ei=-uAEUr7kILKo0AX1m4HYDg&biw=1440&bih=728&sei=_eAEUrLEMe
e30QWUqIHQBQ#facrc=_&imgrc=Mk-NE6fEBiUfvM%3A%3BU8oGSPcxYQPCsM%3Bhttp%253A%25
2F%252Fwww.meinbergglobal.com%252Fimages%252Ftime-code-irig.gif%3Bhttp%253A%
252F%252Fwww.meinbergglobal.com%252Fenglish%252Finfo%252Firig.htm%3B2464%3B1
260>

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 13:28
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 9390-55108 IRIG


The refclock utilises AGC and winds the mixer input up to full volume.
It is supposed to be a mic input so it would be over loaded.

I think its AM as there is a carrier with peaks.
Perhaps a picture from an oscilloscope would be a better way to describe it?
Listening to it, I hear 1KHz and 50(100?)Hz hum?

--marki

-Original Message-----
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob Kimberley
Sent: Friday, 9 August 2013 10:03 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 9390-55108 IRIG

Mark,

What is your ref clock driver 6 expecting to see?

IRIG-B can be in a modulated or un-modulated form (Datum called this DC
code)

The DC code was usually TTL compatible PWM and the IRIG-B would be 3V pk-pk
AM. Marker 8 cycles, "1" 5 cycles and "0" 2 cycles wide. Spaces 1V pk-pk.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 12:16
To: time-nuts@febo.com
Subject: [time-nuts] 9390-55108 IRIG

I am trying to get a Datum 9390-55108 to work with NTPD using refclock
driver 6.
So far I have been unsuccessful.
The output looks like IRIG-B (modulated 1Khz with 50% greater amplitude
pulses) I can't get it to work with NTPD.
Unless of course, my NTPD version is broken!

Does anyone have information on these old type of 9390 that suggests the
IRIG standard they output?


--marki
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Re: [time-nuts] 9390-55108 IRIG

[Rob Kimberley]

<https://www.google.co.uk/search?q=IRIG+B&oe=utf-8&rls=org.mozilla:en-GB:off
icial&client=firefox-a&channel=np&gws_rd=cr&um=1&ie=UTF-8&hl=en&tbm=isch&sou
rce=og&sa=N&tab=wi&ei=-uAEUr7kILKo0AX1m4HYDg&biw=1440&bih=728&sei=_eAEUrLEMe
e30QWUqIHQBQ#facrc=_&imgrc=Mk-NE6fEBiUfvM%3A%3BU8oGSPcxYQPCsM%3Bhttp%253A%25
2F%252Fwww.meinbergglobal.com%252Fimages%252Ftime-code-irig.gif%3Bhttp%253A%
252F%252Fwww.meinbergglobal.com%252Fenglish%252Finfo%252Firig.htm%3B2464%3B1
260>

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 13:28
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 9390-55108 IRIG


The refclock utilises AGC and winds the mixer input up to full volume.
It is supposed to be a mic input so it would be over loaded.

I think its AM as there is a carrier with peaks.
Perhaps a picture from an oscilloscope would be a better way to describe it?
Listening to it, I hear 1KHz and 50(100?)Hz hum?

--marki

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob Kimberley
Sent: Friday, 9 August 2013 10:03 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] 9390-55108 IRIG

Mark,

What is your ref clock driver 6 expecting to see?

IRIG-B can be in a modulated or un-modulated form (Datum called this DC
code)

The DC code was usually TTL compatible PWM and the IRIG-B would be 3V pk-pk
AM. Marker 8 cycles, "1" 5 cycles and "0" 2 cycles wide. Spaces 1V pk-pk.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 12:16
To: time-nuts@febo.com
Subject: [time-nuts] 9390-55108 IRIG

I am trying to get a Datum 9390-55108 to work with NTPD using refclock
driver 6.
So far I have been unsuccessful.
The output looks like IRIG-B (modulated 1Khz with 50% greater amplitude
pulses) I can't get it to work with NTPD.
Unless of course, my NTPD version is broken!

Does anyone have information on these old type of 9390 that suggests the
IRIG standard they output?


--marki
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Re: [time-nuts] 9390-55108 IRIG

[Rob Kimberley]

Mark,

What is your ref clock driver 6 expecting to see?

IRIG-B can be in a modulated or un-modulated form (Datum called this DC
code)

The DC code was usually TTL compatible PWM and the IRIG-B would be 3V pk-pk
AM. Marker 8 cycles, "1" 5 cycles and "0" 2 cycles wide. Spaces 1V pk-pk.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 09 August 2013 12:16
To: time-nuts@febo.com
Subject: [time-nuts] 9390-55108 IRIG

I am trying to get a Datum 9390-55108 to work with NTPD using refclock
driver 6.
So far I have been unsuccessful.
The output looks like IRIG-B (modulated 1Khz with 50% greater amplitude
pulses) I can't get it to work with NTPD.
Unless of course, my NTPD version is broken!

Does anyone have information on these old type of 9390 that suggests the
IRIG standard they output?


--marki
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Re: [time-nuts] GPS Spoofing

[Rob Kimberley]

I've just been catching up on this thread. 

The subject says GPS Spoofing, but most of the replies seem to revolve
around jamming. Not the same thing.

Just a thought...

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. Forster
Sent: 28 July 2013 20:06
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS Spoofing

The point about the duty cycle being low is correct. And, there are
commercial linear power amps, like the used ones made by ENI and others,
that can easily put out 1 kW plus narrow pulses.

Furthermore, the pulse generator is trivial to make with a Rb, 3 or more
Tektronix DD501s, a simple OR gate and a gated oscillator at about 100 kHz.
I've cobbled up that setup several times as a LORAN-A simulator.

The main difficulty is getting a reasonable match to an efficient antenna at
100 kHz.

-John

=



> Hi
>
> Since it's a pulse system, and you get to position your pulse for 
> maximum effect, I don't see any reason to generate CW power. Simply 
> mimic the lowest power slave in the chain. There's very little 
> redundancy with Loran, so spoofing one station will mess it up. No 
> need to mask the entire chain. At most you would need to hit two low power
slaves.
>
> Math wise:
>
> Wavelength is 10,000 ft / 3,000M. Throw things off by ~10% of that and 
> you have problems in a harbor. You would need to play a bit to see 
> weather a pulse every so often does the trick or not. Is that 20 db 
> below the slave or not ? You'd have to play with it. It's in that 
> range. A spoof that says they are on the other side of the world isn't 
> going to work. One that says you are on the north side of the channel 
> (when you are on the south side) is what would work.
>
> Power within a pulse set at a  5:1 duty cycle. For a 50,000 us GRI you 
> have another 50:1. For longer GRI's you might add another 2:1. Net is 
> a peak to average ratio of 250-1000 to 1. Put another way, a 500W 
> pulse is ~
> 1 average.
>
> Power at 100 KHz = what's in a fairly cheap switching power supply. 
> Plug it into the wall. A couple hundred watts (or even KW) pulse is 
> cheap. Say you have 120W out of the wall (or a car battery). If the 
> math above is correct and you can run 80% efficiency, that's a pretty
powerful pulse.
> It's probably cheaper to generate something at 50:1 rather than the 
> whole
> > 200:1. A 5KW is a *lot* of RF, even into a simple antenna.
>
> Antenna - there's a couple ways to do that. All of them are tradeoffs 
> (size / cost / power). The cheap way is to use a wire that's already 
> there.. Since you don't need to propagate (near field), the antenna 
> efficiency could be higher than you would think for some antennas.
>
> Is it easier than that with some smarts involved in the pulse - 
> probably yes. Do the smarts raise the hardware cost significantly? - 
> you'd have to build a few and find out. What really drives this or 
> that Loran receiver nuts? I'm quite sure you could work that out with one
to play with.
>
> Am I gong into the Loran-C jammer business? No, so don't contact me 
> off list to buy one. The point is not *have* I built one, but could 
> one be built easily.
>
>
> Bob
>
>
> On Jul 28, 2013, at 1:29 PM, "Poul-Henning Kamp" 
> wrote:
>
>> In message , Bob Camp
>> writes:
>>
>>> I'm not talking about taking out Loran-C over the entire North 
>>> Atlantic.
>>> The target is a harbor sized area. For that, you certainly do not 
>>> need a 600' antenna or megawatts of power.
>>
>> No, you need about 600W (continuous) and a loop-antenna about 5m in 
>> diameter.
>>
>> Do the math, It's not as easy as you think.
>>
>> --
>> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
>> p...@freebsd.org | TCP/IP since RFC 956
>> FreeBSD committer   | BSD since 4.3-tahoe
>> Never attribute to malice what can adequately be explained by 
>> incompetence.
>
> ___
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> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>


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Re: [time-nuts] BPSK decoder for WWVB

[Rob Kimberley]

I assume you mean MSF...



Sent from Samsung Mobile

 Original message 
From: Brian Alsop  
Date:  
To: Discussion of precise time and frequency measurement  
Subject: Re: [time-nuts] BPSK decoder for WWVB 
 
Apparently this modulation scheme is less prone to "jammers".
There is is British station which "jams" east coast WWVB.

Brian/K3KO

On 7/3/2013 18:00, Tim Shoppa wrote:

> Potentially the BPSK encoding ought to offer much better decoding here on
> the East Coast of US. Many of the commercially available, pre-BPSK WWVB
> consumer clocks didn't sync so well in the summertime due to high noise
> levels.
>
> Tim N3QE



-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.2242 / Virus Database: 3204/5961 - Release Date: 07/03/13

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[time-nuts] Glonass Payload lost...

[Rob Kimberley]

http://www.bbc.co.uk/news/science-environment-23140665

Rob


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Re: [time-nuts] The "auction site"?

[Rob Kimberley]

I always thought it was a bit strange. As we say over here: "call a spade a 
spade"


Sent from Samsung Mobile

 Original message 
From: Doug Calvert  
Date:  
To: Discussion of precise time and frequency measurement  
Subject: [time-nuts] The "auction site"? 
 
Hello,
Why do people go out of their way to avoid writing ebay on this list?
The statements are purposely written so that it is obvious that the
"insert mystical phrase"  is ebay and not a generic auction site. What
history am I not aware of?
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Re: [time-nuts] Language -- The eternal barrier

[Rob Kimberley]

Classic!!!
:-)


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of gandal...@aol.com
Sent: 01 July 2013 09:45
To: time-nuts@febo.com
Subject: [time-nuts] Language -- The eternal barrier

 
 
 
Having recently bought a couple of MV89As I found listed on AmazonUK I
received a feedback request a couple of days ago from the seller and took
the opportunity to point out that whilst one was fine the other was much
noisier than the first, and also in comparison with others I'd previously
bought elsewhere.
 
The seller has very kindly provided a solution to my  problem..
 
---
Dear Nigel,

Thank you for your reply.

We are very sorry  for the issue. We suggest that you could wear earphone to
reduce the noise when you use the oscillators.

Sorry for  all the inconvenience again.


Your understanding will be highly  appreciated in advance.
--
 
Off topic I know, so apologies for that, but thought others  might enjoy it
too:-)
 
Regards
 
Nigel
GM8PZR
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Re: [time-nuts] Datum 9390 issues & Spectracom 8195a woes

[Rob Kimberley]

That should have said: is it drawing any current...

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob Kimberley
Sent: 11 June 2013 11:40
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

Didier,

Is it taking any current?

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Didier Juges
Sent: 10 June 2013 18:56
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

Rob, 

I have 50 feet of RG-6 in excellent condition, which is the same cable I
used to test the other antennas. I have thought it may be bad, but there are
so few components inside that it is hard to imagine any failure mode other
than flat dead, yet it is not dead, just a few dBs short.

Anyhow, I have a Symmetricom antenna driving a Symmetricom active splitter
obtained from someone on the list, may have been John A, which works very
well, so the Bullet is taking a rest :)

Didier


Rob Kimberley  wrote:

>Didier,
>
>The 9390s were supplied with Trimble Bullets and were usually very 
>sensitive as long as you watch cable length/attenuation.
>It sounds like you Bullet is faulty.
>Rob
>
>-Original Message-
>From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
>Behalf Of Didier Juges
>Sent: 09 June 2013 19:42
>To: Discussion of precise time and frequency measurement
>Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes
>
>My own Trimble Bullet, and others as far as I can tell by reading this 
>list, is not very sensitive in general. I get much better results with 
>a Symmetricom than with the Bullet. For that matter, I also see more 
>satellites with a cheap mag-mount GPS active antenna than with the 
>Bullet.
>It is working, but not well.
>However, if you don't see any satellite with it and it is mounted 
>reasonably well, it may be broken.
>
>Didier
>
>
>On Sun, Jun 9, 2013 at 12:15 PM, Tammy A Wisdom
>wrote:
>
>> Hi all
>> I have a datum 9390 that will pick up GPS and get the date etc but 
>> will not go into oscillator lock state. Anyone have any suggestions
>on
>this?
>>
>> Next up is the spectracom 8195a I have. Allegedly it was working when
>
>> removed from an American tower site. Sadly it doesn't see any GPS 
>> satellites. I'm guessing when it was removed someone cut the antenna
>coax.
>> It still has 4.5v dc on the antenna port but never sees any
>satellites.
>> This device uses oncore gps module. Does anyone know if a) if I 
>> replace said oncore module will it actually work & b) is there 
>> anything goofy they did with the antennas on these units?  & c) is it
>
>> possible they blew the front end of the oncore?  I'm using a trimble 
>> bullet antenna with both devices
>>
>> That all said. If you have a working 9390 or 819x gps reciever that 
>> you would consider parting with please let me know. I'm trying to put
>
>> together a ntp server for my collocation facility.
>>
>> Thank you
>> Tammy A Wisdom
>>
>>
>> Sent from my iPhone
>> ___
>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
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>>
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Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

[Rob Kimberley]

Didier,

Is it taking any current?

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Didier Juges
Sent: 10 June 2013 18:56
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

Rob, 

I have 50 feet of RG-6 in excellent condition, which is the same cable I
used to test the other antennas. I have thought it may be bad, but there are
so few components inside that it is hard to imagine any failure mode other
than flat dead, yet it is not dead, just a few dBs short.

Anyhow, I have a Symmetricom antenna driving a Symmetricom active splitter
obtained from someone on the list, may have been John A, which works very
well, so the Bullet is taking a rest :)

Didier


Rob Kimberley  wrote:

>Didier,
>
>The 9390s were supplied with Trimble Bullets and were usually very 
>sensitive as long as you watch cable length/attenuation.
>It sounds like you Bullet is faulty.
>Rob
>
>-Original Message-
>From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On 
>Behalf Of Didier Juges
>Sent: 09 June 2013 19:42
>To: Discussion of precise time and frequency measurement
>Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes
>
>My own Trimble Bullet, and others as far as I can tell by reading this 
>list, is not very sensitive in general. I get much better results with 
>a Symmetricom than with the Bullet. For that matter, I also see more 
>satellites with a cheap mag-mount GPS active antenna than with the 
>Bullet.
>It is working, but not well.
>However, if you don't see any satellite with it and it is mounted 
>reasonably well, it may be broken.
>
>Didier
>
>
>On Sun, Jun 9, 2013 at 12:15 PM, Tammy A Wisdom
>wrote:
>
>> Hi all
>> I have a datum 9390 that will pick up GPS and get the date etc but 
>> will not go into oscillator lock state. Anyone have any suggestions
>on
>this?
>>
>> Next up is the spectracom 8195a I have. Allegedly it was working when
>
>> removed from an American tower site. Sadly it doesn't see any GPS 
>> satellites. I'm guessing when it was removed someone cut the antenna
>coax.
>> It still has 4.5v dc on the antenna port but never sees any
>satellites.
>> This device uses oncore gps module. Does anyone know if a) if I 
>> replace said oncore module will it actually work & b) is there 
>> anything goofy they did with the antennas on these units?  & c) is it
>
>> possible they blew the front end of the oncore?  I'm using a trimble 
>> bullet antenna with both devices
>>
>> That all said. If you have a working 9390 or 819x gps reciever that 
>> you would consider parting with please let me know. I'm trying to put
>
>> together a ntp server for my collocation facility.
>>
>> Thank you
>> Tammy A Wisdom
>>
>>
>> Sent from my iPhone
>> ___
>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
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Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

[Rob Kimberley]

Didier,

The 9390s were supplied with Trimble Bullets and were usually very sensitive
as long as you watch cable length/attenuation. 
It sounds like you Bullet is faulty.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Didier Juges
Sent: 09 June 2013 19:42
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Datum 9390 issues & spectracom 8195a woes

My own Trimble Bullet, and others as far as I can tell by reading this list,
is not very sensitive in general. I get much better results with a
Symmetricom than with the Bullet. For that matter, I also see more
satellites with a cheap mag-mount GPS active antenna than with the Bullet.
It is working, but not well.
However, if you don't see any satellite with it and it is mounted reasonably
well, it may be broken.

Didier


On Sun, Jun 9, 2013 at 12:15 PM, Tammy A Wisdom
wrote:

> Hi all
> I have a datum 9390 that will pick up GPS and get the date etc but 
> will not go into oscillator lock state. Anyone have any suggestions on
this?
>
> Next up is the spectracom 8195a I have. Allegedly it was working when 
> removed from an American tower site. Sadly it doesn't see any GPS 
> satellites. I'm guessing when it was removed someone cut the antenna coax.
> It still has 4.5v dc on the antenna port but never sees any satellites.
> This device uses oncore gps module. Does anyone know if a) if I 
> replace said oncore module will it actually work & b) is there 
> anything goofy they did with the antennas on these units?  & c) is it 
> possible they blew the front end of the oncore?  I'm using a trimble 
> bullet antenna with both devices
>
> That all said. If you have a working 9390 or 819x gps reciever that 
> you would consider parting with please let me know. I'm trying to put 
> together a ntp server for my collocation facility.
>
> Thank you
> Tammy A Wisdom
>
>
> Sent from my iPhone
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
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Re: [time-nuts] 9390 GPS RX

[Rob Kimberley]

Mark,

What is the full model number (from label on rear)? It will be 9390-.  

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark C. Stephens
Sent: 22 May 2013 07:56
To: time-nuts@febo.com
Subject: Re: [time-nuts] 9390 GPS RX

Just a Follow up,

I checked the 10 Mhz output of the 9390 and it was... ~12 MHz.
Uhuh, Wiggling some cables I came across one that when pressure was put on
it, the frequency dropped back to 10Mhz.
The was J9 on the main (logic?) board.

Now I need to mention this particular 9390 has a separate board for the
16.368 oscillator.
>From the photo's I posted earlier, it is the 2nd card in from the front on
the right.
>From earlier posts I have gathered this is normally present on the Trimble
GPS monstrosity.
My Point is, this particular 9390 isn't your average model.

With the frequency now at 10 Mhz I tried a number of different antennae /
terminator combinations and eventually I was able to find a satellite.
Just 1? And it dropped in and out all the time.

Watching the 10 Mhz, it was drifting  +/- 500Hz.

That definitely wouldn't do, so I plugged the house standard into the
(external) time base input and the 9390 10 Mhz output became stable.
After a few minutes, I had 2 satellites! Cool.. 5 minutes we had 4 birds and
we are doing "GPS Correction"

Being the inquisitive sort I went in reverse, unplugging the house standard
from the (external) time base input.
Uhuh, we are back to 1 satellite dropping in and out. The GPS receiver
definitely doesn't like the 10MHz reference wobbling about all over the
place like a drunk sailor on shore leave..

Of course I plugged the House standard back in and we are in business again
with 4 Satellites, locked and loading.
No drop outs either. Interesting.

So My question is, (mostly to myself) Is the Efratom FRK Faulty and the root
of the Drift?
And how do I fix it, I ask myself?

I have downloaded the FRK manual for perusal, I believe there is an external
adjustment to bring it into lock area.
It may also be a problem with the PLL loop, fun stuff because I don't have a
schematic.

You see, the service manual I was supplied with when I purchased the 9390
isn't for this unit.
It's for the much newer varieties.
There is no mention of this particular Trimble GPS receiver with its
multiple sub-boards nor mention of a FRK oscillator in it.

I did a search of earlier time nuts posts and found there are quite a few
time nuts with 9390's, although there appear to be drastic differences
between the different 9390's.
Perhaps I should be going on the postfix, for instance mine is a 9390-55024.

Bah, I just noticed the GPS day is wrong, I think we are ~142 but its saying
278, Is that a GPS receiver bug?

So, Any helpful navigation hints before I embark on this Journey?


Many thanks,
Marki

From: Mark C. Stephens
Sent: Tuesday, 21 May 2013 8:42 PM
To: 'time-nuts@febo.com'
Subject: 9390 GPS RX

Hello Fellow time nuts,

I received a Datum 9390 GPS receiver I bought off eBay today. It had a PSU
fault and I am running it off a bench supply until I can get the PSU working
again. All the PSU does is supplies 28V so I can probably adopt a more
recent supply to fit if I can't fix the old one. I pulled the PSU apart and
so far found a blown triac. There is bound to be more 'things' blown but I
want to see if it's worth repairing first. I mean, it's not much use
repairing something that proves to be useless?

Funnily enough in the back of the Manual binder was a second manual. A
service Manual for a Trimble 5000A GPS/TIME frequency monitor. I'll scan it
if anyone needs it?

This particular 9390 is an odd Chap, doesn't look at all like picture in the
supplied manual.
http://www.vk2hmc.net/blog/wp-content/uploads/2013/05/9390-fr.jpg

When I opened it up,
http://www.vk2hmc.net/blog/wp-content/uploads/2013/05/9390-insides.jpg  I
saw an Efratom FRK!
http://www.vk2hmc.net/blog/wp-content/uploads/2013/05/frk.jpg


I am having a bit of problem identifying the GPS module. It says Trimble
navigation on the board:
http://www.vk2hmc.net/blog/wp-content/uploads/2013/05/gps-bd.jpg
I measured the antenna Jack for the expected 15V normally on a Datum 9390,
but found it was 5.1 volts.
I could not get rid of the Antenna feed error until I put a 50 ohm
terminator on it. I tried higher values (75-180R) but the only value that
cleared the feed error was 50 ohms. So I used a BNC 'tee' and terminated the
output of the GPS distribution amp to the 9390. I fear this GPS RX requires
an antenna with a down-convertor -or- a whacking great L1 signal. I always
thought the 9390 had a Trimble svee6 module in them. But this one's
positively ancient.
I have entered my approximate co-ordinates to see if it finds any birds but
so far no luck.

If you know anything about this GPS board, please leave me a message?

The interface convertor from the Trimble to the Datum:
http://www.vk2hmc.net/blog/wp-content/uploads/2013/05/gps-bd-if.jpg is
lab

Re: [time-nuts] Austron 2200A investigation

[Rob Kimberley]

Maybe a bit quick off the mark here. 

They definitely used the DDS technique with their later telecom modules, but
thinking about it, I'm now not sure the 2200 or 2201 used this.

Apologies for any confusion.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob Kimberley
Sent: 19 May 2013 17:43
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Austron 2200A investigation

The Rb was externally calibrated and then left to free run. They then used
DDS to get frequency o/p. 
Austron used this technique a lot with their later telecom GPS modules.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Luciano Paramithiotti
Sent: 19 May 2013 09:14
To: time-nuts@febo.com
Subject: [time-nuts] Austron 2200A investigation

Hi,

I have an Austron 2200A with FRS rubidium option. After 30 min. powerup and
locking, PPS and Freq alarm goes up. The receiver position and the FRS  are
ok. Looking the Rubidium and controller connection cable, I have seen the
pin 8 (frequency control)of the rubidium is never been connected. The
question are:

1) how the PLL can happen?  Cannot ! Different operation?
2) some one have the interface's schematic p.n. 10312676 "Osc cntl freq
cntr" ?

thank you,
--
Luciano
Timeok
visit : www.timeok.it
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Re: [time-nuts] Austron 2200A investigation

[Rob Kimberley]

The Rb was externally calibrated and then left to free run. They then used
DDS to get frequency o/p. 
Austron used this technique a lot with their later telecom GPS modules.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Luciano Paramithiotti
Sent: 19 May 2013 09:14
To: time-nuts@febo.com
Subject: [time-nuts] Austron 2200A investigation

Hi,

I have an Austron 2200A with FRS rubidium option. After 30 min. powerup and
locking, PPS and Freq alarm goes up. The receiver position and the FRS  are
ok. Looking the Rubidium and controller connection cable, I have seen the
pin 8 (frequency control)of the rubidium is never been connected. The
question are:

1) how the PLL can happen?  Cannot ! Different operation?
2) some one have the interface's schematic p.n. 10312676 "Osc cntl freq
cntr" ?

thank you,
--
Luciano
Timeok
visit : www.timeok.it
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Re: [time-nuts] for Mark C. Stephens re 2200 downconverter

[Rob Kimberley]

AFIK, these won't be compatible with the Austron 2200. The IF on the Austron
is 75MHz, with a L.O. of 10 MHz.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of mike cook
Sent: 16 May 2013 06:57
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] for Mark C. Stephens re 2200 downconverter

Mark,
  The thread on your 2200 indicated that these downconverters were used by
various manufacturers. I just happened on paybay item 280918789321 which may
fit your app. 
regards, Mike
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Re: [time-nuts] NTP, PPS and < 10 us offsets

[Rob Kimberley]

Check if you have a Max Poll setting in your config file. 

max poll 5 = 32 seconds
max poll 6 = 64 seconds
max poll 7 = 128 seconds 

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Miguel Barbosa Gonçalves
Sent: 15 May 2013 01:31
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] NTP, PPS and < 10 us offsets

Hi!

I am trying to figure out why NTP takes so long to react to oscillator
changes... I want it to track the PPS from a Trimble Acutime as closely as
possible.

When checking ntptime on startup I see that the NTP daemon is using PLL and
starts the adjustment interval at 8 s. It then increases to 16, 32, 64, 128
and stops at 256.

I read in the documentation that this limit should be 128 but is now 256.

--- start from http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm --- intervals
57 says that there were 57 calibration intervals. When PPS pulses are
arriving, this number should increase. Each frequency adjustment requires a
good calibration interval. The length of the current calibration interval
can be found as interval 128 s (128 seconds is the default maximum length).
Remaining numbers count abnormal conditions as explained below.
--- end ---

How can I make it stop earlier? At 64 s for example?

Any ideas?

TIA,
Miguel
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Re: [time-nuts] NEW subject

[Rob Kimberley]

John,

I don't believe there is any connection.

As an aside, "Dimension 4" was one of the names we looked at when Odetics
Telecom changed its name to Zyfer.

Cheers
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Ackermann N8UR
Sent: 09 May 2013 22:07
To: time-nuts@febo.com
Subject: Re: [time-nuts] NEW subject

I didn't look at this initially because I thought it was a reference to the
(s)NTP time setting program for Windows that came, I think, from a company
called Dimension4.  I wonder if there is any connection?

John


On 5/9/2013 3:46 PM, Bob Camp wrote:
> Hi
>
> A little poking at the web site:
>
> 1) 4 people listed as working there
> 2) Most recent information is from late 2011
> 3) "create your own web site for free" plastered here and there
> 4) Confusion between 100 mW and 100 uW. Various other inconsistent 
> data points page to page.
>
> It looks like they are trolling for funding.
>
> Bob
>
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] 
> On Behalf Of Erno Peres
> Sent: Thursday, May 09, 2013 12:40 PM
> To: time-nuts@febo.com
> Subject: [time-nuts] NEW subject
>
>
> Anybody have seen this product or has more info about it???
>
> http://d4atomicclock.wix.com/dimension4#!products
>
>
> Rgds Ernie.
> ___
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Re: [time-nuts] NEW subject

[Rob Kimberley]

No specifications. Web site a bit flaky. 

$10 for atomic accuracy?

I don't think so...

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Erno Peres
Sent: 09 May 2013 17:40
To: time-nuts@febo.com
Subject: [time-nuts] NEW subject


Anybody have seen this product or has more info about it???
  
http://d4atomicclock.wix.com/dimension4#!products


Rgds Ernie.
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Re: [time-nuts] Questions about Austron 5000 Loran C receiver

[Rob Kimberley]

Hi,

I don't know this model from Austron, but you could try asking fellow Time
Nuts if anyone has a manual for the 5000 which should include the full
calibration procedure. 

I know on the Austron 2000C the calibration procedure was quite a long to
set it up correctly. I'm sure that the 5000 will be similar.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of mehdi
Sent: 13 April 2013 13:08
To: time-nuts@febo.com
Subject: Re: [time-nuts] Questions about Austron 5000 Loran C receiver


> >hi dears
i'm newer here.
i have some questions about loran-c receiver.can you help me?
i want to know how can i find third zero crossing in loran-c receiver?
i find third zero cross by peterson 's method from this paper:
Analysis of Noise and Cycle Selection in a Loran Receiver but due to Gausian
noise,when i find third zero cross,it is not correct and it is before or
after correct third zero cross.i want to know how can i track and correct
third zero cross?(in other words what is acquisition in loran-c receivers
and how can i do?) have you any matlab code or papers or thesis for this
problems?
please help me?
:(
thanks a lot

> 
> 




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Re: [time-nuts] UPDATE: DATUM 9390-52054 Grief again...

[Rob Kimberley]

Burt, what is your DAC setting now it's stabilised? It is normally set so it
is mid-range when setting these units up.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Burt I. Weiner
Sent: 12 April 2013 19:49
To: time-nuts@febo.com
Subject: [time-nuts] UPDATE: DATUM 9390-52054 Grief again...

Sorry for the delay in posting this update.  Things have been hectic, and
then there was NAB.

Here's what I've discovered:  The receiver started working after about 6
hours of just sitting.  However, the 9390's internal Vectron oscillator was
quite a ways off frequency and did not want to lock after trying to
stabilize all night.  I had to tweak the adjustment screw quite a ways and
then, after a while, it locked.  Prior to this episode the oscillator had
been sitting at only a few E-12.  I suspect that this oscillator has had an
intermittent problem for a long time, and I should not have had to tweak it
as far as it wanted to go.  The receiver portion has not failed in the few
weeks since it decided to start seeing satellites again.  Maybe because I
had tweaked the oscillator?

So, I got brave and changed the oscillator out with a smaller Vectron
oscillator that I got from my friend Stu, K6YAZ.  This is not a commercial,
but he sells these oscillator modules on eBay.  See: 
http://www.ebay.com/itm/10-MHz-precision-crystal-oscillator-in-sealed-oven-5
-volts-voltage-adjustable-/190820631639?pt=LH_DefaultDomain_0&hash=item2c6dc
bc457#ht_848wt_1143

The new oscillator requires 5 Volts rather than 12 Volts, which I simply
grabbed from the from the power supply's 5 Volt rail.  It was not a lot of
fun removing the original oscillator from the circuit board and the
associated fine traces, but once I plucked it from the board I put short
wire leads in the original circuit board holes for the various connections
to the new oscillator.  I cut a piece of foam about the size of the old
Vectron and carved out it's innards to accept the new, much smaller
oscillator.  This should provide some thermal stability and also insulate
the new oscillator from the circuit board.  I connected everything up,
substituting the 5 Volt rail lead for the 12 Volt lead.  When I powered the
9390 up everything seemed to work and the oscillator was within 1-Hertz,
except that the output was about 20 dB higher than with the original
oscillator was when it was working properly.  Once the receiver locked up to
4 satellites and started "OSC Stabilizing", the oscillator suddenly jumped
about 18 Hz low and shortly afterwards the DAC went to all zeros.  I let it
sit all night figuring that it would eventually find itself.  Well, it
didn't, it just sat at 18 Hz low and the DAC at all zeros, and the EFC
(Electronic Frequency Control) voltage at 0.19 Volts.  (What a revolting
development!)

Very early this AM I got up and put a simple 10:1 voltage divider using a
series 680 Ohm and 68 Ohm resistor from the oscillator's RF out to ground
This brought the levels pretty much back to the same as my good 9390.  I
also substituted a pot for the EFC voltage.  I used a 1 K pot in series with
a 300 Ohm resistor to the 5 Volt rail.  The resistor was on the high side,
the bottom end to ground, and the wiper to the EFC terminal.  I was able to
tune the oscillator to precisely 10 MHz long enough to measure the
substitute EFC at +2.15 Volts.  Leaving it hooked up this way I let the
receiver do it's thing just to see what would happen.  It went through it's
normal routine and finally the green lock light came on.  Although the
oscillator wasn't being controlled by the 9390, the 9390 thought it was
happy and the DAC went to about 28,000 - very close to ideal.  I tweaked the
pot hither and yon to move the frequency and to see which way the EFC
voltage went.  It went the right direction to properly steer the oscillator
and should have worked.

Pondering the situation, I powered the 9390 down and reconnected the 9390's
EFC voltage back up to see what would happen this time.  This time it locked
up quickly and the oscillator homed in on 10 MHz.  The EFC voltage is 2.15
Volts and the DAC settled in nicely at 28302 - very close to the recommended
DAC numbers.  It's been cooking for about an hour now and is presently at
112E-12 and moving closer all the time.  When comparing the two GPS
receivers I am not seeing the random drifts that I had seen in the past.

I suspect that the problem with the frequency jumping to -18 Hz and the DAC
going to all zeros was the result of the new oscillator over-driving the
following circuitry.  In hindsight, maybe I should have probed a bit with
the scope to see if that is a correct assumption, but I didn't do that.

By the way, Stu sells the oscillators fully tested and with a note giving
the EFC voltage for each unit to tune it to 10 MHz.  If this turns out to be
as good a modification as it now appears, I'm going to get more of the
oscillators from him.  I may replace the one in my othe

Re: [time-nuts] Connectors

[Rob Kimberley]

It's a very useful material, also called "Self Amalgamating Tape". 

Been using it for years for all sorts of outside cable work.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Azelio Boriani
Sent: 12 April 2013 14:00
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Connectors

Sorry, not neoprene but self-sealing polyisobutyl tape, very effective for
the outdoor antenna work**. I have recently opened a sealed connection,
after 10 years, and the protected connector appears as new.

On Fri, Apr 12, 2013 at 2:38 PM, Azelio Boriani
wrote:

> I use neoprene tape to make really water tight connections for all 
> type of connectors.
>
>
> On Fri, Apr 12, 2013 at 1:27 PM, Bob Camp  wrote:
>
>> Hi
>>
>> The fancy F connectors are indeed waterproof if:
>>
>> 1) You have the right cable
>> 2) The cable and connector match up
>> 3) The tool and the connector match up
>>
>> The auction sites are a great place to get samples of connectors and 
>> tools that apparently work with no known cable .
>>
>> If you are not careful about the trim on the dielectric / positioning 
>> , they can have issues above 1 or 2 GHz. Even a lot of care they 
>> don't really do the job above 5 GHz. Exactly where they drop out 
>> depends (of course) on your return loss expectations.
>>
>> Bob
>>
>> On Apr 11, 2013, at 4:21 PM, Gordon Batey  wrote:
>>
>> > Greetings,
>> >
>> > I have used the longitudinal compression F connectors for some time 
>> > now
>> with
>> > several GPS units and RG-6 cable.  They certainly appear to be
>> waterproof
>> > and quite sturdy.  Not inexpensive but very serviceable.  I found a 
>> > kit
>> with
>> > the installation tool and connectors and separate connectors at 
>> > LOWES
>> that
>> > does a nice job.  I also found one for BNC that use the same 
>> > principle
>> but
>> > have not used it yet.  Gordon WA4FJC
>> >
>> > ___
>> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>>
>> ___
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>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
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Re: [time-nuts] GPS antenna??

[Rob Kimberley]

Hi

Sorry, I was using old info. I've been a bit out of touch on that side of
things for some time.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Atkinson
Sent: 10 April 2013 07:43
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS antenna??

Hi Rob,
See my earlier post on using repeaters / re-radiators in the UK. Ofcom are
insitituting a "light" licencing scheme for GPS / GNSS repeaters. The
"transmit" antenna must be inside and the licence fee is £75. No mention
that I've seen of type approval but they should of course meet CE
requirements. Connecting an active and passive antenna  back to back (with a
bias tee or inline amp) is illegal in the UK unless you get a licence from
Ofcom first. A quick seach on Ofcon GPS repeaters will bring up a bunch of
references.
 
Robert G8RPI.




________
From: Rob Kimberley 
To: 'Tom Van Baak' ; 'Discussion of precise time and
frequency measurement' 
Sent: Tuesday, 9 April 2013, 12:51
Subject: Re: [time-nuts] GPS antenna??

Unfortunately, (I think this is still valid in the UK), we are not allowed
to use GPS re-radiators. I need to check latest rules & regs.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: 08 April 2013 22:12
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS antenna??

Alan,

Google for words like GPS re-radiator or GPS repeater. There are also units
on eBay. If not to buy, at least to study examples.

The one I have is made by www.gpssource.com but it seems you could build one
yourself. It's easy to test by looking at your indoor SV count and reception
levels. With patch antennae you don't have to worry about RHCP issues,
right?

/tvb


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Re: [time-nuts] GPS antenna??

[Rob Kimberley]

You still need to set your position to get accurate results with one SV.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Grant Hodgson
Sent: 09 April 2013 09:28
To: time-nuts@febo.com; time-nuts-requ...@febo.com
Subject: Re: [time-nuts] GPS antenna??

Alan

As has already been stated by others, if the purpose of the GPS signal is
for a GPSDO, then putting an active patch next to a SW facing window should
work fine.  No need to re-radiate.  You only need to receive 1 satellite in
order to get a timing signal - more satellites will give better (lower)
jitter/ADEV, but if you just want an accurate frequency source for a counter
or signal generator then the setup you describe should be fine.

If that's the case, then it might be worth taking a Rubidium source as a
higher-performance back-up than the GPSDO in holdover, although some GPSDOs
are more equal than others in holdover performance.

regards
Grant

Quoting time-nuts-requ...@febo.com:
>
> Hi all an interesting problem you may have encountered, I want to use 
> a GPS frequency standard inside a building with no opening windows 
> (opening windows are known as air conditioning in the UK :-))  ) This 
> is part of a two day amateur microwave conference so we should have 
> the expertise.
>
> I intend to try and pass the signal through a a double glazed glass 
> window unit (hopefully not metalised) using a couple of patch 
> antennas. The outer GPS antenna is active so will need  a 5v supply 
> via an inserter. Inner patch active, outer patch passive to avoid 
> problems of feedback. Main antenna can be shielded from the "coupling" 
> either physically or with a slab of absorber.
>
> Has anyone tried this? does it work?.any gotchas?
>
> Thanks
> Alan
> G3NYK
>
>
>

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Re: [time-nuts] GPS antenna??

[Rob Kimberley]

Unfortunately, (I think this is still valid in the UK), we are not allowed
to use GPS re-radiators. I need to check latest rules & regs.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak
Sent: 08 April 2013 22:12
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS antenna??

Alan,

Google for words like GPS re-radiator or GPS repeater. There are also units
on eBay. If not to buy, at least to study examples.

The one I have is made by www.gpssource.com but it seems you could build one
yourself. It's easy to test by looking at your indoor SV count and reception
levels. With patch antennae you don't have to worry about RHCP issues,
right?

/tvb

- Original Message - 
From: "Alan Melia" 
To: "time-nuts measurement" 
Sent: Monday, April 08, 2013 9:59 AM
Subject: [time-nuts] GPS antenna??


> Hi all an interesting problem you may have encountered, I want to use a
GPS 
> frequency standard inside a building with no opening windows (opening 
> windows are known as air conditioning in the UK :-))  )
> This is part of a two day amateur microwave conference so we should have
the 
> expertise.
> 
> I intend to try and pass the signal through a a double glazed glass window

> unit (hopefully not metalised) using a couple of patch antennas. The outer

> GPS antenna is active so will need  a 5v supply via an inserter. Inner
patch 
> active, outer patch passive to avoid problems of feedback. Main antenna
can 
> be shielded from the "coupling" either physically or with a slab of 
> absorber.
> 
> Has anyone tried this? does it work?.any gotchas?
> 
> Thanks
> Alan
> G3NYK 


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Re: [time-nuts] GPS antenna??

[Rob Kimberley]

You will see more SVs from the northern hemisphere is you face south, and
vice versa.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of li...@lazygranch.com
Sent: 08 April 2013 20:51
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS antenna??

Aren't GPS birds all over the sky. South facing is for the Clarke belt. 
-Original Message-
From: "Bob Camp" 
Sender: time-nuts-boun...@febo.com
Date: Mon, 8 Apr 2013 15:28:14
To: 'Discussion of precise time and frequency
measurement'
Reply-To: Discussion of precise time and frequency measurement

Subject: Re: [time-nuts] GPS antenna??

Hi

Is the proposed window south facing? If not, you will need enough cable
outdoors to get your second antenna to a south facing location. 

Assuming it's south facing and reasonable sky view, have you tried a patch
antenna on / at the window? That should at least give you some idea of how
likely the signal is to get through it. It's not uncommon to run GPSDO's
with window mounted antennas. 

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Alan Melia
Sent: Monday, April 08, 2013 1:00 PM
To: time-nuts measurement
Subject: [time-nuts] GPS antenna??

Hi all an interesting problem you may have encountered, I want to use a GPS
frequency standard inside a building with no opening windows (opening
windows are known as air conditioning in the UK :-))  ) This is part of a
two day amateur microwave conference so we should have the

expertise.

I intend to try and pass the signal through a a double glazed glass window
unit (hopefully not metalised) using a couple of patch antennas. The outer
GPS antenna is active so will need  a 5v supply via an inserter. Inner patch

active, outer patch passive to avoid problems of feedback. Main antenna can
be shielded from the "coupling" either physically or with a slab of
absorber.

Has anyone tried this? does it work?.any gotchas?

Thanks
Alan
G3NYK 

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Re: [time-nuts] GPS antenna??

[Rob Kimberley]

Alan,

I used to do a lot of my Datum demos with customers with antennae up against
a window as outside access wasn't available. 

Usually worked OK, unless as you say, the glass is metalised.
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Alan Melia
Sent: 08 April 2013 18:00
To: time-nuts measurement
Subject: [time-nuts] GPS antenna??

Hi all an interesting problem you may have encountered, I want to use a GPS
frequency standard inside a building with no opening windows (opening
windows are known as air conditioning in the UK :-))  ) This is part of a
two day amateur microwave conference so we should have the expertise.

I intend to try and pass the signal through a a double glazed glass window
unit (hopefully not metalised) using a couple of patch antennas. The outer
GPS antenna is active so will need  a 5v supply via an inserter. Inner patch
active, outer patch passive to avoid problems of feedback. Main antenna can
be shielded from the "coupling" either physically or with a slab of
absorber.

Has anyone tried this? does it work?.any gotchas?

Thanks
Alan
G3NYK 

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Re: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief again...

[Rob Kimberley]

You need to be careful as Nigel says as Datum had special SVeeSix units from
Trimble in the early days which were specifically modified for timing. 

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of gandal...@aol.com
Sent: 07 April 2013 18:37
To: time-nuts@febo.com
Subject: Re: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief
again...

Hi Robert,
 
You need to be careful on this one.
 
I've never owned a Placer 400, so can't be 100% sure, but whilst  I have
seen it suggested that it contained an SVeeSix I've have also  seen at least
one quite emphatic comment, from a not very happy  user, stating that it's
definitely not an SVeeSix, but that there was a  firmware upgrade available
for the Placer 400 at one time to  make it SVeeSix compatible, whatever that
might imply.
 
What I can confirm is that the version that's more generally available on
Ebay, the Placer 450, consists of a single board inside the housing that
integrates a GPS receiver with the control section.
I discovered this the hard way after I bought a couple, and expecting  them
to contain one of the usual Trimble GPS modules with  a separate PCB for the
control section, silly me:-)
 
Quite what the GPS section of that board might be derived from I don't know,
but it would seem very unlikely that it's going to be a drop in replacement
for a standard module.
 
Nigel
GM8PZR
 
 
 
In a message dated 07/04/2013 17:47:40 GMT Daylight Time,
robert8...@yahoo.co.uk writes:

Hi,
IIRC the early Trimble Placer vehicle tracking GPS receivers  used the
SVee6 and SVee8. I think the Placer 400 used  the SVee6. These  units turn
up on ebay etc at very low cost.

Robert  G8RPI.





From:  "gandal...@aol.com" 
To: time-nuts@febo.com
Sent: Sunday, 7 April 2013, 8:53
Subject: [time-nuts] Trimble SVeeSix  -- was DATUM 9390-52054 Grief again...

The Trimble TNL 22880-B was  indeed the original SV6, or SVeeSix as Trimble
chose to call it, I  have just confirmed this from a photo I took some time
ago, and of  which I can supply a copy if required.

The SVeeSix manual from 1992 is  here.
http://rapidshare.com/files/446743737/Trimble_SveeSix.pdf

and  a much smaller, optimised version,  here..
http://rapidshare.com/files/446744995/Trimble_SveeSix_Optimised.pdf

Thanks  for these should be directed to Rob Kimberley on the list who   
provided the original printed copy.

This original SVeeSix was  approx 4 x 3.5 inches and was  eventually
replaced by the SVeeEight  of similar appearance and  again the same size.
The SVeeSix Plus and  SVeeEight Plus were the same modules mounted  in metal
boxes.
The  SVeeEight Plus manual from 2000 is available on the Trimble ftp   site.

I know of at least one application where an SVeeEight PCB module  has been
used as a drop in replacement for an SVeeSix, the Rapco  1804M GPS frequency
standard, albeit using the opposite serial port,  but don't know if this was
an "out of the box" drop in or whether the port  needed to be configured
first.

The smaller, 1.8 x 3.3 inches,  version of the SVeeSix is  the SVeeSix-CM3
embedded module, and the  1997 manual for that is also on  the Trimble ftp
site in the  manuals/CM3 folder.

It's possible that an SVeeSix-CM3 could be  configured as an SVeeSix
replacement but I've not investigated this,  both the SVeeSix and SVeeEight
came fitted with 1 or 2 standard  serial ports on DB9 connectors, the
SVeeSix-CM3
used  an 8 pin header  with I/O at TTL  levels.

Regards

Nigel
GM8PZR



In a message  dated 06/04/2013 23:10:28 GMT Daylight Time, b...@att.net   
writes:

(Note:  additional information about the receiver  module has been  added.)

Burt

Gang,

You will  remember several months ago I  had some stranges that I thought
were  related to a defective Vectron  oscillator in one of my DATUM
9390-52054.  That turned out to be a  the internal switching  
power supply so I replaced it with an external  Cisco unit.   I've done 
this in three units, two are mine and one  belongs to Stu,  K6YAZ.

Well, I now have a different grief in one of my   units.  It had been 
cooking along swell with no problem ever since  I  replaced the power
supply.  This morning I notice that one of  my  units had the lock and
tracking lights out.  The display  said that  the signal level was low and
there were no usable  satellites.  The 10  MHz output is also about
20 or more dB  low.  I assumed the power  supply is all right because the
display was working and it said it was  9-E9, not so good, but working -
sorta.  I swapped antennas and the  good Datum was  happy so I know the
antenna is ok.  when I got inside  I checked  the power supply rails and
they're within .05 Volts of where  they  should be.  There is 5 Volts on the
GPS module and there is  4.96  Volts on the antenna Type-N connector
(measured with the  antenna l

Re: [time-nuts] Network jitter with NTP

[Rob Kimberley]

Sarah, David,

I've changed my Minpoll and Maxpoll settings as suggested by David and now
getting much better results (1 - 2 mS) when settled for the Meinberg Stratum
1 units. I'm also using Meinberg's version of NTP (6.2.6).

I'm still experimenting with settings, but it looks like my original post
regarding the Ethernet over Power adapters might have been a red herring.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Sarah White
Sent: 13 February 2013 01:42
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Network jitter with NTP

David,

Thanks for posting that. I'm currently doing some testing over wifi links
myself, and found that page very useful. You do a really good job
documenting your experiences with GPS-based NTP refclocks, and I appreciate
all the hard work.

I just wanted to ask though, are you compiling your own NTP now or what?

http://www.davehart.net/ntp/win/x86.please.see.http.support.ntp.org-people-h
art-win-x86/

but then under http://support.ntp.org/people/hart/win/x86/

... most recent seems to be ntp-4.2.7p310

^Basically, you were previously documenting use of dave hart's builds
(overlaid over a meinberg ntp install or otherwise)

Sorry rob, I don't have any experience with powerline adapters, but I'm
treating your experiences (which don't seem to be promising) as a data point
showing that they're no better for timing than using wifi...

I'm getting high & unpredictable jitter with NTP over wifi as well (compared
to cat 6 RJ-45 crossover cable directly between NTP servers)

1-20ms jitter for 5ghz band, 802.11n connection running with bitrate
manually limited to 6mbit/s

5-70ms jitter for the 2.4ghz band, 802.11g connection running with bitrate
auto-negotiation (up to 54mbit/s)

... My best case scenario for NTP jitter is about 0-5ms between a stratum 1
and a stratum 2 server directly connected via gigabit ethernet crossover
(and the stratum 1 itself with a connected refclock seems to be at a
baseline of 0-1ms most of the time, and rarely higher than 2ms)

Those are just rough estimates based on casual observation, and I haven't
done any long-term measurements yet like David Taylor's work...
I'm "getting there" though it's coming slowly because of my trouble with
learning curve in this area.

--Sarah

P.S. I renamed this post. The title "Possibly off topic - Jitter on Ethernet
over poweradapters" seemed silly.

> Rob,
> 
> It's not quite clear which direction you are measuring.  I take it 
> your Meinberg servers are "perfect" in NTP terms, and you are 
> monitoring from the house?  Or vice-versa?  Anyway, my first guess is 
> that jitter might be not dissimilar to Wi-Fi, in which case my 
> lightly-loaded Wi-Fi results might be a starting point:
> 
>  http://www.satsignal.eu/mrtg/performance_ntp_wifi.php
> 
> Note the improvement with Windows-8 and the latest NTP (top graph, PC 
> Bergen), and the others are somewhat variable.
> 
> Cheers,
> David

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Re: [time-nuts] GPStar Plus: Rubidium, anyone?

[Rob Kimberley]

Bruce,

Just a slight correction on the part number the Odetics GPStar Plus was
model 365. When the company changed to Zyfer and they upgraded the unit it
became a 565.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bruce Lane
Sent: 12 February 2013 20:55
To: time-nuts@febo.com
Subject: [time-nuts] GPStar Plus: Rubidium, anyone?

Fellow Time Trackers,

Does anyone happen to have an Odetics GPStar Plus (their model 565,
if I
recall) with the rubidium option installed?

If so, could I bother you for some detailed photos of the innards,
particularly the main PC board jumpers, the additional power supply and any
extra cabling the rubidium module uses?

My goal is to retrofit my own GPStar.

Thanks much.


Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies
(http://www.bluefeathertech.com) Assoc. member, AAZK & IAATE "Salvadore
Dali's computer has surreal ports..."

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Re: [time-nuts] Possibly off topic - Jitter on Ethernet overpower adapters

[Rob Kimberley]

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 11 February 2013 16:13
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Possibly off topic - Jitter on Ethernet overpower
adapters

All,

Strangely today the jitter numbers seem to be behaving themselves! Nothing
has been done to the set up.

Thanks to everyone for their comments. I'm looking at putting a direct
Ethernet cable in here to see what the difference might make.

Attached is a picture of latest NTP Monitor readout. Bottom two devices are
the Meinberg LanTimes. The others are pool servers.

Rob
===

Rob,

Two comments from your screen-shot.

- NTP version 4.2.4p8 is now rather old.  You may well find better
performance using a more recent version, and especially with the most recent
development versions on Windows-7 and Windows-Vista.  There are some upgrade
notes on my Web site.

  http://www.satsignal.eu/ntp/setup.html#updating

- with a local stratum-1 server, you can get better performance using a more
frequent poll i.e. limit maxpoll.  For my PCs I typically have (with NTP
4.2.6 or later):

_
# Local stratum-1 LAN-based servers
server192.168.0.3 iburstminpoll 5 maxpoll 5prefer# Pixie
server192.168.0.2 iburstminpoll 5 maxpoll 5# Feenix

# External servers from the UK pool
pooluk.pool.ntp.orgminpoll 10
_


For measurement, you may want to let the poll interval drift to 1024s, but
for lower offsets keeping poll to 32s (maxpoll 5) gives better results.

My apologies if you were already aware of this.

Cheers,
David
-

David, 

Many thanks for that. I do have a copy of 6.2.6 which I have tried, but the
jitter numbers appeared higher. I will try again and also change the minpoll
settings as suggested.

The settings shown were the default settings from Meinberg and I haven't
tweaked them.

Will see what I get.

Rob




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Re: [time-nuts] Possibly off topic - Jitter on Ethernet over power adapters

[Rob Kimberley]

I'm using Meinberg GPS NTP Servers. They are working fine and no problem
with SVs.

Still doing some tests. Will report back once I have anything extra to add.

Thanks.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: 10 February 2013 16:15
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Possibly off topic - Jitter on Ethernet over power
adapters

THose power over Ethernet devices work with analog signals and don't
evn look at the data packets.   All they do is place a DC bias on the
twisted pair.Ethernet is always transformer coupled so your
routers, switches and computers never see DC.

What is your NTP server using for a reference clock?  I'd suspect that
is the problem.   If the reference is an Internet pool server than a
few mS is about what you should expect.   If using GPS then look to
see if you have a good signal from enough satellites.

But those POE boxes don't mess with the data packets, or at least the
are not designed to do that.   If one is broken it could be adding
noise to the line.  Broken hardware can do "anything".



On Sun, Feb 10, 2013 at 3:18 AM, Rob Kimberley 
wrote:
> I'm not sure if this is the best place to ask the question, but does 
> anyone have experience of using Ethernet over power line adapters? I 
> have an outside office, and my router is in the house plugged into the 
> phone master socket. I have used two Ethernet over power adapters, one 
> at the router and one in the office here to get internet access. The 
> output of the adapter then goes to a multi-port hub to give me 
> Ethernet to all my office devices including two Meinberg NTP servers.
>
>  I've noticed large jitter readings on Meinberg's NTP monitor program.  
> Can be as low as 2ms, but much higher (50mS +), and at this point NTP 
> goes haywire.
>
> Not sure if it is the physical set up or something else.
>
> Any comments appreciated.
>
> Thanks.
>
> Rob
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



-- 

Chris Albertson
Redondo Beach, California
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Re: [time-nuts] Possibly off topic - Jitter on Ethernet over power adapters

[Rob Kimberley]

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 10 February 2013 11:39
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Possibly off topic - Jitter on Ethernet over
poweradapters

From: Rob Kimberley
[]
I'm not sure if this is the best place to ask the question, but does anyone
have experience of using Ethernet over power line adapters? I have an
outside office, and my router is in the house plugged into the phone master
socket. I have used two Ethernet over power adapters, one at the router and
one in the office here to get internet access. The output of the adapter
then goes to a multi-port hub to give me Ethernet to all my office devices
including two Meinberg NTP servers.

I've noticed large jitter readings on Meinberg's NTP monitor program.  Can
be as low as 2ms, but much higher (50mS +), and at this point NTP goes
haywire.

Not sure if it is the physical set up or something else.

Any comments appreciated.

Thanks.

Rob
==

Rob,

It's not quite clear which direction you are measuring.  I take it your
Meinberg servers are "perfect" in NTP terms, and you are monitoring from the
house?  Or vice-versa?  Anyway, my first guess is that jitter might be not
dissimilar to Wi-Fi, in which case my lightly-loaded Wi-Fi results might be
a starting point:

  http://www.satsignal.eu/mrtg/performance_ntp_wifi.php

Note the improvement with Windows-8 and the latest NTP (top graph, PC
Bergen), and the others are somewhat variable.

Cheers,
David


David, 

Thanks for the reply. I'm monitoring in the office at the end of the link
described above. The NTP servers are on the same hub as the PC. 

Next step is to move the PC into the house and measure directly at the
router. This means the NTP servers in the office will be at the other end of
the Ethernet over Power link. 

Will get back on this.

Rob


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[time-nuts] Possibly off topic - Jitter on Ethernet over power adapters

[Rob Kimberley]

I'm not sure if this is the best place to ask the question, but does anyone
have experience of using Ethernet over power line adapters? I have an
outside office, and my router is in the house plugged into the phone master
socket. I have used two Ethernet over power adapters, one at the router and
one in the office here to get internet access. The output of the adapter
then goes to a multi-port hub to give me Ethernet to all my office devices
including two Meinberg NTP servers.

 I've noticed large jitter readings on Meinberg's NTP monitor program.  Can
be as low as 2ms, but much higher (50mS +), and at this point NTP goes
haywire.

Not sure if it is the physical set up or something else.

Any comments appreciated.

Thanks.

Rob



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Re: [time-nuts] TrueTime 820-350 display

[Rob Kimberley]

I believe there were variations of IRIG which sent the signal (un-modulated
or DC code) over a differential circuit, so Triax may have been used.

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: 09 February 2013 16:45
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] truetime 820-350 display

Yes that was the way they used to send differential data most likely a
timecode signal, but also most likely not IRIG it would not have ever needed
a triax feed. Triax was quite expensive and fell out of favor about 1985.
How many of these things do you have??
Many of the old true-times like the dc goes 468 are simply nice cases with a
display. Virtually every other bit of the insides is useless. I do use the
cases for projects and typically pick them up at hamfests for $5. Great
1 rack unit case. Plus I do like the old displays. :-) Anyhow if you do run
across a True-time DC-60. Keep me in mind. Now that they no longer work with
WWVB I want to pick one up to experiment with.
Regards
Paul.

On Fri, Feb 8, 2013 at 10:19 PM, Tammy A. Wisdom
wrote:

> Any idea what the triax connector is for?
>
> --Tammy
>
>
>
>
> - Original Message -
> > From: "Tom Knox" 
> > To: "Time-Nuts" 
> > Sent: Friday, February 8, 2013 4:08:28 PM
> > Subject: Re: [time-nuts] truetime 820-350 display
> >
> >
> > Hi Tammy;
> > Here is a link to the operation and service manual on Symmetricoms site:
> > www.symmetricom.com/link.cfm?lid=5283
> > Best Wishes;
> > Thomas Knox
> >
> > 4475 Whitney Place
> > Boulder Colorado 80305
> >
> > 1-303-554-0307
> >
> > > Date: Fri, 8 Feb 2013 15:35:56 -0700
> > > From: tammy-li...@wiztech.biz
> > > To: time-nuts@febo.com
> > > Subject: [time-nuts] truetime 820-350 display
> > >
> > > Hi All,
> > >
> > > I ended up with some trutime 820-350 displays and I am trying to 
> > > find
> out
> > > anything about them.  Does anyone here have a manual paper or
> electronic
> > > for them?  What timecode format do they use?  These displays have 
> > > a
> triax
> > > BNC on them so im scratching my head as to what they were 
> > > connected
> too.
> > > Please let me know if you have any ideas.
> > > Thanks
> > > --Tammy
> > >
> > >
> > >
> > >
> > > --
> > >
> > > Tammy A Wisdom
> > > The Summit Open Source Development Group
> > > http://www.sosdg.org   /  http://www.ahbl.org
> > >
> > > ___
> > > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > > and follow the instructions there.
> >
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> >
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Re: [time-nuts] Systron 6153 troubleshooting

[Rob Kimberley]

I wish I could remember! I used to service these and the 6053's in the 70's
at Systron-Donner's UK office.

I do know it will help if you make yourself an extender cable for the 14
(16?) pin dual in line red connector so you can get the input module on the
bench.

They usually suffered front end damage and the mixer diodes were dead. We
also had the occasional bad chip resistor. 

I know this is not much Chris, but if I can remember anything more, I will
let you know.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Howard
Sent: 09 February 2013 11:34
To: time-nuts@febo.com
Subject: [time-nuts] systron 6153 troubleshooting


Any advice on troubleshooting the D channel of a Systron 6153 counter?

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Re: [time-nuts] Racal MA-259 Crystal frequency standard on UK eBay

[Rob Kimberley]

Agreed, and about 30 miles from where I live. 

However, do I really need one?

:-)

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: 23 January 2013 14:18
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Racal MA-259 Crystal frequency standard on UK eBay

Very tempting but its a local pickup only.

On Wed, Jan 23, 2013 at 8:41 AM, David C. Partridge <
david.partri...@perdrix.co.uk> wrote:

> 
>
> Dave
>
> ___
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[time-nuts] Raspberry Pi Competition...

[Rob Kimberley]

http://www.electronicsweekly.com/Articles/28/09/2012/54676/raspberry-pi-gets
-a-competitor.htm

Rob K



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[time-nuts] PiFace: Raspberry Pi I/O board

[Rob Kimberley]

Please see attached article

<http://www.electronicsweekly.com/Articles/10/01/2013/55341/piface-raspberry
-pi-io-board.htm?dm_i=1GUU,17S1R,805O95,440WA,1>

Rob Kimberley




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Re: [time-nuts] An embedded NTP server

[Rob Kimberley]

Michael,

Which version of Meinberg's NTP build did you install? I've had problems
with high jitter content on one of them.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Michael Tharp
Sent: 25 December 2012 20:44
To: time-nuts@febo.com
Subject: Re: [time-nuts] An embedded NTP server

On 12/25/2012 02:51 PM, David J Taylor wrote:
> I think you should be able to do better on the jitter as your 
> algorithms develop.

Yes, for starters something is causing a silly amount of extra latency hence
the 2.4ms round-trip. I managed to cut that in half by changing compiler
options but talking to someone using the same stack I should be able to get
it down to ~ 400us round-trip, at worst. I have some ideas on how to achieve
that but I want to get all the functionality working before I start
optimizing.

The main lack of functionality, which may or may not be the cause of the
jitter, is that I haven't actually integrated the PLL/disciplining stuff
yet. I just have a timer that resets with each GPS pulse, and runs at
whatever nominal frequency the oscillator has. Not great but it succeeded at
getting results fast. Not up to time-nuts standards though. 
Now I'm going back and adding the PLL.

> "SNTP" does imply something else, so perhaps avoid calling it that, 
> although if it doesn't respond to all the NTP management calls I'm 
> unsure what it should be called!

I suppose that I could call it NTP and still sleep at night since, while not
a traditional NTP implementation, it does still feature control loops
similar to those found in purely software-based NTP. I have not yet looked
at what administrative/query functionality I could implement. 
Some of it like listing peers does not make sense but perhaps other commands
could be mapped to make it more complete. I would also like to expose some
of the internal statistics via SNMP or some other means for graphing.

> Oh, and your Windows box 172.24.0.68 is either poorly configured or 
> broken - they can work much, much better than yours illustrates as I 
> expect you know.

Yes, it's not healthy. I installed Meinberg's NTP build and configured it
using defaults other than the server list but it seems to not be tracking
well. Right now it's "only" 30ms off but as shown in the forum snippet it
makes excursions into the hundreds. Still an improvement over default
Windows timekeeping but I'd love for it to work properly.

-- m. tharp


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Re: [time-nuts] Timing performance of servers

[Rob Kimberley]

We used to filter out anything 10 - 20 degs above the horizon when setting
up timing receivers. Typically there's a lot of noise down low (multipath
and tropo effects). As long as you've got plenty of SVs you don't need to go
way down to the horizon.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chris Albertson
Sent: 25 October 2012 20:09
To: li...@lazygranch.com; Discussion of precise time and frequency
measurement
Subject: Re: [time-nuts] Timing performance of servers

On Thu, Oct 25, 2012 at 11:02 AM,   wrote:
> The GPS seeing the horizon isn't required. Those satellites are filtered
out by software.

OK, technically it needs to see down to within 10 degrees of the
horizon.   But when you are choosing a location for the mast to the
horizon or withing 10 degrees of it looks pretty much the same.   I
don't want a huge tree of building due south of the antenna.  But for
timing all you really need is to see "most" of the sky.   It depends
on if you want it to work or work as well as it can.


Chris Albertson
Redondo Beach, California

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Re: [time-nuts] Timing performance of servers

[Rob Kimberley]

Thanks for that David.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 25 October 2012 09:51
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Timing performance of servers

http://www.meinberg.de/english/sw/ntp.htm

You can get NTP for windows and also their NTP Monitor. 

Free download.

Rob Kimberley
=

.. with user-oriented install instructions here:

  http://www.satsignal.eu/ntp/setup.html

Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk

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Re: [time-nuts] Timing performance of servers

[Rob Kimberley]

http://www.meinberg.de/english/sw/ntp.htm

You can get NTP for windows and also their NTP Monitor. 

Free download.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Edgardo Molina
Sent: 25 October 2012 01:05
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Timing performance of servers

Dear Mangus,

I will allow myself to share a comment on your thread. 

Timing on windows servers is not one of their plausible strengths. It was
clearly pointed out during the SIM conference last week at CENAM. In fact
there was an interesting discussion about the drawbacks when using NTP
Windows based servers and all kind of NTP appliances compared to full size
Linux based NTP servers. The example of what NIST is using nationwide for
their servers set an example of good server hardware and linux to provide
the nation's NTP pulse.

I haven't done any experiments with Windows for NTP services, still it could
be interesting as to set a benchmark while comparing it to the Linux boxes.

I am currently trying out the Domain Time II NTP client from Symmetricom for
the thesis. I have to come back to Symmetricom's Miguel García to decide on
purchasing a Domain Time II NTP client kit.  How is the Mainberg NTP client
different from the Symmetricom version? Have you tried both? If not I will
be more than glad to help comparing both if you can help me pointing out the
source for a demo version of Mainberg's software. Maybe then an objective
review of both clients will be in order, I will be more than glad to do it
or to test them against Windows NTP services, appliances and/or Linux NTP
boxes. I have at least an example of those at the office.

-13
Just my  2x10   cents.


Regards to you and the group,



Edgardo Molina
Dirección IPTEL

www.iptel.net.mx

T : 55 55 55202444
M : 04455 20501854

Piensa en Bits SA de CV



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On Oct 24, 2012, at 5:47 PM, Magnus Danielson 
wrote:

> Fellow time-nuts,
> 
> When spending time on a conference last week, I heard one interesting
comment that they lost data due to bad timing on their Windows servers.
> 
> Now, I know that the standard Windows uses SNTP in order to achieve the
goal of having the timing of the machines sufficiently aligned to allow
Kerberos authentication. SNTP suffice for that, as it needs to be a handful
of minutes in line.
> 
> If you need better performance than that, you should use NTP (and then
download and install Meinbergs Windows-client for NTP).
> 
> Then again, I would point out that for this type of data, it would most
probably be better served on a Linux box.
> 
> What should be a nice wake-up call for them would be a summation of how
different strategies would give them clock precision of sufficient grade.
So, does anyone know of such measurements presented anywhere?
> 
> There are bits and pieces, but the ideal for this case would be if they
where collected in one page/paper.
> 
> This is an awareness thing, so that people can do a little more
well-informed choices.
> 
> Cheers,
> Magnus
> 
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Re: [time-nuts] Odetics 365

[Rob Kimberley]

I've just re-read this post after looking at the replies.

If the 365 is Time locked and showing and offset of 2.98E-13 then it looks
to working fine, and I would suspect that it is the frequency counter
oscillator that is drifting. 

Is the frequency counter free running or locked to any other standard?

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rob S.
Sent: 18 October 2012 07:40
To: time-nuts@febo.com
Subject: [time-nuts] Odetics 365

Hello Group,  first time post

I have just got my Odetics 365 working again after it being packed away for
a few years. I have it connected to a HP 5386A frequency counter and am
monitoring the 10 MHz output ( down to 0.01 Hz res ).

I am noticing the frequency is drifting about 1.5 to 2 Hz over the day and
settling low for a few hours ( aprox midday ) and then settling high about
12 hours later. The 365 is showing TFOM4 and Time locked, has a GDOP of 3.68
and displays a frequency error of +2.98E-013  and a Std error of Est of
4.80E-008. The averaging is turned off and it "see's" 3 to 5 satellites
continuously.  My question is would this be normal behavior ( + or - 2 Hz )
for this type of equipment or is it looking like I have something that is
drifting a bit ? Also would switching the averaging on help ?

Any thoughts would be appreciated Group,

Thanks and Cheers,

Rob.

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Re: [time-nuts] Tracking NTP displacement and correlation between two clients.

[Rob Kimberley]

Just catching up on all my emails after holiday...

Try Meinberg's NTP Monitor
http://www.meinberg.de/english/sw/time-server-monitor.htm

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brent Gordon
Sent: 04 October 2012 18:34
To: Discussion of precise time and frequency measurement; bow...@gmail.com
Subject: Re: [time-nuts] Tracking NTP displacement and correlation between
two clients.

David Taylor has all sorts of NTP monitoring scripts, software, and tips at
his web site.  Start at http://www.satsignal.eu/software/net.htm#NTPmonitor
and look around.

Brent

On 10/4/2012 8:44 AM, bownes wrote:
> It had to happen eventually. Time Nut interest overlapped with $DAY_JOB.
>
> Due to reasons I really can't go into, a systems user is concerned with
the displacement of two servers from the same pair of stratum 2 NTP servers.
>
> I'm convinced that it really isn an issue as long as the two systems in
question remain within a few 10's of ms. However, I have no off the shelf
method of collecting and correlating the data. Before I go out and invent
the wheel, I thought I would check and see if anyone has done such a thing
and saved the scripts and whatnot.
>
>
> Thanks!
> Bob
>

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Re: [time-nuts] messy workbenches

[Rob Kimberley]

Hi Brooke,

I'm not sure I should have done that test as I scored 35. Hmmm...

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Brooke Clarke
Sent: 29 September 2012 14:11
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] messy workbenches

Hi:

Recently I've discovered Asperger's Syndrome.  Although I don't meet all the
criteria, I do have a number of the traits.
One is living with clutter (this is different from obsessive hording).  A
common occupation is engineering.
AS people are much more comfortable with things as opposed to people.
People who work in technical fields or have strong interests, like extremely
precise time, may also have this.
To find out you can take an online test at:
http://www.aspergerstestsite.com/

or read the Wiki page at:
http://en.wikipedia.org/wiki/Asperger_syndrome

and a movie:
  "Mozart and the Whale" that's about this.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html

DaveH wrote:
> And Bob Pease trumps all:
>
> http://eetimes.com/electronics-blogs/other/4217103/How-messy-is-your-d
> esk-
>
> There is even a gallery of 24 of Engineering's messiest desks here:
>
> http://www.eetimes.com/electronics-blogs/social-mania-blog/4217145/Pho
> to-gal
> lery--Engineering-s-messiest-desks
>
> My primary love is music (analog synthesizers and digital instruments 
> with
> recording) and the first messy desk pictured is from Christopher 
> Nelson who designs the Sweetwater Sound Creation Station computers -- 
> I own one and love it.
>
> It is ironic that:
>
> Pease was killed in the crash of his
> 1969 Volkswagen Beetle, on
> June 18, 2011. He was leaving a
> gathering in memory of Jim Williams,
> who was another well-known
> analog circuit designer.
>
> >From Bob's wikipedia entry:
>
> http://en.wikipedia.org/wiki/Bob_Pease
>
>
> Dave (who has a messy workbench but I know where everything is!!!)
>
>
>> -Original Message-
>> From: time-nuts-boun...@febo.com
>> [mailto:time-nuts-boun...@febo.com] On Behalf Of Grant Saviers
>> Sent: Friday, September 28, 2012 18:48
>> To: time-nuts@febo.com
>> Subject: [time-nuts] messy workbenches
>>
>> George's is a far distant competitor to the bench of the late Jim 
>> Williams, see 
>> http://www.computerhistory.org/atchm/an-analog-life-rememberin
>> g-jim-williams/
>>
>> Which was on display at the Computer History Museum and just was 
>> returned to Linear Tech.
>>
>> Grant Saviers
>>
>> ___
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>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
> ___
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> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>


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Re: [time-nuts] Why the fuss - GPS Interference...

[Rob Kimberley]

Tom,

Nice story. Thanks. Last I heard Rich had moved on from FEI-Zyfer. I don't
know where he is now. Nice guy!

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Curlee
Sent: 29 September 2012 04:53
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Why the fuss - GPS Interference...

I've also had some odd dealings with Rich Bailey.  Some time in the mid
1990's I was a contractor at a USN cal lab.  We had sent out a Datum time
code generator for repair, and when it came back, one of the functions
didn't work.  I called Datum and after describing the problem, the tech
support guy remembered that there had been a software upgrade, one that, for
some unknown reason, had removed the function we needed.  He promptly sent
me a set of PROMs that had the previous software version and all was well.  

Skip ahead 6 or 8 years, and I was at a family function and got to talking
to my cousins husband.  He vaguely mentioned that he worked for a company
that 'made very accurate clocks'.  For some reason, I blurted out "do you
work for Datum?"  He was shocked that I knew who, and what, they were.  We
got to comparing notes, and, yep, same Rich Bailey that sent me the PROMs. 
I agree, he really is a nice guy.  Last I heard, he was the sales manager
for FEI-Zyfer.

Tom WB6UZZ

--- On Fri, 9/28/12, Burt I. Weiner  wrote:

From: Burt I. Weiner 
Subject: [time-nuts] Why the fuss - GPS Interference...
To: time-nuts@febo.com
Date: Friday, September 28, 2012, 9:20 AM

Yes, Rob, It was Rich Bailey. A good guy! He worked for DATUM in Anaheim, CA
and as I recall, he lived in Riverside. I noticed that he didn't wear a
watch and when I jokingly commented about it, considering what he did for a
living, he told me that he had been so aware of precise time for so many
years that he got tired of knowing precisely what time it was. We had fun
together that day.

Burt, K6OQK


>From: "Rob Kimberley" 
>To: "'Discussion of precise time and frequency measurement'"
>         
>Subject: Re: [time-nuts] Why the fuss - GPS Interference...
>
>
>Hi Burt,
>
>This sounds familiar! It wasn't a guy called Rich Bailey was it? That's 
>what he suggested I do, but I got onto Trimble and got one of their 
>Bullet antennae with the 3 pole filter (Bullet III?).
>
>That worked for us.
>
>Rob

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
b...@att.net
www.biwa.cc
K6OQK 


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Re: [time-nuts] Why the fuss - GPS Interference...

[Rob Kimberley]

Hi Burt,

This sounds familiar! It wasn't a guy called Rich Bailey was it? That's what
he suggested I do, but I got onto Trimble and got one of their Bullet
antennae with the 3 pole filter (Bullet III?). 

That worked for us.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Burt I. Weiner
Sent: 28 September 2012 16:34
To: time-nuts@febo.com
Subject: [time-nuts] Why the fuss - GPS Interference...

I had a similar experience while working on the Seiko pager watch project
some years ago.  We were using DATUM GPS 9390 GPS receivers to time the
system at each FM station transmitter site.  One particular FM site on Edom
Hill near Palm Springs, California (U.S.A.) had a problem from not only the
associated FM transmitter but also from a nearby UHF TV running a bazillion
or so Watts ERP.  We finally installed a Symerticom WWVB receiver, but that
was not as reliable as we needed.  Not because of any interference, but
because of propagation issues at 60 kHz at this mountain top site.

I called DATUM to see about filters that could be put ahead of the antenna.
The fellow I talked to lived within 50 miles of the site.  We
intellectualized for a while and finally agreed that I would pick him up in
the morning and take him to the site. Well, when I picked him up he had a
shopping bag that he put in the back seat.  We had planned on getting
something to eat before we went up the mountain so I asked, "Bringing a
snack?"  He said, "No, it's a surprise."  I also had one of the DATUM
receiver running in my car off of 12 Volts with the antenna attached to my
roof mount.

As we approached the site the receiver in my car lost all satellites.  He
looked at the receiver in the Seiko system and then went back to the car and
got the shopping bag.  He then revealed his secret - a two pound coffee can
with a few holes poked in the side near the bottom.  We went up on the roof,
disconnected the DATUM's antenna, and mounted it inside the coffee can.  He
told me that you have to be sure the antenna and the coffee can are
electrically (RF
wise) connected together.  He then placed the coffee can on the roof
orienting it so that it would have the best view of GPS satellites as
possible given the site location and "Coffee Can Aperture" .  By the time we
got back in the building the receiver was tracking four GPS birds and a
short time later was happily doing its thing.

What he did was to use the coffee can as a waveguide beyond cutoff
attenuator.  Not really as an attenuator, but as a high pass filter.  It did
attenuate the FM band signal quite a bit and attenuated the UHF TV signal
sufficiently so that it was no longer a problem for the system.  A few says
later I went back to the site and installed the "Hi Pass Filter" in a large
upside down bottle.  This ran reliably for several years until the Seiko
project came to an end.

I have since done this same trick at a few transmitter sites on Mt. 
Wilson, which overlooks Los Angeles and is home to most of the Southern
California FM and (now) DTV transmitters.

An aside:  When Seiko ended the project they wholesaled a lot of the
non-proprietary equipment out.  I purchased four of the DATUM Time and
Frequency receivers with Y2K updates.  One I gave to a "FMT-Nuts" 
buddy, one went to a buddy who runs a Metrology Lab and the other two are
running in my shoppe.  See: http://www.k5cm.com/k6OQK%20FMT%20NEW.htm

Burt, K6OQK


>Tom,
>
>We had a similar problem at a BBC site when I was selling Datum in the UK.
>We managed to get round the problem with a better antenna. The third 
>harmonic of the UHF wasn't slap bang on L1 but close enough with a 
>basic GPS antenna to kill GPS.
>
>Rob
>
>-Original Message-
>
>Behalf Of Tom Miller
>Sent: 27 September 2012 18:44
>Subject: Re: [time-nuts] Why the fuss?
>
>Under other issues, I have one where GPS could not be used. It was at a 
>UHF TV station where the third harmonic fell right in the L1 band. A 
>220,000 watt UHF transmitter driving a gain antenna for 5 MW EIRP will 
>always produce some third harmonic near the antenna. There was no 
>access to GPS within 1 km of the site.
>
>They were using the WWVB signal as the time and frequency reference.
>Luckily, the conversion the DTV moved them to a new channel and now 
>they can use the GPS.
>
>Tom

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
b...@att.net
www.biwa.cc
K6OQK 


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Re: [time-nuts] Why the fuss?

[Rob Kimberley]

Tom,

We had a similar problem at a BBC site when I was selling Datum in the UK.
We managed to get round the problem with a better antenna. The third
harmonic of the UHF wasn't slap bang on L1 but close enough with a basic GPS
antenna to kill GPS.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Miller
Sent: 27 September 2012 18:44
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Why the fuss?

Under other issues, I have one where GPS could not be used. It was at a UHF
TV station where the third harmonic fell right in the L1 band. A 220,000
watt UHF transmitter driving a gain antenna for 5 MW EIRP will always
produce some third harmonic near the antenna. There was no access to GPS
within 1 km of the site.

They were using the WWVB signal as the time and frequency reference. 
Luckily, the conversion the DTV moved them to a new channel and now they can
use the GPS.


Tom

- Original Message - 
From: "Bob Camp" 
To: "'Discussion of precise time and frequency measurement'" 

Sent: Thursday, September 27, 2012 1:02 PM
Subject: Re: [time-nuts] Why the fuss?


Hi

Right here in PA for one. You essentially can not buy a new house without
there being various conditions written into the title. One universal one is
"no antennas". The only exception is for one 19" sat dish for TV, since
that's a federal mandate.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of brent evers
Sent: Thursday, September 27, 2012 10:57 AM
To: j...@quikus.com; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Why the fuss?

Zoning, Legal?

Where?

Brent

On Thu, Sep 27, 2012 at 10:41 AM, J. Forster  wrote:
> Because:
>
> LORAN-C is gone.
>
> Not all can use GPS because of siting, horizon, zoning, legal, and other
> issues. Not everyone can erect antenna towers.
>
> There is nothing else, except perhaps WWV or CHU on HF.
>
> -John
>
> ==
>
>
>
>> I cannot think of a time-nuts WWVB reference requirement
>> that cannot be better satisfied with a GPSDO.
>>
>> Will  NIST publish a public domain reference circuit?
>> That would allay patent concerns.
>>
>> --
>> Chuck Forsberg WA7KGX N2469R c...@omen.com   www.omen.com
>> Developer of Industrial ZMODEM(Tm) for Embedded Applications
>>Omen Technology Inc  "The High Reliability Software"
>> 10255 NW Old Cornelius Pass Portland OR 97231   503-614-0430
>>
>>
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>
>
>
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[time-nuts] Javad Letter to FCC...

[Rob Kimberley]

I'm wondering how much LightSquared are paying this guy?

Rob




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Re: [time-nuts] Javad's J-Shield

[Rob Kimberley]

I understand fully what Javad said, having followed the LightSquared debacle
recently. I just thought that the article was very biased and somewhat
derogatory in its reference to other parties.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Larry McDavid
Sent: 19 September 2012 17:28
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Javad's J-Shield

Yes, interesting. But, note that article is also a political statement by a
highly-biased individual owning a related business.

I'm not saying he is wrong or even that I disagree. I do believe it is
worthwhile to know who is saying what.

Larry

On 9/19/2012 7:07 AM, Rob Kimberley wrote:
> Page 19 - 30  in the latest edition of GPS World.
>
> http://editiondigital.net/publication/?i=125872
>
> Interesting read..
...

--
Best wishes,

Larry McDavid W6FUB
Anaheim, California  (SE of Los Angeles, near Disneyland)

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[time-nuts] Javad's J-Shield

[Rob Kimberley]

Page 19 - 30  in the latest edition of GPS World.

http://editiondigital.net/publication/?i=125872

Interesting read..

Rob




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[time-nuts] Comments on GPS Spoofer on LinkedIn

[Rob Kimberley]

<http://www.linkedin.com/groups/Here-it-is-Build-sophisticated-1877372.S.130
052818?view=&srchtype=discussedNews&gid=1877372&item=130052818&type=member&t
rk=eml-anet_dig-b_pd-ttl-cn&ut=3qd1OcFjEQyRo1>

Hope the link works OK.

Rob Kimberley




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Re: [time-nuts] ET-6000 firmware

[Rob Kimberley]

Good luck!!


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Didier Juges
Sent: 26 August 2012 19:09
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] ET-6000 firmware

KO4BB is busy cutting plywood and boarding windows, will be back to fun
stuff after Isaac...

Didier KO4BB

Robert Watzlavick  wrote:

>I finally got a flash programmer so I uploaded all three ROM images 
>(TCXO, OCXO, Rub) for the Datum ET-6000 / 9390-6000 to the KO4BB 
>website.  Last year I sent them 3 chips and asked for all the variants 
>so I could play with converting my TCXO unit to an OCXO unit (and 
>potentially a Rubidium some day).  I think the images are in the upload
>
>folder awaiting their final home.
>
>This latest firmware addresses the GPS date problem.
>
>DT101E = TCXO
>DT102E = OCXO
>DT103E = Rubidium
>
>Some guy is selling DT101E chips on eBay for $50 (sorry if you're on 
>the
>list...)
>
>-Bob
>
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--
Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other
things.
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Re: [time-nuts] Trimble TimeKeeper

[Rob Kimberley]

I believe there have been posts on this subject before. Please try checking
the Time Nuts archives for an answer.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of James Fournier
Sent: 31 July 2012 22:11
To: time-nuts@febo.com
Subject: [time-nuts] Trimble TimeKeeper

Trimble TimeKeeper sets my clock date on my Windows 7 machine to the year
2020. Anyone have a clue why? Many thanks.
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Re: [time-nuts] Leap second? Yay or nay?

[Rob Kimberley]

http://www.bbc.co.uk/news/technology-18672173

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tony Finch
Sent: 02 July 2012 16:26
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Leap second? Yay or nay?

Jim Lux  wrote:
>
> which is an interesting thing.. if instead of DST (for which I think 
> there's little practical reason to have in the first place).. say you 
> just shifted the clock one minute earlier or later each day, gradually 
> moving it to the new alignment relative to solar day.

DST exists because people prefer to align the timetabled active part of the
day to sunrise rather than midday. But there are too many difficulties with
counting time from actual sunrise and reconciling differences due to
latitude and longitude. So we quantize everything to an hour (mostly).

Tony.
--
f.anthony.n.finchhttp://dotat.at/
Trafalgar: Northerly 5 to 7, but mainly 4 in northwest. Moderate. Fair.
Moderate or good.

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Re: [time-nuts] Leap Second on Datum ExacTime 6000...Oh well...

[Rob Kimberley]

Seem to remember they had a bug in them. Thought it had been fixed

Rob 

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bert, VE2ZAZ
Sent: 01 July 2012 01:44
To: time-nuts@febo.com
Subject: [time-nuts] Leap Second on Datum ExacTime 6000...Oh well...



Hi,

This is to report the behavior of my Datum ExacTime 6000 unit dealing with
the leap second. I think the behavior shows the age of the unit (around year
2000). It has firmware DT102E.

- It showed two "58" seconds, that would be the leap second insertion...

- It showed a "60" second... what? That made it two leap seconds... 

- It skipped the "05" second of the following minute to subtract the
extraneous leap second added above...

I have captured this on video and will likely put that on Youtube for those
who may be interested. I captured CHU's audio in the background. By the way,
CHU's transmitted data was an extra tick for the "60" second.

Regards,

Bert, VE2ZAZ


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[time-nuts] The Patent Brouhaha

[Rob Kimberley]

Murky waters!!

<http://www.gpsworld.com/gnss-system/patent-brouhaha-13157?utm_source=GPS&ut
m_medium=email&utm_campaign=GNSS-Design_06_29_2012&utm_content=patent-brouha
ha-13157>


Rob Kimberley



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Re: [time-nuts] Leap second coming...

[Rob Kimberley]

I seem to remember someone from NPL telling me that they actually increment
the each of the last 10 seconds before the epoch by 100mS, rather than
putting in one whole second.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Van Baak (lab)
Sent: 29 June 2012 17:39
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Leap second coming...

There's an old list of how to (and how not to) watch a leap second:
http://leapsecond.com/notes/leap-watch.htm

The NMEA output of some GPS receivers is fun to watch. Some use a double
:59:59 or double :00:00 instead of :59:60 for a positive leap second.

/tvb (iPhone4)


On Jun 29, 2012, at 17:10, David McGaw  wrote:

> Besides leapsecond.com, online there is also of course NIST/USNO's site
http://time.gov and you can listen to WWV at 303-499-7111.  If you want to
hear it online you could use Skype.
> 
> David
> 
> On 6/29/12 2:21 AM, jim s wrote:
>> I've got a note set for 6/29/2012 @ 5pm PST.  Hopefully that is the right
time.
>> 
>> any way for a challenged one to "listen"  I'm currently grazing for an
internet version of wwv to listen to, but recommendations would be great.
>> 
>> Thanks for the program pointer, Hal.
>> thanks
>> jim
>> 
>> On 6/28/2012 9:37 PM, Hal Murray wrote:
>>> Everybody ready for the big event?:)
>> 
>> 
>> 
>> ___
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Re: [time-nuts] Clockwise.

[Rob Kimberley]

...and still good enough for a lot of folks!

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Holmes
Sent: 26 June 2012 15:24
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Clockwise.

Until we arrogant humans decided that we could do better, it WAS the clock.

Tom Holmes, N8ZM
Tipp City, OH
EM79


> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] 
> On Behalf Of Javier Herrero
> Sent: Tuesday, June 26, 2012 10:17 AM
> To: time-nuts@febo.com
> Subject: Re: [time-nuts] Clockwise.
> 
> It can be a reference. I was not meaning a good one :) And surely it 
> is
not that bad
> as a clock.
> 
> 
> El 26/06/2012 15:32, Azelio Boriani escribió:
> > OK, in my opinion the iPhone is not a reference but, well, if you 
> > say it
is
> > then OK.
> >
> > On Tue, Jun 26, 2012 at 3:20 PM, Javier Herrero
> wrote:
> >
> >> See below, after /tvb ;)
> >>
> >> El 26/06/2012 15:08, Azelio Boriani escribió:
> >>
> >>> Yes, and the reference?
> >>>
> >>> On Tue, Jun 26, 2012 at 2:32 PM, Tom Van Baak (lab)
>   wrote:
> >>>
> >>>   With four points one can compute ADEV...
> 
> 
> 
> 
> 
>  /tvb (iPhone4)
>  __**_
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>  to
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> nuts
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> 
>    __**_
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> >>> https://www.febo.com/cgi-bin/**
> >>> mailman/listinfo/time-nuts bin/mailman/listinfo/time-nuts>
> >>> and follow the instructions there.
> >>>
> >>>
> >>>
> >> __**_
> >> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> >> https://www.febo.com/cgi-bin/**
> >>
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> >>
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Re: [time-nuts] Morion MV89A pics

[Rob Kimberley]

Bob,

FEI as far as I know do own Morion. That's certainly what I was told when I
worked for Zyfer (also owned by FEI).

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bob Camp
Sent: 09 June 2012 02:15
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Morion MV89A pics

Hi

I do not believe FE owns Morion. The most certainly own space in the Morion
factory. Last time I was there I saw the space.

Bob

On Jun 8, 2012, at 9:00 PM, Arthur Dent wrote:

> I just got an DOXCO made by Frequency Electronics, Inc., so the first 
> thing I did was remove the screws from the outer cover to open it up 
> and check out the insides. Once I removed the foam so I could see the 
> oven, I had the feeling of deja vu. but I'd never owned one of these 
> units before. I realized that it was exactly the same as the oven 
> inside a Morion MV89A that I've seen on this list and where FEI 
> apparently owns Morion it wasn't too much of a surprise. The OXCO part 
> number is FE-489A which is pretty close to the Morion MV89A part 
> number as well. Attached is a photo of the FE on the left and the photo of
the Morion from this list on the right.
> 
> http://i906.photobucket.com/albums/ac262/rjb1998/FE-489A89A1024.jpg
> 
> Here is a view of the entire board which has a DB-9 connector to 
> connect to the outside world. In the foreground is the output which 
> converts the 5Mhz output of the oscillator to 15Mhz that goes to the 
> SMA connector. The size of this OXCO is exactly the same as the 5650A
rubidium oscillator by FEI.
> Adjustment may be digital and/or analog.
> .   
> http://i906.photobucket.com/albums/ac262/rjb1998/FE-489A606-1.jpg
> 
> -Arthur
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Re: [time-nuts] Quadrifilar Helix Antenna

[Rob Kimberley]

I had a go at making one in 1986 for a broken NBS unit (huge two 19" RMK,
single channel GPS), which had been damaged in transit. Used small sections
of semi-rigid coax soldered together. 

It worked well enough to track SVs and get data we needed.

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Azelio Boriani
Sent: 08 June 2012 21:29
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Quadrifilar Helix Antenna

OK here a summary of the IV3QBN article (original in Italian) on QFH:



This article suggests that instead of buying one, you can make your GPS
antenna. After two antenna examples (fig.1 an Amsat plane spiral antenna and
fig.2 a 9GHz array of patches) the author suggests to use a backfire
quadrifilar helix, directly fed by a 50OHM coax cable.
The helix is only half a turn, but the pitch is much greater than the
classic helix.
The result can be seen in fig.3 and 4. The turn diameter must be an integer
fraction of the lambda, as suggested by Kilgus [C. Kilgus: Resonant
Quadrifilar Helix-IEEE Transactions on Antenna and Propagation. Vol AP-17,
May 1969] and the length of the turn must be 0.28 times the lambda. To
compensate for the reactive part of the antenna impedance, the trick is to
make the wire pairs one longer and one shorter than the computed length so
that one is seen as capacitive and the other inductive compensating each
other. The 4 wires are soldered on the outer conductor of the coax cable
(bottom of the helix, GND) and on top of the cable two wires (one from each
pair) on the center conductor and the other two on the outer conductor. This
way the helix will radiate/receive from the top and the gain will be maximum
in the 40degrees direction (radiation pattern in fig.3). You need a piece of
UT141 coax cable and 4 enamelled copper wires 1.5 upto 1.8mm in diameter.
The longer pair is 103mm in length and the shorter is 99mm, the diameter of
the helix will be 30mm. See fig.5 for a detail of the helix. At the bottom
the distance between the two pairs is 5mm and the length is 69mm (the
shorter) and 73mm (the longer). In fig.6 you can see how to solder the top
of the cable [but the detail is not so clear, IMHO]. The length [69 and 73?
He doesn't say explicitly] can be adjusted to trim the return loss but a
network analyzer or a sweep is needed to check the result. The antenna is
wound anticlockwise as seen from the top. In
fig.4 you can see the HP8714ES analyzer result for the antenna [that the
author claims to have seen after the first try, without adjusting anything].
To use this antenna directly, don't forget to put a DC blocking capacitor in
order not to short the antenna supply from the GPS receiver or use a MMIC
(MAR3, INA,ERA, MSA) [and a filter would be best] to have an active antenna.




On Fri, Jun 8, 2012 at 4:05 PM, paul swed  wrote:

> Good reads.
> Thanks Raj
> Paul
> WB8TSL
>
> On Fri, Jun 8, 2012 at 8:00 AM, Azelio Boriani 
>  >wrote:
>
> > Meanwhile take a look at these:
> >
> > http://www.kunstmanen.net/WKfiles/Techdocs/RQHA/RQHA1999-1eng.pdf
> >
> > http://w2du.com/r2ch22.pdf
> >
> >
> >
> http://www.rish.kyoto-u.ac.jp/digitalbeacon/information/Building_QFH_A
> ntenna_Guide.pdf
> >
> > http://ap-s.ei.tuat.ac.jp/isapx/2006/pdf/1E2a-5.pdf
> >
> > On Fri, Jun 8, 2012 at 1:04 PM, Azelio Boriani 
> >  > >wrote:
> >
> > > I have made a QFH but then found a Procomm GPS4 in Germany for a 
> > > good price...
> > >
> > >
> > > On Fri, Jun 8, 2012 at 12:49 PM, Raj  wrote:
> > >
> > >> Not to worry Azelio, if you could tell us the gist of it. I 
> > >> thought
> > maybe
> > >> I could
> > >> try and brew one for my tbolt.
> > >>
> > >> At 08-06-2012, you wrote:
> > >> >I have tried to translate with Google (yes, I'm Italian but need 
> > >> >time
> > to
> > >> >translate the whole PDF) but the result is very poor. If you can
> wait I
> > >> can
> > >> >prepare a short summary or a complete traslation (more time).
> > >> >
> > >> >On Fri, Jun 8, 2012 at 10:31 AM, Raj  wrote:
> > >> >
> > >> >>
> > >> >> I came across this article. I dont understand Italian!
> > >> >>  From RadioKit Elettronica 2003-03
> > >> >>
> > >> >> https://dl.dropbox.com/u/10377704/IV3QBN%20QuadHelix.pdf
> > >> >>
> > >>
> > >>
> > >> ___
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> > >> to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > >> and follow the instructions there.
> > >>
> > >
> > >
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Re: [time-nuts] Time-nut gettogether in Boulder

[Rob Kimberley]

When is the next one Alan? I've tried looking on the NPL site but nothing
showing. I've missed some recent ones due to some health issues.

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Alan Melia
Sent: 06 June 2012 23:45
To: Tom Van Baak; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Time-nut gettogether in Boulder

Then there is the NPL Time & Frequency Club at Teddington..oh sorry that
is the wrong side of the Atlantic :-))

Alan
G3NYK

- Original Message -
From: "Tom Van Baak" 
To: "Discussion of precise time and frequency measurement" 

Sent: Wednesday, June 06, 2012 11:00 PM
Subject: Re: [time-nuts] Time-nut gettogether in Boulder


> Tom,
>
> Agreed. We've given this some thought and I've polled people in the past. 
> The issue is usually location and budgets so nothing has ever happened. 
> Note that besides the NIST conference there are several other venues where

> time nuts are frequently spotted:
> - Dayton hamvention (I've never been, but I know many others have).
> - PTTI (I try to go every year).
> - FCS, ION GPS, NAWCC (I attend if they're close enough).
>
> /tvb
>
> - Original Message - 
> From: "Tom Knox" 
> To: "Time-Nuts" 
> Sent: Wednesday, June 06, 2012 9:37 AM
> Subject: Re: [time-nuts] Time-nut gettogether in Boulder
>
>
>>
>> After following posts for a number of years I have learned the Time-Nuts 
>> community are not only a good source of knowledge but more important a 
>> great group of people. But even knowing that I am a bit overwhelmed after

>> personally meeting several Time Nuts.  Of coure this is common knowledge 
>> to may of you long time members. That said the chance to get to know 
>> Magnus, David, John, and locals Hank and Skip has left me thinking.
>> In my humble opinion it would be great to put together an annual 
>> gathering of the Time and Freq Community, perhaps in conjunction with 
>> NIST's annual Seminar. If the time I have spent with Magnus and the other

>> visiting Time-Nuts is any indication I  think a Time-Nuts gathering would

>> quickly develop into the must attend event for people serious about time 
>> but the fantastic people researching it. I see this evolving not only a 
>> social gathering, but also a place for professions and amateurs to could 
>> showcase ideas and products.
>> Best Wishes;
>>
>> Thomas Knox
>
>
>
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Re: [time-nuts] hey - warning

[Rob Kimberley]

This is the second one I've had supposedly from the group.

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. Forster
Sent: 29 May 2012 01:37
To: Discussion of precise time and frequency measurement
Cc: dlh4im...@aol.com
Subject: Re: [time-nuts] hey - warning

It's a Malware spam. I've seen at least 2 dozen in the past week or so.
ALL hijacked Yahoo accounts, BTW.

Forward the spam to:

ab...@yahoo.com
and
ab...@ukrnames.com  (the domain Registrar)

Best,

-John

==




> Looks like his account got hacked, don't click on the link..
>
> Sent From iPhone
>
> On May 28, 2012, at 16:31, Robert Atkinson  wrote:
>
>>
>> this is pretty awesome you should look into this
>>
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Re: [time-nuts] AccuBeat AR-40A manual

[Rob Kimberley]

Hi Magnus,

Have you tried contacting AccuBeat? 

I believe that Avi Stern is still with them. Try him, I'm sure he will be
able to help (and please give him my kind regards).

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Magnus Danielson
Sent: 12 May 2012 10:31
To: Time-Nuts
Subject: [time-nuts] Accubeat AR-40A manual

Fellow time-nuts,

I was just asked to assist on the debugging on a Accubeat AR-40A. He has
serial port interface, but not knowing the commands it's a bit hard to get
started. He has 2 working and 1 failing, so comparing readings is possible.

Does anyone has manuals for it? I looked at the Accubeat site, and all that
I really could get from them is a 2-page datasheet, which is nice but not
really satisfactory.

Cheers,
Magnus

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Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?

[Rob Kimberley]

Wasn't this the company that was "championing" Lightspeed?

:-)

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark Sims
Sent: 11 May 2012 12:20
To: time-nuts@febo.com
Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?


I like "Less than $20... Not for Sale"  Sounds like vaporcrap to me...
-
Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A):
http://www.javad.com/jgnss/products/triumph.html

  
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Re: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?

[Rob Kimberley]

Zyfer produced a paper on WAAS for timing. 

<http://support.fei-zyfer.com/downloads.aspx>

You will need to create a log-in and password to download their stuff.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark Sims
Sent: 11 May 2012 05:02
To: time-nuts@febo.com
Subject: [time-nuts] Trimble Resolution SMT - good/bad/indifferent?


Why in the hell would anybody build a 50 channel receiver?  At most you
MIGHT see 12 usable GPS sats...  I don't think that I've seen over 10.  WAAS
should be fairly useless for a timing receiver.

Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR
were uploaded to the KO4BB site). 
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Re: [time-nuts] question about Thunderbolt geo acuracy

[Rob Kimberley]

How accurate do you need your height? 

Remember that height is the least accurate of GPS parameters due to the fact
that you rarely have a GPS satellite directly overhead.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of swingbyte
Sent: 10 May 2012 13:50
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] question about Thunderbolt geo acuracy

Hi all,
Hope this isn't too chat roomy, however, I have need of a survey precise
geolocation type gps.  I was wondering if the precise timing abilities
extend to its precision in position output?  I have a thunderbolt and one of
those conical white aerials from china and would like to know if this
combination will give me accurate height data.

Thanks

Tim

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Re: [time-nuts] First "accurate" atomic clock video

[Rob Kimberley]

Mike,

Thanks for posting that. A wonderful film, and a great insight into early Cs
development. 

I was lucky to see one of their Cs fountains a few years ago when attending
an NPL T&F Club meeting. They also gave us a view of the work being done on
optical clocks. 

Louis Essen would have been most impressed.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Michael Costolo
Sent: 08 May 2012 11:22
To: time-nuts@febo.com
Subject: [time-nuts] First "accurate" atomic clock video

I've always been fascinated with science history.  If you all haven't seen
this already, here is a video from 1955 about the first "accurate" cesium
atomic clock designed by Louis Essen and made in the UK's National Physical
Laboratory.  Interesting that the one made after the prototype was 17 feet
long.

http://www.youtube.com/watch?feature=player_embedded&v=MGoVXLzUDsQ

-Mike-
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Re: [time-nuts] Oh dear

[Rob Kimberley]

I must get one of their line cords to see if it will improve my timing
system!!

You just have to laugh at this nonsense.

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Burt I. Weiner
Sent: 07 May 2012 15:39
To: time-nuts@febo.com
Subject: [time-nuts] Oh dear

A friend of mine signed me up for a catalog from the "Audio Advisor".  He
said I deserved this - I was afraid to ask what he meant by that!  Spend a
few minutes looking over this
site:  http://www.audioadvisor.com/  Be sure to check out their "Power
cords" at: http://home-audio.audioadvisor.com/search?w=Power+Cords

Burt, K6OQK


>From: "Rob Kimberley" 
>To: "'Discussion of precise time and frequency measurement'"
> 
>Subject: Re: [time-nuts] Oh dear
>
>
>An old saying: "a fool and his money are often parted".
>
>Sums things up nicely I feel.
>
>Rob Kimberley

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
b...@att.net
www.biwa.cc
K6OQK 


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Re: [time-nuts] Chat Room?

[Rob Kimberley]

I've not seen many questions ignored on this excellent group. 

If they were, then maybe, just maybe no one had an answer at that time.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Roberto Barrios
Sent: 07 May 2012 14:18
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Chat Room?

Hi Bert,

Couldn't agree more with you. On the other hand, and which is even worse,
questions from not-so-hardcore-time-nuts are simply ignored on a random
basis.

I'm leaving the group. If you ever come to or need something from Spain, let
me know.

Regards,
Roberto EB4EQA



-Original Message-
From: ewkeh...@aol.com
Sent: Monday, May 07, 2012 2:15 PM
To: time-nuts@febo.com
Subject: [time-nuts] Chat Room?

Time nuts has turned in to a chat room to  people that have diarrhea  of
their fingers. The result is that many of us  converse off list and do not
contribute to meaningful dialog.
Are there not rules and if yes, should they not be respected  and adhered
to?
Bert Kehren

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Re: [time-nuts] Oh dear

[Rob Kimberley]

An old saying: "a fool and his money are often parted". 

Sums things up nicely I feel.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Javier Herrero
Sent: 07 May 2012 11:30
To: time-nuts@febo.com
Subject: Re: [time-nuts] Oh dear

El 07/05/2012 11:20, Attila Kinali escribió:
> But to bring this back to time nutty topics, have a look at 
> http://www.colorfly.eu/product.html It's an MP3 player with high 
> precision timing. It does not only use two TCXOs with <5ps Jitter..
> No! It also employes a technique known as "Jitter Kill" for the 
> ultimate mobile sound experience! :-) Attila Kinali

It plays MP3 or uncompressed audio? ;). And the sliding potentiotemer... 
prone to all kinds of noises and imbalance, and the nice wood enclosure,
hand engraved, of course manufactured in a controlled temperature and
humidity environment, that no doubt has a very positive effect on the sound,
probably as good as the EMC shielding that provides. Also I love this
paragraph "On month day of year, the technique of circuit named Jitter Kill
was registered as a patent for the other special technique of the Pocket
HIFI player". When was/will be month day of year? 
excellent accuracy :)

I imagine Steve Wan and his team laughing out loud everytime their get a
purchase order.

Regards,

Javier


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Re: [time-nuts] Anyone from Italy here ?

[Rob Kimberley]

Lucky those who don't have to live in the EU!!

Rob K (UK)

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Knox
Sent: 02 May 2012 17:35
To: Time-Nuts
Subject: Re: [time-nuts] Anyone from Italy here ?


Sadly; It is currently one of the few growth industries in the EU. 

Thomas Knox



> From: david.partri...@perdrix.co.uk
> To: time-nuts@febo.com
> Date: Wed, 2 May 2012 17:30:40 +0100
> Subject: Re: [time-nuts] Anyone from Italy here ?
> 
> No, Italian law doesn't require DOB or place of birth registering for
purchases, I suspect his email has been hi-jacked by someone who's
attempting to get into the identity theft business.
> 
> Dave
> -Original Message-
> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] 
> On Behalf Of cfo
> Sent: 02 May 2012 16:48
> To: time-nuts@febo.com
> Subject: [time-nuts] Anyone from Italy here ?
> 
> :
> 
> Here in Italy is requiring by law.. that for all customers that have
bought something from us, I need to have also birthplace and birthday.
> 
> 
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[time-nuts] Interesting Clock Project

[Rob Kimberley]

I personally like the simplicity of this one.

 

Material cost quite low, but takes a good team effort.

 

http://iprl.wz.cz/

 

Rob Kimberley





 

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Re: [time-nuts] LORAN-C

[Rob Kimberley]

I should say so!!
Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. Forster
Sent: 01 May 2012 16:14
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] LORAN-C

Antenna envy!

-John

=



> Hello The Net:
>
> LORAN signals are still being received at a 89700 microsecond GRI.
> I concur with others that there is only one station transmitting the
> master(M) and the slave(X) signals.
> My SRS FS-700 Rx shows equal received signal strength for both signals.
> Reports indicate the transmitter is at the old Coast Guard LORAN 
> engineering site at Wildwood NJ.
>
> Since I turned the equipment on last Sunday night, I have had 
> continuous lock on the FS-700, Austron 2100, and a 2100F.
>
> Compared to the GPS/DO 10 MHz from the T'Bolt, I am getting accuracies 
> to the mid -13s, as indicated on the FS-700 phase meter.
>
> Next step is to lock up the signal on an oscope, triggered by an 
> accurate 11.148272 KHz signal ( reciprocal of 89700microsec).
> That way I should be able to see the pulses and the E-LORAN 
> experimentation.
>
> My set up at home uses a 40' high delta loop antenna, 2 orthogonal 
> loops terminated on the top with a
> 600 ohm resistor, a ARR preamplifier with battery at the antenna , a 
> RG6 coax run to the shack, Astron 2084 multicoupler, then the 
> receivers.
>
> Stan, W1LE  Cape Cod FN41sr
>
>
>
>
> z
>
>
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Re: [time-nuts] Ashtech 3DF GPS

[Rob Kimberley]

These are specifically for attitude determination in mobile environments.
Not sure how good they would be for timing though. I remember seeing
something from Trimble a few years back which did similar.

Rob K

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Stan
Sent: 01 May 2012 14:08
To: time-nuts@febo.com
Subject: [time-nuts] Ashtech 3DF GPS

On more or less of a whim, I found and bought an Ashtech 3DF GPS. The
interesting thing about this particular GPS is that it uses four separate
GPS antennas mounted in a diamond pattern about 1 meter on a side and can
compute not only the "usual" stuff, but also heading, roll, and pitch
angles. I had heard of this being possible, but never actually seen it done.
There are no accessories included with this unit, other than the power cord.

Does anyone know where I can find a manual for it?
Will this GPS work with just four ordinary active antennas or are the
antennas special?
Given the complexity of the additional data massaging it does to extract the
angular data, does this also mean that it will have more accurate position
and or timing performance?
Does it need all four antennas to be able to do anything at all, or can it
compute position and time with just one antenna connected?

Thanks,
Stan


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Re: [time-nuts] An interesting freq counter

[Rob Kimberley]

The good old days.
:-)

Rob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark Sims
Sent: 30 April 2012 23:05
To: time-nuts@febo.com
Subject: [time-nuts] An interesting freq counter


With a rather freaky display that I have never seen:
http://www.electricstuff.co.uk/venner.html

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Re: [time-nuts] OT: The tick-tock of the optical clock ....

[Rob Kimberley]

I believe that NPL and PTB are working together on this project.

Rob Kimberley

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: 27 April 2012 11:24
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT: The tick-tock of the optical clock 

> Hi David,
>
> very similar work was done at PTB in Germany 
> http://www.ptb.de/en/aktuelles/archiv/presseinfos/pi2012/pitext/pi1203
> 01.html
>
> ... the charm of forbidden things...
>
> Best regards
>
> Bernd Neubig

Danke,

David
--
SatSignal software - quality software written to your requirements
Web:  http://www.satsignal.eu
Email:  david-tay...@blueyonder.co.uk 


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