Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV), with 5071A cesium clocks

[Rex]

I just watched it on PBS. Nicely done recreation of your GREAT 
experiment, Tom. Good to see you had a couple personal appearances, and 
especially for the final results.


Looks like your SR620 counter had a hyperdrive undercarriage lighting 
option. :-)




On 5/17/2016 7:50 PM, Tom Van Baak wrote:

The TV show is tomorrow, Wednesday evening. 8/9 PM, or something like that.

Here are fresh web pages with background information, photos, and plots:

http://leapsecond.com/great2016a/

http://leapsecond.com/great2016a/photos.htm

I have no idea how minor my role is in the actual TV episode, but if nothing 
else, the above two pages will share some time nuts sort of details of the 
clock experiment itself. If you have any questions let me know.

/tvb

- Original Message -
From: "Tom Van Baak" 
To: "Discussion of precise time and frequency measurement" 
Sent: Friday, May 13, 2016 12:00 PM
Subject: [time-nuts] GENIUS by Stephen Hawking (PBS TV),with 5071A cesium clocks


Fellow time nuts,

Here in the US, a new six-part TV series on National Geographic / PBS starts next 
Wednesday, May 18th, 2016. The title is "Genius by Stephen Hawking" and episode 
1 is: Can We Time Travel?

Having not seen it yet, I can't make a promise of its "SNR" (Science to 
Nonsense Ratio). It might be quite educational, or at least, very entertaining. And I'm 
definitely going to watch it with my family.

So why do I mention this?

Well, I spent most of December 2015 and January 2016 working with the UK-based 
producers of the show -- in order to pull off another Einstein 100th 
anniversary, general relativity, cesium atomic clock, gravitational time 
dilation experiment. The location chosen was 9000+ foot Mt Lemmon, near Tucson, 
Arizona.

The Hawking series covers a wide variety of topics, and this atomic clock bit 
is just one very small part. They were inspired by the DIY experiment I did ( 
http://leapsecond.com/great2005/tour/ ) and they wanted to create and film 
something similar. So I offered to help. Scenes with (me? and) my 5071A cesium 
clocks and hp 53132A / SR620 time interval counters are in episode 1.

The PR link to the episode is:

http://www.pbs.org/genius-by-stephen-hawking/episodes/episode-1/

Attached is a photo. I will post lots of technical info, plots, photos and FAQ 
here next week:

http://leapsecond.com/great2016a/

/tvb
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Re: [time-nuts] GPSCon for Jackson Labs

[Rex Moncur]

Hi Keith

Does this version allow one to make use of the 1PPS to give accurate timing of 
the PC and what timing accuracy do you expect?

Rex VK7MO


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Re: [time-nuts] MTI 260-0624-D OCXO

[Rex]

About opening cases, I opened one, repaired the oscillator and sealed it 
back up (sort of).


In the early 2000's I had a 10 MHz OCXO that I used as the main 
reference for my 10 GHz ham rover rig. It was really doing the job for 
me until I accidentally hooked it up to DC power backwards and killed 
it. I was hoping I could find some way to fix it. The oscillator was one 
of the larger metal packages about 3" long by about 2" square. Here's 
how I opened it.


Earlier I had tried to unsolder a smaller oscillator (about the size of 
the MTI 260) with a torch. It's hard to heat the two sections fast with 
a torch to melt the solder and find a way to grab them both ad pull 
apart while the solder is melted. On that attempt, I eventually got it 
apart but desoldered some internal circuit board components in the process.


For this other broken oscillator that I liked, I decided it might be 
better to mechanically cut it apart. I assumed that the bottom piece 
probably had a lip about 1/4 to 3/8 " long that fit tightly inside of 
the top case and that lip was soldered to join the two pieces. I wanted 
to cut off the top case right where the solder joint ended. I first 
drilled a small test hole into the side of the outer case about where I 
guessed the solder joint ended inside, Ideally just through the outer 
case. Then with a small Dremel bit I enlarged this hole to to figure out 
exactly where the solder seam ended. Then I carefully cut the main case 
around the end of the solder joint. Ideally I cut just a little below 
the end of the inner lip to keep a slight aligning surface for putting 
it back together later.


For the cutting, I had a milling machine that I used, But once you know 
where you want to cut, I think careful hack sawing or a Dremel ceramic 
disk could have done the job. With only a little bit of solder now 
holding the cut top case on, a little prying removed it.


[Another option might be to cut vertical slits in the outer case just 
either side of the round corners (8 cuts) and just as long as the 
internal soldered flange. The object is to turn the bottom sides of the 
outer case into tabs that can be bent out. Driving a knife or chisel 
into the solderd seam will hopefully pry the flaps outward. Getting the 
corners loose would probably be the hard part. Cutting them as in my 
other method might be the easiest. With this method, after opening, I 
think you could then cut or melt of excess solder.off the main case and 
base, straighten the main case sides and get a good strong seam on 
reassembly.]


The blown oscillator I cut open had smt components inside. I replaced 
all the active devices and electrolytic caps I found in the circuit and 
checked to find that it worked again. (Yay!) I then was able to solder 
the top case back on the base. Not quite as strong as the original with 
just a narrow solder bead holding it, but working good as new.


Of course, if the oscillator's metal case is providing a hermetic seal, 
you loose that, but most aren't, anyway.


So I just thought I'd mention this other mechanical attack method. I 
think unsoldering the whole solder seal in one go and pulling it apart 
without damaging the internals is a pretty difficult task.


-Rex


On 2/19/2016 9:09 AM, time...@metachaos.net wrote:

Alex,

I did not take opening pictures, but there is nothing to miss.

For the outside of the unopened case, there are plenty of pictures on eBay.
For the actual opening process, that consisted largely of scraping away solder
with a small, triangular file and utility knife until most of what I could
remove was gone and then using a hammer and screwdriver to separate the sides
from the bottom and then prying it off. Nothing pretty, and nothing much for
pictures. I used a tiny drill for my desoldering gun to remove an intial hole
in the solder for the adjustment hole. I then enlarged it with a 1/16th drill
bit (by hand). Ideally, a 2mm drill bit could be used. A 5/64th drill bit will
fit through the hole, but it is very tight. Probably not best to drill with
it because that would most likely enlarge the hole.

I wouldn't open it the same way again, but I'm not sure of the best procedure
that leaves the case and contents undamaged so that it can be reassembled. I
think, perhaps, that I would remove all of the solder that I could as before.
But then, I would make some sort of cut-out for the pins on the bottom and put
it in a pan on the stove and heat it up (hopefully, evenly) until the bottom
could be popped off. The outside case can get pretty hot without damage
because the only contact is the pins and the inside gets pretty hot when
running. The main risk is getting so hot that the plastic spacers on the pins
melt or the pin supports melt. I'm not sure how hot that would be. But, they
must have heated it fairly hot to melt the solder originally, so hopefully
that would work.

However, here are some pictures o

Re: [time-nuts] modification Lucent RFTG

[Rex]

Joerg,

It all looks good to me. I didn't notice any problems at all with the 
English text. Much easier to follow with the improved pictures.


I notice that the annotations on the picture for the German version are 
the same as the English version now. Very little that would change 
("move" and "pad"?) and probably easy to figure out, so probably fine as 
it is. Just thought I would mention it.


Thanks for sharing your Mods. Nicely done. Should be helpful.

-Rex


On 12/13/2015 1:59 PM, Jörg Logemann wrote:

Rex,
I made some modifications to my article and I hope, that everything is
ok now. Please feel free to correct the text if you find some spelling
mistakes (very likely) because my english is not perfect, hi.
Thanks for your help,
best 73s
Joerg, DL2NI


Am 13.12.2015 um 12:00 schrieb Rex:

Joerg,

This looks like a very useful mod on a unit that many of us have. I'm
not aware of any schematics available for these, so I guess you have
reverse-engineered the "black"  part of the schematic that you
provided. -- Nice work!

Having said that, may I offer some minor criticism (constructive and
positive, I hope) of your document?

The schematic you provided shows the key transistors as Q1 and Q2. In
the text you refer to Q208 and Q209 (which I think are marked on the
board). From the description, I think Q1 = Q208 and Q2 = Q209. It
would be nice if the schematic had the Q-numbers changed, or at least,
you mentioned the equivalence in your text.

(Trivial) Aren't you using an existing SMA connector for your output?
So, maybe it should be black in the schematic.

Your picture of the board rework is pretty low resolution; even
zooming into it just gives bigger blurry image. You have added some
annotations but they are in red over the green board color. Combined
with the low resolution they are very hard to read. I'm pretty sure
they remain in German in the English version too.

My suggestions:
 - Edit the schematic to change the Q-numbers to match the board
and text, or at least give the equivalence in the text.
 - Use a higher resolution picture and make the annotations more
readable with different color or background shading.
 - The picture you provide is "after". It would be nice to also
have "before". If you don't have a before picture, I or some other
member could probably take one.
 - Consider having picture annotations in English for the English
version.

I think what you have done is great. I just think the sharing document
could be improved to make it easier for others to duplicate.

If you like, I could possibly help make a more readable annotated
picture if you can provide me a higher res picture of the board. Just
an offer to help if you would consider my suggestions. I think you
will see my email in my post.

-Rex   KK6MK



On 12/12/2015 4:39 PM, Jörg Logemann wrote:

Hi,
I worked out a modification of the Lucent GPSDO to get 10MHz out of it
which I offer to the community. The article is available in english and
german (attached).

best 73
Joerg, DL2NI



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Re: [time-nuts] modification Lucent RFTG

[Rex]

Joerg,

This looks like a very useful mod on a unit that many of us have. I'm 
not aware of any schematics available for these, so I guess you have 
reverse-engineered the "black"  part of the schematic that you provided. 
-- Nice work!


Having said that, may I offer some minor criticism (constructive and 
positive, I hope) of your document?


The schematic you provided shows the key transistors as Q1 and Q2. In 
the text you refer to Q208 and Q209 (which I think are marked on the 
board). From the description, I think Q1 = Q208 and Q2 = Q209. It would 
be nice if the schematic had the Q-numbers changed, or at least, you 
mentioned the equivalence in your text.


(Trivial) Aren't you using an existing SMA connector for your output? 
So, maybe it should be black in the schematic.


Your picture of the board rework is pretty low resolution; even zooming 
into it just gives bigger blurry image. You have added some annotations 
but they are in red over the green board color. Combined with the low 
resolution they are very hard to read. I'm pretty sure they remain in 
German in the English version too.


My suggestions:
- Edit the schematic to change the Q-numbers to match the board and 
text, or at least give the equivalence in the text.
- Use a higher resolution picture and make the annotations more 
readable with different color or background shading.
- The picture you provide is "after". It would be nice to also have 
"before". If you don't have a before picture, I or some other member 
could probably take one.
- Consider having picture annotations in English for the English 
version.


I think what you have done is great. I just think the sharing document 
could be improved to make it easier for others to duplicate.


If you like, I could possibly help make a more readable annotated 
picture if you can provide me a higher res picture of the board. Just an 
offer to help if you would consider my suggestions. I think you will see 
my email in my post.


-Rex   KK6MK



On 12/12/2015 4:39 PM, Jörg Logemann wrote:

Hi,
I worked out a modification of the Lucent GPSDO to get 10MHz out of it
which I offer to the community. The article is available in english and
german (attached).

best 73
Joerg, DL2NI




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Re: [time-nuts] Motorola Oncore UT+ firmware upgrade & backup power questions

[Rex]

On UT+ firmware update. I don't think it is possible to update the 
firmware in a UT+.


Back in 2006, time-nuts had a member, Randy Warner, who worked at 
Synergy. In the message linked here

http://www.mail-archive.com/time-nuts%40febo.com/msg02684.html

He describes the firmware update as a factory-only process that could be 
done then for $25. Now I doubt there is any way to get it done. I have 
never heard of any way to accomplish it without unobtanium factory tools 
and images.


If you search in that mail-archive time-nuts section (linked above), for 
the subject "Oncore GPS models", you may find some more information.



On 3/13/2015 1:33 PM, Pete Stephenson wrote:

Hi all,

After a few years of using a Garmin GPS 18x LVC for timekeeping, my
budget now allows for some upgrades and I had a small field day on eBay:
I acquired a Trimble Thunderbolt, two Trimble Resolution Ts, and two
Motorola Oncore UT+s (seconds purchased for spares and testing).

The documentation for the Trimbles is clear, but I had several questions
regarding the Oncores that I was unable to find clear answers to online.
I would be very much obliged if the folks here might be able to help.

1. Is it possible to upgrade the firmware on the Oncore UT+? If so,
where can one acquire the latest firmware (3.2, I believe) files and how
would go one about installing it? Is this something WinOncore can do? I
ask because the receivers on eBay are of varying vintage and may not be
fully upgraded.

Since Motorola exited the GPS business a relatively long time ago,
firmware updates and directions have proven difficult (impossible so
far) for me to find.




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[time-nuts] Centennial Pi Day

[Rex]

This is somewhat time related, so...

Tomorrow is a centennial Pi Day, since the year is 15. Major local 
observation times are just before 9:27 AM or PM.


3-14-15 9:26:54 or for time-nuts 9:26:53.589793... (take it as far as 
you like)


Here's one Pi Day web page,
http://www.chiff.com/home_life/holiday/pi-day.htm

There's also a Wiki page with history, and a search on Pi Day will find 
many more.


Note to Europeans, etc. You have to accept the US-style date format 
(m/dd/yy) or this doesn't work.


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Re: [time-nuts] HP 58503A Com 4 conflict

[Rex]

You left out a lot of details, like what OS your PC is running, Assuming 
it is Windows XP or greater, you may be able to juggle the assigned com 
port.


If you are using a USB/serial adapter, be sure it is plugged in so it 
shows on the devices list.


You need to open Device Manager. One way is Start/settings/Control 
Panel. If it is Win 7+ Device Manager should be in the list. If XP, 
select System, the Hardware tab at the top, then the Device Manager 
button. -- I don't have a Win 8 machine; I assume it is the same as Win 7.


Find your serial device under 'Ports (Com & LPT)'. If you are not sure 
which one and it is a USB adapter, you can unplug it and see which one 
goes away.
Double-click on the one you want to change. In the window that opens, 
select the Port Settings tab at the top.  You'll get a window with the 
baud rate, etc. Select the Advanced button. Then in the lower left of 
the window is the assigned Com Port. Click the pull-down triangle button 
and you'll get a list where you can select a different Com Port number. 
If all the ones you want are flagged with (In use), you may have to back 
out and try to find a listing for the device that is using a low Com 
port and select it to change its number higher to free the one you want 
to use. I'm not sure what happens if you try to change to a port that is 
(In use). Maybe it tries to work it out for you. I haven't tried it.


I'd suggest Com 4 or Com 2 as your best choices.

So I don't have an exact answer. It depends on what is using the lower 
numbers now, Hopefully you can rearrange them using this method to find 
something that works.




On 1/4/2015 7:50 AM, James Robbins wrote:

My new old HP58503A wants to connect to my PC on Com 1-4.  Other PC devices are 
already using those 4 Com ports.

Is there any way to connect it to a Com port other than one of those 1 to 4?

I currently use an Edgeport USB-to-Serial Converter which works very well to 
communicate with the PC and to assign Com ports to my various GPS units.  But, 
as far as I know, the chosen Edgeport Com port must fall within the range of 
Com ports which for which the device is designed.

If this has been answered, please point me to the discussion.  Many thanks.  
And, Happy New Year to all, with wishes for a more peaceful (and timely - 
couldn't resist) year.

Jim Robbins
N1JR
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Re: [time-nuts] New Years Eve TV countdown

[Rex]

TV doesn't seem to care about time sync much these days. It also depends 
a lot on the path getting to you,


I get most of my TV via satellite (Dish network). The receiver I have 
also can get OTA. I have happened to notice, once, that I had a local 
channel on two TVs. One was receiving the local via satellite and one 
was tuned to OTA local broadcast. The satellite was many seconds (at 
least 5, probably more) behind the OTA. I walked from one room to the 
other and had a brief period of deja vu. Hmm, just occurred to me, an 
earphone on the early one while watching the later one with friends 
would make you a living room Jeopardy game show super star.


But that satellite delay all makes sense.

One thing annoys me though. Many channels don't care much about start 
and stop times. If I program something to record using the schedule, 
often I miss the end of it. They frequently go over the half-hour or 
hour mark by a minute or two. Occasionally they complicate it more by 
starting a show a little early too. That irks me.


But for New Years, I didn't try to measure anything exactly, but I know 
they were off by about 3 hrs. I live in California. I was watching New 
York's events on my TV and the ball dropped at about midnight local 
time. I am enough of a time nut to know that should have happened at 9 
PM local time.


See, you just can't trust the media for accuracy these days.


On 12/31/2014 11:23 PM, David J Taylor wrote:

The local ABC network affiliate WJLA in Washington DC was approximately 4
seconds behind WWV in their on-screen countdown clock for New Year's 
eve. The
local NBC affiliate's clock was about 8 seconds late when I checked 
them at

two minutes before midnight. Happy New Year!

Dan Schultz N8FGV


Dan,

I think you just illustrated the delays in digital TV transmission.  
When watching events from abroad (e.g. F1 races) where precise timing 
is available, I typically see a delay of 7-8-9-10 seconds, depending 
on the location.  That is likely a delay to the studio, and then delay 
through Sky satellite TV.  The BBC here no longer shows a clock, 
perhaps partially for that reason.


At least there was no leap -second to confuse things!

Happy New Year!

73,
David GM8ARV


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Re: [time-nuts] was 10MHz LTE-Lite (Phase Matrix)

[Rex]

I had not realized that EIP continued to live on in a different form. 
Counters even kept the same name on the front panel.


http://www.phasematrix.net/phasematrix/company/about-us


On 11/20/2014 2:40 PM, Alex Pummer wrote:

they are affordable and good:


   585C/588C Frequency Counters

CW, pulsed, and other time-varying microwave and millimeter-wave 
signals can be automatically measured by the 585C and 588C frequency 
counters. VCO measurements, chirped radar profiling, and 
frequency-agile system analysis are all made with unparalleled ease. 
Pulsed signals can be fully characterized, including carrier 
frequency, frequency linearity, pulse width, and pulse period. The 
585C measures signals up to 20 GHz and the 588C's range reaches 26.5 
GHz with an option to extend to 170 GHz.


- See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf 




   585C/588C Frequency Counters

CW, pulsed, and other time-varying microwave and millimeter-wave 
signals can be automatically measured by the 585C and 588C frequency 
counters. VCO measurements, chirped radar profiling, and 
frequency-agile system analysis are all made with unparalleled ease. 
Pulsed signals can be fully characterized, including carrier 
frequency, frequency linearity, pulse width, and pulse period. The 
585C measures signals up to 20 GHz and the 588C's range reaches 26.5 
GHz with an option to extend to 170 GHz.


- See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters 


73
Alex
CW, pulsed, and other time-varying microwave and millimeter-wave 
signals can be automatically measured by the 585C and 588C frequency 
counters. VCO measurements, chirped radar profiling, and 
frequency-agile system analysis are all made with unparalleled ease. 
Pulsed signals can be fully characterized, including carrier 
frequency, frequency linearity, pulse width, and pulse period. The 
585C measures signals up to 20 GHz and the 588C's range reaches 26.5 
GHz with an option to extend to 170 GHz. - See more at: 
http://www.phasematrix.net/phasematrix/products/frequency-counters/585c588c-full-rack-frequency-counters#sthash.x7L7VuWM.dpuf


On 11/20/2014 1:40 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

Said,
For a general purpose lab source, to feed things like

* 22 GHz spectrum analyzer
* 4.5 and 20 GHz signal generators
* 3 and 20 GHz VNAs
* 20 or 40 GHz frequency counter (I'm just looking to buy one)




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Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812A GPSDO system

[Rex]

Here's another reference on driving 10-ish MHz square wave outputs via 
digital chips.


A few years ago I hacked my HP Z3816 to covert its 4 - 19.6608 MHz 
square wave outputs to be 4 more 10 MHz outputs. In the process I 
reverse engineered some of what was there. I found each of these outputs 
came from one 74ACT040 inverter chip per output connector with several 
gates in parallel through 100 ohm resistors to give low impedance drive. 
Maybe all the parallel gates are overkill for most needs, but anyway, in 
the process I drew a schematic of the arrangement that was found there.


You can find the schematic picture, labeled "One of the 19.6608 MHz 
Outputs", near the middle of this page for the whole hacking project:

http://www.xertech.net/Projects/Z3816/3816_mod.html

Bob, I might add parenthetically, that while your responses always seem 
accurate and informative, many times they are presented in such a 
sketchy bullet-point way that only those who already understand what you 
are describing can accurately follow what you are trying to share. Maybe 
it is just my less-than-expert point of view, but I think a lot of your 
posts would benefit if you could give a bit more detail or maybe a link 
to some kind of example or explanation. I appreciate all you offer, it 
takes time to read and reply, but I think often you are preaching to the 
choir when a little more detail could reach the whole congregation. 
Change or not, please keep posting. Even the cryptic stuff contains 
meaning, perhaps a spur to dig deeper.


Bruce, when posting here, used to baffle me too, but he often shared 
links to papers or schematics to aid in following the details of what he 
was describing.




On 10/31/2014 5:02 PM, Bob Camp wrote:

Hi

A  $0.15 each dual / quad / hex / octal buffer IC’s will get you > 15 dbm per 
pair of gates. For under $10 in active parts you can have 30 or 40 outputs. I 
suspect that if you look inside the 3812 that’s exactly how they are generating 
the 10 MHz you are looking at.

Bob


On Oct 31, 2014, at 7:01 PM, Graham / KE9H  wrote:

Bill:

On cable TV systems, 50 MHz to 500 (or higher) are the forward channel.
(Head-end to client.)
Below 30 MHz is the reverse channel, for data going from the client to the
cable company.
The band 30 to 50 is a cross over zone for the band splitting filters.


It is designed to not amplify the forward direction below 50 MHz.

--- Graham

==

On Fri, Oct 31, 2014 at 4:07 PM, Bill Riches 
wrote:


Hi Bob,

I connected 10 MHZ test jack output to a 15 db el-cheepo CATV amp and the
output of that to a 4 way splitter.  Splitter outputs went to 3336-3586 and
counter.  All seem to like the ref signal.  Output of the amp takes makes
the semi-square wave into a sick saw tooth.  Amp is only rated from 50 to
500 mhz so strange things are happening with 10 MHZ input.  Other CATV amps
do have better low fx response - will play with that later.

I have 10 mhz pulse from Lucent into trigger input of 465 scope and
Thunderbolt gps output into vertical input of scope.  Time base is set for
.01 Usec per div. I notice that trace moves right to left then left to
right about every 5 min or so.  Moves about 3 div before changing
directions.  Why?  Is the Lucent still making a list?  It has only been on
for a few hours.  It takes about 10 min for GPS to go out from a cold
start. (My Thunderbolt and RB do not change direction when using one as
trigger and the other for vert input to scope)

I ordered a USB to RS422 converter cable - will be here next week.  What
program is sort of working?  Using Windoze 7 64bit and have an old XP
machine available.

Sure do appreciate all the info from our time nuts gurus!

73,

Bill, WA2DVU
Cape May, NJ




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Re: [time-nuts] HOW WE GOT TO NOW WITH STEVEN JOHNSON | "Time" An Inside Look | PBS

[Rex]

It's a series. The first night there were two shows back-to-back and I 
think the 2nd one was the time-related one.


Its vaguely like the old "Connections" PBS series where; this thing  
lead to that thing, which led to...
I was multitasking so might not be the best critic, but I found it very 
grade school level. Most of the interesting stuff was glossed over. I 
was unimpressed enough that I never watched any of the following shows 
after those two.


Maybe others have other opinions.

-Rex


On 10/25/2014 11:51 AM, Brooke Clarke wrote:

Hi:

I don't have TV and wonder if anyone who has PBS can comment on this 
program?

preview at:
https://www.youtube.com/watch?v=RhDvGhFbpq8



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Re: [time-nuts] LTE-Lite Eval Kit available

[Rex]

On 24/09/2014 12:16 PM, Dave Martindale wrote:

Hello.  Please add me to the list of people interested in the LTE-Lite eval
kits.

(I did not send a previous email, and you did not lose it - I've just been
slow in writing).

Thanks,
 Dave

On Tue, Sep 23, 2014 at 8:05 PM, S. Jackson via time-nuts <
time-nuts@febo.com> wrote:


Hello Time-Nuts,

we put together an email list with the large number of email  info-requests
I got for the LTE-Lite eval kits over the weekend.

I have just sent an email to everyone on that email list from my  corporate
email account.

Unfortunately my AOL account has a tendency to "eat" emails, so if you did
not receive the info email from me today and should be on that list then
please drop me a line directly and I will add you to the list immediately.

I apologize in advance in case I did not properly  capture your email,
thanks,
Said
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Re: [time-nuts] Noise and non-linear behaviour of ferrite transformers

[Rex]

On 7/19/2014 6:38 PM, Richard (Rick) Karlquist wrote:

Or
another way of putting it is you do a bunch of
measurements and then construct a theory to
explain what you already know experimentally. 


I like that. Or perhaps, stated another way, in the real world engineers 
are just as important as physicists in the theoretical world.


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Re: [time-nuts] Synergy-GPS SSR-6tru problems

[Rex]

I think your story is rather incomplete. You never (to my deduction) 
told us what you are plugging this into. You mention a GPSDO so I guess 
that is where it is plugged while not doing what you want, but you never 
mention what that GPSDO might be.


You blew off Art Sepin's reply as not relevant. Why? What is the 
communication path to the receiver from whatever you are using to send 
commands? Is it through the GPSDO? If so, it seems to me the 
communication may not be direct and may be filtered by the GPSDO so the 
commands you are sending aren't reaching the new board in the way you 
would like.


I never used one of these new boards you are trying to use, but if you 
want good answers I think you need to tell us exactly what you are 
plugging it into and through what signal path you are issuing the commands.




On 7/15/2014 2:36 PM, Bob Stewart wrote:

I got one of these recently, along with the adapter board.  This is the ublox 
only version, and I am using u-center version 8.11 software.  I am unable to 
make it work properly.  The NMEA section happily sends out messages, but I 
cannot get anything else to work.  e.g. it ignores the commands to turn off 
antenna power.  It ignores the command to put it in Survey-In mode.  Nothing is 
displayed when monitoring the SVIN field.  I sent the board back and received 
one that they have tested there at the site.  Same story.  When I plug my UT+ 
into the same connector in my GSPDO, it works just fine and responds properly 
to commands from WinOncore12.  I have used both a serial port adapter and a 
USB-adapter to drive the TTL lines to the board.


So, there is something wrong at my end, and it's probably something so trivial that 
no-one would think to mention it.  Has anyone tried this board?  Can you think of any 
setting that's "inherently obvious to the most casual observer" that a newbie 
could repeatedly overlook?  For example, is there some first setting that you always do 
in u-center to shut down the NMEA and turn on the UBX, but the setting does not save on 
the board and the u-center software always overrides it?


The configuration is this:  The adapter does the 3V to 5V stuff, and plugs into 
the same connector as my UT+.  The antenna lead is connected to a non-powered 
port on my GPS Source splitter.  The splitter connects to a puck in the attic 
via RG-6.  The SNR of the received signals is in the 20-50 range on the 
u-center display window.  I have tried driving a different puck directly that 
is in my lab room.  No change except for lower SNR values.


Bob - AE6RV
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Re: [time-nuts] Introduction and info about a Lucent RFTG

[Rex]

Several years ago there were a number of these showing up pretty cheap 
on eBay, so I bought one. As I recall there were a couple of similar 
versions with some differences so take this recollection with a grain of 
salt.


I did some tracing of the internals on the one I had and found the 
rubidium unit had no connection on the tuning pin (C-field) to the board 
circuits. So it was free running, only for backup in the system, and not 
GPS lockable. I don't remember there being any useful power supply in 
the box, so my advice would be to remove the LPRO rubidium and use it 
directly. (It does need heat sinking, so maybe some parts of the box 
mechanicals are useful.) In my opinion, working out how to use the 
supporting circuit board is not worth the effort, unless you really have 
a need for the 15 MHz they create.


You should be able to find documentation for the internal module LPRO 
rubidiums on the web. I haven't looked today but KO4BB site probably has it.



On 7/4/2014 1:47 PM, Denver wrote:

Hi all,

My name is Denver I am currently a freshman in college and the time bug has
struck me. I recently acquired a Lucent RFTG on ebay to have a time
standard for my lab(and yes already realize its 15MHz output but may be
able to change that and or just use the 10MHz test point from the rubidium
source). I made a power connector for it. Now that I have power applied and
sort of verified its operation I am looking for more info about the
connectors on the front panel. I have the KO4BB user documentation on it
but it doesn't mention much about connectors and pinouts. I also have
already searched the group for other mentions of the RFTG but all I am able
to come up with is some of the newer models the -m and such. Maybe one of
you could help point me in the right direction or give me some other ideas
on how to get more use out of this unit.

Thanks in advance
-Denver
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Re: [time-nuts] National Standards labs worldwide - specifically Australia

[Rex Moncur]

Hi David

Standards Australia performs a somewhat different function in that it does
not maintain reference standards or do testing but rather it produces
written standards such as for construction of buildings, electrical wiring
and food standards. Standards Australia is certainly authoritative in that
it is partly supported by a Government grant and has a range of specialist
committees with Industry and Government representation and the written
standards it produces are often referred to in Federal and State Government
legislation and then have the authority of Law. Reference standards are
maintained by a range of other bodies but the prime one is the National
Measurement Institute.

http://www.measurement.gov.au/Pages/default.aspx


In terms of the sort of measurement such as reflection of a 50 ohm load this
work is normally done by NATA (National Association of Testing Authorities)
accredited laboratories.

http://www.nata.com.au/nata/



73 Rex VK7MO


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Re: [time-nuts] GPS puck?

[Rex]

On 6/26/2014 10:45 PM, David J Taylor wrote:


Amazon UK want over $200!  A Garmin GPS 18x LVC would be half the 
price..


Cheers,
David


The UK Amazon listings are crazy. There's a listing of the USB version 
at 35 pounds or about $60 (still pretty high) but the only serial 
version listed is 107 pounds or $182.Wow!?


All the US listings I saw had the serial version higher priced than the 
USB (why?) but Amazon prices I found were only a little less than eBay.


Not much logical about the prices, it seems.



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Re: [time-nuts] GPS puck?

[Rex]

I just did a little shopping after Tom's recommendation on USGlobalSat 
pucks. Here is a little more detail.


BU-353-S4 is the current USB version
BR-355-S4 is the Serial version

Not as "dirt cheap" as Mark's unit, these close to $40 each, but 
reasonable with enclosures, ready to go. In the US I found Amazon a 
little cheaper than eBay listings.


Serial has a PS-2-style connector but needs an adapter for connection to 
PC. Connector pin-out is here...

http://www.usglobalsat.com/p-689-br-355-s4.aspx#images/product/large/689.jpg

-Rex


On 6/26/2014 1:59 PM, Tom Van Baak wrote:

David,

Also check the web/eBay for: GlobalSat GPS BU353 S4

Dirt cheap, well made, water proof, high performance, NMEA or binary. They come 
in both USB (if you want to use them with a PC or SBC) or RS232/serial (if you 
want to use them with microcontrollers or data loggers or PC or SBC). The 1PPS 
is available at the IC, which you can access by opening the case (screws, not 
glue).

/tvb

- Original Message -
From: "David C. Partridge" 
To: "'Discussion of precise time and frequency measurement'" 

Sent: Thursday, June 26, 2014 1:01 PM
Subject: Re: [time-nuts] GPS puck?



Mark,

Thank you that looks ideal, now all I need is a suitable weatherproof cover
and I'm in business.

Regards,
David Partridge


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Re: [time-nuts] Weather/units question for European members

[Rex]

I have a crappy Chinese-made handheld propeller anemometer. I'm not in 
Europe but FWIW the output can be selected as: m/s, km/h, ft/min, knots 
or mph. So, the first  two of those seem to be likely metric choices.


Your method sounds interesting. Would you be willing to share any 
details about how you are using the ultrasonic modules? Do they just 
point out into open space or is there something more involved?  Was 
there a reference that got you started on this idea?




On 5/23/2014 6:16 PM, Mark Sims wrote:

I am building a weather sensor that includes a ultrasonic anemometer to measure 
wind speed, direction, and air temperature.  It uses 4 cheap ($1 each) HC-SR04 
ultrasonic rangefinder modules that output a pulse width proportional to the 
time of flight of the sound signal  (topic is time nut related since  it 
simultaneously measures the speed of sound in 4 directions to a pretty good 
accuracy/resolution using a cheap-ass microprocessor - ATMEGA328 (like and 
Arduino)...  and does so without using any counter-timer channels).
Now the question...  I would like it to be able to output data in imperial or 
metric units.  In what units is the typical wind speed reported  (meters/sec,  
km/hour, ?).   Also air pressure (millibars/hectopascals/pascals/?).
   
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Re: [time-nuts] FEI-5660 Rubidium Oscillator

[Rex]

On 3/27/2014 8:47 PM, Mark Sims wrote:

Granite tends to be rather radioactive (particularly avoid the pink stuff).

Apologies before I begin...

He who holds the scintillation detector has a gamma ray-son detre.

Paranoia strikes deep
into your home it will creep
There's a man with a Geiger counter over there
telling me I ought to beware

OK, sorry, crawling back into the stonework.
TIC Tic tic

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Re: [time-nuts] Aircraft ping timing

[Rex Moncur]

> 
> There is a newer system getting phased in:  ADS-B
>   



For info MH370 did transmit ADS-B signals up to 17:21 UTC on 7 March when it
seems it was either switched off or disabled.  You can still see the track
it took up to this time using the playback facility on Flight Radar 24 by
say starting at around 17:00 UTC on 7 March. The flight No on ADS-B is
slightly different and shows as MAS370 rather than MH370. Both are quoted on
Flight Radar 24 when you click on the aircraft to see its track.

http://www.flightradar24.com/7.69,100.35/6

Regards
Rex VK7MO

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Re: [time-nuts] Tom's "Adventures of a Time Nut" (Banquet Talk)

[Rex]

If you take the link in the original message (it is a youtube 
presentation), the player on that page has an option to open the video 
in Youtube.

Anyway, it goes here:
http://www.youtube.com/watch?v=MT2reYXPvGg



On 1/30/2014 8:30 PM, Max Robinson wrote:
Tom.  Could you give us a link to the u tube version. I haven't 
mastered searching on u tube yet.


Regards.

Max.  K 4 O DS.



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Re: [time-nuts] 24 hr clock movements...

[Rex]

Jim, I think you missed the main point I was trying to address.

It seems that many of the newer quartz movements do not move the second 
hand in one-second steps. They move it in some way that appears smooth 
to a human observer. (Even if there is no actual second hand, the same 
motive issues need to be looked at.) I assume the smooth motor is still 
some kind of stepper but being driven by pulses at a much higher rate 
than a one-second rate. If you receive one of these versions, you will 
have a more difficult job to drive it. You'd need to figure out what 
rate is driving it and generate that. The 1-second step versions would 
be easier for us to generically interface with.


The description on the Klockit page wasn't very clear about which type 
it is (also it was somewhat ambiguous about using a secondhand, at all, 
if desired -- there is a footnote that I couldn't quite decipher).



On 1/20/2014 4:04 PM, Jim Lux wrote:

On 1/20/14 3:32 PM, Rex wrote:

That listing is a bit vague about if it has a second hand. For the kind
of pulse drive that has been discussed here, it seems you would want a
definite second capability and step vs. smooth second hand drive.

I know nothing except a little web searching, but this one seems to have
the right features...
http://www.clockparts.com/clock-part/24-hour-high-torque-movement/

but, although they mention a 24-hour dial available, the page for it on
the site has no content.



it is very much a matter of buying a few and trying them.

If you don't install a second hand, then that solves the inertia of 
the secondhand problem.


The challenge is that because the "motor" for these things is 
basically a step at a time, if the hand has too much inertia, then the 
hand will either not move enough to get to the next tep (dying battery 
syndrome we've all seen), or, it will move past (because the "braking 
torque" isn't high enough.


It's sort of the torsional resonance effect that afflicts stepper 
motors in another form.  The magnetic impulse is basically driving a 
spring (the magnetic field) with a mass on it.


These things are always highly idiosyncratic. I would imagine that 
fiddling with the duration and magnitude of the step pulses (or, for 
that matter the "shape" of the pulse) could have a huge effect if one 
wanted to optimize it. A couple decades ago we built a large (5-6 foot 
diameter) stopwatch prop with a stepper motor, and we had to play with 
the drive voltage, the capacitance and resistance in the step channels 
to make it work right.  Today, you'd do microstepping, or use a clever 
algorithm to customize the step waveform.  Generally you want a 
voltage profile that's sort of a spike (to get the current flowing in 
the winding) with a back porch, and then a reverse polarity at the end 
(to stop the motion).


(I note that this problem is not unique to AA powered clocks.  The 
hands of the clock on the UC Berkeley Campanile are wood for a similar 
reason.)


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Re: [time-nuts] 24 hr clock movements...

[Rex]

I think there is a slight flaw in slowing the drive to half rate. The 
hour hand could then go around once in 24 hours, but the minute and 
second hand movement is halved too. Rather non-intuitive to read unless 
you only put on the hour hand and make a new 24-hour dial face.


On 1/20/2014 5:57 PM, Robert LaJeunesse wrote:

Since most of those cheapo movements are a simple single-coil motor, energized with alternating 
polarity short pulses, it would seem that there is no need for a "24 hour" movement. You 
can just have your micro pulse it twice the normal period, but with the same as normal pulse 
width(s). Check out the movement teardown in "lunchtime clock" at Instructables.com - 
http://www.instructables.com/id/Lunchtime-Clock/

Bob LaJeunesse





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Re: [time-nuts] 24 hr clock movements...

[Rex]

That listing is a bit vague about if it has a second hand. For the kind 
of pulse drive that has been discussed here, it seems you would want a 
definite second capability and step vs. smooth second hand drive.


I know nothing except a little web searching, but this one seems to have 
the right features...

http://www.clockparts.com/clock-part/24-hour-high-torque-movement/

but, although they mention a 24-hour dial available, the page for it on 
the site has no content.


Searching eBay gave some hits, but most of what I saw for 24-hour 
movements seemed to have smooth second hand (not step).



On 1/20/2014 10:17 AM, Jim Lux wrote:

On 1/20/14 10:06 AM, Jim Lux wrote:

On 1/19/14 1:51 PM, Tom Van Baak wrote:
  Use 24h clocks for

best results. They can be had from www.clockkit.com, an excellent
source of DIY quartz clock parts.




I couldn't find 24hr movements on the clockkit.com site.. where are 
they?




http://www.klockit.com/depts/SpecialtyClockMovements/dept-379.html



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Re: [time-nuts] Interesting HP oscillators...

[Rex]

This document lists that part number...

http://www.leapsecond.com/museum/10811a/90027-1.pdf

It says (I think -- in a quick scan) that it is mostly the same specs as 
a 10811 D/E except a narrower EFC tuning range.




On 1/13/2014 6:19 PM, Brian, WA1ZMS wrote:

I have happened upon a pair of working "HP 10811-like" oscillators. They are
marked HP 0507-60219.  I do know they came from a special custom 1990's
attempt at a single oven version of the Z3801A.

  


Does anyone have any info or specs on such an OCXO?

  


They are surplus to my needs and they both test fine so unless they are
determined to be some kind of ultra-low PN oscillator, I could as well offer
them for sale to the Time-Nuts group.

  


Comments welcome.

  


Regards,

-Brian, WA1ZMS/4

  

  


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Re: [time-nuts] Question about the FE-5680A

[Rex]

The FE5680A has about ten years of history on time-nuts. The FEI webpage 
bears little resemblance to most of the units that you will find. I have 
never seen one with a factory separate connector for oscillator output. 
Many needed both 15V and 5V to operate. Different versions have  outputs 
for PPS and/or (x)MHz (some can be programmed for output frequency). I 
don't think there are any markings on the various versions that clearly 
identify what, exactly, their features might be. Members here have 
hacked the internals to describe two basic evolutions of design.


I suggest you do some hours to weeks of reading and come back with any 
specific questions. Here are places to start...


The KO4BB Wiki -- http://www.ko4bb.com/dokuwiki/doku.php -- scroll down 
to find a couple of FE5680A links.


The time-nuts searchable archive -- 
http://www.mail-archive.com/time-nuts@febo.com/info.html -- put in 5680A 
or similar and get many many posts to read.




On 12/12/2013 5:24 AM, Sidney Cadot wrote:

Hi all,

I recently bought a second-hand FE-5680A for some light
experimentation via ebay.

There seems to be a number of variants floating around. Mine in
particular lacks a J2 (where I would expect to see the 10 MHz
connector), so I only have the DB9 J1 connector.

The unit is working, If I supply 15V over DB9 pins 1/2, the unit heats
up, after a while pin #3 drops to indicate a lock, and pin 6 shows a 1
microsecond wide PPS that I am happy to see, since that is what I am
most interested in.

I have a few questions:

* Does anyone else have a unit that lacks a J2 10 MHz output? Is the
intention of such a unit solely to provide a PPS?

* Is there a way to tell which revision/Option I have, eg.via inquiry
on the serial port?

My unit has no "Option" indication, all I have is FE-5680A / UN17491 /
serial nr. 27727W / Revision: B.
Without opening the unit at least, there are no other visible markings.

* J1-1 has function +15V, J1-2 is "+15V return", which, as I
understand it, means "ground" for the main power (I don't know how to
interpret "provides DC return" other than that).

However, there is also GROUND (J1-5), and there are at least the
following signals:

   - J1-3 Loop Lock Indicator (output; appears to be 5V, with 5V
meaning "no lock")
   - J1-6 Manual says "not used", but it carries a 1 us PPS (5V)
   - J1-8 RS-232 Rx (input for the FE-5680A)
   - J1-9 RS-232 Tx (output for the FE-5680A)

Should I assume that pins 3, 6, 8, 9 are all in reference to the
ground provided by pin 5?
Is pin 2 only "ground" for the pin 1?
Is there any relation between the voltage levels at pin #2 and pin #5?



Any help is greatly appreciated!

Sidney
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Re: [time-nuts] Efratom Rubidium SPTB-100/LN-001 info wanted

[Rex]

I have an SPTB-100. It seems to be a custom version of a standard 
FRK(LN) rubidium for Tektronics.


I got mine around 2000. (Mine is an 88 date-code vs. your ancient 86 
version.) It didn't work initially because the internal Xtal oscillator 
wouldn't sweep through lock frequency. Changed a cap in the oscillator 
and it worked again. I've only powered it up a few times; I assume mine 
is still working. I was told it is low-noise for a rubidium.


Somewhere locally, I got a copy of a manual for it. Other than the cover 
page, it seems to be a standard FRK manual, which the KO4BB pages 
already have. Today, I made a short PDF with a scan of the cover page 
and a few notes I wrote up.


You can get it here:
http://www.xertech.net/pub/SPTB-100%20notes.pdf

I also uploaded it to KO4BB for future references.

If anyone knows more or sees any problems with what I wrote up, please 
let me know and I'll correct or update.


-Rex KK6MK


On 12/4/2013 7:08 PM, Jerome Peters wrote:

Hello,

Can anybody shed some light on this particular model:
Model - SPTB-100/LN-001
Efratom part No. 703-200-11
Date Code 8609

(I have looked at K04BB's website, it has lots of other models, but not this 
one).

Thank You,
Jerome
AF6UX

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[time-nuts] Coax cable for volute antenna

[Rex]

On 10/16/2013 8:26 PM, quartz55 wrote:
I've been searching for the small copper hardline I can use for the 
feed on the gps volute (egg beater) antenna.
Can anyone steer me where to get a foot or so of the small 50 ohm 
line so I can make a few antennas?

I've been searching mouser to no avail.

Dave
N3DT

Maybe something like eBay listing  380470709575  ?

Search in  'Business & Industrial' for 141


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Re: [time-nuts] Coax cable for volute antenna

[Rex]

I wish you had learned to post a new message, rather than replying to a 
previous message with an unrelated new subject.

(screws up threading displays in mail readers)


On 10/16/2013 8:26 PM, quartz55 wrote:

I've been searching for the small copper hardline I can use for the feed on the 
gps volute (egg beater) antenna.  Can anyone steer me where to get a foot or so 
of the small 50 ohm line so I can make a few antennas?  I've been searching 
mouser to no avail.

Dave
N3DT
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Re: [time-nuts] FTS 4060 Cesium Time & Frequency Standard, Datum

[Rex]

On 10/4/2013 9:41 AM, Tom Miller wrote:



Maybe someone can tell me the best way to search the time-nuts 
archive. Do you need to download all the files to a common DB?



Regards,
Tom


I usually use this for time-nuts searches...

http://www.mail-archive.com/time-nuts@febo.com/info.html

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Re: [time-nuts] Help in Locking a Windows Computer to GPS Time

[Rex Moncur]

Hi David

Yes I did not make myself clear but I am looking for UTC time from a GPS.
Thanks for all your references which I will work through and see how I go.

Regards Rex VK7MO

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of David J Taylor
Sent: Thursday, 22 August 2013 6:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Help in Locking a Windows Computer to GPS Time

From: Hal Murray

I think you are missing the big picture.

The OP wanted GPS time.

NTP isn't setup to work with GPS time rather than UTC.
[]
=

I think the OP wants "UTC time from a GPS" rather than "GPS time".  But even
if it /was/ GPS time, couldn't a set of simple "fudge" statements in the NTP
configuration provide that?  OK, you would need to change the fudge lines
when the GPS to UTC offset changed...

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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[time-nuts] Help in Locking a Windows Computer to GPS Time

[Rex Moncur]

I am trying to lock a Windows XP computer to GPS time taking advantage of
both the NEMA sentence and the 1PPS with the hope of getting to within a few
ms.

I am using a Garmin GPS 18PC and the NMEATime program.  When I tick the box
to implement the 1PPS feature on NMEATime the program locks up each time it
attempts to correct the PC time.  Perhaps there is something I need to do to
configure the GPS 18PC to fix this.

I would be grateful for advice as to whether and how one can use NMEATime
for this purpose with a Garmin GPS 18 PC or advice on other programs to
achieve accurate locking of the PC.

Rex VK7MO

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Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module?

[Rex]

I don't think the rubidium module for these systems can be disciplined. 
I think they were only intended as a backup if the XO section or GPS 
failed. The XO section does discipline but I don't know the details.


I'm not sure of the model number, Lucent had several variations on the 
same theme in that time frame. I had one of the rubidiums that may be 
the same as yours. Trying to trace out some of the circuits, I found 
that the EFC on the LPRO connector was not being used at all.



On 8/15/2013 7:52 AM, Alan Kamrowski II wrote:

Hi Everyone,

  


I've only got the RFTGm-II-Rb module.  I found an interface cable
specification here:

  


http://www.ko4bb.com/Manuals/05%29_GPS_Timing/RFTG-m/RFTGm%20Interface%20Cab
le.pdf

  


Does anyone know if feeding a 1pps signal to pin 9 might discipline it?  Or
does it need the other connections such as GPS data, etc.

  


Is there a ground on this connector?

  


Thanks!

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Re: [time-nuts] Removing "goop" was: =>Re: 10811 Outer oven controller schematic

[Rex]

On 7/31/2013 5:42 PM, Don Latham wrote:

Xylene is availble as "goof-off" in paint departments.



Goof-off now seems to be a whole family of products. See...
http://www.goofoffproducts.com/
Maybe "Heavy Duty Remover" or "power Cleaner and Degreaser" might be the 
best current options.


The one MDS for Goof-off I looked at didn't mention xylene. At least 
here in California, I think law has forced removal of xylene and toluene 
from most products several years back and is tightening more and more. I 
didn't find a good link describing current laws in my searches.


I think the bug and tar remover that I suggested was first formulated 
with either xylene or toluene but the product I have been using for the 
last few years doesn't have either of those VOC's mentioned. Probably 
works less well, but still worked for most of my non-water-based gunk or 
glue removal tasks. My three main go-to's are soap and water, alcohol, 
and the bug and tar, depending on what gunk I am looking at. 
Occasionally I might use acetone, some other hydrocarbon mix, or some of 
the small remaining amount of MEK I bought before it was banned for sale 
here.


But maybe this is all a bit tangential or off-topic for the group.

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Re: [time-nuts] Removing "goop" was: =>Re: 10811 Outer oven controller schematic

[Rex]

On 7/31/2013 7:06 PM, Dr. Edward H. Currie wrote:

DW-40 is a good label goop remover ...


 Does the DW stand for dyslexic writing? :-)

Pretty sure you meant WD-40 as in this link...
http://en.wikipedia.org/wiki/WD-40



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Re: [time-nuts] 10811 Outer oven controller schematic

[Rex]

I suspect by gas he meant gasoline.

I don't know about what paint remover he meant but I have another 
suggestion that might have worked. For cleaning label gunk off of used 
test equipment I have used automotive bug and tar remover. Seems to 
loosen up lots of gunk but not so strong it hurts the panel paint and 
lettering.



On 7/31/2013 1:51 AM, Magnus Danielson wrote:

Paul,

gas? What gas?

what soft plastic paint remover?

A little more specifics would help if someone is in the need.

Cheers,
Magnus

On 20/07/13 23:22, paul swed wrote:

Hello to the group.
As the various posts mention pulling the outer oven and taped wire 
off is a

job. But thats done.
The Osc is 45 Hz low hot and 200 Hz low cold. Bobs on target with his
comment on what to expect. It does warm up and behave as you might 
expect
but its all relative not exact even according to the 10811 service 
manual.

So it could be off temperature. But very hard to say until I get a
thermocouple in there.
Will say the various rubbery stuff and shock absorbing stuff left one 
heck

of a gooey mess.
Oily sticky stuff.I tried oil, alcohol, turpentine, and finally gas. 
None

really did anything. But what did was a soft plastic paint remover. That
peeled the old tape and goo off very nicely.
What was left was the true glue and that was removable by gas.
It went from a gooey mess that stuck to everything to a pretty clean 
can.
Next I used a small torch one of those small butane refillable units. 
Had
it for years and never really had a use for it till now. I have 
started the

process of opening the can. Thats not complete yet. But I cleaned enough
goo off that when I heat things I don't have a smelly smoldering mess.
Regards
Paul
WB8TSL
















On Sat, Jul 20, 2013 at 1:57 PM, Bob Camp wrote:


Hi

If a 10811 oven is simply not working, the output will be> 400 Hz off
frequency.

Bob

On Jul 19, 2013, at 12:48 PM, ed breya wrote:


Paul,

If the 10811 is that far off, are you sure the oven is working?  A few
years ago mine had a failure of a particular date code range of the 
opamp

that controls the oven, that were prone to failure.at high temperature.
The symptom in the Z3801A was that the outer oven seemed bad - it 
did not

turn on, but it was because it was waiting for the inner one to reach
nominal temperature, but it never did. Once you get it all apart,
replacement of the IC is no big deal, but what a PITA to get to it. I
vaguely recall posting the whole story on that website that has big
coverage of the Z3801A - I can't remember the name, since I haven't 
been
there in a while, but it should be easy to find. The website had all 
kinds

of Z3801A info, including a nice writeup on how to take the oven apart,
which is where I started.


Ed



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Re: [time-nuts] RS 232

[Rex]

FWIW, it was clear as mud for me too.

Bert began with, "Since joining time  nuts over four years ago I have 
not used a  single MAX

232 chip. Two  reasons MAX do not give me isolation and do generate  noise
in critical  applications."

From that I took that he was doing RS232 using opto isolators. That 
implies + and - voltages to me. Where do they come from and where are 
they relative to the isolation boundary? If the goal is really 
isolation, how do these supplies get isolated? If the noise is cured by 
isolation, these details seem important as the supplies need isolation 
too. Maybe the switcher in the MAX232 is causing the noise. Then how do 
we get a negative supply from, say, +5V without the noise? Then, maybe 
he was saying RS232 sucks and this other way (not RS232 compatible) 
works better.


The word picture of Bert's solution, which provided more details, left 
me less much less than clear too. Maybe I'm just not up on circuit 
shorthand terminology enough to follow what sort of current limiter is 
limiting what current to what, and what is being blocked by a diode from 
which negative level. Not really sure if I even got the big picture of 
what he is describing. Is it an isolated equivalent of a MAX232 
interface or something else that wouldn't talk to an RS232 device?


So, more clarification, or possibly that picture (~= 1k words) might 
help. Or maybe I'm just obtuse and everyone else is getting it. (Seems 
Marki may also be in the confused camp.)




On 7/25/2013 3:34 PM, Mark C. Stephens wrote:

Although your description,
" I prefer the use of two H11 opto couplers which
work  perfect. On the receiving end the diode along with a current limiter
and  blocking diode for the negative level works perfect. On the output side
a  power  source is needed." Is a perfect circuit description, I'd be more 
confident with a schematic :)


--marki


-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf 
Of ewkeh...@aol.com
Sent: Friday, 26 July 2013 5:32 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] RS 232

I do not understand your question, I am referring to low noise applications  
like counters for dual mixers or other AV measurements, but also Shera and even 
 Tbolt where external noise should be kept to a minimum. When you chase 1 E-14, 
 isolation is key and I always like to err on the cautious side and as I stated 
 we use blue tooth or USB but in the case of USB there are always H11 in the  
circuit. Some still like to use RS 232 and the subject came up and I have on my 
 boards H11's like on the counter Corby uses but he ended up using an external  
power source and I like to eliminate that requirement. David had the right  
answer using the power that the RS 232 mouse uses out of a DB 9, started 
looking  but I do not have one any more and I can not find any data.
Bert
  
  
In a message dated 7/25/2013 2:48:43 P.M. Eastern Daylight Time, ma...@non-stop.com.au writes:


Hi  Bert,

I am sure your circuit is clear in your head, but would you mind  attaching 
detail?
You have perked my interest with the "low-noise" keyword  ;)


-marki

-Original Message-
From:  time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of  ewkeh...@aol.com
Sent: Thursday, 25 July 2013 11:39 PM
To:  time-nuts@febo.com
Subject: [time-nuts] RS 232

Since joining time  nuts over four years ago I have not used a  single MAX
232 chip. Two  reasons MAX do not give me isolation and do generate  noise
in critical  applications. I prefer the use of two H11 opto couplers which
work  perfect. On the receiving end the diode along with a current limiter
and  blocking diode for the negative level works perfect. On the output side
a  power  source is needed. If one uses an USB adapter it does have the + 5
volt which  again works perfect.  How ever many prefer to use RS 232
direct and that is  why I hope to get some comments and suggestions from  the
list. Corby used on our  counter circuit that he described a separate  power
source.
Present MAX circuits use a + 1.4 volt threshold but   considering legacy
the question is what should the voltage swing be to make  it  compatible for
most PC's and what options exist to get the necessary  voltage. In  the past
other pins on the RS 232 port where an ideal power  source. Still an  option?
Bert  Kehren
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Re: [time-nuts] The "auction site"?

[Rex]

On 7/1/2013 11:59 PM, Doug Calvert wrote:

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?



I dunno either. There seems to be a trend in all engineering-friendly 
sites / lists to not mention the name eBay outright. Maybe they worry 
about conjuring up something like  the movie "Beetlejuice"?


There are pros and cons to liking the online trading. A couple decades 
back I liked going to the local swaps, but now it is easier to sit here 
and do my browsing or make my bids online. Many of the old sellers have 
gone to the internet or base their pricing on the current "going rate". 
The negative is that cheap deals are getting rarer as the dealers will 
swoop in if the price is too good, to buy it and sell higher later. The 
good is that there is much more stuff to entice me than the random local 
supplies usually could offer.


There might be some oasis of good deals (like MIT swap?) and I might 
tend to sell locally at a small bargain, but that is no longer common.


Like it or not, eBay is the main game now. and I see no reason to encode 
mentions of EBAY. Who here hasn't made a purchase or sale that way?



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Re: [time-nuts] What is the deal with li...@lazygranch.com

[Rex]

OK, I sent that last email as a short text message, but in html-only 
format. Seems the html got deleted, leaving an empty message.


I suspect that is the problem with li...@lazygranch.com messages 
recently. On another email reflector we started seeing a batch of this 
lately.




On 6/18/2013 5:25 PM, Rex wrote:

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Re: [time-nuts] What is the deal with li...@lazygranch.com

[Rex]

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Re: [time-nuts] WWVB remodulator for the spectracom 8170 the schematic is to large

[Rex]

On 6/17/2013 9:52 AM, Chris Albertson wrote:

Here is an even smaller version, at the same resolution.The trick is to
remove the background.  Then all you have is mostly a plank sheet and a
small amount of ink that compresses very well.

What you do is adjust the contrast until you have only pure white and pure
black.  That alone does 90% of the work.  Save it as a monochrome file to
kill the color channels then set the JPG compression as strong as you can.

That is basically the steps I used to make my version, except the jpg 
encoding. Jpg is great for photos but not ideal for line art. If you 
zoom into the jpg version you will see clouds of noise around the line 
features. Gif doesn't do that.


When I made my gif version last night I used 64-level grayscale. That's 
more than necessary. I just tried a version with 8-level grayscale and 
the file size went from 95k to 43k.


Of course the other key compression was reducing resolution. The 
original was 6600 x 5100 pixels. I cut down to 1400 x 1082 which still 
may be a bit more than needed.


This is a bit off-topic for the group, though.


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Re: [time-nuts] Spectracom 8170 Time of Day grief...(WWVB Clock)

[Rex]

On 6/13/2013 9:02 AM, J. L. Trantham wrote:

However, as a 'modern art' piece, I might have a chance. :^)

Joe




Like this?

http://www.rfcafe.com/references/electrical/images/Bob%20Pease%20Breadboard.jpg

Hmm, maybe not.

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Re: [time-nuts] Good (cheap) PIC chip choice for project?

[Rex]

On 5/25/2013 1:22 PM, Bob Camp wrote:

If you are going to code on a cheap PIC (the PIC16 series) you will likely need 
to learn PIC assembler. All my coding on those parts was in assembly language. 
They are old enough / slow enough / small RAM enough that things like C (or the 
other high level languages you listed) really don't do well on them.


Several years back I did a bunch of stuff with various PIC16 series 
chips. All of it, except for some minor assembler tweaks, was done in C. 
Glad I did not know it wasn't practical. I would have wasted a lot of 
time coding it in assembler. Of course my goal was just getting 
something done, not being elegant or very efficient. Time-nutty stuff 
like TVB's frequency divider may require the detail and efficiency only 
provided by assembler.



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[time-nuts] Checking Time difference between PCs

[Rex Moncur]

I wonder if anyone has suggestions as to how to check the timing variations
between two PCs that are running windows.

The background to this request is that I am running two instances of the
Weak Signal Program WSJT on the same computer and get variations of +/-0.2
seconds.  It has been suggested that the variations might be caused by the
windows operating system.  As a check on this I am proposing to run two PCs
locked by GPS-18 USB and set by NMEATime which should show the difference on
WSJT.  But is there some program that will show the difference due to the PC
clocks alone? Or perhaps a program that outputs the PC time as a pulse on a
sound card so I can compare these on a CRO.

Regards Rex VK7MO

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Re: [time-nuts] Precise positions for GPSDOs

[Rex]

PHK, the big pdf link in your sneak page is broken (gives 404). Can you 
fix that for us?


P.S., while you are there you could change "goory' to "gory".


On 5/2/2013 5:22 AM, Poul-Henning Kamp wrote:

In message 
, Stewart 
Cobb writes:


The next best idea is to locate your antenna on Google Maps. [...]

If your GPSDO's self-survey isn't better than the registration of
Google Maps, you have different problems.

In particular, be aware that the GPSDO does not need to know the
antennas _actual_ position, it needs the _apperant_ position, which
takes the reflection environment into account. (GW: "fresnel zone")

This is a much better strategy:

http://phk.freebsd.dk/raga/sneak/




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Re: [time-nuts] Time nut newbie

[Rex]

It doesn't affect the general magnitude conclusions by Bruce, but as 
long as we are making corrections, my calculator seems to think
60 * 60 * 24 * 12 = 1036800 seconds in 12 days, not 1024800.  That does 
come out to 115.7 days for 1 sec error. Maybe the 12-day number was a typo?


-Rex


On 4/30/2013 12:57 PM, Bruce Griffiths wrote:
12 days is 1024800 s ie just over 1 million seconds so a frequency 
offset of 0.1ppm results in a time error of ~ 0.1s not 1s.

1sec error would occur in just under 116 days,

Bruce

Bob Camp wrote:

Hi

If you take a look down in the fine print on the OCXO spec, the aging 
rate

is 100 ppb / year in the first year. If you are off by 0.1 ppm (100 ppb)
your clock will gain a second in less than 12 days.

Bob



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Re: [time-nuts] Are there any rubidiums programmahttps://mail.google.com/mail/?shva=1#inboxble to 40 MHz?

[Rex]

Please tell us if I am parsing the content of your message correctly 
with my inserted comments.


On 3/25/2013 9:09 AM, Stan, W1LE wrote:

Hello Dave,

The problem I experienced with a Rb at 10 MHz stabilizing a AD6IW PLL 
at 106.5 MHz

for a DB6NT 10 GHz G2 transverter,
I assume by "stabilizing" you mean that the rubidium was providing the 
reference frequency to the PLL.



was the significant microphonics after multiplication.
The original xtal oscillator did not have microphonics, but would drift.

My solution was to add a ISO-Temp 10 MHz OCXO as  a reference to the PLL.
By "add" I think you mean replace, as in, the rubidium is no longer used 
but the OCXO has replaced it as the PLL's reference. If you really meant 
add, that would imply that somehow the rubidium is disciplining the 10 
MHz OCXO.



This provided me with the frequency accuracy and stability
needed for a weekend of microwave contesting, USB/CW

My 10 GHz operation is portable and I rove.

Stan, W1LECape Cod   FN41sr



On 3/25/2013 10:17 AM, David Kirkby wrote:

I'm possibly looking for a 40 MHz source and I know some of the
rubidiums are programmable. But can any of the affordable ones be
programmed to work at 40.0 MHz?

I was looking for a source to drive this 144 MHz -> 10 GHz transceiver.

http://www.chris-bartram.co.uk/products.html

The TCXO oscillator is off the board and a separate item, but costs
£40 and then one ideally wants to lock that to a more precise source.
The oscillator will lock to an external 10 MHz source, but then one
needs to buy both a 10 MHz rubidium as well as this 40 MHz TCXO. Hence
I was wondering if there was a cheaper more compact solution, which
just used a rubidium, and dispensed with a TCXO.

Dave


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Re: [time-nuts] Win XP and NIST time

[Rex]

I'm running Microsoft Windows XP Professional -- Version 5.1.2600 
Service Pack 3 Build 2600.


I still get occasional notifications and update my OS with latest 
changes. (Don't know how much longer that will continue.) The time on my 
system updated OK and is currently correct. I haven't noticed any issues 
with the DST changeover. I just asked it to do a time synchronization 
and that completed OK.


So rumors of XP being broken seem to be exaggerated.



On 3/23/2013 5:06 PM, J. Forster wrote:

If you double left click on the clock; click on the Time Zone tab, there
is a check box for DST update on/off. Since the dates of DST have changed,
it does not work right.

Best,

-John

=



Hi all,

I am a new member, in St Pete, Florida. I noticed that last week, my XP
laptop had not updated at the arrival of summer time and I had to do it
manually.

Cheers.

Jay
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Re: [time-nuts] Lady Heather numbers

[Rex]

Do you think that the oven is working correctly? Is the DC current high 
on power-up then dropping to a steady lower value after warm-up time?


My concern is that the resistors may have unsoldered themselves because 
the oven ran away into an over-temp condition.



On 3/12/2013 9:55 AM, Garren Davis wrote:

Bob,

Took your advice and ordered another OCXO. While waiting for it I decided to 
cut open the
OCXO with a bad heater that came with the thunderbolt. I found the 1 ohm 
resistor from the
12 volt pin to the heater circuit popped off its solder pads and was laying 
between the
insulation and the metal enclosure. While unsoldering the circuit board to fix 
this the
1 ohm resistor in the oscillator circuit popped off its solder pads. For others 
that have
OCXO's that don't work this is an easy fix. They are large surface mount 
resistors and easy
to solder. Anyways I put the circuit board back in the metal enclosure but did 
not seal
it. I put the OCXO back in my double oven and started a run. The enclosed 
picture is a 72
hour display. Even though the DAC was still increasing it looked like the PPS 
had stabilized
so I did an auto calibrate. You can see this at marker 1. That was almost two 
days ago.

Questions:
1. Is it normal to take this long for the PPS to stabilize?
2. Is it normal for the DAC to keep increasing after two days?
3. In general what numbers would be considered good for the PPS and OSC?

Thanks.

Garren





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Re: [time-nuts] frequency reference for portable operation

[Rex]

I do the stuff on your list that is easy. Controlling the environment -- 
orientation, ambient  temp, etc. -- is not worth the extra effort. Much 
of what I discussed is that perfection isn't necessary.


The quality of the oscillator probably matters a good bit, but recently 
I am learning, don't trust word of mouth or "specifications". Over the 
last few years I have accumulated many "decent" OCXOs. But  I don't have 
a base standard 10 MHz reference that I consider pristine 
phase-noise-wise and until recently had no way that I trusted to make 
any kind of phase noise measurements. Recently I got into a project 
where I built a board that uses a LMX2541 chip to make 3600 MHz using a 
10 MHz reference with a pretty wide loop bandwidth. The board multiplies 
the 10 MHz reference up to a point where a good SA can see the phase 
noise. Measuring that on my 8566 SA with John Miles software, I learned 
a couple things.


First - My measurement setup doesn't give real accurate phase noise 
measurements compared to passing my DUT and sources on to someone with 
real quality instrumentation.


Second - Comparing my measurements to the very good equipment, it is 
clear that my measurements give a close approximation to the good one's, 
only not exact across 10 Hz to 10 KHz. But my measurements are good for 
a qualitative feel within, say 5 dB, and certainly good for relative 
comparison of the contribution from different 10 MHz reference sources.


So, I have bought a lot of 10 MHz OCXOs from eBay over the last few 
years. The best phase noise baseline reference I have found so far is my 
Z3805. I have lots of OCXOs in the 2x2x1.5 inch size. Many had good 
specs pointed at by the listings or word of mouth. When I used them with 
my board and SA most were pretty crappy compared to the Z3805. A couple 
of the ones I bought were Morion MV89As. - supposedly good, but what I 
saw didn't look very great. One of the best ones I have is a small 
2x2x.75 inch Wenzel I bought a few years back. It has a custom part 
number of 500-11935. But don't buy by name. I recently picked up a 1x1x3 
Wenzel 10 MHz with sma output connector and its phase noise looks pretty 
horrible.


Some old Isotemps were decent, but not as good as the Z3805 and I 
haven't measured some 10811s and 10554s I have in the back of my box 
because they are harder to feed DC-wise.


My point is, I collected a lot of OCXOs that are not nearly as good as I 
thought they would be. But all would probably make reasonable references 
for frequency stability. Not sure if the level of not-great phase noise 
from many of them would be noticeable if they were used to lock a good 
10 GHz radio. If I was younger, I'd probably go for that experiment. -- 
In reality, don't know if I ever will.


-Rex



On 3/10/2013 5:15 PM, Bob Camp wrote:

Hi

If you go with one of the better DOCXO's on eBay (spend the full $30 not $15) you 
should get something that will hold < 0.3  ppb for 48 hours. You would have to 
do a few things:

1) Keep it on power for a couple weeks ahead of time.
2) Keep it on power the whole weekend.
3) Make sure it's always in the same orientation (base down or whatever)
4) Put it in something like a cooler to keep the drafts off of it
5) Regulate the supply and efc tightly.

You might have to buy three and sort them, but I suspect not.

One ppb at 10 GHz would be 10 Hz. The carefully minded DOCXO should keep you 
within 3 Hz.

Bob
  
On Mar 10, 2013, at 6:24 PM, Rex  wrote:



I agree with using an OCXO for amateur radio operation.

The main activity in the US is the 10 GHz and Up contest which takes place over 
two weekends, mid-August and mid-September. I've been active in most of them 
for the last 15 years. Full participation requires operating something like 12 
hrs each of the two weekend days. Occasionally I have operated into the wee 
hours Saturday night. Some people go to a high location like a mountain top and 
stay there all weekend. Many rove, driving hundreds of miles, or some 
combination of the two strategies. Very few have AC power available so operate 
on batteries for the two days, though sometimes with the option of charging 
batteries between stops or by just running your engine or a generator. By 
contest rules, to count as a new contact, at least one of the two stations 
needs to move 10 miles or more from a previous location -- hence the rover 
strategy.

To reduce your levels of uncertainty in making contacts, two things matter, 
antenna pointing accuracy and frequency accuracy and stability. Being exactly 
on frequency is nice, but being off a few hundred Hz at 10 GHz is usually in 
the radio passband and good enough. So in my experience a good OCXO is fine. It 
is accurate enough, very stable for many minutes of contact operation, has good 
phase noise and moderate power consumption. I think most people in the contest 
are using OCXOs. 

Re: [time-nuts] frequency reference for portable operation

[Rex]

On 3/10/2013 6:10 PM, Hal Murray wrote:

r...@sonic.net said:

or if you have a beacon in range that you can find to establish your
offset.

What do you do after you determine the offset?

Do you tweak it out with a trimmer (R or C)?  Or tell the software?  Or do
the corrections with pencil and paper?




The typical rig would use a 2 meter radio as the low end transceiver. 
The microwave radio usually would be set up so that 10368 MHz would tune 
down to 144 MHz on the "IF" radio. So if you tune a beacon that you 
expect to be at 10368.300 and find it at 144.301, you now know your 
radio tunes 1 kHz high so you transmit and listen 1 kHz high vs the 
dial. Or you could go, "1 KHz isn't a lot", so just ignore it and assume 
the other more experienced operators will figure it out. After a couple 
contacts I usually figure out that I should listen for another 
particular station with a certain offset. More complicated, a certain 
station may have an offset of xxx Hz between Tx and Rx. I hate that 
because my IF radio is a pain to tune RIT (receive vs Tx offset) so it 
is hard for me to correct and we wind up chasing each other. up or down 
the band between tx/rx iterations.



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Re: [time-nuts] frequency reference for portable operation

[Rex]

I agree with using an OCXO for amateur radio operation.

The main activity in the US is the 10 GHz and Up contest which takes 
place over two weekends, mid-August and mid-September. I've been active 
in most of them for the last 15 years. Full participation requires 
operating something like 12 hrs each of the two weekend days. 
Occasionally I have operated into the wee hours Saturday night. Some 
people go to a high location like a mountain top and stay there all 
weekend. Many rove, driving hundreds of miles, or some combination of 
the two strategies. Very few have AC power available so operate on 
batteries for the two days, though sometimes with the option of charging 
batteries between stops or by just running your engine or a generator. 
By contest rules, to count as a new contact, at least one of the two 
stations needs to move 10 miles or more from a previous location -- 
hence the rover strategy.


To reduce your levels of uncertainty in making contacts, two things 
matter, antenna pointing accuracy and frequency accuracy and stability. 
Being exactly on frequency is nice, but being off a few hundred Hz at 10 
GHz is usually in the radio passband and good enough. So in my 
experience a good OCXO is fine. It is accurate enough, very stable for 
many minutes of contact operation, has good phase noise and moderate 
power consumption. I think most people in the contest are using OCXOs. I 
never checked exact accuracy, but I think, even with a lot of driving 
and temperature extremes my rig stays within a few tens of Hz at 10 GHz. 
A few operators use rubidiums. To my thinking, the extra accuracy is not 
really needed and the extra power consumption is not worth going that 
way if you are running off batteries. Usually, the ones available tend 
to have a bit worse phase noise than a good OCXO too, though I'm not 
sure if enough worse to matter in real contacts.


I have thought about taking a rubidium along to power on occasionally 
and calibrate the OCXO but never found my OCXO frequency to be an issue 
so never bothered to take the rubidium. There are applications like 
microwave EME where very weak signals are extracted by post-processing 
the data of a long contact in the noise level. In that case rubidium 
accuracy is needed for very narrow bandwidth contacts.


You mentioned operating while driving. A few people have the omni 
antennas to do that and I have worked some of them. For that the 
frequency accuracy becomes moot. At freeway speeds the doppler shift at 
10 GHz is very significant in the audio range. Because of that, the 
mobile-while-moving contacts are usually made in FM mode with wide 
bandwidths and no need for very accurate frequency. That mode can't do 
the long distances of dishes and narrow SSB or CW but it has worked 
better than I would have expected. Also, the 10-mile rule tends to make 
the FM mobile less useful and it usually happens as an experiment while 
someone is driving home at the end.


One side note about doppler. Often several guys roam in small packs. To 
begin a contact, often one station will put up a steady carrier for the 
other end stations to find. Often the rovers are set up near a freeway 
and a station receiving near the guy sending steady carrier will hear 
whoops in the steady tone caused by doppler bouncing of the signal off 
the freeway traffic.


In my view, using GPS locked oscillators has the same disadvantage of 
power consumption as the rubidiums. If you are in one location (a 
mountain top, etc.) for long periods of time, it might work, especially 
if you have AC available, but for roving, with the many locations, I 
would think it would either not give you much accuracy or would cause a 
big operational time penalty for multiple surveys. I'm not aware of any 
roving operators around here using GPS (except for location, which 
almost everyone now uses to determine their operating location).


A few operators, get by with an only moderately stabilized frequency. 
This might be a "brick" oscillator with its so-so internal oven. It's 
better to get out than to stay home thinking about better options. The 
poor frequency control is usually on new operator's rigs and was more 
common 10 years back. If the frequency is fairly stable, then the 
drifting can be reined in by going out with other hams who have good 
frequency to calibrate from, or if you have a beacon in range that you 
can find to establish your offset.


So, yes, OCXO is the way most hams lock their mobile microwave rigs.

-Rex, KK6MK


On 3/10/2013 7:23 AM, Jim Lux wrote:

Asking here on behalf of a friend..

With respect to portable amateur microwave operation.. you want good 
close in phase noise (so you can use narrow band filters) AND good 
frequency accuracy (so you can find the signal)>


the typical operation is "drive somewhere, operate a bit, drive 
somewhere operate a bit" repeated (contacts from different grid 
squares

Re: [time-nuts] PTS 3200 remote programming

[Rex]

If you have a pdf manual, you probably have the same one I have. When I 
was looking today, I did see that the input pin numbers listed in the 
table, where it describes the programming (p 29 in the one I have or p32 
of the pdf), does not match SCHEMATIC, PE-1121 (figure 7 or p44 of the 
pdf). I think the schematic is not really for the 3200 as it doesn't 
seem to show any inputs for the two GHz bits.



On 3/1/2013 4:37 PM, Iban Cardona wrote:

Hi Alan,

thanks for answer. Yes I have the manual, but the latches on my pts
not are as are showed in the user manual. Maybe my unit it is a
different version or release, or have some customozation from the pts
guys.

In myunit, I tested the SO-2005 module that is that generates the
100Mhz decade, and I tested manually the 4bit to generate the 800Mhz
and works well.

My unit dont have front panel, only can be controllated remotelly.

The differences from the user manual, is that un the user manual the
1ghz and 100mhz decade shares latch, and in my unit the shares latch
the 100mhz with the 10mhz. The 1ghz latch is shared by the 1hz decade.

Best regards

73! Iban
eb3frn


On Fri, Mar 1, 2013 at 8:27 PM, Alan Melia  wrote:

Hi Iban do you have a manual? they are available. From memory because its a
while since I worked on my Wavetek- Rockland unit I believe the remote
programming is in parallel with the front panel switches. The reason for
raising this is that there may be a problem on the back of the panel
switches.mabe a wire off. Does the 800Mhz front panel switch setting
work correctly ??

Alan
G3NYK

- Original Message - From: "Iban Cardona"
To:
Sent: Friday, March 01, 2013 6:42 PM
Subject: [time-nuts] PTS 3200 remote programming



Hi,

I'm traying to use to program the bcd interface of a PTS 3200.

My truble us tha the 100Mhz decade 8 value bit is ignored by the PTS,
then if I send 800Mhz to the PTS dont get output, and if send 900Mhz
then I get 100Mhz.

I checked the unit and the hardware looks OK. And my code is working
well in another PTS units like the 620.

The 3200 have some trick?

Thanks for all

73! Iban
eb3frn
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Re: [time-nuts] PTS 3200 remote programming

[Rex]

I looked at a copy of the 3200 manual I found a while ago. I used to 
have a bunch of PTS stuff on my web pages but was asked by the company 
to take it down. I think KO4BB manual pages have the same issue. Do you 
have the manual?


It doesn't look like there is anything unexpected in the interface. 
Sounds like something is broken in the path for your 8-weighted bit 
(from pin 42 on the BCD connector according to the manual's table). 
Pete's guidance may be helpful.



On 3/1/2013 10:42 AM, Iban Cardona wrote:

Hi,

I'm traying to use to program the bcd interface of a PTS 3200.

My truble us tha the 100Mhz decade 8 value bit is ignored by the PTS,
then if I send 800Mhz to the PTS dont get output, and if send 900Mhz
then I get 100Mhz.

I checked the unit and the hardware looks OK. And my code is working
well in another PTS units like the 620.

The 3200 have some trick?

Thanks for all

73! Iban
eb3frn
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Re: [time-nuts] Looking for Z3801

[Rex]

Here is a Z3816a -- 271152849045
I don't know the seller but has lots of sales.

3816 requires no serial configuration (like 3801) and has two 10 MHz out 
standard. Several years back I came up with a mod to convert the 4 
19...MHz outputs to additional 10 MHz square outputs. -- 
http://www.xertech.net/Projects/Z3816/3816_mod.html


If the picture matches the unit, this one needs +20 to 72 V. I run mine 
on +28V.


3805 is also good (better receiver) but I haven't looked for listings today.



On 2/14/2013 6:14 AM, Greg Broburg wrote:

Hello

I am looking for a working Z3801 for a shop bench reference.

Located in Minneapolis.

I see that there is essentially nothing on eBay.

Considering T-Bolt or Z3805 also.

Greg



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Re: [time-nuts] altinex switches

[Rex]

Yes, this switch matrix seems intended for video signals, so 75 ohms is 
the expected standard. I doubt that would be much of a problem for 50 
ohm timing signals. Some of us shall see soon. BNCs may be 75 ohm 
versions too, but probably not a big issue.



On 2/11/2013 6:20 PM, J. L. Trantham wrote:

Looks like 75 ohms if I understand the manual correctly.

Joe

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Don Latham
Sent: Monday, February 11, 2013 8:00 PM
To: time nuts
Subject: [time-nuts] altinex switches

I bought a couple of
180986059633
switches. The manual is at:
http://pdf.textfiles.com/manuals/STARINMANUALS/Altinex/Manual/Archive/Home%2
0Run%20(HR)%20Series.pdf

You get 8 inputs switchable to 12 outputs IN ANY COMBO. meaning it can be a
12 output distribution amp. isolation amps all round, and either
200 or 300 MHz bandwidth. dc coupled, have a look. There are some left.
Don



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Re: [time-nuts] FRK-L Rubidium

[Rex]

Do you have the service manual? If not, get it here...
http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Efratom

As I recall there's pretty good trouble shooting in the manual. Several 
years ago I fixed an FRK-H that wouldn't lock. The crystal osc had 
drifted enough that the trimmer didn't have enough range to tune to the 
lock freq. Fix was to pull one small cap that was in parallel with the 
trimmer. (C-11 on Osc schematic A21.)


If you have a counter that you trust, it should be easy to see if tuning 
is reasonable. The manual will show where the trimmer is. I think I 
recall looking at the modulation signal as shown in fig 3-2 in the 
manual as I didn't have an accurately calibrated counter at the time. (I 
wasn't able to get to a balanced 2fm output signal until I modified the 
circuit.)




On 2/8/2013 6:50 PM, Garren Davis wrote:

I've let it run for hours and it gets warm. It has a heat sink and it all gets 
warm. There are two adjustment screws. One under the heat sink and one on the 
side of the unit. Is one for the vco and the other for the C-field?



On Feb 8, 2013, at 4:53 PM, "jmfranke"  wrote:


How long do you let it run? Does the crystal oscillator oven get warm? If you 
let it run more than 15 minutes, and the oven gets hot, the next thing to check 
is the output frequency range as the tuning voltage sweeps. Not having a 
frequency counter hurts but there are other methods. One is to use WWV on 10 
MHz. You should hear the output slowly sweep through WWV, first on one side of 
zero beat and then through zero beat to the other side. If the beat stays on 
one side, the VCO needs tweaking to get the sweep somewhat symmetrical about 
the 10 MHz WWV signal.

John  WA4WDL

--
From: "Garren Davis"
Sent: Friday, February 08, 2013 7:12 PM
To:
Subject: [time-nuts] FRK-L Rubidium


Been lurking on the list for a while and finally started playing with a FRK-L  
rubidium frequency standard. I've had
this thing for a while and decided to power it up and see what it would do. I 
do not get a lock. What I see is the
lamp voltage at 8.54 volts which I think is good but the xtal control voltage 
swings from 2 volts to 15 volts and back
to 2 volts and keeps cycling like that. I don't have a good frequency counter 
but I have a 3 Ghz 40 G/sample scope
and it shows that the 10 MHz signal is there. I just don't know how accurate it 
is. Has anyone seen a problem like
this? Can anyone point me to a place to start debugging this? I have the 
schematics and test tools. I am a test
engineer so I'm not afraid to poke around in the guts of this thing. Hopefully 
I can get this thing running. I also
have a thunderbolt that I'll get running this weekend. I don't know how deep 
I'll get into this time-nuts thing but
I have this nice scope and a Wavecrest sitting in my garage and I'd like to put 
them to use. Any help would be appreciated.

Garren


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Re: [time-nuts] Low noise power supplies?

[Rex]

On 1/31/2013 12:20 AM, Bruce Griffiths wrote:
With some care its possible to make the emitter current of the shunt 
transistor approximately PTAT so that, at least for small signals the 
temperature dependence of the rejection is reduced significantly.


Sorry, what does PTAT mean? I'm not familiar with that term.



Its also possible to build a feedback style shunt regulator that has 
considerably higher supply rejection than the Wenzel circuit using an 
opamp and a shunt transistor together with a small resistance in 
series with one of the supply leads.


Bruce


The Wenzel article gives three circuit topologies. The third shows an 
opamp feeding a 2N4401 across 0.05 ohm in the power path. Sounds like 
what you are describing. Did you miss that one or are you describing 
something different?


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Re: [time-nuts] Interval Timer Recommendation

[Rex]

On 1/9/2013 12:48 PM, Azelio Boriani wrote:

and don't forget the PM6681 (50pS)


The PM6681 was sold by Fluke/Philips. The same counter is also 
occasionally seen as the Pendulum CNT-81. Additional good features: 
small, light, and quiet.




On Wed, Jan 9, 2013 at 7:29 PM, Magnus Danielson
wrote:
On 01/09/2013 05:39 AM, Ed Palmer wrote:


In the past there has been much discussion on this list regarding the
relative strengths and weaknesses of the 5370 (20ps resolution) and the
5371/5372 (150ps resolution) units. There are other units that have even
better resolution, but they tend to be pricey and/or more specialized.


The 5371/5372 has a 200 ps resolution. They where designed to allow
extension to 100 ps resolution. The FLASH-interpolators have 200 ps steps,
sufficiently good trigger such that you get 150 ps resolution performance
on the white-noise limit.


Cheers,
Magnus




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Re: [time-nuts] 10 MHz -> 16 MHz clock multiplier

[Rex]

On 1/4/2013 4:48 PM, Bob Camp wrote:

Hi

As I recall the spec was:

1) Cheap
2) no phase slips on the 16 MHz relative to 10 MHz
3) Cheap

Bob



GAK!

Here is the original from TVB

What's the simplest way to generate 16 MHz from 10 MHz? This will be for 
clocking a microcontroller at 16 MHz given 10 MHz (Cs/Rb/GPSDO). Low price and 
low parts count is a goal; jitter is not a concern but absolute long-term phase 
coherence is a must.

The ICS525 (as in TAPR Clock-Block) is a good candidate but I was wondering if 
there's something cheaper, less functional, and maybe not SSOP. Any suggestions?

Thanks,
/tvb

This cluster f**k of responses losing track of the original but blathering on 
for days is so typical of the group lately.






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Re: [time-nuts] 10 MHz -> 16 MHz clock multiplier

[Rex]

On 1/3/2013 6:22 PM, David wrote:

Alternatively if you just want to divide by
5 or some other small fixed number, you can use a couple of flip-flips
and gates.

Flip-flips are good for digitally implementing tick-tick clocks, right? 
:-) (Use flop-flops for tock-tock.)



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Re: [time-nuts] Is now the timepod a symmetricom product ?

[Rex]

I didn't really intend my comment as a criticism, more an observation 
about the number of posts to the group making it hard for people to 
follow everything.


I know that I just skim most topics and have recently block-deleted 
multiple messages (unread) in some threads. Took me a while to locate 
those two spots, that I knew I had read, about Symmetricom picking up 
John's product.



On 12/20/2012 3:21 AM, Timeok wrote:

Yes Mr Rex,

I am guilty .. not all people are perfect!

best regards form Timeok


Il 2012-12-19 23:26 Rex ha scritto:

This is a sign that people can't digest all the messages on time-nuts.

There was this...
http://www.mail-archive.com/time-nuts@febo.com/msg53586.html
(thread replies included John)

and this...
http://www.mail-archive.com/time-nuts@febo.com/msg53811.html


On 12/19/2012 1:29 PM, Didier Juges wrote:
You may have noticed that the miles.io URL now redirects to the 
Symmetricom

page.

That would be a clue :)

Didier


On Wed, Dec 19, 2012 at 2:56 AM, Timeok  wrote:


see :  http://www.symmetricom.com/lp/**gbu/email/phase-noise-test-**

probe-landing-page/?emailid=**3120A_Launch_Email_Quote<http://www.symmetricom.com/lp/gbu/email/phase-noise-test-probe-landing-page/?emailid=3120A_Launch_Email_Quote> 



it seem the same KE5FX  product.


timeok



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Re: [time-nuts] OT: Mayans

[Rex]

Ha, ha. That brightened my afternoon.

On 12/19/2012 9:13 AM, J. Forster wrote:

-John

===
[Cartoon]



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Re: [time-nuts] Is now the timepod a symmetricom product ?

[Rex]

This is a sign that people can't digest all the messages on time-nuts.

There was this...
http://www.mail-archive.com/time-nuts@febo.com/msg53586.html
(thread replies included John)

and this...
http://www.mail-archive.com/time-nuts@febo.com/msg53811.html


On 12/19/2012 1:29 PM, Didier Juges wrote:

You may have noticed that the miles.io URL now redirects to the Symmetricom
page.

That would be a clue :)

Didier


On Wed, Dec 19, 2012 at 2:56 AM, Timeok  wrote:


see :  http://www.symmetricom.com/lp/**gbu/email/phase-noise-test-**
probe-landing-page/?emailid=**3120A_Launch_Email_Quote

it seem the same KE5FX  product.


timeok



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Re: [time-nuts] EIP545A 18GHz counter query

[Rex]

I have an EIP counter with a problem, stashed, that I need to look at 
eventually. So have been following the thread a bit.


If you guys get somewhere conclusive (or not), might be nice to post a 
summary of all important details, techniques, or circuit notes beyond 
the manual, found, to this thread for closing to posterity searchers. 
(And me.)


And, in the mean time, good luck, bon debugging.

-Rex


On 12/9/2012 8:41 AM, paul swed wrote:

Chris
TP4 is not all that helpful its a control signal.
So let me back up for a minute. What are we troubleshooting?
I was thinking band 2 was semi working and you still had a totally dead
band 3.
My comments have been around trying to see what was going on with 3.
Other comment.
I think we should take this offline. Most likely driving time-nuts nuts. :-)
Do you use skype?
Regards
Paul




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Re: [time-nuts] Nifty "MINI TIC" for DMTD work please hold off, 4 channel pic...

[Rex]

Bert,

I have been waiting for more details to become available. Thanks for the 
update.


Not sure exactly what this means:

but I have to depend on volunteers to do the drawings and they have to make
their time available when convenient.

Depending on if the input is in some kind of standard, or a 
transmittable sketch format, and what the desired output is, maybe I 
could help. Contact me if you think another cook could possibly help the 
broth.


-Rex in San Jose, CA


On 12/9/2012 3:20 AM, ewkeh...@aol.com wrote:

We have a choice of two dual mixers, my copy of the original NBS with minor
  changes and Bill Riley's unit. Comparison tests are ongoing to pick the
best. If  Bill's shows better results I plan on laying one out using leaded
components. 2  channel and 4 channel counters are completed and are being used
for testing.  Corby has done some more tests plotting single channel using
the period mode.  Great results. Can use phase or period.
A documentation package is being prepared to be placed on Didier's site,
but I have to depend on volunteers to do the drawings and they have to make
their time available when convenient.
Juerg is continuing his work on programming a PIC for LCD display but that
will only be an added feature one can use the counters direct with a PC and
as  you may have noticed Corby sold his SR 620.
Bert Kehren



In a message dated 12/8/2012 5:50:35 P.M. Eastern Standard Time,
w1...@earthlink.net writes:

What is  the status of this project ? I may have missed a few e-mails.

Thanks,  Dick, W1KSZ




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[time-nuts] Poor termination effects?

[Rex]

I live in the San Francisco bay area. You may recall that back in 1989 
we had a big earthquake that did a lot of damage.


The epicenter was near Loma Prieta, which became the name for this 
earthquake. That is about 60 miles south of San Francisco, yet a lot of 
the bad damage occurred there, at the tip of the peninsula. My twisted 
engineer's mind caused me to think that such a locus of damage so far 
from the source may have been due to a poor termination of the peninsula 
into the ocean/bay.




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Re: [time-nuts] Z3801A Problem

[Rex]

Back in the early 2000's Randy Warner was working at Synergy and posting 
here. He provided a lot of good and accurate details about the Oncores 
to the list. You might want to search the archive for his name and scan 
through the posts. He was a fabulous, accurate source while he was 
posting here, but left Synergy around 2006-2007.


One document he provided is this:
http://www.febo.com/pages/hardware/VPCommands.pdf

In there he mentions the VP firmware versions and that Synergy could 
re-flash the firmware for you, but I doubt that option still exists. I 
think it may have been mentioned that there was no way to update the 
firmware outside of the factory. That is what I remember.


-Rex

On 11/7/2012 5:05 AM, Azelio Boriani wrote:

Never found an Oncore firmware file... can you point me to anyone of them?
I'm curious to see one.

On Wed, Nov 7, 2012 at 1:30 PM, Bob Camp  wrote:


Hi

There were a *lot* of firmware updates to the Oncores. I don't know if the
re-flash images are still out there or not. If they are, it wouldn't hurt
to upgrade the card. I don't think it will fix your problem, but it won't
hurt either.

Bob

On Nov 7, 2012, at 1:06 AM, Ed Palmer  wrote:


Hi Mike,

My unit has the standard 6 channel VP.  In fact, here's the ID message:

COPYRIGHT 1991-1995 MOTOROLA INC.
SFTW P/N # 98-P39972M
SOFTWARE VER # 8
SOFTWARE REV # 4
SOFTWARE DATE  13 JUL 1995
MODEL #B1121P1114
HDWR P/N # _
SERIAL #   SSG0239632
MANUFACTUR DATE 7H18
OPTIONS LISTIB

I understand that the 'B1' start to the model number means that it's

quite old.

I don't remember if I ever did a full reset so I just did one. We'll see

what happens.

Thanks,
Ed

On 11/6/2012 10:20 PM, Mike S wrote:

On 11/6/2012 2:59 PM, Ed Palmer wrote:

But if this is a firmware issue, shouldn't there be lots of Z3801As

with

this problem?  I suspect that there's a fault with my unit, but I can't
imagine what.

Does your unit by chance have an 8 channel Oncore VP instead of the

stock 6 channel one?

Also, have you tried a full reset (:system:preset)?

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Re: [time-nuts] Z3805 etc

[Rex]

Yes, 5 MHz MTI 260 in both my Z3085 and Z3816A, doubled somewhere inside 
for the 10 MHz output.



On 10/15/2012 12:32 AM, Azelio Boriani wrote:

5MHz? Then it is doubled to have 10MHz at the output...

On Mon, Oct 15, 2012 at 8:17 AM, Murray Greenmanwrote:


Ulrich is right about the use of MTI 260 use in GPSDOs. I have a
Korean-made Z3815A clone (it's labelled Agilent) which has a little
daughter board with a 5MHz MTI 260 DOCXO in place of the original E1938A
used in these models. I understand that there were production and
reliability issues with the E1938A.

73,
Murray ZL1BPU




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Re: [time-nuts] HP Z3805A com port and monitoring questions

[Rex]

On 10/14/2012 10:43 PM, Ulrich Bangert wrote:

There's another telco model that has an MTI 260 oscillator, that I
think was manufactured in Korea but does not have the Samsung logo on
the front.  I don't know much about that one.

I do own a Z3805 WITH the Samsung logo on the front AND WITH a MTI 260 inside.

Regards
Ulrich Bangert



Me too -- same description of Z3805. For some reason the output of that 
3805 seems a bit cleaner (in PN) than my Z3816A which also has an MTI 
260 oscillator.


BTW, Ulrich, I use your software as the main monitor for both. Thanks 
for all your work!




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Re: [time-nuts] Mouser connector

[Rex]

I think these are correct...
24-pin LOPRO WRMNT
3M D-Subminiature Connector
is printed on the envelopes from Mouser.

Plug
Mouser 517-3548-100 , (3M 3458-1000)

and
Socket
Mouser 517-3549-1000 , (3M 3549-1000)

If I remember right when I ordered about a year ago, there was a problem 
in the Mouser catalog pages where the picture was wrong for the gender 
of one or both types, so be careful about the pictures.



On 10/14/2012 5:00 PM, Joseph Gray wrote:

I remember someone mentioning long ago about making GPIB cables with
ribbon cable and IDC connectors from Mouser. I can't find that
information again. What is the Mouser part number for those IDC
connectors?

Thanks,

Joe Gray
W5JG

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Re: [time-nuts] "Best" GPSDO

[Rex]

On 9/28/2012 8:31 PM, Chris Albertson wrote:

You can guess the real question here: "how good does the 10MHz
reference need to be to test real-world receivers?



Pretty sure the answer is good enough, but... Depends on the receiver 
and what it is receiving.


I got interested in time-nuttyness because I am a ham. My interests are 
mainly in the microwave bands, typically 10 GHz and higher. I got a 
couple GPSDOs primarily to make accurate measurements in the many-GHz 
range by feeding ref inputs to my test equipment. Mostly I wasn't 
interested in the nitty-gritty, just being good enough for good 
"trustworty" results. Before the GPSDOs, getting accuracy to 100's of Hz 
at 10 GHz was an act of faith. Now, to Hz is pretty easy.


Recently I got involved in building some boards for an intermediate IF 
(is that redundant?) for a 24 GHz radio that have their LO at 3600 MHz 
and are locked to 10 MHz. (Details to be presented at Microwave Update 
2012 in a couple weeks -- http://microwaveupdate.org/ . Feel free to 
sign up and attend if you are interested.)


Around 2006, John Miles shared with us some measurements he did using 
microwave "brick" phase locked oscillators to get the phase noise from 
OCXOs multiplied up enough to see the differences on a decent spectrum 
analyzer. ( http://www.ke5fx.com/brick/brick.htm ) He used an 8566b SA 
and his own PN  software ( http://www.ke5fx.com/gpib/pn.htm ) to drive 
it with GPIB to make the measurements. Many thanks to John for all he 
has shared with us.


I hadn't made any measurements like this before, but this seemed like a 
good way to get a feel for the quality of the 3600 MHz boards (which 
turned out good.) I also have an 8566b SA, so that with John's PN 
software seemed like a good setup to try. The 3600 board has a loop 
filter about 10 KHz wide so in the audio range the output PN is related 
to the quality of the 10 MHz reference.


My two main frequency references are two GPSDOs, an HP Z3816A and (few 
years ago added) a Z3805A Sumsung. Both have an MTI 260 OCXO as their 
internal locked source. Testing the 3600 MHz board using these two 
references, the best phase noise came with the 3805 at about -90 dBc. 
The 3816 was about 7 dB higher. Not sure why. The MTI 260 oscillators 
are 5 MHz so are doubled in the GPSDOs to 10 MHz. Maybe that is part of 
it, or maybe the two MTI 260s are that much different.


I also measured with two small eBay oscillators from China -- all in 
equivalent small packages about 2 inch square by 1.5 inch high. A CIC 
STP2145A gave results similar to the 3816. A Morion MV89A was the worst 
so far, about 10 dB higher than the 3805. Clearly, the affects of the 
the oscillator PN are quite visible when multiplied by 360 to 3600 MHz. 
(20 log 360 = 51 dB.) I'm not sure about the exact accuracy of my 
measurements, but I am certain I am seeing the relative effects of the 
PN from the OCXOs.


I have a bunch of 10 and 5 MHz OCXOs I have accumulated and now that I 
have this tool for evaluating, I need to take the time to fire them up 
and sort them by PN quality. I guess I need to build a trustworthy 
doubler too, for the 5 to 10 MHz like the ones on Bruce's pages at KO4BB.






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Re: [time-nuts] messy workbenches

[Rex]

Another serious contender in the messy but productive realm was Bob Pease.
http://www.eetimes.com/electronics-blogs/social-mania-blog/4217103/How-messy-is-your-desk-

Quite ironic that Bob died while leaving the memorial for Jim Williams.
http://www.edn.com/electronics-blogs/readerschoice/4368147/Analog-engineering-legend-Bob-Pease-killed-in-car-crash



On 9/28/2012 6:48 PM, Grant Saviers wrote:
George's is a far distant competitor to the bench of the late Jim 
Williams, see 
http://www.computerhistory.org/atchm/an-analog-life-remembering-jim-williams/


Which was on display at the Computer History Museum and just was 
returned to Linear Tech.


Grant Saviers




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Re: [time-nuts] FTS 1000B oscillator for sale

[Rex]

Per the datasheet I just found...
http://www.gigatest.net/datum/1000b-r2.pdf

it should be 5 MHz and 10 MHz. I assume the 10 MHz is from an internal 
doubler.


Corby,
Another question. I just found that datasheet but nothing about the 
1000A. What's the difference between A and B?


-Rex


On 9/10/2012 1:38 PM, Tom Knox wrote:

Hi Corby;
What is the freq?
Thaks;
Thomas Knox




To: time-nuts@febo.com
Date: Mon, 10 Sep 2012 11:22:56 -0700
From: cdel...@juno.com
Subject: [time-nuts] FTS 1000B oscillator for sale

Hi,

I put an FTS 1000B oscillator on sale at eBay see item # 320980495168 if
you are interested.

I will also be selling several FTS1000A in the near future.

Thanks,

Corby




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Re: [time-nuts] REF osc distribution.

[Rex]

A couple links on what Bob is referencing:

http://www.ko4bb.com/~bruce/IsolationAmplifiers.html

http://www.ke5fx.com/norton.htm


On 9/5/2012 9:46 AM, Bob Camp wrote:

Hi

There are a number of discrete transistor buffers that have very good
isolation and short term stability / phase noise performance. I'd take a
look at the one from the NIST papers and Bruce's more modern re-design.  All
are in the archives. http://tf.boulder.nist.gov/general/pdf/498.pdf is a
pretty good place to start.

Mostly what they do is to run a common emitter amplifier followed by several
common base amplifiers. They may or may not follow that with a buffer. Each
channel gets a separate string of amplifiers. All the common emitter amps
are driven in parallel by the reference source.

The transistors used are normally cheap stuff like the 2N3904. Except for
the power supply nothing in the circuit costs much. None of it is hard to
find.

Bob

-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Rui Martins
Sent: Wednesday, September 05, 2012 10:19 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] REF osc distribution.

Bob and Paul,



I have at moment 6 equipment's maximum which I want sync with 10MHZ only.

The video distribution is an idea but the kit from Ve2zaz have other way but
the problem is the isolation.

I have 2 independent Nortel GPSTM but I don't need redundancy for the job.

G3ruh and ve2zaz Kits and rubidium oscillators only for analyzing the data
and compare.

I will use one of them with a doubler to get 20MHZ for driving a transceiver
(Crazy huh).

Any ideas will be considered.



Regards



CT1EBH

Rui Jorge Martins

Proudly user of FT-ONE, FT-980, FT736R, FT726R, FT-2000 and FL-7000

73!







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Re: [time-nuts] Isotemp OCXO trimpot question...

[Rex]

I would think the knob on a 10 KW pot would look something like the 
latch wheel on a navy hatch.


To need the 10 KW rating on a 10K ohm pot, ohms law seems to tell me 
Vref would be close to 10 KV. Perhaps a bit high for most varactor diodes.



On 8/28/2012 6:13 PM, Michael Blazer wrote:

The ohm symbol in the symbol character set is the same code as the "W".

I've seen some 10 kW rheostats.  You could use the OCXO as decoration 
on the shaft.


Mike

On 8/28/2012 7:24 PM, jmfranke wrote:

Now I need to find a 10 KW potentiometer!

John

--
From: "Jerry" 
Sent: Monday, August 27, 2012 8:10 PM
To: "'Discussion of precise time and frequency measurement'" 


Subject: Re: [time-nuts] Isotemp OCXO trimpot question...

I don't know if the list allows attachments but I tried to attach to 
this
email a datasheet for a very similar Isotemp 10Mhz OCXO (Model 
OCXO134-10;
PN 6624.2).   Just in case the attachment doesn't come thru here 
is the

relevant section.

I am not certain whether the pins are the same as your model but I 
believe

all the Isotemp OCXO have same arrangement:

3. ELECTRICAL FREQUENCY ADJUSTMENT
3.1. Range > ±0.45 PPM
< ±1.2 PPM (At time of shipment) (Referenced
to nominal frequency)
3.2. Control 0 VDC to Vref (0 VDC to +8 VDC ) or a 10 kW
potentiometer connected between pins 2 and 4 with wiper connected to 
pin 3.

3.3. Slope Positive
3.4. Center Vref/2 ±10% of Vref (+4 VDC to +0.8 VDC)


Jerry




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Re: [time-nuts] Isotemp OCXO trimpot question...

[Rex]

Read more carefully, Bob. It was a joke based on a typo.


On 8/28/2012 5:44 PM, Bob Camp wrote:

Hi

I wouldn't go to crazy digging up a 10K pot. I suspect that anything in the 10K 
to 50K range will work ok.

Bob

On Aug 28, 2012, at 8:24 PM, jmfranke  wrote:


Now I need to find a 10 KW potentiometer!

John

--
From: "Jerry"
Sent: Monday, August 27, 2012 8:10 PM
To: "'Discussion of precise time and frequency measurement'"
Subject: Re: [time-nuts] Isotemp OCXO trimpot question...


I don't know if the list allows attachments but I tried to attach to this
email a datasheet for a very similar Isotemp 10Mhz OCXO (Model OCXO134-10;
PN 6624.2).   Just in case the attachment doesn't come thru here is the
relevant section.

I am not certain whether the pins are the same as your model but I believe
all the Isotemp OCXO have same arrangement:

3. ELECTRICAL FREQUENCY ADJUSTMENT
3.1. Range>  ±0.45 PPM
<  ±1.2 PPM (At time of shipment) (Referenced
to nominal frequency)
3.2. Control 0 VDC to Vref (0 VDC to +8 VDC ) or a 10 kW
potentiometer connected between pins 2 and 4 with wiper connected to pin 3.
3.3. Slope Positive
3.4. Center Vref/2 ±10% of Vref (+4 VDC to +0.8 VDC)


Jerry





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Re: [time-nuts] Understanding Oliver Collins Paper "Design of Low Jitter Hard Limiters"

[Rex]

On 8/21/2012 1:22 PM, David wrote:

On Tue, 21 Aug 2012 10:50:43 -0600,  wrote:


Hello everyone,

I am new to this forum.
It looks like a lively discussion on various topics.

A colleague of mine here at Agilent pointed me to this paper entitled "The Design of Low 
Jitter Hard Limiters" by Oliver Collins. In Bruce Griffiths' precision time in frequency 
webpage, this paper is described as "seminal."
(http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html)

Since I'm trying to create a limiter that will accept frequencies ranging from 1 MHz to 100 MHz, I thought it would be 
good to understand the conclusions of this paper (if not the mathematics as well).  The mathematics turned out to be 
quite challenging to decode. Has someone on this forum unraveled the equations? It appears Collins has recommendations 
on the bandwidth and gain of a jitter minimizing limiter, and then extends this analysis to provide the bandwidth and 
gain of a cascade of limiters.  But the application is still fuzzy.  In figure 5, he shows a graph showing the 
dependence of jitter on crossing time.  Is the crossing time (implied by equations 7) considered a design parameter one 
can vary? Also, on figure 4, the "k" parameter has been varied to show the rising waveform as a function of 
"k".  The threshold is always assumed to be 0.5.  So could "k" be related to "tau", the 
time constant of the RC filter?

Thanks in advance for all your help.

Yours

Raj

I would love to take a look at this but the links to the paper at the
IEEE are dead.  My Google search just turned up others looking for the
same paper.


Just search for the title on IEEE -
http://ieeexplore.ieee.org/search/searchresult.jsp?newsearch=true&queryText=The+Design+of+Low+Jitter+Hard+Limiters&x=29&y=18

Of course then you need to figure out how to pay IEEE for the privilege 
of reading the 672 kb paper.




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Re: [time-nuts] What size graphs do people like? (How big is yourscreen?)

[Rex]

Hal,

I never tried to use SVG before, but after your messages tonight I 
played around with it a bit. I would never have expected it, but I think 
you are right about the issue being a server configuration.


I copied your SVG file and got the same results. On my local hard drive 
it opens as a graph. I copied it to my own web pages and I also saw it 
display as text.


I browsed around and found this SVG picture: 
https://upload.wikimedia.org/wikipedia/en/2/22/Heckert_GNU_white.svg
It displays fine at that link. I copied the svg file to my web 
directories (hosted by GoDaddy) and there the same file displays as text.


I have a debugging tool add-on on FireFox. I displayed a thing called 
'Response Headers' that (I think) come from the server. For the svg link 
on my pages I see one field: 'Content-Type: text/plain'. If I do the 
same response header display on the wikimedia.org link I see 
'Content-Type: image/svg+xml'. So that seems to be what makes it work or 
not work.


If you go to: http://validator.w3.org and enter your link into the 
address field 
(http://www.megapathdsl.net/~hmurray/time-nuts/coax/Front-5ns-800x600.svg) 
then click Check, you will get a message that sort of explains the 
situation, except I still don't know how to get the server configured 
for for svg file => 'Content-Type: image/svg+xml'.


So it seems most browsers are now ready for SVG, but many servers are 
not. Maybe someone else can give us more details on what change might be 
required. In the mean time it looks like I won't be using any SVG on my 
pages either.


-Rex


On 8/7/2012 11:57 PM, Hal Murray wrote:

albertson.ch...@gmail.com said:

So you are saying that SVG can't work because one example of it is broken.
   Also, there are other vector formats, like Postscript and PDF.

No.  I think my ISP's web server has a simple misconfiguration.

It does work for ps and pdf, at least with my copy of Firefox.
   http://www.megapathdsl.net/~hmurray/time-nuts/test/

ps and pdf, at least the way I see them, are not in the same boat as SVG.
SVG is an image format that can easily be included in a html page.  ps and
pdf are stand alone.  They assume they control the whole setup and are
targeted at paper.  Think 8.5x11 or A4.

Yes, if you have a good pdf display program, you can zoom in/out.  But I
haven't seen pdf graphs included inside normal html pages.

Again, my knowledge of this area is not-great.  I could easily have missed
something.






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Re: [time-nuts] Cables dor 10 mHz

[Rex]

Many years back I bought a long coil of the orange cable with N 
connectors on it at a flea market. Only when I got home did I notice 
that vampires had been gnawing on it in many places :-(

I should have known better and spotted the holes.

I'm pretty sure I know which box holds my vampire tool and a MAU or two, 
but I worked for 3Com starting in 86.



On 7/30/2012 5:02 PM, Pete Lancashire wrote:

Weird timing, I was digging through the attic and two weeks ago found
a box with AMP stinger repair kits, a couple unopened MAUs,
and at least one said tool or two in the bottom of the box. There use
to be a few N connectors but I still use them so they ended up in the
RF connector box.

I use to have a few spools of the cable but one ham radio swap meet
and they went fast.

One of MAUs is bigger then one of my Linux based single board
computers with a network jack ! And I bet cost more to buy.

-pete

On Mon, Jul 30, 2012 at 4:50 PM, Chuck Harris  wrote:

Chris Albertson wrote:
...   I wonder how many


people here remember the old 10base5 stuff.  We used to call it
"Frozen yellow garden hose".  It was a perfect description.  I think
it was about 1980. And I still remember being astounded when I saw
that a "vampire tap" could work.


Or maybe more to the point, I wonder how many of us have installed
10base5 cable, and done vampire taps?  I think I still have one of
the tools around here somewhere... probably with my G-D wirewrap
gun.

-Chuck Harris




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Re: [time-nuts] Lightsquared questionfor SFO area....

[Rex]

I've had a graph logging on my HP3816A in San Jose. I see one big glitch 
on 7/27 ~17:00 UTC. I don't know if it unlocked, nor if it was from 
something received, or some jump in my hardware. Other than that one 
jump, I don't see anything unusual over the last week or so.


There must be others around here who also have been logging GPSDO's.


On 7/27/2012 6:42 PM, Brian, WA1ZMS wrote:

Does anyone know if there is ANY recent active Lightsquared testing taking
place in the SFO area of the US?



I'm dealing with a day-job issue with GPS clocks in the Bay Area showing
"GPS unlocked" errors from 3rd party equipment.







-Brian, WA1ZMS



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Re: [time-nuts] Leap Second Results

[Rex]

Nice list. You clearly have the disease. (Where do you find the time? :-)  )

I think the first, Z3810A, was meant to be Z3801A, correct?


On 6/30/2012 7:32 PM, BD Systems Inc. wrote:

In testing and loggging the Z3810A, Z3805A, Z3815A, Z3816A, 59503A, 58503B and 
the 59551A GPS Receivers, all of which sequenced as follows (Note Denver MST)
  
17:59:59

18:00:00
18:00:01
18:00:01 (at this point the Leap Second indicator was cleared).
  
Chuck Zabilski



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Re: [time-nuts] Different or defective FE-5680A?

[Rex]

On 6/9/2012 12:35 AM, Chris Albertson wrote:


Any idea WHY someone would design something like that?  A programable
frequency standard where the frequency does not come out of the box.

What next and audio amplifier that only drives an internal dummy load?
  Light bulb with a metal envelope?

Chris Albertson
Redondo Beach, California

Fairly common, I think. Their business is responding to big-customer 
RFQs. The customer told them what the specifications were and they 
responded with a price for various quantities. What's cheaper, make a 
new design or cripple an existing design to meet a customer request?


I worked for a big main-frame computer company once. If you had the 
secret knowledge, a simple jumper on one of the boards would enable a 
many-$k feature. (Not easy to find or do, but true.)


FEI and particularly the 5680A seems to be a prime example of many 
flavors of one product. Only FEI knows how many variations they did and 
that is between them and the customers that requested them. It appears 
they did at least one major redesign but kept the same model number.


Time-nuts members have been pretty good at figuring out differences and 
adaptations.
Read the KO4BB wiki and update it if new variations or modifications are 
found:

http://www.ko4bb.com/dokuwiki/doku.php

-Rex


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Re: [time-nuts] Antenna question about RHCP/LHCP I'm sure a time-nut can answer

[Rex]

I took a scan through Kraus "Antennas" since he did much of the 
definitive work on Helical antennas. In his chapter on Wave Polarization 
he gives a mathematical definition of Left- and Right-circular 
polarization, then quickly mentions that the IEEE definition is the 
opposite. He has a footnote: "This IEEE definition is opposite to the 
classical optics definition."


So it seems our current antenna engineering uses the IEEE definition for 
RHCP and LHCP, but earlier work on EM wave theory had defined 
right-circular and left-circular exactly reversed from IEEE. So, combine 
that with the reflection flipping and it is not hard to think why there 
might be confusion.


I looked all around for a simple definition of the RH, LH quality of the 
wave from a helix antenna. I assume I might have extracted it from pages 
of formulas and theoretical explanations, but why not just clearly state 
it in a book that is largely about helical antennas. Somewhere else (in 
Kraus) I read that the IEEE definition of a RHCP or LHCP wave from or to 
a helical antenna had the same handedness as the helix of the antenna. 
Unfortunately in that writing he did not bother to explicitly mention 
what he meant by the handedness of a helix. I assume he meant it to be 
the same as the handedness of a screw, but he didn't say that, so once 
again, a missed opportunity.


I'm not arguing with you, Chuck, just pointing out why there might be 
room for confusion in some circles. (Pun intended.)



On 6/5/2012 6:23 AM, Chuck Harris wrote:

I guarantee you it doesn't cause any controversy among those that
use circularly polarized antennas.

That the polarization changes from RHCP to LHCP when reflected is
certainly the cause of some confusion about the antennas.  A RHCP
antenna that directly emits a wave towards the source will become a LHCP
antenna if it is illuminating a parabolic dish.

The easiest way to think about it is to mentally think of the path from
the transmitter to the receiver as a very long piece of threaded rod, and
the wave being emitted as being a nut traveling on the rod.  No matter
which side of the rod you are observing from, you will observe a nut
traveling away from that end turning in the same direction (clockwise
for RHCP).

Another point of confusion could be that if you are standing at the
transmitter watching the nut travel away from you, it will be rotating
clockwise but if you are standing at the receiver watching the
nut traveling towards you, it will be rotating counter-clockwise.

Both cases are RHCP.

If I hired an engineer to work on circularly polarized antennas and he
didn't know this, I too would be thinking of firing him!

-Chuck Harris


David Kirkby wrote:

On 5 June 2012 01:12, Dave Martindale  wrote:

I don't think that's correct.


This is a funny topic. No matter where see it discussed, there are
people with different views on it. I looked on the edaforum

http://www.edaboard.com/forum26.html

and found a thread (can't find it now unfortunatey), where someone was
adament they needed to be one way (I forget whether both RHCP or
RHCP+LHCP), and someone else was adament a colleague nearly lost his
job after making that mistake. I think there was about a 50:50 mix of
views on the topic



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Re: [time-nuts] Those helix antennas in the photos...

[Rex]

On 6/5/2012 5:36 AM, George Dubovsky wrote:

On (B) and (C), helices are tapered to broadband their frequency response.
Usually the pitch changes along with the diameter.

73,

geo - n4ua


I was just reading in the 3rd edition of Antenna Engineering Handbook, 
that the sharp taper at the end gives a better axial-ratio over a wider 
bandwidth (more circular as opposed to a bit of elliptical 
polarization). There is some trade-off as the gain is lowered a little too.




On Tue, Jun 5, 2012 at 7:47 AM, Michael Baker  wrote:


Time-Nutters--

What I saw in the photos of the helix antennas that I
found interesting was:

A) The tapered cone-shaped cup that some of the
 helix antennas sat in.   What does this do?  Most
helix antennas seem to sit over a flat ground plane
but these are different.

B) Some of the helix antennas are tapered in diameter
very gradually from the base to the top-end.  Why?

C) Some of the helix antennas that are tapered gradually
along their entire length have an abrupt taper at the end.
Why?

And lastly; what is the material that is used for winding the
helix elements onto?

I have some large sheets of copper foil with an adhesive
backing that would be ideal for fabricating helix antennas
similar to the ones seen in the photos.   I tried building a
3-turn helix to feed my 1.8 meter, 0.39 F/d dish on 1.7 GHz for
downlinking the NOAA HRPT digital imagery.  After several
iterations I finally only got mediocre performance.  I think
this was due to poor illumination of the dish.   I then tried
to build a circular polarity patch feed by scaling the dimensions
for a 2.4 GHz patch feed but this was a dismal failure as I never
could get the circular polarity right.   I finally wound up with a
coffee-can style feed which works OK.   Not wonderfully well,
but just OK.Here is a DropBox link to a recent image:
<  
http://dl.dropbox.com/u/**60102282/FLA%201130-3May12.JPG>

The HRPT imagery is pretty neat but now a group of us are
working on figuring out how to demodulate/decode and display
the much higher resolution (and far more natural looking)
imagery from the AQUA and TERRA birds.  These birds
imaging telemetry comes down at 8.2 GHz at 15 Mbps
in a Staggered Quadrature Phase Shift (SQPSK) format.
I am currently trying to come up with an efficient 8.2 GHz
feed and LNA or LNC for my dish.  Should be a fun project!
Here is a DropBox link to a sample TERRA image from the
NASA archives:

<  
http://dl.dropbox.com/u/**60102282/Web%20Terra-Aqua%**20Sample.jpg>

Mike Baker
--**---

_



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Re: [time-nuts] GPS and Rubidium frequency standards and noise question (new...

[Rex]

Said,

Thanks for the info and congrats on the stats from the Jackson Labs stuff.

You mentioned the older HP Z3801. I wonder if you (or others) happen to 
have comparison numbers on the Z3816A with the MTI 260 oscillator or the 
Z3805 with (I think) the same oscillator. I thought I heard the MTI 260 
might be slightly better than the 10811 but can't recall if anyone here 
actually made measurements,


Not to say that any of the HP Z stuff is seen for sale often these 
days. But I have one of each of the above mentioned.


Guess it may be close to the *time* where I should take the *time* to 
build or set up a system where I could get trustworthy measurements of 
these *timing* quality things myself. I keep reading but never seem to 
find the time to actually do it.


-Rex


On 6/3/2012 1:46 AM, saidj...@aol.com wrote:

Jerry, Chris,

it's all relative, while the Lpro may be a good Rb standard, it's phase
noise is not that good really. You list:

-96dBc/Hz @ 10Hz, -138dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz  offsets

For the Lpro. The new Jackson Labs Technologies LN CSAC GPSDO with SC-cut
phase noise and ADEV filter achieves the following:

-138dBc/Hz @ 10Hz, -148dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz  offsets.

At 1Hz offset we see -105dBc/Hz and better on that unit.

The FEI-5680A Rubidium that we discussed here some time ago has a much
worse phase noise plot of course, because the 10MHz is generated digitally
through a DDS, not a 10MHz crystal oscillator..

It all depends on your requirements, and your budget.. I think the Z3801A
(or it's brother the 58503A) is still one of the lowest phase noise and
best ADEV GPSDO on the surplus market if you get a typical unit, and if you can
  locate one.

bye,
Said

From: Jerry Mulchin<_jmulchin@cox.net_ (mailto:jmulc...@cox.net)>
Date: June 2,  2012 16:44:14 PDT
To: Discussion of precise time and frequency  measurement
<_time-nuts@febo.com_ (mailto:time-nuts@febo.com)>
Subject:  Re: [time-nuts] GPS and Rubidium frequency standards and noise
question  (newbie).
Reply-To: Discussion of precise time and frequency  measurement
<_time-nuts@febo.com_ (mailto:time-nuts@febo.com)>





Chris,

To answer your question  regarding using a Rubidium standard as a frequency
  reference
for your  Transverters.

GPS really has nothing to do  the main requirement regarding Phase Noise
and  your
Transceivers. But the 10MHz oscillator inside the  Rubidium standard is the
item
that will be the Phase Noise  problem if you get the wrong Rubidium
standard. There
are  cheap Rubidiums and there are good Rubidium standards to  consider.

An LPRO-101 is actually a very  good Rubidium standard, and exhibits Phase
Noise
values of  -96dBc/Hz @ 10Hz, -138dBc/Hz @ 100Hz, -152dBc/Hz @ 1KHz  offsets
from carrier. This is what I use for my 10GHz  Transverter reference, but I
don't lock it
to GPS when in  the field. LPRO-101's can be gotten pretty  reasonably.

Locking the LPRO-101 to a GPS  will require more support circuitry, and
most of the
folks  on this list can help you with that.

Also,  Thunderbolt GPS disciplined units are nice, but I do not know the
Phase  Noise
numbers of a typical Thunderbolt unit. Others here  probably know the
answer to that.

The  important thing to remember is you don't what to use 10MHz oscillators
that  have
poor Phase Noise performance as it will effect your  weak signal capability
if you use
a poor Phase Noise  oscillator.

Jerry

At  03:05 PM 6/2/2012, you wrote:

If you want a frequency reference.  There is nothing better than GPS.  In


fact it you bought a Rubidium you would  still need the GPS so you could


calibrate its  frequency.





Some GPSes might be noisy but then you can  lock a good double oven crystal


oscillator to it and have what they call a  "GPS disciplined crystal


oscillator or "GPSDO".











On Sat, Jun 2, 2012 at 2:57 PM, Chris Wilson<_chris@chriswilson.tv_
(mailto:ch...@chriswilson.tv)>   wrote:
















I am looking to get a frequency standard  for my amateur radio shack,




initially for verifying test gear  readings, but later as a standard




to lock receiver and transmitter  oscillators to. I was going to buy




a GPS frequency standard but a friend  warned me these may have noise




issues when I come to use it with an  oscillator in RX / TX




applications. It's not something I had  considered, so what's the




score here please? Should I not buy a GPS  standard? Thanks. Any




links to known safe suitable purchase  sources from personal




experience welcome, either here or by PM  or e-mail. I am in the UK.









--




Best  regards,




Chris Wilson  _mailto:chris@chriswilson.tv_ (mailto:ch...@chriswilson.tv)














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Re: [time-nuts] USGS: GPS for seismic work

[Rex]

On 5/19/2012 10:22 PM, Hal Murray wrote:

Another gadget that I saw was a "two color" laser ranging setup.  It was good
for 1 mm over 5 km.  (ballpark)

I think I saw that too. Pretty old; mid-80's probably. The number 
switches caught my attention. Made me try to figure out the vintage. My 
guess was late 70's but history indicated maybe a little newer than that.



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Re: [time-nuts] USGS: GPS for seismic work

[Rex]

I was at the USGS open house for a couple hours. My first time to go.

Was also my first time to see a commercial choke ring GPS antenna up 
close. Was interesting to see the antenna shifted a few inches and 
causing a step function on the internet screen where they where 
monitoring it along with a few permanent logging station antennas that 
were (fortunately) stable while we were watching.


Also enjoyed seeing a hand held XRF Spectrometer (Xray Fluorescence) for 
identifying the material in random samples. And good to chat with the 
guy who carried it around Afghanistan for the last few years helping 
(the Afghanies?) learn what neat stuff their country contains. He also 
had an entertaining story about shopping for silver items -- "90% 
silver, sir." He pulls the XRF out of his pack and scans to find more 
like 20% silver.


Quite a few interesting discussions with several people around the 
place. Also bought a nice large wall map of California with nice relief 
view of the mountains for $9.


Well worth the drive from San Jose.



On 5/19/2012 6:09 PM, Hal Murray wrote:

It wasn't hard to find the right people at the Open House.

GPS is interesting for big quakes.

Most seismometers measure acceleration.  It's a double integration to get
displacement which is what they are used to working with.  Big quakes last
longer which leads normal seismometers to get into troubles with drift.  GPS
doesn't have any drift problems.  The cross over is somewhere in the mag 7-8
range.

Japan has a large earthquake warning system.  On the big tsunami of last
year, they weren't looking for long enough.  They estimated 7.9.  In
hindsight, they probably could have gotten better data sooner by using GPS.

This news story says that they can see the disturbance in the ionosphere.
   http://www.cbc.ca/news/technology/story/2012/04/23/f-tsunami-research.html





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Re: [time-nuts] Buffering a PPS signal

[Rex]

In line with what Bob suggests, here is one of the square wave outputs 
of an HP Z3816A...


http://www.xertech.net/Projects/Z3816/Output_circ.gif

Or look at the project for context...

http://www.xertech.net/Projects/Z3816/3816_mod.html



On 5/17/2012 6:17 PM, Bob Camp wrote:

Hi

Parallel up as many inverters (or logic buffers) as you feel you need. Much 
less delay than the MOSFET drivers. Small packages for easy layout. Run off of 
5 volts (or what ever…). Put a resistor in series with the output of each of 
them and they will equalize very well.

Bob

On May 17, 2012, at 7:35 PM, Michael Tharp wrote:




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Re: [time-nuts] Holy cesium clock, Batman!

[Rex]

On 4/7/2012 5:59 PM, Mark Sims wrote:

One of the nose-bleed channels (MeTV) just showed an old 1980's Batman show...


For a time nut, you are off by at least 14 years. (1980 - 1966 = 14)

The Clock King's Crazy Crimes  October 12, 1966
The Clock King Gets Crowned   October 13, 1966

The ABC television network went on the air on April 19, 1948. So I 
calculate the error as over 70%.


But, how much DID a cesium clock cost in 1966?



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Re: [time-nuts] Book by William Riley

[Rex]

On 3/24/2012 3:54 PM, Magnus Danielson wrote:

and the Hanbook of Frequency Stability Analysis


You didn't mention looking at that one. Any comments about it?


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Re: [time-nuts] FCC Chair Talks Spectrum, Gets GPS Letter

[Rex]

There's also a few cars, trucks, emergency vehicles, hand-helds and 
timing receivers that he didn't bother to mention at all. I suspect most 
of those would be "fixed" by complete replacement. (If a full fix is 
even possible in all situations.)



On 3/6/2012 7:37 PM, saidj...@aol.com wrote:

I'm sorry, but Mr. Javad is on crack.

A simple WAAS upgrade on a GENERAL AVIATION aircraft already costs about
$8000 fully installed.

This includes an antenna upgrade that I remember to be about $3000
installed for the antenna itself.

$500 per plane to fix the issue? Yeah right. In what world does he live  in?

bye,
Said


In a message dated 3/6/2012 16:38:28 Pacific Standard Time,
j...@cornell.edu writes:

The cost  of such retrofits is under $500 per aircraft. It would cost less
than $20M to  fix any existing issues within the industry and only take a
few months to  complete. Please also note that all existing GPS receivers are
semi-obsolete  and will soon need to be replaced anyway (with or without
LightSquared)  because current systems do not track the modernized signals of
GPS, GLONASS  and Galileo.


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Re: [time-nuts] nanoseconds in the news

[Rex]

John,

I agree with what you have said about the markets causing bad effects on 
society because the focus is all short-term, but you are talking about 
effects on the human time scale. HFT is orders of magnitude faster and 
more insane.


I saved two links from after the time of the 2010 "flash crash" of the 
stock market. In addition to some analysis, they both show amazing 
graphics of what the trading algorithms looked like on the actual market 
activity.


http://www.nanex.net/20100506/FlashCrashAnalysis_Intro.html

http://www.nanex.net/FlashCrash/CCircleDay.html



On 2/16/2012 2:45 PM, J. Forster wrote:

Frankly, I think the rapidity of the financial system is not a good thing.
It encourages the kind of speculation on Wall Street that more properly
belongs in Las Vegas.

It has bred the demands for ever increasing quarter-over-quarter results
that result in cooking of the books and so on that deters long-range
planning and thinkingt.

YMMV,

-John




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Re: [time-nuts] FE-5680A Question

[Rex]

The Efrotoms (FRS-C. Lpro) find the lock by modulating the microwave 
frequency with an audio signal (127 Hz if I remember right) which causes 
the light sense modulated signal to double in frequency when centered on 
the hyperfine frequency. See the manuals for nice description. The 5680A 
seems to accomplish the same thing by stepping the frequency +/- 700 Hz 
rather than mixing in modulation. Never saw any documentation on that, 
but seems to be implied by the great hacking Javier Herrero has done on 
the loop frequencies.


Seems to me that finding lock, that is finding the dip, may be a bit 
harder with the stepping than with the modulation. Maybe the observed 
drop in frequency during start up is part of the algorithm to walk the 
stepped frequency to center on the hyperfine light transmission dip.




On 2/13/2012 4:39 PM, Bob Camp wrote:

Hi

If they are looking for a pattern what is the pattern?

Bob



On Feb 13, 2012, at 3:35 PM, paul swed  wrote:


The reason to sweep low is to establish a particular lock pattern to look
for.
Check the programmed offset before retuning. Mine was at mid range 
Search the threads for sending commands to the FE5680.

On Mon, Feb 13, 2012 at 2:56 PM, Bob Camp  wrote:


Hi

For what ever reason, most of the FE's sweep down to about 200 to 250 Hz
low. Few sweep more than 50 Hz high. I have one unit that locks fine and
only sweeps 5 Hz high.

Yes, I would open it up and re-tune. I think I would only bump it about 50
Hz or so. I have no idea *why* they are all tuned low, but there may be a
reason (like avoiding a false lock).

Bob




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Re: [time-nuts] PTS synthesizers

[Rex]

Ah so, master Joe, your net-fu is very good. I forgot that my stuff 
might be archived. Fabulous resource.


So, while we are at it, here is some more PTS info. There are two 
general families of these synthesizers. I may not get this exactly 
right, from memory, but it should be close enough for discussion. The 
first group (older design, I think) used a bunch of modules to 
synthesize decades of frequencies and mix to generate the output. The 
second group uses a more modern DDS synthesis process with fewer 
internal modules. The PTS 160 and 250 are common examples of models in 
the first group. I also have a D310 which contains two of the second 
family synthesizers inside, and only has GPIB control in the one I found.


The KO4BB site, manuals section, used to have some helpful documents. 
The 500 manual was an example of the first group and the 310 manual, an 
example of the second group. These scans had many extras, including 
scans of many module descriptions with schematics. There is one module, 
in both manuals, that covers the GPIB interface for units with that 
feature. The scans were in the 20 Mb size range since they are all 
images, not searchable text.


Using Joe's lead, there are disappeared links...
http://web.archive.org/web/20071013115001/http://www.ko4bb.com/Manuals/
specifically...
http://web.archive.org/web/20071013115001/http://www.ko4bb.com/Manuals/PTS500.pdf
http://web.archive.org/web/20071013115001/http://www.ko4bb.com/Manuals/PTS310.pdf

Hope that helps the OP's quests.

-Rex


On 2/9/2012 5:45 PM, Joseph Gray wrote:

I don't have any PTS gear, but the Internet Archive has this old page:

http://web.archive.org/web/20080821140147/http://www.xertech.net/Tech/PTS.html

And a quick Google turned up these links:

http://w8bl.com/page/5
http://www.artisan-scientific.com/info/pts_3200_manual.pdf

I don't expect companies to provide documentation on obsolete
equipment, but I don't see the harm in someone else doing so. I think
in the long run, supporting older equipment generates good will toward
a company and possible sales.

Joe Gray
W5JG





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Re: [time-nuts] PTS synthesizers

[Rex]

The pin-outs are the same on the BCD input connector, but how the 
high-order controls map differs between models.


For example, the PTS-160 doesn't use the 4-bits for 100 MHz, but rather 
takes input on the 10 MHz bits up to a value of 16. The PTS-250 does use 
the 100 MHz bits, with values of 0, 1, or 2 as possibilities. One might 
expect the PTS-160 to respond to 0 or 1 on the 100 MHz inputs, but that 
isn't the way it is designed.



On 2/9/2012 2:15 PM, Geraldo Lino de Campos wrote:

Yes, the pinout is the same for all models. If anyone is interested, I have
the manual for the PTS-3200 and can send the interface pinout.



Message: 9
Date: Thu, 09 Feb 2012 11:41:52 -0800
From: ed breya
To: time-nuts@febo.com
Subject: Re: [time-nuts] PTS synthesizers
Message-ID:<201202091942.q19jg15d031...@mail16c40.carrierzone.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

Thanks, Nigel, I think your history description is about right - I
vaguely recall seeing the Rockland brand too. I guess PTS is the
current survivor - the PTS D310 seems quite new, and the company
seems to be still in business in their niche.

Ignacio sent me a pinout page for the PTS 040/160/250, which probably
represents a standard arrangement used for all the models, hopefully
just extended by including more bits for higher frequency units. The
D310 is a dual .1 - 310- MHz type, with two program connectors. Also,
I do recall that they used IEC color codes on the ribbon cables for
convenient tracing of the 8,4,2,1 bits within each BCD digit, so it
should be fairly easy to figure out the details.

Ed






Geraldo Lino de Campos
gera...@decampos.net
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Re: [time-nuts] PTS synthesizers

[Rex]

On 2/9/2012 8:39 AM, EB4APL wrote:
About the remote control info, I have a sheet  entitled 
"PTS-040-1600_Prog.doc" that I downloaded some time ago, but I'm not 
able to find from where, maybe it was from your page. I has everything 
that is needed for external control.


Best regards,
Ignacio, EB4APL



The "PTS-040-1600_Prog.doc" was created by me -- looks like in 2007. It 
is very similar to the info in various PTS manuals I was able to find, 
but tries to define differences in the control bits that are used across 
the various units from the PTS-040 to the PTS-1600. It was based on some 
guesswork, so not sure if it is totally correct, but never heard of any 
problems, except one big one...


I had it on my web pages (xertech.net), with some other accumulated 
documentation. It is one of the things I was directly asked by PTS to 
take down, as it is based on PTS copyrighted material but additionally 
was not an exact copy from PTS documents.


C'est la vie. "Ob-La-Di, Ob-La-Da."

-Rex, KK6MK


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Re: [time-nuts] PTS synthesizers

[Rex]

I had a web page up with PTS info that I had gathered, corrected (some), 
and consolidated for multiple devices in one doc.


I got an email from PTS requesting I remove the documents. I now have a 
place holder page recommending people look for HP test equipment rather 
than PTS. PTS doesn't share HP's (now Agilent) openness about sharing 
documents.


-Rex, KK6MK


On 2/8/2012 2:57 PM, gandal...@aol.com wrote:


I still haven't had time yet to try your remote interface, which I  suspect
others here might also find very interesting, but I  have completed the
scans of my X10 and PTS250 manuals and  will be making those available as soon
as I've finished processing the  images.

Regards

Nigel
GM8PZR


In a message dated 08/02/2012 22:11:29 GMT Standard Time, wlfuq...@uky.edu
writes:

I am new  to the list and would like to know if anyone has a list of the
suffixes  (options) for PTS synthesizers. There seem to be a number of them
that are  not in their catalog.

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