[time-nuts] FEI FE-5440A (TD-1251/U, O-1824A/U) Manual Request

[Skip Withrow]

Hello Time-Nuts,
Just wondering if anyone out there has a copy of the Frequency
Electronics FE-5440A cesium clock manual? Yes, Silosurplus has one on
ebay for a stupid price but I'm not THAT interested.  The aviation
version was the TD-1251/U and the mil version was the O-1824A/U.

I would be more than happy to pay the postage both ways, do the
scanning/copying, and would definitely get it back to you.

Thanks,
Skip Withrow

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Poul-Henning Kamp]

In message 
, Dana 
Whitlow writes:

>This would seem to imply that purposely overrating a 'lyt is pretty pointless.
>
>Any comments on this notion?

I've always wondered that myself, and found very little documentation or
wisdom available.

As I understand it, even very brief voltage spikes must be kept under the
rated voltage, so overrating would buy some transient durability, but
other than that...

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Clock project request from IEEE

[Mark Sims]

Lady Heather has a feature designed just for this application.  The TS keyboard 
command (and the /ts? command line options) allow setting the system clock from 
the time message sent by a GPS receiver (assuming the program has permission to 
set the clock).  This typically gets the system time set to under 50-100 msecs.

There are several issues that had to be overcome to make this work properly... 
the main one was characterizing and compensating for the delay / offset between 
when the GPS  time message arrives at the computer and the actual time encoded 
in the message.   I characterized the "time sync offset" for all the receivers 
that Heather supports and the program applies those default values.  You can 
also set the value manually (/tsx=) if your receiver / configuration / system / 
serial port does not match the default value.

The TS keyboard command sets the clock on demand.  The various /ts? command 
line options let you set the clock on a scheduled basis or whenever the system 
clock and GPS time diverge by a specified amount.  

The big disadvantage of Heather's clock setting algorithm is that the time set 
is a rather dumb "jamsync:" of the time... there is none of the smooth, 
monotonic clock adjustment that things like NTP do.   Jamming the time in can 
screw up file system time stamps, etc (hey! new file write looks like it 
occurred before an older file write, etc).  But, if you in a place without 
internet access it works quite well.  I develop Heather on a Windows XP box 
that is NEVER connected to the internet... the system clock drifts around a 
second per day.

-

> This does have an application that I've recently experienced, manually
setting the time on a PC that's used for amateur radio digital (FT8)
communications which require the computer's clock to be accurate
within 1 second.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Dana Whitlow]

I remember often reading that if you run a 'lyt at a voltage much reduced
from its rating,
the oxide layer would get thinner over time so that in the end, the
effective rating of the
capacitor was about what you had been running it at.  This would seem to
imply that
purposely overrating a 'lyt is pretty pointless.

Any comments on this notion?

Dana


On Sun, Feb 24, 2019 at 7:01 PM Gerhard Hoffmann  wrote:

>
> Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist:
> >
> > yet they got a pass and became SOP.  The R lab manager
> > at Santa Clara Division famously said "no customer chooses
> > HP products because they have great power supplies."
> >
> G..  My HP16500C has a defective PS and my 4274A RLC bridge
>
> had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke!
>
> I re-caped the bridge, it took me a day on the DIgikey site to find
> replacements.
>
> I had to use substantially larger voltages to make them fit mechanically.
>
> But that is a good thing.
>
> cheers, Gerhard
>
>
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Clock project request from IEEE

[Ben Bradley]

I have a bit of a "crude but effective" idea regarding getting
Daylight Savings and local time and such - get the current time (hour)
from local cellular signals with a cellular phone module, like one of
these:
https://www.adafruit.com/category/281
If I understand correctly, you don't need cellular service to receive
the date and time signals.

This could even be the basis for a separate project using only the
cellular module, a more "crude" clock that's only accurate to however
good the cellular system is (I'm sure others here know exactly how
good it is, but I'm thinking it's much better than within one second).
This does have an application that I've recently experienced, manually
setting the time on a PC that's used for amateur radio digital (FT8)
communications which require the computer's clock to be accurate
within 1 second. Without Internet access, I did this at the command
line in Admin mode using the Time command while listening to WWV. This
worked, but a separate clock with a one-second-accurate seconds
display would have made things easier.

Ben, AK4XL.

On Sun, Feb 24, 2019 at 5:04 PM Magnus Danielson  wrote:
>
> Hi,
>
> Yes, that would be a cool feature, but would come with complexity that
> would be best outside of such a core system. With enough interface, you
> could let an off-system configuration tool do that and then setup the
> time-zone rules. Conversion from position to time-zone and then look up
> the time-zone data is conceptually no hard, but clearly not a handful of
> lines of code in small MCUs. The benefit of keeping that as separate
> system is that the core functionality can be tested and well understood,
> and such add-ons does not need to be run very often or be part of the
> real-time, so then they should be run separate. The important thing is
> that the core system is built such that it allows this add-on later. So,
> the off-line system should be able to get the time and positiion and
> then be able to set the time-zone offsets and cut-over rules. The later
> may actually at first be forced to be just cut-over time for new offset,
> but maybe it is simple enough to express the full rules with a handful
> of parameters.
>
> As always, the devil is in the details, and the system architect needs
> to make the core system as simple as possible while flexible enough,
> although fairly stupid. More intelligent adaptation can then be added.
> Keeping things robust and testable has challenges.
>
> This is also the challenge of doing designs, the creeping featurism.
> It's somewhat of an art form to balance simple enough and providing ways
> to support cool features later.
>
> Anyway, there would be many pieces of a beast like this that I would
> priority first. Once a core functionality works, only then features can
> be added. One of the keys to succses is clear monitoring of error
> conditions, which helps already in the early integration to figure out
> issues quickly.
>
> Cheers,
> Magnus
>
> On 2019-02-24 12:51, John Reid wrote:
> > I would love something that gave a list of options set from the location in 
> > the NMEA string.
> >
> > Such as this time zone or different, with nearby zones first; DST on/off. 
> > Could get to be a significant effort very quickly, but maybe there are xml 
> > files out there that would make it easy?
> >
> >
> > John
> >
> >
> > On 24/2/19 4:00 am, 
> > time-nuts-requ...@lists.febo.com 
> > wrote:
> >
> > Message: 4
> > Date: Sat, 23 Feb 2019 15:47:11 +0100
> > From: Magnus Danielson 
> > To: time-nuts@lists.febo.com, Glenn 
> > Zorpette 
> > Subject: Re: [time-nuts] Clock project request from IEEE
> > Message-ID: 
> > <4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se>
> > Content-Type: text/plain; charset=utf-8; format=flowed
> >
> > Hi,
> >
> > On 2019-02-22 19:31, Tom Van Baak wrote:
> >
> >
> > I received the following email and permission to post it on time-nuts:
> >
> >
> >
> > Hello,
> >
> > I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum.
> > I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of
> > using it to build a very precise clock that I would share with Spectrum's 
> > readers.
> >
> > I would like to partner with an engineer with experience in digital clocks, 
> > who
> > would be credited as co-author on this project.
> >
> > Can you suggest someone who might be interested in this project? I would be
> > much obliged if you had some suggestions.
> >
> > Kind regards,
> > -Glenn
> >
> >
> > Glenn's contact info is:
> >
> >
> >
> > Glenn Zorpette
> > g.zorpe...@ieee.org
> >
> >
> > You can just imagine all the many ways the project could head. Send Glenn a 
> > note if you want to help. Or post here if you have suggestions.
> >
> >
> > I think we should contribute with 

[time-nuts] Arduino clock with NTP Input and analog meter outputs

[MITCHELL JANOFF]

I’ve designed and built an Arduino based clock that receives the time from an 
NTP server, converts the time to voltages, and outputs the voltages to analog 
volt or ammeters using the PWM pins on the Arduino. The clock displays hours, 
minutes and seconds, each on a separate analog meters with customized clock 
faces. The design, code, and clock faces, and a picture of the clock are in the 
public domain, and I’ve posted all the information required to build this clock 
in a GitHub folder (www.github.com/majanoff). The clock faces are in PDF format 
(for Weston 301 panel meters) that can be printed and glued onto the meter 
metal faces. If you are interested in building the clock, I can create custom 
faces based on your meters or there is a link in the folder pointing to the 
meter face software.  I’ve also built the same clock using time from a GPS 
receiver and a DS1307 real time clock module (posted on GitHub)  in-place of 
the NTP internet connection. I used lookup tables for the output voltages for 
each of the meters, as there is a bit of non-linearity in the output, which can 
be corrected via the lookup tables. 

Please contact me directly if you are interested in more information. 

Mitch.
Kc2mfb




On Sun, 2/24/19,   wrote:

 Subject: time-nuts Digest, Vol 175, Issue 33
 To: time-nuts@lists.febo.com
 Date: Sunday, February 24, 2019, 12:00 PM
 
 Send time-nuts mailing list submissions to
     time-nuts@lists.febo.com
 
 To subscribe or unsubscribe via the
 World Wide Web, visit
     http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
 or, via email, send a message with
 subject or body 'help' to
     time-nuts-requ...@lists.febo.com
 
 You can reach the person managing the
 list at
     time-nuts-ow...@lists.febo.com
 
 When replying, please edit your Subject
 line so it is more specific
 than "Re: Contents of time-nuts
 digest..."
 
 
 Today's Topics:
 
    1. Re: Bricked Garmin GPS 18x
 LVC (Hal Murray)
    2. Re: Clock project request
 from IEEE (John Reid)
    3. Re: HP Stories: An
 architectural view of the HP 5060/5061 and
       awkward oscillator
 adjustments. (Rice, Hugh (IPH Writing Systems))
 
 
 --
 
 Message: 1
 Date: Sat, 23 Feb 2019 14:23:34 -0800
 From: Hal Murray 
 To: Discussion of precise time and
 frequency measurement
     
 Cc: hmur...@megapathdsl.net
 Subject: Re: [time-nuts] Bricked Garmin
 GPS 18x LVC
 Message-ID:
     <20190223222334.2405d406...@ip-64-139-1-69.sjc.megapath.net>
 Content-Type: text/plain;
 charset=us-ascii
 
 
 > If you open it up, then simply
 connect a load resistor, perhaps in the
 > neighborhood of 100 ohms (but
 definitely not a direct short!) across the
 > super cap to drain it faster. 
 
 I couldn't open mine up.
 
 I got one into a useless state.  I
 don't know how I did it, but it wasn't 
 updating firmware.  Mine recovered
 after a while, but I don't know how long it 
 took.  I tossed it on the junk
 pile because it was useless.  Eventually, I 
 tried again and it worked.
 
 Note that trying too soon probably
 charges up the super cap and thus restarts 
 the clock.
 
 
 -- 
 These are my opinions.  I hate
 spam.
 
 
 
 
 
 
 --
 
 Message: 2
 Date: Sun, 24 Feb 2019 11:51:13 +
 From: John Reid 
 To: "time-nuts@lists.febo.com"
 
 Subject: Re: [time-nuts] Clock project
 request from IEEE
 Message-ID:
     

     
 Content-Type: text/plain;
 charset="utf-8"
 
 I would love something that gave a list
 of options set from the location in the NMEA string.
 
 Such as this time zone or different,
 with nearby zones first; DST on/off. Could get to be a
 significant effort very quickly, but maybe there are xml
 files out there that would make it easy?
 
 
 John
 
 
 On 24/2/19 4:00 am, 
time-nuts-requ...@lists.febo.com
 wrote:
 
 Message: 4
 Date: Sat, 23 Feb 2019 15:47:11 +0100
 From: Magnus Danielson 
 To: time-nuts@lists.febo.com,
 Glenn Zorpette 
 Subject: Re: [time-nuts] Clock project
 request from IEEE
 Message-ID: 
<4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se>
 Content-Type: text/plain;
 charset=utf-8; format=flowed
 
 Hi,
 
 On 2019-02-22 19:31, Tom Van Baak
 wrote:
 
 
 I received the following email and
 permission to post it on time-nuts:
 
 
 
 Hello,
 
 I am the executive editor of the IEEE's
 flagship magazine, IEEE Spectrum.
 I recently acquired a TAPR "Pulse
 Puppy" and I am intrigued by the idea of
 using it to build a very precise clock
 that I would share with Spectrum's readers.
 
 I would like to partner with an
 engineer with experience in digital clocks, who
 would be credited as co-author on this
 project.
 
 Can you suggest someone who might be
 interested in this project? I would be
 

Re: [time-nuts] GN-GGB0710 GNSS Antenna

[djl]

Probably tapped for 1/2" pipe thread.
Don

On 2019-02-24 12:40, Ben Hall wrote:

Good evening all,

After almost a month in transit, my GN-GGB0710 GNSS antenna arrived
from the auction site "we all know and love."  ;)

Unit was not tapped to a proper 5/8"-11 TPI thread.  A standard 5/8-11
bolt went in maybe two full threads.  I modified an old tap I had in
the drawer into a 5/8"-11 bottom tap and cleaned it up.  Best I can
tell, the thread cut by the manufacturer was slightly tapered.

I wasn't thrilled with the seal around the edge.  Because it's flat,
some water might wick in, so I ran a quick bead of seal around both
the top and bottom end of the blue rubber seal.

Unit seems to work well.  It's not mounted to the top of my antenna
pole, about 16 feet up from the ground, where it can see a pretty much
unobstructed view of the sky.  All the GPS units on it thru the
splitter are getting excellent signal.

Now to wait until uBlox releases the ZED-F9T dev board.  I did get a
response back from uBlox sales to my work e-mail address (which is a
very large organization) saying it's still in development with a
target release date of May or so...

thanks much and 73,
ben

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.


--
Dr. Don Latham  AJ7LL
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Clock project request from IEEE

[Thomas D. Erb]

for local time keeping with NEMA strings we just use a local offset with DST 
rules.



Thomas D. Erb
o:508-359-9684
p:508-359-4396 x 1700
f:508-359-4482
a:97 West Street, Medfield, MA 02052 USA
e: t...@electrictime.com
w:www.electrictime.com
Tower & Street Clocks Since 1928

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] how to feed multiple GPS receivers ?

[shouldbe q931]

After starting off with a single GPS module on a RaspberryPi, and
discovering the issues of just having a single clock... I now have
three GPS receivers (and a fourth on the way) of various types, each
with their own antenna. I'm aware that I'm heading off down an
interesting road that will consume ever more of my time, but at the
moment it's still fun (-:

To remove the difference of multiple antennas (different skyviews
etc), I'm thinking about using a single antenna and "distributing" the
feed to the receivers.

I should also add that I'm doing this in the UK (in central London),
and as inexpensively as possible.

Reading back through the mailing list several people appear to have
used SatTV splitters with GPS signals to apparently good results, and
I've ordered one of these
https://vision-products.co.uk/8-way-single-port-dc-pass-splitter/
which if I understand it correctly, will passthrough DC from one port,
and block DC from the other ports. From other reading of the mailing
list, it looks as if I will also need to present a DC load to the
other receivers, and if I've read corectly this would be a "Bias tee"
used with a resitive load instead of a DC voltage, but am not sure if
I have understood correctly.

I'm aware of impedance matching issues with using a mix of 75 ohm and
50 ohm parts, but as I said, I'm doing this as inexpensively as
possible, and a 58536A is way over budget at the moment.

Any suggestions gratefully received.

Cheers

Arne

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Gerhard Hoffmann]

Am 24.02.19 um 14:39 schrieb Richard (Rick) Karlquist:


yet they got a pass and became SOP.  The R lab manager
at Santa Clara Division famously said "no customer chooses
HP products because they have great power supplies."


G..  My HP16500C has a defective PS and my 4274A RLC bridge

had a major explosion inside. OMG, WHAT A MESS! All that black magic smoke!

I re-caped the bridge, it took me a day on the DIgikey site to find 
replacements.


I had to use substantially larger voltages to make them fit mechanically.

But that is a good thing.

cheers, Gerhard



___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[paul swed]

Adrian I had the same thing in the same unit. I guess the electrolytic's
were bad in allowing hum through. The tants go Bang and burn. Though all
caps can go bang I suspect.
Paul
WB8TSL

On Sun, Feb 24, 2019 at 5:04 PM Adrian Godwin  wrote:

> Just to sneak that back on-topic .. the most recent tant failure I had was
> in a KS-24361. It was after the dc-dc converter so it didn't look like a
> short to the input - it just increased the current draw. Running off a
> cheap laptop supply, which overheated and melted instead of shutting down
> or blowing a fuse. It took out the breaker for the whole ring main.
>
> Replacing the tant was the only action necessary for the KS-24361 itself.
> No other internal damage.
>
> On Sun, Feb 24, 2019 at 2:02 PM Adrian Godwin  wrote:
>
> > I think I've had as many shorted-out tants as dried-out electrolytics.
> > It's just that they appear in 80s gear instead of 60s. Then there was the
> > flood of high-esr electrolytics from when - early 2000s ?
> >
> >
> > On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) <
> > hugh.r...@hp.com> wrote:
> >
> >> Several people have asked about the Len Cutler ban on Aluminum
> >> Electrolytic Capacitors in HP Frequency Standards.   Rick Karlquist
> could
> >> shed more light on this too.   The legend of the ban was passed along to
> >> me, perhaps by Lou Mueller, who liked to tell stories of the old days.
>  In
> >> 1985, we were not taking the ban literally.   For example, the 2400uF
> main
> >> power supply filter capacitor was AL-Electrolytic, as were a few other
> >> smaller capacitors on the power regulator.   I sidestepped the capacitor
> >> issues on my simple battery charger by not having a filter cap after the
> >> transformer/full-wave-bridge, and just used 120 Hz pulses, since the
> >> battery didn't care about DC vs. pulsed DC.   (I thought it was pretty
> >> clever to leave out the main filter cap.) Where possible, Tantalum
> >> capacitors were used.For the few places where AL caps were used,
> they
> >> were heavily de-rated, operating at 50% of rated voltage for example.
> >>
> >> As one reader pointed out, back in the 1965 when the 5060A was
> developed,
> >> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I
> >> worked on the 5061B.
> >>
> >>
> >> From: time-nuts  On Behalf Of Rice,
> >> Hugh (IPH Writing Systems)
> >> Sent: Saturday, February 23, 2019 8:49 PM
> >> To: time-nuts@lists.febo.com
> >> Subject: [time-nuts] HP Stories: An architectural view of the HP
> >> 5060/5061 and awkward oscillator adjustments.
> >>
> >> Hello Time-Nuts,
> >>
> >>  Stuff deleted .
> >>
> >>
> >> It was fantastically reliable. Only linear power circuits, with robust
> >> heat sinking of all power devices. The legendary Len Cutler ban on
> aluminum
> >> electrolytic capacitors. 5060s were still in use in 1985, after 20
> years of
> >> constant operation. Likewise, 5061As were abundant in time standards for
> >> 25+ years until they were replaced by the 5071A in the 1990s.
> >>
> >> ___
> >> time-nuts mailing list -- time-nuts@lists.febo.com
> >> To unsubscribe, go to
> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >> and follow the instructions there.
> >>
> >
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: Cesium Standards on Subs and Sperry

[djl]

Love milspec stories!   Always reminds me of some of my favorite quotes:

 “Mechanical rules are never a substitute for clarity of thought.” -- 
Brian Kernighan

". . .  rules are a substitute for thought . . ." -- Robert Gunning
 "A foolish consistency is the hobgoblin of little minds . . ." --  R.W. 
Emerson


Don

On 2019-02-24 06:37, Rice, Hugh (IPH Writing Systems) wrote:

While HP wasn't a direct defense contractor, we did sell a lot of test
equipment to defense contractors.The big American submarines had a
Cesium Standard or two as part of their instrumentation systems.I
know little about the application, but heard it was part of the
communication and/or navigation systems.Maybe some of you have
experience with this, and can add to the story.

None the less, Sperry corporation was a sub-contractor into the
greater DOD eco-system, and integrated the 5061A into some larger
system they sold to the submarine builders.Sperry was a "real"
defense contractor, and had to live by all the DOD rules.There
were a number of defense contractors in Silicon Valley, with Lockheed
Missiles and Space Company being perhaps the largest employer in the
area.   Both my father, and my wife's father were engineers at LSMC
for their careers.   We used to joke at my High School that
"everyone's dad worked for Lockheed."Thus, DOD companies were not
a foreign concept to me.   But they way the DOD procurement process
worked was very unlike how HP worked and interfaced with our
commercial customers.

Sperry wanted to turn HP into defense supplier when they purchased
5061A's from us.   First, they had their special "Sperry Blue" paint
job.   Our sheet metal and paint shops had to custom build the
cosmetic parts for Sperry in a lovely baby blue color.Next, they
wanted to make sure what was purchased was exactly what was specified.
 EXACTLY.   The technique to enforce this was to document and inspect
everything.A special Sperry material list was created, with every
resistor, screw and wire listed.   HP part numbers, approved
suppliers, and supplier part numbers, for everything.   It turns out
there are a lot of components in a 5061A. Sperry would then insist
that HP segregate all the components that were going into their sacred
5061As, and have our incoming quality department inspect every single
tiny part, to ensure it was the correct component, coming from proper
suppliers.   The attention to detail was both impressive and
maddening.This was way outside our normal
 manufacturing processes, and a huge hassle.

The representatives from Sperry were from a different planet than HP
people.This part of Sperry had it's headquarters in the NYC area,
and the lead representative was like a movie character from a God
Father movie.   Short, plump, arrogant, Italian, in charge.  He was
THE MAN, and expected to be treated as such.  He was cordial on the
surface, but was unmovable when trying to negotiate what we though
would be a sensible compromise of some kind. To him, change, any
change, was bad.Because if anything ever happened, for the rest of
human history, that could be traced back to a change he allowed, he
would be held accountable.He wanted to be held accountable for
buying 8  Cesium Standards, not for adding risk to that purchase.
He had a young assistant to grind through all the details.   This guy
was about 30, and knew his role in the game.   There were procurement
rules his company must follow, and his job was to make sure every
detail got done.  EVERY DETAIL.He br
 ought exactly zero judgment or critical thinking to the process.

Mr. Mafia man told a story about why not changing things was so
important.  As I recall, Sperry made some kind of targeting system for
artillery, probably dating back to WWII, and a vendor had upgraded the
insulation on some wiring from a fabric weave to more modern extruded
plastic insulation.For some reason this led to a failure.  (Likely
heat related).   This was used as indisputable proof that even the
most innocent looking changes can cause a problem, problems are the
enemy, and change was it's root cause.

And then HP invented the 5061B, and changed a bunch of stuff from the
5061A.   Sperry had a contract that required another batch of HP
Cesium Standards, and  wanted nothing to do with the 5061B.   They had
made several previous purchases of 5061As, and their overall system
had not changed, and they didn't want the Cesium Standard to Change
either.Since I was the 5061B guy, and young and expendable and
ignorant (never had worked with Sperry before), I was assigned the
task of getting Sperry happy with the 5061B.I remember Jeanie
Young, an energetic women from our marketing department being the lead
contact with Sperry on business stuff (fuss with contracts, and be
responsible for the wine-and-dine aspects), as I did the
"engineering".

I think our basic position is that not only we don't make the 5061A
any more, we COULD 

Re: [time-nuts] Jackson Labs Phase Station

[John Miles]

> Hi all,
> I have not found details about the new product of the Jackson Labs, the
> Phase Station.
> The new driver is now added to the  V1.32 Beta version of Timelab.
> It seems to be an alternative of Timepod.
> Can anyone anticipate something?

The PhaseStation 53100A can be thought of as the spiritual successor to the
TimePod 5330A, currently wrapping up development.  It has similar
capabilities as the 5330A (phase noise, AM noise, phase/freq-difference
charts, ADEV and so forth) plus a few additional features including support
for VHF sources through 200 MHz.  

Right now the hardware is performing well in 5/10 MHz applications, so I'm
focusing on debugging and general optimization at the higher frequencies.
The V1.32 beta version of TimeLab is mostly for 53100A development support,
but also to support preproduction units for evaluation and testing at
customer sites where its current capabilities (meaning HF measurements) are
useful.  

Most TimeLab users won't need to bother upgrading to the V1.32 beta release,
since the only real differences from V1.31 are geared towards 53100A
support.  We'll have more info later as we get closer to production. 

-- john
MDLLC/Jackson Labs



___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Poul-Henning Kamp]

In message 
, Adrian Godwin writes:

>I think I've had as many shorted-out tants as dried-out electrolytics.

I doubt Len worried about dry-out, he was worried about shorts.

A lot of people failed, and still fail, to realize that tube-voltage
electrolytics are an entirely different kettle of fish from
semiconductor-voltage electrolytics.

The crucial difference is that in an unpowered high-voltage 'lyt the
oxidelayer will degenerate over time, and then when you apply power
again, it shorts through and bad things happen.

This is where the "Ramp up the voltage with a variac" thing comes from,

As you raise the voltage slowly, the oxide layer has time to reform
to the required thickness for the the normal operating voltage[1].

Low voltage 'lyts do not have this problem, because the final layer
of oxide is not going anywhere in benign chemical environments.

Before that knowledge had rippled out through the EE community,
'lyts had got a reputation for being unreliable and prone to
"unprovoked" venting and/or explosion, in particular in the
"grew up with tubes" generation of EEs.

There is no precise voltage to separate "high" and "low" voltage,
it depends on the chemical formulation of the electrolyte, but as
a rule of thumb 'lyts exposed to less than 50V do not short when
powered up.

Any 'lyt with a higher operating voltage should be ramped up slowly,
if it has been without power for more than a year or two.

Where this gets tricky is badly designed switch-modes, where the
control circuit fails to start or latches up.

Best advice there is to use a dummy load rather than Unobtanium if
you can, or try find a way to disable the control circuit
until you have ramped the 'lyt up.

Drying out is an entirely different failure mode, caused mainly by
high temperatures, either from ambient (Tubes) or self heating due
to ripple-current in the ESR.

Poul-Henning

[1] I have tried to find out how slow one needs to ramp.
People with chemical clue tell me that electrochemistry, is
a matter of seconds.  I round up to minutes.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: Cesium Standards on Subs and Sperry

[jimlux]

On 2/24/19 5:37 AM, Rice, Hugh (IPH Writing Systems) wrote:

While HP wasn't a direct defense contractor, we did sell a lot of test 
equipment to defense contractors.The big American submarines had a Cesium 
Standard or two as part of their instrumentation systems.I know little 
about the application, but heard it was part of the communication and/or 
navigation systems.Maybe some of you have experience with this, and can add 
to the story.

None the less, Sperry corporation was a sub-contractor into the greater DOD eco-system, and 
integrated the 5061A into some larger system they sold to the submarine builders.Sperry was a 
"real" defense contractor, and had to live by all the DOD rules.There were a number 
of defense contractors in Silicon Valley, with Lockheed Missiles and Space Company being perhaps 
the largest employer in the area.   Both my father, and my wife's father were engineers at LSMC for 
their careers.   We used to joke at my High School that "everyone's dad worked for 
Lockheed."Thus, DOD companies were not a foreign concept to me.   But they way the DOD 
procurement process worked was very unlike how HP worked and interfaced with our commercial 
customers.



Yes, and this how you wind up with $600 hammers/toilet seats/aircraft 
coffee makers.


It afflicts the space business too - We call it "heritage" - for 
instance, you're designing a new spacecraft.  A subsystem, or box, or 
anything, that already exists, you know the mass and power of, so you 
can put it into your "Master Equipment List" (MEL) and only add 5% 
margin.  Something new, might have to have significantly more margin, 
maybe 25% or 30%.


But on most spacecraft  you're severely mass and power constrained, 
because the rolled up budgets for those are often set by "what did the 
last one do"  - or maybe you've got the max mass you can send to Mars on 
the rockets that are available.


Even if the new design is infinitely superior in performance, the 
additional risk of "something new" gets in the way.  Most NASA 
Announcements of Opportunity (AO, similar to a RFP) say "Technology 
shall be at TRL 6, or a plan shall be presented to insure that it will 
reach TRL 6 by Preliminary Design Review" TRL 6 = "demonstrated in a 
relevant environment" - basically, you've built the box and run it 
through thermal vacuum and vibe testing, but maybe you used parts that 
aren't screened.


Notwithstanding that the parts list for that heritage box includes parts 
that are no longer available, or that have insanely high minimum order 
quantity (the mfrs way of telling you, "use another part, but if you 
insist") - that's what gets designed in.


And as Hugh points out, there's a whole team of people who look for ANY 
discrepancy from the original design. And those people aren't empowered 
to make judgement calls about whether the change is good or bad - it's a 
change.


One can, in fact, get waivers.  Or, you can, if you have sufficient 
budget (Hah!) you could say that your primary design alternative leading 
up to PDR is to use the Heritage Unit, but you'll be developing a new 
one to replace it, and if it's ready, you can pitch it at PDR (or maybe 
CDR).


However, it might be easier (from a risk assessment, budget, and 
schedule standpoint) to just use the old design. That is, the extra pain 
and cost for finding obsolete parts (Rochester Electronics, "the leader 
in the trailing edge of electronics" is your friend) is less than the 
pain and cost of getting waivers for a new design.




___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: Cesium Standards on Subs and Sperry

[Richard (Rick) Karlquist]

On 2/24/2019 5:37 AM, Rice, Hugh (IPH Writing Systems) wrote:
While HP wasn't a direct defense contractor, we did sell a lot of test equipment to defense contractors.The big American submarines had a Cesium Standard or two as part of their instrumentation systems.I know little about the application, but heard it was part of the communication and/or navigation systems.Maybe some of you have experience with this, and can add 


One of my jobs between college and HP was with Boeing.
The military half of Boeing, not the airplane manufacturer.
The head manager of test equipment told me that the
default test equipment vendor was HP.  They only looked
at HP competitors in the event that HP simply didn't
even make what was required.  Who knew I would someday
work for HP for 35 years?  My old Boeing buddies would
have been proud; they all told me to leave.

Part of the HP orientation process about "The HP Way"
covered how HP did a lot of military contracts during WWII.
When the war ended, so did the contracts and the post
war recession started.  Dave had lay off a bunch of
workers.  He stated that HP would never again get
involved (at least in any serious way) with government
contracts because "We don't want to be a hire and fire
outfit".

Boeing, of course, was exactly that.

Rick

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Clock project request from IEEE

[Mark Sims]

I've looked at automatically determining the local time zone offset from UTC a 
few times... and always considered jumping off a cliff to be a better option.   
Huge, unreliable, always changing boundary data bases... local anomalies due to 
political reasons...  lotsa really boring testing and verification, etc.   So, 
Heather just lets the user tell it what the local time zone and daylight 
savings time rule is.  Ahhh, the sweet, sweet bliss of shuffling off a complex, 
error prone something onto the user... 
 
I did consider (if the user did not specify the time zone) to default it to 
assume every 15 degrees longitude was a 1 hour time zone.   Sort of like 
Heather's algorithmic guess of the current leap second count (GPS-UTC time 
offset value) if the receiver / input device does not send a UTC offset 
value... it's not always right but is better than nothing.  If it's not right 
the user can specify the correct value.  Guessed values are shown on the screen 
in red,  user specified values are shown in yellow,  device supplied values are 
shown in white.  Speaking of which,  aren't we getting close to needing a new 
leapsecond... it's been a while since the last one?



> Maybe Lady Heather could use that to find local time (if
she doesn't already do it).

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] GN-GGB0710 GNSS Antenna

[Ben Hall]

Good evening all,

After almost a month in transit, my GN-GGB0710 GNSS antenna arrived from 
the auction site "we all know and love."  ;)


Unit was not tapped to a proper 5/8"-11 TPI thread.  A standard 5/8-11 
bolt went in maybe two full threads.  I modified an old tap I had in the 
drawer into a 5/8"-11 bottom tap and cleaned it up.  Best I can tell, 
the thread cut by the manufacturer was slightly tapered.


I wasn't thrilled with the seal around the edge.  Because it's flat, 
some water might wick in, so I ran a quick bead of seal around both the 
top and bottom end of the blue rubber seal.


Unit seems to work well.  It's not mounted to the top of my antenna 
pole, about 16 feet up from the ground, where it can see a pretty much 
unobstructed view of the sky.  All the GPS units on it thru the splitter 
are getting excellent signal.


Now to wait until uBlox releases the ZED-F9T dev board.  I did get a 
response back from uBlox sales to my work e-mail address (which is a 
very large organization) saying it's still in development with a target 
release date of May or so...


thanks much and 73,
ben

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Adrian Godwin]

Just to sneak that back on-topic .. the most recent tant failure I had was
in a KS-24361. It was after the dc-dc converter so it didn't look like a
short to the input - it just increased the current draw. Running off a
cheap laptop supply, which overheated and melted instead of shutting down
or blowing a fuse. It took out the breaker for the whole ring main.

Replacing the tant was the only action necessary for the KS-24361 itself.
No other internal damage.

On Sun, Feb 24, 2019 at 2:02 PM Adrian Godwin  wrote:

> I think I've had as many shorted-out tants as dried-out electrolytics.
> It's just that they appear in 80s gear instead of 60s. Then there was the
> flood of high-esr electrolytics from when - early 2000s ?
>
>
> On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) <
> hugh.r...@hp.com> wrote:
>
>> Several people have asked about the Len Cutler ban on Aluminum
>> Electrolytic Capacitors in HP Frequency Standards.   Rick Karlquist could
>> shed more light on this too.   The legend of the ban was passed along to
>> me, perhaps by Lou Mueller, who liked to tell stories of the old days.   In
>> 1985, we were not taking the ban literally.   For example, the 2400uF main
>> power supply filter capacitor was AL-Electrolytic, as were a few other
>> smaller capacitors on the power regulator.   I sidestepped the capacitor
>> issues on my simple battery charger by not having a filter cap after the
>> transformer/full-wave-bridge, and just used 120 Hz pulses, since the
>> battery didn't care about DC vs. pulsed DC.   (I thought it was pretty
>> clever to leave out the main filter cap.) Where possible, Tantalum
>> capacitors were used.For the few places where AL caps were used, they
>> were heavily de-rated, operating at 50% of rated voltage for example.
>>
>> As one reader pointed out, back in the 1965 when the 5060A was developed,
>> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I
>> worked on the 5061B.
>>
>>
>> From: time-nuts  On Behalf Of Rice,
>> Hugh (IPH Writing Systems)
>> Sent: Saturday, February 23, 2019 8:49 PM
>> To: time-nuts@lists.febo.com
>> Subject: [time-nuts] HP Stories: An architectural view of the HP
>> 5060/5061 and awkward oscillator adjustments.
>>
>> Hello Time-Nuts,
>>
>>  Stuff deleted .
>>
>>
>> It was fantastically reliable. Only linear power circuits, with robust
>> heat sinking of all power devices. The legendary Len Cutler ban on aluminum
>> electrolytic capacitors. 5060s were still in use in 1985, after 20 years of
>> constant operation. Likewise, 5061As were abundant in time standards for
>> 25+ years until they were replaced by the 5071A in the 1990s.
>>
>> ___
>> time-nuts mailing list -- time-nuts@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Adrian Godwin]

I think I've had as many shorted-out tants as dried-out electrolytics. It's
just that they appear in 80s gear instead of 60s. Then there was the flood
of high-esr electrolytics from when - early 2000s ?


On Sun, Feb 24, 2019 at 1:10 PM Rice, Hugh (IPH Writing Systems) <
hugh.r...@hp.com> wrote:

> Several people have asked about the Len Cutler ban on Aluminum
> Electrolytic Capacitors in HP Frequency Standards.   Rick Karlquist could
> shed more light on this too.   The legend of the ban was passed along to
> me, perhaps by Lou Mueller, who liked to tell stories of the old days.   In
> 1985, we were not taking the ban literally.   For example, the 2400uF main
> power supply filter capacitor was AL-Electrolytic, as were a few other
> smaller capacitors on the power regulator.   I sidestepped the capacitor
> issues on my simple battery charger by not having a filter cap after the
> transformer/full-wave-bridge, and just used 120 Hz pulses, since the
> battery didn't care about DC vs. pulsed DC.   (I thought it was pretty
> clever to leave out the main filter cap.) Where possible, Tantalum
> capacitors were used.For the few places where AL caps were used, they
> were heavily de-rated, operating at 50% of rated voltage for example.
>
> As one reader pointed out, back in the 1965 when the 5060A was developed,
> AL-Electrolytic caps were likely a lot less reliable than in 1985 when I
> worked on the 5061B.
>
>
> From: time-nuts  On Behalf Of Rice,
> Hugh (IPH Writing Systems)
> Sent: Saturday, February 23, 2019 8:49 PM
> To: time-nuts@lists.febo.com
> Subject: [time-nuts] HP Stories: An architectural view of the HP 5060/5061
> and awkward oscillator adjustments.
>
> Hello Time-Nuts,
>
>  Stuff deleted .
>
>
> It was fantastically reliable. Only linear power circuits, with robust
> heat sinking of all power devices. The legendary Len Cutler ban on aluminum
> electrolytic capacitors. 5060s were still in use in 1985, after 20 years of
> constant operation. Likewise, 5061As were abundant in time standards for
> 25+ years until they were replaced by the 5071A in the 1990s.
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Richard (Rick) Karlquist]

On 2/24/2019 4:02 AM, Rice, Hugh (IPH Writing Systems) wrote:
Several people have asked about the Len Cutler ban on Aluminum Electrolytic Capacitors in HP Frequency Standards.   Rick Karlquist could shed more light on this too.   The legend of the ban was passed along to me, perhaps by Lou Mueller, who liked to tell stories of the old days.   In 1985, we were not taking the ban literally.   For example, the 2400uF main power supply filter capacitor was AL-Electrolytic, as were a few other smaller capacitors on the power regulator.   I sidestepped the capacitor issues on my simple battery charger by not having a filter cap after 

This discussion is the first I had heard of a ban on aluminum
electrolytics in the Cs standards.  All I know is that in
the early stages of the 5071 project, Len proposed using a
tantalum capacitor for the power supply filter.  None of
the members of the project time were aware of the history
of this, and we objected.  I vaguely remember the cap would
have cost something like $50.  Len eventually backed down on
that idea and in any event, the question became moot when
we went with the Vicor power modules, which surely had
aluminum caps at the front end for energy storage.  The
Vicor's seemed very avante garde at the time, but in practice
they worked very well and were very reliable.

A related thing happened in other instruments.  Previously,
power supplies in instruments were built from scratch,
and there were various reliability dictates, like derating
capacitors, etc.  Then it started to make sense to purchase
off line switchers.  These violated all sorts of "rules",
yet they got a pass and became SOP.  The R lab manager
at Santa Clara Division famously said "no customer chooses
HP products because they have great power supplies."

Rick

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Clock project request from IEEE

[Magnus Danielson]

Hi,

Yes, that would be a cool feature, but would come with complexity that 
would be best outside of such a core system. With enough interface, you 
could let an off-system configuration tool do that and then setup the 
time-zone rules. Conversion from position to time-zone and then look up 
the time-zone data is conceptually no hard, but clearly not a handful of 
lines of code in small MCUs. The benefit of keeping that as separate 
system is that the core functionality can be tested and well understood, 
and such add-ons does not need to be run very often or be part of the 
real-time, so then they should be run separate. The important thing is 
that the core system is built such that it allows this add-on later. So, 
the off-line system should be able to get the time and positiion and 
then be able to set the time-zone offsets and cut-over rules. The later 
may actually at first be forced to be just cut-over time for new offset, 
but maybe it is simple enough to express the full rules with a handful 
of parameters.


As always, the devil is in the details, and the system architect needs 
to make the core system as simple as possible while flexible enough, 
although fairly stupid. More intelligent adaptation can then be added. 
Keeping things robust and testable has challenges.


This is also the challenge of doing designs, the creeping featurism. 
It's somewhat of an art form to balance simple enough and providing ways 
to support cool features later.


Anyway, there would be many pieces of a beast like this that I would 
priority first. Once a core functionality works, only then features can 
be added. One of the keys to succses is clear monitoring of error 
conditions, which helps already in the early integration to figure out 
issues quickly.


Cheers,
Magnus

On 2019-02-24 12:51, John Reid wrote:

I would love something that gave a list of options set from the location in the 
NMEA string.

Such as this time zone or different, with nearby zones first; DST on/off. Could 
get to be a significant effort very quickly, but maybe there are xml files out 
there that would make it easy?


John


On 24/2/19 4:00 am, 
time-nuts-requ...@lists.febo.com wrote:

Message: 4
Date: Sat, 23 Feb 2019 15:47:11 +0100
From: Magnus Danielson 
To: time-nuts@lists.febo.com, Glenn Zorpette 

Subject: Re: [time-nuts] Clock project request from IEEE
Message-ID: 
<4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se>
Content-Type: text/plain; charset=utf-8; format=flowed

Hi,

On 2019-02-22 19:31, Tom Van Baak wrote:


I received the following email and permission to post it on time-nuts:



Hello,

I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum.
I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of
using it to build a very precise clock that I would share with Spectrum's 
readers.

I would like to partner with an engineer with experience in digital clocks, who
would be credited as co-author on this project.

Can you suggest someone who might be interested in this project? I would be
much obliged if you had some suggestions.

Kind regards,
-Glenn


Glenn's contact info is:



Glenn Zorpette
g.zorpe...@ieee.org


You can just imagine all the many ways the project could head. Send Glenn a 
note if you want to help. Or post here if you have suggestions.


I think we should contribute with our wealth of knowledge.

There is several aspects that would form a digital clock. Many of the
pieces is readily available, but we rarely put them together in a system.

The TAPR Pulse Puppy is a nice little thing. I don't have one myself,
but I can see how it could be useful, so thanks for making it aware of it.

The Pulse Puppy obviously solves two things, one having a crystal
oscillator and output a divided down signal.

To build a clock system we should consider from where we get the time,
and how we maintain it. These days the answer will be a GPS module which
output it's time in serial form, such as the NMEA output format. That
will give us the date and time of day that the PPS output represents, in
UTC, and then the PPS pulse would give us the phase. The upside of this
is that we get the date and time, but we don't get it adjusted to our
local time-zone, we also depends strictly on the presence of the GPS
signal. Also, the PPS pulse varies due to GPS properties as well as the
clock-pulse assignment causing the sawtooth error.

As widely known in the group, sawtooth error corrections is available
over the serial interface from several receivers. Further, to make a
more quiet source you want to filter out some of the GPS noise. This is
where the Pulse Puppy can come at handy, as you can steer the oscillator
with the GPS PPS pulse and sawtooth corrections, measure the
time-difference and 

[time-nuts] Jackson Labs Phase Station

[tim...@timeok.it]

Hi all,
I have not found details about the new product of the Jackson Labs, the Phase 
Station.
The new driver is now added to the  V1.32 Beta version of Timelab.
It seems to be an alternative of Timepod.
Can anyone anticipate something?
Luciano
www.timeok.it
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Clock project request from IEEE

[Adrian Godwin]

This python package appears to do what you want
https://github.com/MrMinimal64/timezonefinder

So a small linux distribution on a raspberry pi zero (given that that also
has the usual TZ database, if it's not all in the timezonebuilder data)
would do the job. Maybe Lady Heather could use that to find local time (if
she doesn't already do it).

I did read Glenn's request as being based on the  TCXO in the pulse puppy
rather than GPS, but I can see the pulse puppy is wired for use in a
disciplined system. So I'm not sure if he's looking for GPS clock or just a
counter driven by a good quality oscillator.

Either way, I think most of the elements are available off the shelf (or
off the net).

But what's a suitable display ? He does mention digital, so presumably
isn't thinking of a dial. Nixies and other technologies are perhaps too
whimsical. Maybe LEDs in a Back To The Future setting are too. Current
technology fashion would suggest OLED
or e-ink.


On Sun, Feb 24, 2019 at 1:10 PM John Reid  wrote:

> I would love something that gave a list of options set from the location
> in the NMEA string.
>
> Such as this time zone or different, with nearby zones first; DST on/off.
> Could get to be a significant effort very quickly, but maybe there are xml
> files out there that would make it easy?
>
>
> John
>
>
> On 24/2/19 4:00 am, time-nuts-requ...@lists.febo.com time-nuts-requ...@lists.febo.com> wrote:
>
> Message: 4
> Date: Sat, 23 Feb 2019 15:47:11 +0100
> From: Magnus Danielson 
> To: time-nuts@lists.febo.com, Glenn
> Zorpette 
> Subject: Re: [time-nuts] Clock project request from IEEE
> Message-ID: <4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se> 4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hi,
>
> On 2019-02-22 19:31, Tom Van Baak wrote:
>
>
> I received the following email and permission to post it on time-nuts:
>
>
>
> Hello,
>
> I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum.
> I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of
> using it to build a very precise clock that I would share with Spectrum's
> readers.
>
> I would like to partner with an engineer with experience in digital
> clocks, who
> would be credited as co-author on this project.
>
> Can you suggest someone who might be interested in this project? I would be
> much obliged if you had some suggestions.
>
> Kind regards,
> -Glenn
>
>
> Glenn's contact info is:
>
>
>
> Glenn Zorpette
> g.zorpe...@ieee.org
>
>
> You can just imagine all the many ways the project could head. Send Glenn
> a note if you want to help. Or post here if you have suggestions.
>
>
> I think we should contribute with our wealth of knowledge.
>
> There is several aspects that would form a digital clock. Many of the
> pieces is readily available, but we rarely put them together in a system.
>
> The TAPR Pulse Puppy is a nice little thing. I don't have one myself,
> but I can see how it could be useful, so thanks for making it aware of it.
>
> The Pulse Puppy obviously solves two things, one having a crystal
> oscillator and output a divided down signal.
>
> To build a clock system we should consider from where we get the time,
> and how we maintain it. These days the answer will be a GPS module which
> output it's time in serial form, such as the NMEA output format. That
> will give us the date and time of day that the PPS output represents, in
> UTC, and then the PPS pulse would give us the phase. The upside of this
> is that we get the date and time, but we don't get it adjusted to our
> local time-zone, we also depends strictly on the presence of the GPS
> signal. Also, the PPS pulse varies due to GPS properties as well as the
> clock-pulse assignment causing the sawtooth error.
>
> As widely known in the group, sawtooth error corrections is available
> over the serial interface from several receivers. Further, to make a
> more quiet source you want to filter out some of the GPS noise. This is
> where the Pulse Puppy can come at handy, as you can steer the oscillator
> with the GPS PPS pulse and sawtooth corrections, measure the
> time-difference and then create a servo-loop to steer the oscillators
> frequency and phase to an average of that from the GPS. The produced PPS
> pulse can be made more quiet for the short term stability while
> following the GPS long-term. In that regard we can filter and get a more
> stable clock.
>
> Another drawback may be that we loose GPS signal. There are many
> possible sources for that, but regardless which source, one needs to
> cover up the loss. This you do with hold-over, which is the secondary
> function of an oscillator. During hold-over the steering of the
> oscillator should be such that it minimize the time-error of a properly
> operating time and that of the clock in the oscillator. This is 

[time-nuts] HP Stories: Cesium Standards on Subs and Sperry

[Rice, Hugh (IPH Writing Systems)]

While HP wasn't a direct defense contractor, we did sell a lot of test 
equipment to defense contractors.The big American submarines had a Cesium 
Standard or two as part of their instrumentation systems.I know little 
about the application, but heard it was part of the communication and/or 
navigation systems.Maybe some of you have experience with this, and can add 
to the story.

None the less, Sperry corporation was a sub-contractor into the greater DOD 
eco-system, and integrated the 5061A into some larger system they sold to the 
submarine builders.Sperry was a "real" defense contractor, and had to live 
by all the DOD rules.There were a number of defense contractors in Silicon 
Valley, with Lockheed Missiles and Space Company being perhaps the largest 
employer in the area.   Both my father, and my wife's father were engineers at 
LSMC for their careers.   We used to joke at my High School that "everyone's 
dad worked for Lockheed."Thus, DOD companies were not a foreign concept to 
me.   But they way the DOD procurement process worked was very unlike how HP 
worked and interfaced with our commercial customers.

Sperry wanted to turn HP into defense supplier when they purchased 5061A's from 
us.   First, they had their special "Sperry Blue" paint job.   Our sheet metal 
and paint shops had to custom build the cosmetic parts for Sperry in a lovely 
baby blue color.Next, they wanted to make sure what was purchased was 
exactly what was specified.  EXACTLY.   The technique to enforce this was to 
document and inspect everything.A special Sperry material list was created, 
with every resistor, screw and wire listed.   HP part numbers, approved 
suppliers, and supplier part numbers, for everything.   It turns out there are 
a lot of components in a 5061A. Sperry would then insist that HP segregate 
all the components that were going into their sacred 5061As, and have our 
incoming quality department inspect every single tiny part, to ensure it was 
the correct component, coming from proper suppliers.   The attention to detail 
was both impressive and maddening.This was way outside our normal 
manufacturing processes, and a huge hassle.

The representatives from Sperry were from a different planet than HP people.
This part of Sperry had it's headquarters in the NYC area, and the lead 
representative was like a movie character from a God Father movie.   Short, 
plump, arrogant, Italian, in charge.  He was THE MAN, and expected to be 
treated as such.  He was cordial on the surface, but was unmovable when trying 
to negotiate what we though would be a sensible compromise of some kind. To 
him, change, any change, was bad.Because if anything ever happened, for the 
rest of human history, that could be traced back to a change he allowed, he 
would be held accountable.He wanted to be held accountable for buying 8  
Cesium Standards, not for adding risk to that purchase.He had a young 
assistant to grind through all the details.   This guy was about 30, and knew 
his role in the game.   There were procurement rules his company must follow, 
and his job was to make sure every detail got done.  EVERY DETAIL.He 
brought exactly zero judgment or critical thinking to the process.

Mr. Mafia man told a story about why not changing things was so important.  As 
I recall, Sperry made some kind of targeting system for artillery, probably 
dating back to WWII, and a vendor had upgraded the insulation on some wiring 
from a fabric weave to more modern extruded plastic insulation.For some 
reason this led to a failure.  (Likely heat related).   This was used as 
indisputable proof that even the most innocent looking changes can cause a 
problem, problems are the enemy, and change was it's root cause.

And then HP invented the 5061B, and changed a bunch of stuff from the 5061A.   
Sperry had a contract that required another batch of HP Cesium Standards, and  
wanted nothing to do with the 5061B.   They had made several previous purchases 
of 5061As, and their overall system had not changed, and they didn't want the 
Cesium Standard to Change either.Since I was the 5061B guy, and young and 
expendable and ignorant (never had worked with Sperry before), I was assigned 
the task of getting Sperry happy with the 5061B.I remember Jeanie Young, an 
energetic women from our marketing department being the lead contact with 
Sperry on business stuff (fuss with contracts, and be responsible for the 
wine-and-dine aspects), as I did the "engineering".

I think our basic position is that not only we don't make the 5061A any more, 
we COULD NOT make a 5061A.   Either take the 5061B, or nothing.   While the 
5061B wasn't exactly the 5061A, nothing else available in the world was even 
close.   They were stuck with us and the hated 5061B and all its changes.
One of the even more annoying aspects of the 5061B is that we had gone thorough 
many of the systems, 

Re: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and awkward oscillator adjustments.

[Rice, Hugh (IPH Writing Systems)]

Several people have asked about the Len Cutler ban on Aluminum Electrolytic 
Capacitors in HP Frequency Standards.   Rick Karlquist could shed more light on 
this too.   The legend of the ban was passed along to me, perhaps by Lou 
Mueller, who liked to tell stories of the old days.   In 1985, we were not 
taking the ban literally.   For example, the 2400uF main power supply filter 
capacitor was AL-Electrolytic, as were a few other smaller capacitors on the 
power regulator.   I sidestepped the capacitor issues on my simple battery 
charger by not having a filter cap after the transformer/full-wave-bridge, and 
just used 120 Hz pulses, since the battery didn't care about DC vs. pulsed DC.  
 (I thought it was pretty clever to leave out the main filter cap.) Where 
possible, Tantalum capacitors were used.For the few places where AL caps 
were used, they were heavily de-rated, operating at 50% of rated voltage for 
example.

As one reader pointed out, back in the 1965 when the 5060A was developed, 
AL-Electrolytic caps were likely a lot less reliable than in 1985 when I worked 
on the 5061B.


From: time-nuts  On Behalf Of Rice, Hugh (IPH 
Writing Systems)
Sent: Saturday, February 23, 2019 8:49 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] HP Stories: An architectural view of the HP 5060/5061 and 
awkward oscillator adjustments.

Hello Time-Nuts,

 Stuff deleted .


It was fantastically reliable. Only linear power circuits, with robust heat 
sinking of all power devices. The legendary Len Cutler ban on aluminum 
electrolytic capacitors. 5060s were still in use in 1985, after 20 years of 
constant operation. Likewise, 5061As were abundant in time standards for 25+ 
years until they were replaced by the 5071A in the 1990s.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Clock project request from IEEE

[John Reid]

I would love something that gave a list of options set from the location in the 
NMEA string.

Such as this time zone or different, with nearby zones first; DST on/off. Could 
get to be a significant effort very quickly, but maybe there are xml files out 
there that would make it easy?


John


On 24/2/19 4:00 am, 
time-nuts-requ...@lists.febo.com wrote:

Message: 4
Date: Sat, 23 Feb 2019 15:47:11 +0100
From: Magnus Danielson 
To: time-nuts@lists.febo.com, Glenn Zorpette 

Subject: Re: [time-nuts] Clock project request from IEEE
Message-ID: 
<4d54789a-e3eb-46f6-0d0d-523954c41...@rubidium.se>
Content-Type: text/plain; charset=utf-8; format=flowed

Hi,

On 2019-02-22 19:31, Tom Van Baak wrote:


I received the following email and permission to post it on time-nuts:



Hello,

I am the executive editor of the IEEE's flagship magazine, IEEE Spectrum.
I recently acquired a TAPR "Pulse Puppy" and I am intrigued by the idea of
using it to build a very precise clock that I would share with Spectrum's 
readers.

I would like to partner with an engineer with experience in digital clocks, who
would be credited as co-author on this project.

Can you suggest someone who might be interested in this project? I would be
much obliged if you had some suggestions.

Kind regards,
-Glenn


Glenn's contact info is:



Glenn Zorpette
g.zorpe...@ieee.org


You can just imagine all the many ways the project could head. Send Glenn a 
note if you want to help. Or post here if you have suggestions.


I think we should contribute with our wealth of knowledge.

There is several aspects that would form a digital clock. Many of the
pieces is readily available, but we rarely put them together in a system.

The TAPR Pulse Puppy is a nice little thing. I don't have one myself,
but I can see how it could be useful, so thanks for making it aware of it.

The Pulse Puppy obviously solves two things, one having a crystal
oscillator and output a divided down signal.

To build a clock system we should consider from where we get the time,
and how we maintain it. These days the answer will be a GPS module which
output it's time in serial form, such as the NMEA output format. That
will give us the date and time of day that the PPS output represents, in
UTC, and then the PPS pulse would give us the phase. The upside of this
is that we get the date and time, but we don't get it adjusted to our
local time-zone, we also depends strictly on the presence of the GPS
signal. Also, the PPS pulse varies due to GPS properties as well as the
clock-pulse assignment causing the sawtooth error.

As widely known in the group, sawtooth error corrections is available
over the serial interface from several receivers. Further, to make a
more quiet source you want to filter out some of the GPS noise. This is
where the Pulse Puppy can come at handy, as you can steer the oscillator
with the GPS PPS pulse and sawtooth corrections, measure the
time-difference and then create a servo-loop to steer the oscillators
frequency and phase to an average of that from the GPS. The produced PPS
pulse can be made more quiet for the short term stability while
following the GPS long-term. In that regard we can filter and get a more
stable clock.

Another drawback may be that we loose GPS signal. There are many
possible sources for that, but regardless which source, one needs to
cover up the loss. This you do with hold-over, which is the secondary
function of an oscillator. During hold-over the steering of the
oscillator should be such that it minimize the time-error of a properly
operating time and that of the clock in the oscillator. This is in it's
most trivial form achieved by ensuring that the frequency steering of
the oscillator is maintained as if it was locked to the GPS. The
hold-over properties to a high degree depends on how well the oscillator
is steered, and how stable the oscillator is to start with, but it ends
being a material sport in that you go from TCXO, small OCXO, bigger
OCXO, double-oven OCXO, rubidium clock, cesium clock etc. The GPS module
has a small TCXO, but for these purposes you probably want to have
something better.

The digital clock part would at first look very trivial, it has a simple
clock counter that counts 24 hours, 60 minutes and 60 seconds. OK, so we
need to set this clock. Oh, we might have time-zones. Oh, we might have
shifts to and from daylight savings. Oh, we might have leap-seconds.
Already there we have a little bit of added complexity. Nothing that
can't be handled thought.

Also, we want to set the time from the GPS module, so that would require
us to have a serial link just to get the NMEA data or similar at least.
We probably want to get additional data to be warned about leap-seconds,
get the UTC-GPS offset, GPS week number