Re: [time-nuts] UPS for my time rack

[Bob Benward]

Dave, 
You could use a 120V relay and switch the high capacity battery from its own
charger to the battery pack in the UPS.  When power comes back, the relay
automatically switches the battery out and back to its own charger.

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr.
>>> David Kirkby (Kirkby Microwave Ltd)
>>> Sent: Saturday, October 10, 2015 6:07 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] UPS for my time rack
>>> 
>>> On 10 October 2015 at 14:20, Chris Waldrup  wrote:
>>> 
>>> > Hi,
>>> >
>>> >
>>> > I have decided I'd like to get a UPS to put on the rack containing my
>>> > Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>>> >
>>> 
>>> There's one issue with them that I don't see anyone mention.
>>> 
>>> I was thinking of doing the same a while back, and intended getting a
UPS
>>> and adding a large external battery pack, so if the mains failed late at
night, I
>>> could run the GPS receiver and a few other things overnight, and
consider
>>> starting the generator in the morning.  I contacted a dealer on eBay,
who
>>> specilaises in UPSs. He told me that the smaller units with built in
batteries
>>> will die if you put large external batteries on them.
>>> Essentially the charging circuits are not designed to run as long as
needed to
>>> charge big batteries. Even on ones designed for external batteries,
there's a
>>> recommended limit on the size of them. So if you think you might want to
>>> increase runtime by adding some batteries, buy one designed for that
service.
>>> 
>>> I've had two here which were HP/Compaq 5 kW units. These were different
>>> to the normal, in that the batteries added up to over 300 V, so could
produce
>>> 240 VAC with no need to step it up. Both these blew up on me, for
reasons I
>>> never worked out. The load was never anywhere near 5 kW.
>>> 
>>> Lots of people mention sine wave. Of course, if you keen enough, you
could
>>> make a class A amplifier and sine wave oscillator. The problem is that
the
>>> pure sine wave inverters tend to be very inefficient.
>>> 
>>> As with most things, there are a lot of things to balance - runtime,
cost,
>>> quality of output, audio noise, RFI  etc etc.
>>> 
>>> Dave
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4435/10788 - Release Date:
>>> 10/09/15

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[time-nuts] Rohde & Schwarz GPSDO

[Bob Benward]

 

If anyone is interested, a Rohde & Schwarz GPSDO:

 

 

Rohde & Schwarz GPS RECEIVER ED170MP MEINBERG 2105.5504.00

 

http://www.ebay.com/itm/262081245211?_trksid=p2055119.m1438.l2649
=STRK%3AMEBIDX%3AIT

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Re: [time-nuts] Z3805A firmware?

[Bob Benward]

Not sure if this is the same problem but my Z3801 seems to have the same
problem.  It doesn't run long due to the 10811 crapping out after a hour,
but even leaving it on, the date never seems to update.  It's stuck
somewhere around 1996 (wild guess).

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom
>>> Van Baak
>>> Sent: Tuesday, September 29, 2015 1:41 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Z3805A firmware?
>>> 
>>> David Gravereaux wrote:
>>> > I've had my unit off and in the closet for quite some time, then
>>> > played around with it yesterday.  :GPS:INIT:DATE wasn't taking
>>> > 2015,09,28 and kept returning E-222 "data out of range" and was stuck
>>> > in 1996.  A few power cycles and it got to 2007.  A few more power
>>> > cycles and finally it got it right.
>>> >
>>> > Is this that 1025 week epoch thing?
>>> 
>>> Good detective work. Yes, it sounds like a GPS 2^10 = 1024 WNRO issue,
but
>>> no one else has ever reported this AFAIK, so it's very curious. Thanks
for
>>> posting. Did you check that the NVRAM battery is good? When you measure
>>> the voltage after power-off, see if it decays over a few seconds or
minutes.
>>> 
>>> List -- if it turns out not to be a NVRAM issue, can anyone else with a
Z3805
>>> try to duplicate David's observation?
>>> 
>>> > Anyway, I was wondering about freshening the firmware if possible
>>> > before I go delving into the embedded project of adding on an NTP and
>>> > PTP grandmaster time server with this as the source.
>>> 
>>> 1)  I've never seen firmware updates for the Z38-series. The problem
some
>>> old GPSDO have (like the Datum TS2100 earlier this year) is usually not
in
>>> instrument firmware anyway; it's in the OEM GPS timing receiver board.
>>> 
>>> 2) A decades-old surplus eBay GPSDO like this is good to absolutely
stunning
>>> for home and casual lab use. But I would avoid using them for embedded,
>>> serious, professional, or life-safety applications. Can you tell us more
what
>>> your application is?
>>> 
>>> Thanks,
>>> /tvb
>>> ___
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10728 - Release Date:
>>> 09/29/15

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Re: [time-nuts] Z380XA The saga of the aging 10811

[Bob Benward]

In a few weeks I will be posting another plot.  After the EFC slope drift
reversal from positive to negative, it is now starting to flatten again and
it looks like it will be again reversing and going positive again.  Starting
to look sinusoidal.

Bob


>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of James
>>> Flynn
>>> Sent: Friday, September 25, 2015 10:40 AM
>>> To: time-nuts@febo.com
>>> Subject: Re: [time-nuts] Z380XA The saga of the aging 10811
>>> 
>>> Bob Benward <rbenward@...> writes:
>>> 
>>> >
>>> > Continuing this discussion, I have included a PDF showing the past
>>> 30days of
>>> > EFC.  Amazingly, the drift has reversed direction!  Anyone have any
>>> insights
>>> > into this behavior?  Each data point represents 10 seconds.
>>> >
>>> 
>>> I have found that three things can cause this behavior over a short term
>>> (days) which do not involve failure of the standard itself ( in no
particular
>>> order ):
>>> 
>>> 1) Power supply. Most standards are immune to this but, if your EFC
circuit or
>>> phase detector involves active circuits, it can show up.
>>> 
>>> 2) Grounds. Bad grounds or ground loops, especially those that share
current
>>> with the oven heater can cause unexplained drift. However, these usually
>>> have a diurnal temperature signature unless your set up is very climate
>>> controlled. Screw terminal grounds or connections can "age" and change
>>> things. Best to ahve everything soldered.
>>> 
>>> 3) Cheap components, especially resistors. I recently had this driving
me nuts.
>>> Carbon comp. and the 2 cent metal film resistors have large temperature
>>> coefficients and are even sensitive to humidity. Go for the <10ppm / deg
C
>>> metal film or SMD resistors. Some caps also can be tricky if the circuit
>>> involves large caps.  Leakage is a problem in high impedance circuits
and can
>>> be unpredictable and non-constant.
>>> 
>>> Finally, there is literature that supports resonators can reverse their
ageing
>>> slope. However, this is rare.
>>> 
>>> I hope this helps.  I have been there, scratching my head while the
system
>>> seems to have a mind of its own.
>>> 
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10665 - Release Date:
>>> 09/19/15

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Re: [time-nuts] time-nuts Digest, Vol 134, Issue 23

[Bob Benward]

Hi Dan,
I would love to see your data.  3E-12 is very impressive (I assume an
inferred drift from the EFC counts?).  I am really surprised at the
oscillator turn around, nothing changed in my house or in the setup, so I
was surprised to see the sudden dip.  At first I thought the oscillator was
aging in and settling down.  Now I am curious to see what happens in the
next thirty days.

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dan
>>> Kemppainen
>>> Sent: Wednesday, September 23, 2015 11:02 AM
>>> To: time-nuts@febo.com
>>> Subject: Re: [time-nuts] time-nuts Digest, Vol 134, Issue 23
>>> 
>>> Hi Bob,
>>> 
>>> I have a similar oscillator tied to a GPSDO that another list member is
>>> developing. I have not seen the EFC turn around! That's seems very
unusual.
>>> 
>>> If you are interested, I may be able to give you a plot of my EFC over
the last
>>> ~3000 hours. Pretty boring decay curve, with the oscillator sitting at
around
>>> 3e-12 per day drift. (The oscillator was on for about
>>> 6 months prior to being hooked to the GPSDO...)
>>> 
>>> 
>>> 
>>> Dan
>>> 
>>> 
>>> On 9/23/2015 3:10 AM, time-nuts-requ...@febo.com wrote:
>>> > Date: Tue, 22 Sep 2015 23:49:25 -0400
>>> > From: "Bob Benward"<rbenw...@verizon.net>
>>> 
>>> > Continuing this discussion, I have included a PDF showing the past
>>> > 30days of EFC.  Amazingly, the drift has reversed direction!  Anyone
>>> > have any insights into this behavior?  Each data point represents 10
>>> seconds.
>>> >
>>> > Bob
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10665 - Release Date:
>>> 09/19/15

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Re: [time-nuts] Trimble GPSDO board

[Bob Benward]

Hank,
Thank you!  For some reason I don't have this email.  I looked again, for
the fifth time, and it's just not there.  It may be in my spam folder or my
email rules may have missed placed it. 

I apologize Arthur if I have caused you any grief, and I thank you for your
informative discussion on the RS-232.

Regards,
 Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Hank
>>> Riley via time-nuts
>>> Sent: Monday, September 14, 2015 1:49 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Trimble GPSDO board
>>> 
>>> I sent off-list to Bob, Arthur's August 22 email detailing the RS-
>>> 232information for the Trimble.
>>> Hank
>>> 
>>> ___
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10627 - Release Date:
>>> 09/12/15

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[time-nuts] Trimble GPSDO board

[Bob Benward]

All,

I found my problem, or rather it went away. Even though I probed the base of
the connector with a scope, after jiggling the cable, the output came back.

 

Attached is an infinite persistence scope capture of my Z3805A (blue) vs the
Trimble board (yellow).  Triggering on the Trimble, you can see the Z3805A
moving a total of 205 degrees (+83, -122) relative to the Trimble over a
24hour period. (DS2_quickprint1.bmp)

 

I reset the persistence and triggering on the Z3805A (same colors) and after
1 hour I got about 151degrees of phase shift (DS2_quickprint2.bmp).

Most of the movement is back and forth, overlapping itself several times.  I
am not sure if the drift is repeatable or if there is a random component to
it.

 

Bob

 

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Re: [time-nuts] Z380XA The saga of the aging 10811

[Bob Benward]

Robert,
The drift has slowed down to something around 8xE-10, which is a bit over
the spec of <5E-10.  But this is the single oven, I have not reassembled the
double oven yet.

If the oven regulation was off, I would suspect I would see the EFC go back
and forth a bit, maybe a general trend up, but some retracing would be
expected.  The oven control is an integrator, so unless the offset is very
large compare to the output of the thermistor, a continuously changing
offset voltage will not have a large effect on setpoint.  A crystal
resonator will drift about 1-5E-8/degC, so I guess a loose temperature
control would certainly exhibit the drift I am seeing.

Bob



>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of George
>>> Atkinson
>>> Sent: Monday, September 14, 2015 2:42 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Z380XA The saga of the aging 10811
>>> 
>>> Well, if the batch/revision of op-amps had a doping, contamination or
similar
>>> issue, the input offset could be drifting fairly constantly causing a
>>> temperature channge in one direction.
>>> 
>>> Robert G8RPI.
>>> 
>>> On 9 September 2015 at 04:40, Bob Benward <rbenw...@verizon.net>
>>> wrote:
>>> 
>>> > Hi Ed,
>>> > OK, a bad oven.  I can buy that.  But then if the oscillator is
>>> > constantly drifting, would that not imply that the oven is constantly
>>> > changing temperature, in one direction?
>>> >
>>> > BTW, the curve is starting to flatten out.  It might be flat before It
>>> > gets to 1000K counts.
>>> >
>>> > Bob
>>> >
>>> > >>> -Original Message-
>>> > >>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
>>> > >>> ed breya
>>> > >>> Sent: Tuesday, September 08, 2015 10:55 AM
>>> > >>> To: time-nuts@febo.com
>>> > >>> Subject: Re: [time-nuts] Z380XA The saga of the aging 10811
>>> > >>>
>>> > >>> It could be that the inner oven temperature regulation is off a
>>> > >>> bit, or
>>> > even
>>> > >>> failed. There was a report at one of the popular time-nuts
>>> > >>> oriented
>>> > websites (I
>>> > >>> forget which one, but it's the one that had extensive coverage of
>>> > >>> the
>>> > Z3801A)
>>> > >>> about inner oven problems a few years ago. I took mine apart and
>>> > >>> found
>>> > that
>>> > >>> it had an IC of a particular date code range that was prone to
failure.
>>> > I can't
>>> > >>> recall whether I replaced it with the same type but different
>>> > >>> date, or
>>> > an
>>> > >>> alternative, but it worked just fine after that, with no tweaking
>>> > >>> of
>>> > coarse EFC
>>> > >>> needed.
>>> > >>>
>>> > >>> The IC was a dual opamp I think, that controlled the oven
>>> > >>> temperature according to the thermistor signal, and drove the
heater
>>> transistor(s).
>>> > >>> It was a fairly high performance type, but not that unusual. I
>>> > >>> think it
>>> > was a
>>> > >>> Linear Technology brand part.
>>> > >>>
>>> > >>> Ed
>>> > >>> ___
>>> > >>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> > >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> > >>> and follow the instructions there.
>>> > >>> -
>>> > >>> No virus found in this message.
>>> > >>> Checked by AVG - www.avg.com
>>> > >>> Version: 2015.0.6140 / Virus Database: 4409/10580 - Release Date:
>>> > >>> 09/05/15
>>> >
>>> > ___
>>> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> > and follow the instructions there.
>>> >
>>> ___
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>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10639 - Release Date:
>>> 09/14/15

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Re: [time-nuts] Trimble GPSDO board

[Bob Benward]

Arthur,
I did read your posts before I composed my email.  You made no mention of
getting the RS-232 to work, and you made no mention of the MACT switch.
Yours worked from the start.  I am not having such good luck.

I got it to lock once, I notice the 1pps comes out almost immediately, even
after being off overnight.  I thought this output was a result of GPS lock
and this locked in less than 10 seconds.  So in my case, it still has locked
only once, and I don't see anything coming out of the serial port, so it's
difficult to make any other evaluations.  The green activity light is on
solid then after the oven reaches temp (the current draw goes down) the
light starts blinking.  The output from the oscillator is there, so I will
X-Y it with my Z3805A and see if the oscillator is truly locked to GPS.

Bob


>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur
>>> Dent
>>> Sent: Saturday, September 12, 2015 11:38 PM
>>> To: time-nuts@febo.com
>>> Subject: [time-nuts] Trimble GPSDO board
>>> 
>>> "Did anyone have any luck in talking to this unit?"
>>> 
>>> Reread my posts that describe what I did. Mine works great.
>>> 
>>> -Arthur
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10627 - Release Date:
>>> 09/12/15

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Re: [time-nuts] Trimble GPSDO board

[Bob Benward]

Hi Arthur,
I looked at all your emails.  This is the only reference to reading
something from inside the unit:

>"The one error I did notice is I said the board locked after it found
satellites but that is incorrect."

You have no other details on RS232 on the email of August 22 (I rec at
7:01pm EDT, you sent at 6:25pm EDT).  Are you talking about another email?
I must have missed something.  Help me, please repost that section of your
email please.

Bob


>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur
>>> Dent
>>> Sent: Sunday, September 13, 2015 1:25 PM
>>> To: time-nuts@febo.com
>>> Subject: [time-nuts] Trimble GPSDO board
>>> 
>>> "Arthur,
>>> I did read your posts before I composed my email.  You made no mention
of
>>> getting the RS-232 to work.."
>>> 
>>> 
>>> Again, reread my specific post of Sat Aug 22 11:19:31 EDT 2015 that
>>> describes the RS-232 in detail. The green light is also described in one
of my
>>> posts
>>> 
>>> -Arthur
>>> ___
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4419/10627 - Release Date:
>>> 09/12/15

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[time-nuts] Trimble GPSDO board

[Bob Benward]

Hi All,

I finally hooked up my Trimble GPSDO today.  I noticed it took a long time
to lock and then the 10MHz would not come out until it achieved lock.  I hit
the reset switch and then it lost lock and surprisingly it takes forever to
lock up again.  After cycling power, it did produce and output, but it was
not locked, it was at least 1 cycle off.

 

Does anyone know what the MACT switch does?

 

I probed the RS-232 and saw nothing coning out.  Did anyone have any luck in
talking to this unit?

 

After an hour and a half, still nothing coming out.  I wonder if I have a
lemon.

 

Bob

 

 

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Re: [time-nuts] Z3805 service information ?

[Bob Benward]

Hi Mark,
I suspected my GPS was trashed after the storm as well.  So I swapped the
GPS model between my Z3801A and Z3805A.  I monitored both at the same time
and both eventually got GPS locks.  My antennae are not optimally placed so
that may be why it takes so long.  So much for that idea.  As I said before
in my case it the ocxo running out of EFC range.  Did you check the supply
voltages via the test points?


Bob

P.S. Something I learned about the Z38xx program:  If you need to run two
copies on the same computer, simply place then in different folders.  The
data and init folders remain within the folders allowing you to run two
different Z38xx machines on different com ports.

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark
>>> Spencer
>>> Sent: Tuesday, September 08, 2015 4:41 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Z3805 service information ?
>>> 
>>> Hi it seems the GPS module is not working and I suspect the power supply
is
>>> failing.   After a few power cycles the unit started up and reported via
rs232
>>> that it could not communicate with the GPS receiver
>>> 
>>> The docxo still delivers great performance from an adev perspective and
I
>>> have other gpsdo's so I'm going to defer any more work on this for the
time
>>> being.  The docxo is probably the most valuable part right now.  It is
far and
>>> away better than any of my other 10811's from an adev perspective.
>>> 
>>> Right now I'm kind of glad no one bought my jackson labs fury GPSDO.
>>> 
>>> 
>>> I figure I got my money's worth from the Z3805 and my interest in time
nuts
>>> pursuits has waned in recent years.
>>> 
>>> Also I seem to recall this Z3805 loosing GPS lock during a lightning
storm as
>>> well.  (I recall some one else mentioned this issue with their Z3805.)
>>> 
>>> 
>>> Sent from my iPhone
>>> 
>>> > On Sep 1, 2015, at 9:05 PM, Bob Benward <rbenw...@verizon.net> wrote:
>>> >
>>> > Can you communicate over RS232?  Are you using the Z38xx software?
>>> > What does it say?
>>> >
>>> > Bob
>>> >
>>> >>>> -Original Message-
>>> >>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
>>> >>>> Mark Spencer
>>> >>>> Sent: Tuesday, September 01, 2015 12:54 PM
>>> >>>> To: time-nuts@febo.com
>>> >>>> Subject: [time-nuts] Z3805 service information ?
>>> >>>>
>>> >>>> Hi, I realize this is a long shot but I'm curious if anyone has
>>> >>>> ever
>>> > come across
>>> >>>> any form of a service manual (or insight into a power on self test
>>> > routine) for
>>> >>>> the Z3805 gpsdo ?
>>> >>>>
>>> >>>> One of mine is not working properly after being power cycled.   It
works
>>> > well
>>> >>>> enough to blink the status lights on the front panel hence my
>>> >>>> request
>>> > for info
>>> >>>> about a possible power on self test routine.
>>> >>>>
>>> >>>> I'll likely start by confirming the power supply voltages using
>>> >>>> another
>>> > working
>>> >>>> unit as a guide and then swap parts with another working unit but
>>> > thought I
>>> >>>> would look for service information first.
>>> >>>>
>>> >>>> Thanks in advance for any help.
>>> >>>>
>>> >>>> With the exception of two ocxo's that have a dedicated battery
>>> >>>> backup system all my time nuts gear, computers, freezers, etc was
>>> >>>> power cycled during a two day power outage after a wind storm while
>>> >>>> I was on
>>> > vacation.   I
>>> >>>> have a nice generator that sat un used in my garage (:
>>> >>>>
>>> >>>> Mark Spencer
>>> >>>> VE7AFZ
>>> >>>>
>>> >>>> ___
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>>> >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> >>>> and follow the instructions there.
>>> >
>>> > ___
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>>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> > and follow the instructions there.
>>> >
>>> ___
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>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4409/10580 - Release Date:
>>> 09/05/15

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Re: [time-nuts] Z380XA The saga of the aging 10811

[Bob Benward]

Hi Ed,
OK, a bad oven.  I can buy that.  But then if the oscillator is constantly
drifting, would that not imply that the oven is constantly changing
temperature, in one direction?

BTW, the curve is starting to flatten out.  It might be flat before It gets
to 1000K counts.

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of ed
>>> breya
>>> Sent: Tuesday, September 08, 2015 10:55 AM
>>> To: time-nuts@febo.com
>>> Subject: Re: [time-nuts] Z380XA The saga of the aging 10811
>>> 
>>> It could be that the inner oven temperature regulation is off a bit, or
even
>>> failed. There was a report at one of the popular time-nuts oriented
websites (I
>>> forget which one, but it's the one that had extensive coverage of the
Z3801A)
>>> about inner oven problems a few years ago. I took mine apart and found
that
>>> it had an IC of a particular date code range that was prone to failure.
I can't
>>> recall whether I replaced it with the same type but different date, or
an
>>> alternative, but it worked just fine after that, with no tweaking of
coarse EFC
>>> needed.
>>> 
>>> The IC was a dual opamp I think, that controlled the oven temperature
>>> according to the thermistor signal, and drove the heater transistor(s).
>>> It was a fairly high performance type, but not that unusual. I think it
was a
>>> Linear Technology brand part.
>>> 
>>> Ed
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>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4409/10580 - Release Date:
>>> 09/05/15

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[time-nuts] Z380XA The saga of the aging 10811

[Bob Benward]

Hi All,

I would like to convey the saga of my Z3801A and my Z3805A.

 

I purchased a Z3801A a few years ago at the Dayton Hamfest.  I got it
running and a few months later the unit lost it's GPS lock.  I did some
trouble shooting and finally realized the unit ran out of EFC range.  I
opened the double oven 10811 and retuned the unit to the lower end.  The
unit ran for another year or so, and then the oscillator died.  The
frequency was close, but the amplitude dropped too low for the circuitry to
lock on to.  I put the Z3801A aside and purchased a Z3805A from China (I
think from Yixunhk).

 

I plugged in the Z3805A and it ran for a few years.  One day, a few days
after a relatively active thunderstorm, I notice the alert light was on and
I had lost GPS lock.  I thought a close strike wiped out the GPS receiver.
After a lot of screwing around, I figured out that the 10811 had also lost
EFC range.  The output voltage sat at the neg2.0V level and would not budge.
I opened up the 10811 and readjusted the tuning to put the EFC counts at
below 100K.  I never reassembled the oscillator, I just left it sprawled out
on the table.  Checking the EFC stats, it started with a relatively high
1E-8 per day of drift.  It has since calmed down to 5E-9, and you can see a
slight flattening of the curve in the plot.  I am also running about a
positive 5K counts/day.  The 5E-9 figure is still 10X higher than the basic
10811 spec, and with 5K counts/day, I have only 160 days left ( I am at
about 200K counts now, max=1000K).  It always seems the drift is up in EFC
counts, negative going voltage, and down in frequency.

 

An interesting observation, I would notice a periodic dip in the time
interval error.  I would come home from work, turn on the air conditioning,
and I after an hour or so, I would see the time interval error take a large
dip.  I didn't think the drift vs temperature was that sensitive.

 

I also wonder if the excessive heat of the double oven shortens the life or
accelerates the aging of a typical 10811.  The heat certainly dries out the
polyester tape and silicon rubber foam inside. Could it accelerate the aging
of the oscillator, shorting the life of the oscillator and the useful life
of the GPSDO?  It's no wonder the Morions on Ebay are sold by the
manufacturing date.  Once you run out of EFC, that's all she wrote..  It
makes me question the wisdom of buying a used 10811 double oven oscillator,
how much life is left?

 

So, does anyone have any comments on the excessive drift of the 10811?

 

On another tangent, I tried hooking up a Morion to the Z3805A.  I used an
inverting amplifier for the EFC since the coefficient is positive and on the
10811 is negative.  I never achieved good control before the Morion itself
died.  I will probably continue working on marrying a new OCXO to the Z380XA
control board.  I need an alternate source for the OCXO without depending on
used double oven 10811s.

 

 

Bob

AC2AZ

 

 

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Re: [time-nuts] Z3805 service information ?

[Bob Benward]

Can you communicate over RS232?  Are you using the Z38xx software?  What
does it say?

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark
>>> Spencer
>>> Sent: Tuesday, September 01, 2015 12:54 PM
>>> To: time-nuts@febo.com
>>> Subject: [time-nuts] Z3805 service information ?
>>> 
>>> Hi, I realize this is a long shot but I'm curious if anyone has ever
come across
>>> any form of a service manual (or insight into a power on self test
routine) for
>>> the Z3805 gpsdo ?
>>> 
>>> One of mine is not working properly after being power cycled.   It works
well
>>> enough to blink the status lights on the front panel hence my request
for info
>>> about a possible power on self test routine.
>>> 
>>> I'll likely start by confirming the power supply voltages using another
working
>>> unit as a guide and then swap parts with another working unit but
thought I
>>> would look for service information first.
>>> 
>>> Thanks in advance for any help.
>>> 
>>> With the exception of two ocxo's that have a dedicated battery backup
>>> system all my time nuts gear, computers, freezers, etc was power cycled
>>> during a two day power outage after a wind storm while I was on
vacation.   I
>>> have a nice generator that sat un used in my garage (:
>>> 
>>> Mark Spencer
>>> VE7AFZ
>>> 
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Re: [time-nuts] Chinese GPSDO 10 MHz error

[Bob Benward]

So how does a frequency lock work?  How is it implemented? Can someone sketch a 
schematic?

And what equipment or technique is used to measure a 2hz error at 100GHz?

Bob

 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Tim
 Shoppa
 Sent: Wednesday, August 26, 2015 5:18 PM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] Chinese GPSDO 10 MHz error
 
 Full KE5FX evaluation of BG7TBL GPSDO here:
 http://www.ke5fx.com/gpscomp.htm
 
 I'm wondering out loud if it might, like many hobbyist GPSDO's, be
 frequency-locked rather than phase-locked and thus susceptible to 
 last-digit-
 counter bobble in some long-averaging counter.
 
 Tim N3QE
 
 On Wed, Aug 26, 2015 at 3:18 PM, Perry Sandeen via time-nuts  time-
 n...@febo.com wrote:
 
  Hi,
 
 
 
  On the EEVBLOG  (http://www.eevblog.com/forum/index.php)
 
 
 
  They mention that the 2014-11-06version GPSDO that was “most
  extensively tested, so far (by ke5x and others).
 
 
 
  (Has a) known bug, outputfrequency is not exactly 10mhz
  (9,999,999.999,800 Hz). This translates to ~2hzerror at 100ghz.”
 
 
 
  A question is if this bug isjust for this particular model or all
  other versions suspect?
 
 
 
  I realize that in and of itsself it is very small error, but errors
  tend to multiply or cause incorrectconclusions to testing.
 
 
 
  Another question is will the LHdisplay unit they offer work with other
  Trimble units such as are offered byRDR?
 
 
 
  That said, these models seem tobe a very nice turn-key systems.
 
 
 
  Regards,
 
 
 
  Perrier
 
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Re: [time-nuts] Chinese GPSDO 10 MHz error

[Bob Benward]

Attila,
I concur with you, what Azelio described is a standard off the shelf PLL.
An XOR for a Type I phase discriminator, characterized by a 90 degree phase
lock, and with more complicated logic, a Type II PLL which locks at zero
degrees.  In a well designed loop, in both cases over the long term the
frequency is exact, what it does have to a large extent, is phase jitter.

So how does someone measure an error to 2 parts in a hundred billion?  Or is
that a 2 cycle slip in 100 gig cycles?

Thanks to all that replied.

Bob

 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila
 Kinali
 Sent: Thursday, August 27, 2015 4:51 PM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] Chinese GPSDO 10 MHz error
 
 On Thu, 27 Aug 2015 17:19:34 +0200
 Azelio Boriani azelio.bori...@gmail.com wrote:
 
  The simplest form of a frequency locked loop is the XOR gate, when the
  driving signals are 50% square waves. To achieve lock, the phase
  difference will be proportional to the voltage needed to the VCO to
  generate the desired frequency. Start with a 5V digital gate, suppose
  your VCO needs 2.5V to be in frequency: the XOR output will be at 50%
  duty cycle to generate, out of an RC, 2.5V and the phase difference
  (between the reference and the VCO) will be 90 (or 270) degrees. The
  difference will be more or less than 90 if the required voltage is
  more or less than 2.5V (positive EFC) or will be more or less than 270
  if the VCO has a negative EFC.
 
 This is the description of a XOR gate based PLL, not an FLL.
 
 The basic difference between PLL and FLL is very very simple:
 A PLL measures phase, a FLL measures frequency.
 
 The control loop then steers the measured value to be as close as
possible to
 a predetermined constant. As this steering loop is not perfect, there
will be a
 small error. Depending on what is measured, it's either a phase or a
 frequency error.
 
 Attila Kinali
 
 --
 I must not become metastable.
 Metastability is the mind-killer.
 Metastability is the little-death that brings total obliteration.
 I will face my metastability.
 I will permit it to pass over me and through me.
 And when it has gone past I will turn the inner eye to see its path.
 Where the metastability has gone there will be nothing. Only I will
remain.
 
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Re: [time-nuts] Trimble GPS board

[Bob Benward]

Arthur,
You are correct, I missed that regulator, but may other Trimble oscillators
are powered by +12V.  That's what led me down the wrong path.  I still
suspect that it might have been designed for +12V, as +6.5V is not a common
supply rail.

I just got my Trimble board yesterday and hope to have it running this week.
I am still wrestling with my Z3801, trying to get it to run with a Morion
MV89, but then that crapped out.  Now trying to get it to work with a
Efratom OCXO.

Bob

 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Arthur
 Dent
 Sent: Saturday, August 22, 2015 6:25 PM
 To: time-nuts@febo.com
 Subject: [time-nuts] Trimble GPS board
 
 rbenward at verizon.net wrote: See below, here is a 73090 OCXO (same as
 on some of those GPSDO boards) powered by +12V.
 
 You are incorrect in your assumption that the link you have supplied
shows a
 73090 OCXO powered by +12VDC. The BOARD is indeed powered by 12VDC
 (or 15VDC if you read the listing) but if you look at all the photos you
will see
 a 3-terminal regulator on the bottom of the pc board.
 
 The Trimble GPSDO I'm supplying 6.3VDC to had a 5 volt regulator that
has a
 measured output of 5.00VDC and the supply pin on the oscillator had that
 5.00VDC on it, not the 6.3VDC from my supply.
 A continuity check shows a direct connection from the regulator's
 5 volt output directly to the oscillator's supply pin. Because of the
higher
 current drawn by the 5 volt oven, running the input to the board at
12VDC
 and wasting all that power as heat would not be wise. 6.3VDC makes me
 happy and they chose a LDO regulator for a good reason.
 
 The one error I did notice is I said the board locked after it found
satellites but
 that is incorrect. It does find satellites quickly but takes about 10
minutes to
 lock and that is when the 10Mhz output is enabled. I did some of my
 checking around 1AM and that is not a good time for clear thinking or
 writing.
 
 -Arthur
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Re: [time-nuts] Trimble GPS board

[Bob Benward]

Hi Angus,
Thanks for your reply.  My original suspicion is the +6.5V rail.  That needs
to come from somewhere, and you need headroom if it's an unregulated input.
Pumping 2A through a regulator like that is no easy feat.  Although rated
for 3A, you need to keep the junction temperature below 125C. The part has a
30C/W thermal resistance (Tja) with a 1 square copper pad.  So 6.5V and 3A
calculate as follows: (6.5V-5V)*3A=4.5W.   4.5W*30C/W=135C RISE, add that to
ambient, 25C, and you are 35C over max junction.  In my world we have a 70C
ambient, and that leaves me (125C-70C)/30C/W=1.83W, or a maximum of
1.83W/1.5V=1.22A.  Generally a tab mounted TO-220 (a D2Pak) can have a Tjc
(junction to case) or less than 1C/W.  It's all the reest of the mounting
that piles on the thermal resistance.

The Trimble board has a top layer pad, some far side pad, and probably
multiple layer of ground plane over the rest of the board.  The mounting
post is mostly likely part of the thermal resistance calculation.  There is
also a time constant involved, it probably can't take the 2A forever, just
long enough to get the oven up to temp. I suspect they may have gotten the
thermal impedance down as low as 10C/W.  I will test it with 12V and let
everyone know if I fry the board.

Bob

 -Original Message-
 From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Angus
 Sent: Sunday, August 23, 2015 8:30 AM
 To: Discussion of precise time and frequency measurement
 Subject: Re: [time-nuts] Trimble GPS board
 
 Hi Bob,
 
 I got a Trimble 57963-80  last year and the 73090 OXCO and some other
 parts on it are supplied with 5V from the LT1764A.
 
 The DSP, FPGA, etc., also have various small regulators supplying their
supply
 voltages - one even has a dropper resistor in series.
 These are connected to the main input supply, so raising it above what
it
 should be is probably not a good idea.
 
 I thought at first that the LT1764A would be thermally connected to the
 fixing hole beside it so that the heat could be removed, but it is only
 connected to the copper on the top of board at that point - then again,
that
 may be the way it was mounted.
 
 I did put a temp sensor on the 1764 to see how much it heated up during
 warm up and when running, but neither looked close to being a problem
 when run at 6V and room temperature.
 At 6V, it took 2A during warm up and just over 1A when running at room
 temp, but the warm up is fast.
 
 When I got the board, someone had written on the OCXO with a marker pen
 what the pins were, and the power was marked as 12V, and an EFC voltage
 was also written on (about 0.2V from what I measured) which was all a
little
 weird.
 
 It was listed as having been tested, but since the seller said that they
had no
 connection info, who tested it and how is anyone's guess...
 
 Angus.
 
 
 On Sat, 22 Aug 2015 14:02:35 -0400, you wrote:
 
 Hi Arthur,
 Thank you for this information.  I have not received my board yet, I
 probably still have a few weeks to go.  The LT1764 will take up to 20V,
 but I would never go to the edge.  You could easily do 12V, the only
 downside is the dissipation in the LT17654.  Use a variable power
 supply and raise the voltage slowly.  Monitor the temperature with a
 thermocouple,  IR spot meter (radio shack had one for $10), or just use
 your finger.  If you can keep your finger on it comfortable for a long
 period of time, the temp should be OK.  The junction temp is rated for
 125C.
 
 
 
 
 Now on the flips side, my only concern is the regulator is not
 supplying the oven power.  Most Trimble OCXOs I see on Ebay are powered
 by +12.
 When supplying only 6.5V the oven might not get up to temp producing
 frequency instability and some erratic EFC stats.
 
 See below, here is a 73090 OCXO (same as on some of those GPSDO boards)
 powered by +12V.  It's possible the regulator is meant to be powered
 from +12V, supplying power to the digital logic and to the oscillator
 portion of the OCXO. Then +12V directly supplies the oven.
 
 http://www.ebay.com/itm/10-00MHz-Trimble-Double-Oven-OCXO-
 Trimble-7
 3090-Double-sinewave-15V-12V-/251883335405?hash=item3aa56aaeed
 
 I will post my success and let everyone know how I make out.  I
 purchased this to have a backup for my Z3801  Z3805.  Both are on the
 fritz, I will be post those trials and tribulations on a new thread.
 Thanks so much for your response.
 
 Bob
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Re: [time-nuts] Trimble GPS board

[Bob Benward]

Thank you all for your responses.  

 

I tried to buy one of those adapters but I think there was a language
problem.  Still waiting for a positive response from the seller.

 

It seems this guy is selling those small GPSDOs.  The ones dated 2014-11-06
 2014-12-09 are the Morion, the 2015-07-08 are the Oscilloquartz, and the
latest, 2015-07-17 are the Trimbles, all mounted on the same carrier.  I
assume the numbers are all dates, but why two different models 9 days apart.
I wonder if it's a supply issue.

 

Bob

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[time-nuts] Trimble GPS board

[Bob Benward]

Hi all,

Does anyone have any information or experience with this small Trimble
GPSDO?  There doesn't seem to be any associated model number other than the
model of the OCXO (63090).  I am looking for software, command codes, or
hookup schematics, can anyone help?

 

http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649
http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649ssPageNam
e=STRK%3AMEBIDX%3AIT ssPageName=STRK%3AMEBIDX%3AIT

 

Thanks,

Bob

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[time-nuts] RS-232

[Bob Benward]

To Hal Murray,

I checked my Z3801A and it was already set up for RS-232, regardless, I
finally figured out my problem.  Running a Z3805A and a Z3801A side by side
can lead you down the rabbit hole.  The Z3805A port settings are 9600,N,8,1
while the Z3801A uses an unusual 19200,O,7,1.  It just never occurred to me
that they would be different.  I just ran my Z38xx program on the last known
settings.  

 

Thanks for your previous response.

 

My Z38xx program is running a bit flaky.  Can anyone recommend a another
free program as an alternate?

 

Another question:  How do I continue a thread if I am only getting daily
digests?  Some on this group reported they were able to do this.  I would
appreciate if they could share this tip with me.

 

Thanks,

Bob

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[time-nuts] RS-232 port

[Bob Benward]

I am sure this has been covered, but I did have much luck in the archives.

 

I have an HP Z3805A with the nice faceplate and 6 leds on the front.  I also
have a Z3801A also with 6 LEDs.  What is the difference in the com ports?
The Z3805A works fine with a standard 25pin to 9 pin adapter.  The Z3801
does not.  The Z3801 was my first GPSDO and I once had it working until the
oscillator crapped out.  I recall I might have had a special com port wiring
on that unit but my memory fails me.  Can someone point the differences
between the two and can someon provide the pinouts for the Z3801A.

 

Also, my Z3805A is on the fritz.  Things went south after a lightning storm,
but I can't be sure the two are related.  I looked at it a few days after
the storm and it wasn't working.  The status says it is tracking two,
sometimes three sats, but it just doesn't lock.  I tried two different
antennas, no difference.  Is the GPS damaged possibly?  Any clues?

 

Thanks,

Bob

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