https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
The patent that I posted at
http://gonascent.com/papers/hp/US3323008.pdf has many interesting
facts about the cesium beam tube. It says that the temperature of the
cesium oven is 65° C. I researched the vapor pressure of cesium at
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
We continue to try to achieve lock on our latest HP5061B acquisition.
We found that the -2,500 supply would only come up to -780 V under
normal 55 Meg multiplier load. When we pulled off the HV lead to the
beam tube, it came up to
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
The design on the voltage and current limiter is complete but not
breadboarded yet. We are getting a little more time on our HP5061B
beam tube after beefing up the +3,500 Volt power supply. We have the
frequency control R4 turned
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
I posted another HP cesium beam tube patent at
http://gonascent.com/papers/hp/hp5061/US3387130.pdf . It covers the
formation of the cesium beam and should be of interest. We now have
over a month of operation on our first HP5061B
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
I have posted two HP patents on the cesium beam tube at
http://gonascent.com/papers/hp/US3323008.pdf and
http://gonascent.com/papers/hp/US3397310.pdf . Both are of academic
interest. The first claims that the cesium oven operates at
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
We continue troubleshooting our 2nd HP5061 acquisition. The 200 Meg
resistor in the +3,500 V supply had gone way up in value and made it
appear that the supply was half normal voltage. See the black
resistor in
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
The cesium oven acts as an evaporator for liquid cesium which melts at
28.5° C. One of our beam tubes has 83°C for its operating
temperature. It also calls for a A11R11 and A11R12 of 3.83 K and
42.2K which is 3.51K. Oven power is
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
The -2500 supply is nearly identical to the +3500 supply. We will
post some photos on the disassembly process. We also had to
disassemble the +3,500 supply because the 200 Meg resistor had gone up
in value. It showed only 1,900 V
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
I could not figure out why the A15 Ion Current monitor would not let
the cesium oven turn on with ion current under 25 uA. At the time we
had no way of measuring the +3,500 ion pump supply. We bought some
200 Meg resistors and made
This is my first post. I just bought a non-working HP5061B on eBay
for $350. My old boss KB7APQ in Salt Lake City and I are working on
it. It came in from the Philipines in October of 2015 and was
diagnosed with a bad physics package in March 2016 by AllTest in New
Jersey. We initially found
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
Paul:
I don't think that I made myself clear. This power supply is a rare
example of HP engineering incompetence. The transformer is EASILY
capable of 10 Watts out at 3500 V. Instead they made it where it
can't even put out 100
It looks like that there is about 10% hysteresis on the cesium trip
off/on. That may not be enough to prevent cycling on and off. I may
not have made it clear but instability in the +3,500 voltage makes a
big difference in the threshold ion current required for activation.
If it fades it can
https://www.febo.com/pipermail/time-nuts/2017-March/104374.html
You bring up an interesting point. As the cesium is used up over the
years, it forms a cesium frost which deposits on everything inside the
tube. If it gets thick enough it conducts or can arc between frost
grains. A charged
We are having trouble getting beam current on our #2 HP5061B. Ion
current has gone down in a week from 10 to zero. It looks like the rf
chain is working normally. Both HV power supplies had to repaired.
Beam current is all the way up and which gives 2 on the meter. We are
preparing to do the Low
https://www.febo.com/pipermail/time-nuts/2017-April/104600.html
We hooked up the oscilloscope directly to the electron multiplier in
the beam tube with a 1 Meg termination. We were operating open loop
and varying the fine crystal oscillator adjust for the different
photos. Remember that higher
https://www.febo.com/pipermail/time-nuts/2017-April/104600.html
Here is the plot on the Zeeman frequency data that we gathered this
morning. It is close to Figure 4-43 (page 4-31) in the service manual
for the HP5061B. Thanks to Jonathon for plotting this.
https://www.febo.com/pipermail/time-nuts/2017-April/104600.html
We did our first Zeeman frequency test on our good cesium 05061-6077
Tube with a 1 Meg scope probe and a 11 Meg Digital Voltmeter in
parallel. KB7APQ used his digital generator for the variable
frequency. See paragraph 3-16 on page
https://www.febo.com/pipermail/time-nuts/2017-April/thread.html
I spoke to Corby on the phone a few days ago about our first HP5061B
that locks fine but has ion current on the order of 76 μA. It has not
gone down significantly in two months of pump operation. He mentioned
that the electrodes in
https://www.febo.com/pipermail/time-nuts/2017-April/thread.html
We performed an experiment with our working HP5061B which had been
cold overnight. This was to better determine lock time from cold
ovens. We found that the crystal oscillator oven heats up about twice
as fast as does the cesium
https://www.febo.com/pipermail/time-nuts/2017-April/thread.html
We did some testing to evaluate the advantages of square wave
modulation instead of sine waves for locking to the atomic resonance
peak. We drove J1 on the A3 board with a 2.8 Volt peak to peak
triangle at 20 cps from a signal
https://www.febo.com/pipermail/time-nuts/2017-April/104600.html
I posted this patent assigned to Frequency Control Corporation on hot
wire ionizers at http://gonascent.com/papers/hp/hp5061/US3433944.pdf .
They must have been an HP competitor in the 1960s. It discusses the
physics of cesium
https://www.febo.com/pipermail/time-nuts/2017-April/thread.html
We did not attempt to achieve lock because we saw absolutely no beam
current with the beam adjust all the way up. We were running the oven
above 150° C which is more than 65° above normal oven temperatures.
Cesium pressure should
https://www.febo.com/pipermail/time-nuts/2017-April/thread.html
Yesterday we swept our HP5061B thru the cesium resonance curve. As
far as I know this is the first time that the curves have been
published. The original phase modulation is a very unlinear sine wave
frequency sweep. We built a
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
While I find traces of your article quoted, it seems to have vanished.
It lead me to this interesting article of 16 pages on electronic fires
by a fire investigator. There is a lot here for designers when it
comes to preventing fires
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
These oscillators sold for $800 in 1985 or so. They are on eBay all
working for $250 or more. Where are all the ones with blown thermal
fuses for $25? I want to buy. It would be interesting to have the HP
warranty data for nuisance
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
This is the third report of an open thermistor which would have
resulted in a fire in an HP10811 oven. There are a dozen other
problems that could cause such a fire. See
http://gonascent.com/papers/hp/hp10811/thermal.jpg . The leads
;je...@hanler.com>
Date: Thu, May 11, 2017 at 4:52 PM
Subject: Re: [time-nuts] time.gov
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>
Cc: "Donald E. Pauly" <trojancow...@gmail.com>
I checked it on two different computers and again just now, all w
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
In order to have a runaway trophy, the thermal fuse would have to have
been jumpered and then an oven control failure would have to have
occurred. The rated temperature of 125° C is well above operating
temperature of 82°C. The thermal
--
From: Bob kb8tq <kb...@n1k.org>
Date: Wed, May 17, 2017 at 4:05 AM
Subject: Re: [time-nuts] HP5061B Modulation Adjustment
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>
Cc: "rwa...@aol.com" <rwa...@aol.com>, "Donald E. Pauly"
<
e-nuts] HP10811 Oscillator Thermal Fuse
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>
Cc: "Donald E. Pauly" <trojancow...@gmail.com>
Hi
You will get a lot of diversity of opinion on the topic of the thermal
fuse on the 10811. My feeling is that they a
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
About 10 years ago, I checked my WWVB time code receiver that I built
against time.gov and it was within 0.1 seconds. That was as close as
the eyeball can tell. You report a huge error and if confirmed, you
should complain. I would
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
The poster at
http://www.simonsdialogs.com/2016/09/a-thermal-fuse-and-hp-10811-60111-repair/
reported that the thermal fuse saved an oscillator from destruction
when a thermistor opened. HP made thousands of these which sold for
$800.
eneral/pdf/65.pdf
http://tf.boulder.nist.gov/general/pdf/101.pdf
/tvb
- Original Message -
From: "Donald E. Pauly" <trojancow...@gmail.com>
To: "time-nuts" <time-nuts@febo.com>; "Donald E. Pauly" <trojancow...@gmail.com>
Sent: Thursday, May 2
WB0KV
-- Forwarded message --
From: Tom Van Baak <t...@leapsecond.com>
Date: Fri, May 26, 2017 at 5:36 PM
Subject: Re: HP5061B Versus HP5071 Cesium Line Frequencies
To: "Donald E. Pauly" <trojancow...@gmail.com>
Donald,
I'm enjoying many of your 5061 posts th
https://www.febo.com/pipermail/time-nuts/2017-May/105500.html
We recently did a partial alignment of the lock servo on our #2
HP5061B after replacing the beam tube. The previous owner had tried to
fix it by turning adjustments. This made a big improvement in the
lock. KB7APQ got the idea to use
https://www.febo.com/pipermail/time-nuts/2017-May/105298.html
The synthesizer in the HP5061B generates a frequency of about
9,192,631,772.5 cps when the 5 mc oscillator is exactly on frequency.
First the 5 mc oscillator is multiplied by 18 to 90 mc on the A1
board. That in turn is multiplied by
https://www.febo.com/pipermail/time-nuts/2017-May/105298.html
We recently got our second HP5061B to lock after changing the beam
tube. We did no alignment with the exception of changing the gain on
Beam current. Ion current dropped from 14 to 1 with only a few hours
of operation of the
https://www.febo.com/pipermail/time-nuts/2017-May/105566.html
The lock system on the HP5071 is complex and expensive. My plan to
improve the HP5061B is to to use a pair of third overtone crystals
running at 91.9 mc and 100 mc. I have come up with the magic numbers
to lock them together. This
https://www.febo.com/pipermail/time-nuts/2017-May/105554.html
Our attempt to measure the low frequency noise to determine the
possible lock improvement was a failure. We will have to get access to
the Loop Gain pot to get a flat signal at low impedance. Beware of
low frequency roll off.
I found
it at the turn
> temperature of
> the crystal. That would put you above 50C for an AT and a bit higher still
> for an SC.
>
> Bob
>
> > On Jun 2, 2017, at 2:09 PM, Donald E. Pauly <trojancow...@gmail.com
> <javascript:;>> wrote:
> >
> > https://www.feb
ent and you will match your oven to
> it. If you attempt a zero
> angle cut, you will never really hit it and there is no way to compensate
> for the problem.
>
> Bob
>
> On Jun 2, 2017, at 3:19 PM, Donald E. Pauly <trojancow...@gmail.com>
> wrote:
>
> A cut a
https://www.febo.com/pipermail/time-nuts/2017-May/105566.html
If we build this circuit it would be a bench model not designed to be
inside a hot chassis. It would be able to lock ± 5° C of 25° C. My
idea of an oven is to keep the crystal and oscillator at 25° C ±0.001
°C with 60 second warm
@febo.com>, "Donald E. Pauly" <trojancow...@gmail.com>,
"rwa...@aol.com" <rwa...@aol.com>
Direct multiplication to 9192 MHz isn't used
by any manufacturer of any atomic clock that I
know of, due to its well known disadvantages.
I can state for a fact that it was summaril
--
From: Bob kb8tq <kb...@n1k.org>
Date: Fri, Jun 2, 2017 at 12:43 PM
Subject: Re: HP5061B Versus HP5071 Cesium Line Frequencies
To: "Donald E. Pauly" <trojancow...@gmail.com>
Hi
Which statement is not true:
1) That there is a tolerance on the cut angle of a crystal?
2) That
-- Forwarded message --
From: Richard (Rick) Karlquist <rich...@karlquist.com>
Date: Fri, Jun 2, 2017 at 12:10 PM
Subject: Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies
To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>, "Donald E.
@febo.com>
Cc: "rwa...@aol.com" <rwa...@aol.com>, "Donald E. Pauly"
<trojancow...@gmail.com>
Hi
I think you have thermistors and thermocouples a bit mixed up. You can get
quite substantial output voltages from a thermistor bridge….
Bob
> On Jun 4
We are finishing a pair of HP5061B cesium standards which we have up
and running. We would like to acquire a GPS disciplined oscillator
with 5 or 10 mc output for comparison with the cesium clocks. 1 pulse
per second would be nice but is not mandatory. A roof antenna with
preamp that could
too high. This can become an issue with switchmode drive to a Peltier
cooler.
Bruce
>
> On 03 June 2017 at 11:02 jimlux <jim...@earthlink.net> wrote:
>
> On 6/2/17 2:51 PM, Donald E. Pauly wrote:
>
> > >
> > This is an improvement of 476
https://www.febo.com/pipermail/time-nuts/2017-Jun/date.html
We finally got in the Panasonic thermal fuses for the HP10811 and have
a few extra. They will either plug in or solder. Contact me if you
need one.
πθ°μΩω±√·Γλ
WB0KVV
-- Forwarded message --
From: Van Horn, David
Switching amplifiers are required to drive thermal coolers if you want
to preserve efficiency.
πθ°μΩω±√·Γλ
WB0KVV
-- Forwarded message --
From: Bob kb8tq <kb...@n1k.org>
Date: Fri, Jun 2, 2017 at 12:22 PM
Subject: Re: HP5061B Versus HP5071 Cesium Line Frequencies
To:
--
From: Bob kb8tq <kb...@n1k.org>
Date: Sun, Jun 4, 2017 at 5:15 AM
Subject: Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>
Cc: "rwa...@aol.com" <rwa...@aol.com>, "Donald
: jimlux <jim...@earthlink.net>
Date: Sun, Jun 4, 2017 at 4:47 AM
Subject: Re: [time-nuts] Fwd: HP5061B Versus HP5071 Cesium Line Frequencies
To: time-nuts@febo.com
On 6/3/17 9:56 PM, Donald E. Pauly wrote:
> It was only in the early 70s that Analog Devices invented the AD590
> solid state
m Line Frequencies
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>
Cc: "rwa...@aol.com" <rwa...@aol.com>, "Donald E. Pauly"
<trojancow...@gmail.com>
Hi
Have you checked out the papers from the 1950 and `1960’s where they
actu
<time-nuts@febo.com>
Moin,
This discussion is kind of getting heated.
Let's put some facts in, to steer it away from
opinion based discussion.
On Sun, 4 Jun 2017 08:44:33 -0700
"Donald E. Pauly" <trojancow...@gmail.com> wrote:
> I stand by my remark that thermistors
https://www.febo.com/pipermail/time-nuts/2017-May/date.html
We got a new beam tube for our #2 HP5061B cesium clock. When the tube
was changed, it momentary locked for a couple of minutes but then
unlocked. The oscillator had been set on frequency with our #1
HP5061B a while back but it was
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