Brooke Clarke wrote:
Hi Ulrich:
I think the answer is what other low cost options are available? I
would like to have a more modern TIC capability to add to the clock I'm
working on. But although there's been a lot of discussion about
different ways of making TIC measurements, it's not
Brooks Shera wrote:
- Original Message -
From: Ulrich Bangert [EMAIL PROTECTED]
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Sent: Friday, December 15, 2006 05:47
Subject: Re: [time-nuts] LPRO-101 with Brooks Shera's GPS locking circuit
...
Stephan Sandenbergh wrote:
Hi,
Another question for today - I have checked out some digital PLL ICs (more
specifically the one's from AnalogDevices. It seems as if they've got some
pretty neat stuff.) As I mentioned in my previous mail: I want to lock a
GPSDOs 10MHz to a 100MHz OCXO
Hal Murray wrote:
You still want to produce some form of quality measure for the ADEV
shape in order to form some form of control loop.
Suppose I build I good GPSDO. How do I determine how good it is? (or even
if it is any good)
How much do I learn by just plotting the control
Christopher Hoover wrote:
Folks -
I've got several OXO's suffering from disintegrating insulation between the
can and core. The insulation in these OXO's is the greenish grayish foamy
stuff. It turns to dust over time.
The two units I opened most recently also had mechanical
Christopher Hoover wrote:
Folks -
I've got several OXO's suffering from disintegrating insulation between the
can and core. The insulation in these OXO's is the greenish grayish foamy
stuff. It turns to dust over time.
The two units I opened most recently also had mechanical
John Miles wrote:
Yeah, for one OCXO disciplining another, I'd just use a 74F90 and 74HCT4046,
like that quick-and-dirty design did. The loop gain will be low and the
integration period will be measured in seconds or even minutes, so I don't
believe noise is going to be worth worrying
[EMAIL PROTECTED] wrote:
Hi Ulrich,
good details on how to set the time constant for best GPSDO performance etc!
Some issues you did not mention are but that are essential to get a good
GPSDO are:
* Aging compensation
* Temperature compensation
* fault
[EMAIL PROTECTED] wrote:
Hi Bruce,
would you have pointers to good temperature sensing circuits with sub
millidegree resolution?
thanks,
Said
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[EMAIL PROTECTED] wrote:
Hi Bruce,
would you have pointers to good temperature sensing circuits with sub
millidegree resolution?
thanks,
Said
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[EMAIL PROTECTED] wrote:
Hi Bruce,
great ideas, thanks!
Said
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Said
Attached circuit illustrates how a PT100 may be interfaced to a single
Magnus Danielson wrote:
From: Brooke Clarke [EMAIL PROTECTED]
Subject: Re: [time-nuts] LPRO-101 with Brooks Shera's GPS locking circuit
Date: Tue, 19 Dec 2006 13:42:28 -0800
Message-ID: [EMAIL PROTECTED]
Hi Brendan:
It's interesting that the PRS10 can time stamp the 1 PPS input with a
Hal Murray wrote:
Noise like the oncore sawtooth isn't always a bad thing.
I was going to comment on that area... Thanks for the reminder.
The problem is that the sawtooth isn't noise in the normal Gaussian sense.
If you happen to hit a long/wide hanging bridge, the resulting offset
Tom Van Baak wrote:
Hal writes:
It might be possible to avoid hanging bridges by dithering
the sawtooth. I'm thinking of something like a heater under
the xtal for the GPS unit that gets driven by a medium
frequency - slow relative to the normal sawtooth but fast
relative to the PLL time
The phase detector itself in Brooks Shera's GPS locking circuit has
several problems:
1) There are no synchronisers so that the partial width pulse response
of the counters biases the output.
2) Possible synchronism between the (24MHz) phase measurement clock and
the time interval being
Brooks Shera wrote:
Recently there has been some mention of the influence of 1pps sawtooth and
hanging bridges jitter on the performance of a GPSDO.
It would seem to me that the jitter must average to zero in the long run,
for if it did not the 1pps signal would drift away from its relation
Brooke Clarke wrote:
Hi Bruce:
How to get a copy?
Have Fun,
Brooke Clarke
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com
/Time Interval Averaging: Theory, Problems, and Solutions/, David Chu,
HP Journal June
Randy Warner wrote:
Paul is right about the temp sensitivity. I am surprised he managed to
keep the receiver balancing on one foot for seven minutes, but if you
try hard enough, I guess anything is possible.
I thought everyone on this thread might be interested in what is causing
the hanging
Brooke Clarke wrote:
Hi Ulrich:
Your M12+T plot ends at a little over a day (100k seconds) and the
stability is on the order of 4E-13.
But Cesium and other oscillators can be better than this. So how do you
check them, use longer averaging time?
Have Fun,
Brooke Clarke
w/Java
---BeginMessage---
Brooks Shera wrote:
- Original Message - From: Dr Bruce Griffiths
[EMAIL PROTECTED]
To: Brooks Shera [EMAIL PROTECTED]; Discussion of precise time and
frequency measurement time-nuts@febo.com
Brooks
Stop fooling yourself try reading:
/Time Interval Averaging
Using a GPS timing receiver to quantify the long term stability of an
oscillator whose frequency is not a harmonic of 1Hz, then the technique
of dividing the oscillator frequency down to 1Hz and logging the time
delay between the GPS derived PPS pulse and the leading edge of the
divided down
Brooks Shera wrote:
- Original Message - From: Dr Bruce Griffiths
[EMAIL PROTECTED]
To: Brooks Shera [EMAIL PROTECTED]
Sent: Friday, December 22, 2006 20:52
Subject: Re: [time-nuts] GPS orthodontics: time averaging theory
Brooks Shera wrote:
- Original Message - From
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Using a GPS timing receiver to quantify the long term stability of an
oscillator whose frequency is not a harmonic of 1Hz, then the technique
of dividing the oscillator frequency down to 1Hz and logging the time
delay between the GPS
[EMAIL PROTECTED] wrote:
In a message dated 12/23/2006 15:17:33 Pacific Standard Time,
[EMAIL PROTECTED] writes:
The FIR filter used in some GPSDOCXOs is not the optimum prefilter for
the control loop.
An exponential averaging (IIR) filter is better.
However an FIR filter has the
Brooks
The pitfalls Dave mentions are:
PARTIAL PULSE BIAS: very narrow gated clock pulses are not counted,
thereby introducing a bias as computed in his eq(1). Note that all
the
parameters on the right side of eq(1) are constant, thus the bias is
constant. A constant bias is important
Dr Bruce Griffiths wrote:
[EMAIL PROTECTED] wrote:
In a message dated 12/23/2006 15:17:33 Pacific Standard Time,
[EMAIL PROTECTED] writes:
The FIR filter used in some GPSDOCXOs is not the optimum prefilter for
the control loop.
An exponential averaging (IIR) filter is better
Ulrich Bangert wrote:
Hi folks,
I am starting a new thread because this topic ist still discussed very
controversial. I hope this posting helps to get more insight. What
follows is by no means to be understood as an act of personal
aggression. Nevertheless I will phrase my point of view as
a couple of D Flip-Flops.
I think this is also what's done in the HP paper on printed page number
7 in Fig. 7 Synchronizing Circuit.
Have Fun,
Brooke Clarke
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com
Dr Bruce
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Ulrich Bangert writes:
For the most of you it will already now be kind of evident that the
crossing point defines the magical value that we have to set the loop
time constant to but this fact can be formulated with a bit more of
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Ulrich Bangert writes:
For the most of you it will already now be kind of evident that the
crossing point defines the magical value that we have to set the loop
time constant to but this fact can be formulated with a bit more of
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Dr Bruce Griffiths writes:
As far as I can see on TVB's site, the 8607 is about [EMAIL PROTECTED] sec,
so 1ns/1h sounds perfectly good to me.
Only true when one only considers the data available on Tom's site.
Quartzlock
Didier Juges wrote:
This discussion is fascinating, and as always it has prompted a number
of other questions for me.
I understand the sawtooth correction is provided to allow correction of
1 PPS timing errors when the processor clock is non-coherent with the
GPS signal (at least not
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Dr Bruce Griffiths writes:
Poul-Henning Kamp wrote:
I think what you are trying to express is that the frequency from
the internal Xtal (at times) is in an overtone of the 1Hz PPS, which
gives rise to hanging bridges
Rex wrote:
On Tue, 26 Dec 2006 22:06:28 -0600, Bill Hawkins [EMAIL PROTECTED]
wrote:
What's all this about 15 MHz out?
Bill Hawkins
I have an FRS-C rubidium (10 MHz) that I bought a couple years ago. It
came in a metal box that also contained a circuit board that provided 3
TNC
Dr Bruce Griffiths wrote:
Rex wrote:
On Tue, 26 Dec 2006 22:06:28 -0600, Bill Hawkins [EMAIL PROTECTED]
wrote:
What's all this about 15 MHz out?
Bill Hawkins
I have an FRS-C rubidium (10 MHz) that I bought a couple years ago. It
came in a metal box that also
John Ackermann N8UR wrote:
The 15MHz out surprised me to. I haven't traced out the circuits but
from a couple of the components, I am guessing that they do something
like take the 3rd harmonic of the 10MHz OCXO and dividing that by 2.
John
That is not likely to be the scheme used, as
Didier Juges wrote:
Hi David,
David I. Emery wrote:
On Tue, Dec 26, 2006 at 04:14:45PM -0600, Didier Juges wrote:
When reading the data sheet for the Thunderbolt, and reading all the
pitfalls associated with non-integrated GPSDO designs using stand alone
GPS receivers, such
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Hi David,
David I. Emery wrote:
On Tue, Dec 26, 2006 at 04:14:45PM -0600, Didier Juges wrote:
When reading the data sheet for the Thunderbolt, and reading all the
pitfalls associated with non-integrated GPSDO
Dr Bruce Griffiths wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Hi David,
David I. Emery wrote:
On Tue, Dec 26, 2006 at 04:14:45PM -0600, Didier Juges wrote:
When reading the data sheet for the Thunderbolt, and reading all
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Hi David,
David I. Emery wrote:
On Tue, Dec 26, 2006 at 04:14:45PM -0600, Didier Juges wrote:
When reading the data sheet for the Thunderbolt, and reading all
Rex wrote:
I just received a Lucent RFG-RB (no -m- in this one) rubidium unit eBay
buy from the lady in Atlanta. Thought I'd share a few notes on what it
is. Maybe some of this has already been covered -- I lost track of all
the emails.
Like John, I immediately opened it up, haven't tried it
Has anyone used any of the following signav receivers for timing purposes.
They claim to actually correct the sawtooth error in hardware.
http://www.signav.com/index_files/PDF_Files/New_Brochures/SigNav%20TM3-01%20Brochure%20V1.2.pdf
Bill Hawkins wrote:
Arrgh! Make that TWO 12.5 volt batteries.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Bill Hawkins
Sent: Sunday, December 31, 2006 1:15 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts]
Hal Murray wrote:
If you mean multiply the 15MHz output by 2/3 to generate 10MHz, simply
use asynchronous divide by 3 counter (2 fliplops) to produce a 5MHz 1/
3 duty cycle (or 2/3) output then filter out the 10MHz 2nd harmonic
component with a bandpass filter. The 3rd Harmonic (15MHz) will
[EMAIL PROTECTED] wrote:
On Wed, January 3, 2007 13:40, Stephan Sandenbergh said:
The datasheets mention 25m SEP (haven't got a clue what 'SEP' stands for)
positional accuracy. However, I am sure this is relative to the actual
datum. Does anyone know where I could find information on
Hal Murray wrote:
A spherical error volume is a crude approximation, actually it is an
ellipsoidal with as the height error is usually significantly larger
than the other positional errors which also may have different rms
errors.
Why is the height error usually larger? Is that
Richard W. Solomon wrote:
If you have more than one GPS engine connected, how does it disable
the +5 vdc on the other receivers ? Or do you need to disable the
Preamp DC feed ?
Thanks, Dick, W1KSZ
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of xaos
Hal Murray wrote:
Is it okay to power up the main assembly once it is removed from the
outer shell / insulation?
Lots of info here:
http://www.hparchive.com/Manuals/HP-10811AB-Manual.pdf
I think I saw a warning about that, but maybe it was something else.
It is OK to power up
Jason Rabel wrote:
Lol, thanks Jack... :)
Yeah, I pretty much figured it would overheat because it couldn't regulate
the temperature properly. But also I would imagine you would burn yourself
trying to handle it since the temp is somewhere around 185F give or take.
They also say to let the
Normand Martel wrote:
It's bizarre..
The oscillator is some kind of Colpitts but with coils
instead of capacitors in the feedback path.
(i don't call it a Hartley, bcause Hartley's use a
SINGLE tapped inductor.)
73 de Normand VE2UM
--- Dr Bruce Griffiths [EMAIL PROTECTED]
wrote
Jason Rabel wrote:
Here's some graphs from last night's data while running mode 3, the time
scale is just 30 second intervals it's not the actual time.
http://www.rabel.org/archives/Images/Misc/Phase_Graph.gif
http://www.rabel.org/archives/Images/Misc/DAC_Graph.gif
How do they look for the
Dr Bruce Griffiths wrote:
Jason Rabel wrote:
What voltage goes to the crystal? I may have had my scope scale too high and
just didn't notice, but at first glance I don't think it was getting power.
Jason
-Original Message-
Yes, the black wires are the thermistor
Dr Bruce Griffiths wrote:
Dr Bruce Griffiths wrote:
Jason Rabel wrote:
What voltage goes to the crystal? I may have had my scope scale too high and
just didn't notice, but at first glance I don't think it was getting power.
Jason
-Original Message-
Yes, the black
Jason Rabel wrote:
I'm not sure what happened, if there was a short before or I just missed it
because the signal was so low, but now I'm getting a signal!
It is extremely weak, only about 30mV p-p w/50 Ohm termination. Any thoughts
(besides the AGC circuit)?
I tried to adjust R6, but it
Jason Rabel wrote:
Following the manual I started probing all the points that had AC DC
voltage specs listed.
Q1 Q3 DC voltage is okay.
I could not measure any AC voltage for Q1, and Q3 was a lot lower than the
spec.
CR5 was supposed to be -1.5V DC, but I was only measuring like +.5V?
Dr Bruce Griffiths wrote:
Jason Rabel wrote:
Following the manual I started probing all the points that had AC DC
voltage specs listed.
Q1 Q3 DC voltage is okay.
I could not measure any AC voltage for Q1, and Q3 was a lot lower than the
spec.
CR5 was supposed to be -1.5V DC, but I
Jim Palfreyman wrote:
On Wednesday, January 24, 2007 at 11:30:20 AM, Discussion of precise time and
frequency measurement wrote:
Dr Bruce Griffiths wrote:
The crystal leads are supposed to be welded to the crystal base.
The blue wire looks OK but the green and red wires
Jim Palfreyman wrote:
On Wednesday, January 24, 2007 at 11:30:20 AM, Discussion of precise time and
frequency measurement wrote:
Dr Bruce Griffiths wrote:
The crystal leads are supposed to be welded to the crystal base.
The blue wire looks OK but the green and red wires
Jack Hudler wrote:
If you send me the raw images Greyscale (not BW) 300 DPI or better, I'll put
it
up on hparchive.com
Jack
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Bruce Lanning
Sent: Wednesday, January 24, 2007 9:41 AM
To: Discussion
Jason Rabel wrote:
Thanks for all the tips guys... I'll let you know how it goes later today.
Right now I'm assembling my Brooks Shera GPS in its box so I can get that
going on a more permanent basis. I get some pics online when I'm done.
Bruce mentioned to me to try with some alligator clips
David
David I. Emery wrote:
The interesting thing about these units (which ceased production
in July 2005 - possibly because of the abandonment of the Oncore
receiver family by Motorola) is that they are the second kind of GPS
disciplined clocks - namely phase microstepper based designs
David I. Emery wrote:
Apparently the Austron/Datum versions (they held a patent on
this) have adjustment in the better than 10^12 area but the PRR-10 is a
pretty old design and one could certainly do better with a modern NCO
chip.
The PRR-10 and other Austron designs I am vaguely
David
David I. Emery wrote:
On Sat, Jan 27, 2007 at 01:32:40PM +0100, Ulrich Bangert wrote:
Rob,
are you absolutely sure it works this way? I experimented a lot with a
48 bit dds chip from analog devices for a GPSDO just to learn that THIS
way worked not good. What however works good is
David I. Emery wrote:
On Sun, Jan 28, 2007 at 11:43:11AM +1300, Dr Bruce Griffiths wrote:
The DDS will need to have an internal clock of at least 30MHz or so to
generate a usable 10MHz output.
Agreed, assuming the chip doesn't do clock multiplication as
several do
Dr Bruce Griffiths wrote:
David I. Emery wrote:
On Sun, Jan 28, 2007 at 11:43:11AM +1300, Dr Bruce Griffiths wrote:
The DDS will need to have an internal clock of at least 30MHz or so to
generate a usable 10MHz output.
Agreed, assuming the chip doesn't do
Dr Bruce Griffiths wrote:
Dr Bruce Griffiths wrote:
David I. Emery wrote:
On Sun, Jan 28, 2007 at 11:43:11AM +1300, Dr Bruce Griffiths wrote:
The DDS will need to have an internal clock of at least 30MHz or so to
generate a usable 10MHz output
David I. Emery wrote:
On Sun, Jan 28, 2007 at 03:07:23PM +1300, Dr Bruce Griffiths wrote:
David
I presume that the leading edge of the GPS receiver PPS pulse samples
the DDS phase accumulator register content.
This is not possible with most modern DDS chips with integrated DACs
Didier Juges wrote:
Nice Symmetricom antenna there, Jason. I need to find a similar mount. I
have made an S shaped support with PVC tube, but I have not found a
clean way to secure it to the wall. The metal bracket looks much cleaner.
I will look for laptop hard drive hardware. Even though
Christopher Hoover wrote:
Most (except for Trimble,..) GPS receivers and antennas
are designed to use 50 ohm cable.
Trimble Bullet GPS antennas have a 50 ohm output impedance.
Trimble literature however is ambiguous in that in the
Resolution T receiver datasheets talk about using RG59
to
: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Im Auftrag von Dr Bruce Griffiths
Gesendet: Samstag, 27. Januar 2007 23:43
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Austron PRR-10 GPS discliplined Rb...
Ulrich
Since an adjustment range of a few ppm
Those of you who use multifrequency GPS antennas such as choke ring
antennas may find the following article of some interest.
The new Trimble antenna has better performance than a choke ring antenna
especially if more than 2 frequencies are required.
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Christopher Hoover wrote:
Most (except for Trimble,..) GPS receivers and antennas
are designed to use 50 ohm cable.
Trimble Bullet GPS antennas have a 50 ohm output impedance.
Trimble literature however is ambiguous
Chris
Christopher Hoover wrote:
Most (except for Trimble,..) GPS receivers and antennas
are designed to use 50 ohm cable.
Trimble Bullet GPS antennas have a 50 ohm output impedance.
Trimble literature however is ambiguous in that in the
Resolution T receiver datasheets talk
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Christopher Hoover wrote:
Most (except for Trimble,..) GPS receivers and antennas
are designed to use 50 ohm cable.
Trimble Bullet GPS
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Chris
Christopher Hoover wrote:
Most (except for Trimble,..) GPS receivers and antennas
are designed to use 50 ohm cable.
Trimble Bullet GPS antennas have a 50 ohm output impedance
Poul-Henning Kamp wrote:
In message [EMAIL PROTECTED], Dr Bruce Griffiths writes:
I can see the difference between the short 50 ohm cable terminated in 50
ohms and the short 50 ohm cable terminated in 75 ohms.
It would be instructive to repeat this with a short length of 75 ohm
cable
Didier Juges wrote:
It is true is that the impedance of a transmission line is not constant
with frequency, particularly at the low end (audio).
At the higher end, a lot of things happen, such as impedance,
attenuation and velocity factor all change (a little) with frequency.
Also, at the
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Chris
Christopher Hoover wrote:
Most (except
I think that the simplest explanation for the BIPM's recommendation that
the antenna cables be matched to the antenna output impedance and the
GPS receivers input impedance is as follows:
If one has gone to the trouble and expense of installing an antenna that
is relatively insensitive to
Hal Murray wrote:
Of course for phase comparison with the input, one actually does not
need much filtering as one is only using the NCO digital output as an
input to a phase comparator... spurs and so forth don't count at all
here as they get filtered out in the subsequent loop filter for
Stephan Sandenbergh wrote:
Hi All,
Say for instance you have a 5dBm clean 10MHz sinusoid (such as that provided
by an OCXO). Now you want to run this signal to a device that will take a
minimum of 10dBm and maximum of 15dBm as input. How does one amplify the
5dBm?
The first thing
Stephan Sandenbergh wrote:
Hi All,
Say for instance you have a 5dBm clean 10MHz sinusoid (such as that provided
by an OCXO). Now you want to run this signal to a device that will take a
minimum of 10dBm and maximum of 15dBm as input. How does one amplify the
5dBm?
The first thing
Stephan Sandenbergh wrote:
Hi Bill,
Judging by your question - that is probably something that I should do?
Considering that you'll attenuate the 5dBm signal to about 0dBm and then
amplifying it back up to about 10dBm. My gut tells me that by attenuating
the signal before amplifying it will
Stephan
Attached GIF file is the schematic for a common base amplifier with
about 12dB of gain into a 50 ohm load.
The amplifier will not saturate even if the load is open circuited.
Q102 temperature compensates Q103 which regulates the dc collector
current of the common base transistor.
Stephan Sandenbergh wrote:
Hi Bruce,
A great many thanks for all the hints and tips you gave me.
Yes, I have actually started working my way through Wenzel's hints tips
pages after I posted the first message. I remembered that you pointed me
there in a previous conversation we had.
I
Didier Juges wrote:
Dr Bruce Griffiths [EMAIL PROTECTED] wrote:
The RF amp IC's generally have inferior noise figures and reverse
isolation (20dB for RFIC, 40dB for common base stage) than a well
designed discrete common base amplifier. In fact by stacking common base
amplifiers
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Bruce,
In cases where the output signal does not need to be a sinewave, how would a
common base amplifier compare to a fast comparator and if necessary a
digital buffer as necessary to deliver the necessary power level
Ulrich Bangert wrote:
Bruce and Didier,
i had the opportunity to measure the output to output as well as the
output to input isolation of a diy MAX477 based distribution amplifier
very similar to the TADD-1 (but not identical). The output to output
isolation was in the order of 75 dB while
Howard W. Ashcraft wrote:
I am constructing a GPS disciplined OCXO using an HP10544a. If someone
has a copy of the HP manual/technical data for this oscillator, I would
appreciate getting a scan. I have already received, from a request on
the HP equipment listserv, a copy of an HP10544
Howard
I also have the July 1975, July 1976 10544A datasheets.
The phase noise floor specification is about 15dB lower in these later
datasheets.
The oven controller switching noise decoupling circuits were elaborated
to include a 10mH 0.75A inductor and a 200uf capacitor for filtring
the
Gerald Molenkamp wrote:
Hi Howard,
Please find attached a schematic of the 10544, hope it helps in anyway.
Regards
Gerald
Gerald
The connection of the 10K oven monitor resistor R12 in the schematic is
incorrect.
In this position only the very small deviations in the oven supply
Gerald
Its about 30 years since I had one of these apart for (sucessful) repair
without the aid of any circuit diagram.
At least one can calculate that the nominal crystal current is about 240
uA rms somewhat less than the 1mA in the 10811 with its SC cut crystal.
Bruce
Gerald Molenkamp wrote:
Howard
Attached GIf file depicts the recommended power supply filtering when
the oven circuit shares the same supply as the oscillator.
Bruce
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Don
Don Collie wrote:
Why not use an optocoupler as an isolation amplifier? - to the best of my
knowledge it would provide infinite isolation.
Cheers,...Don Collie
And lots of noise.
You will need a cleanup PLL on the output side.
Also optocoupler
Gerald Molenkamp wrote:
Hi Bruce,
You are right. I havn't checked my unit against the schematic at all. It is
well secured calibrated and operating in my HP 5342 operating well within
the specifications. The scanned schematic came from Leapsecond a few years
ago, and I have not had to use
CORRECTION
Judging from the oscillator and oven controller voltage ranges Tom's
scanned circuit is actually for the later production models of the
10544A with the improved phase noise specification. The input signal to
the oscillator buffer cascode was probably somewhat smaller than 76mV
rms
Lester Veenstra M0YCM wrote:
I have a bad 10544 (received from AST) that I am planning to look into.
No 10 MHz out and very low 12 VDC current.
Has anyone the translation from HP PN to Commercial equiv for the
semiconductors ?
Thanks
Les
Lester B Veenstra
M0YCM K1YCM
Lester Veenstra M0YCM wrote:
I have a bad 10544 (received from AST) that I am planning to look into.
No 10 MHz out and very low 12 VDC current.
Has anyone the translation from HP PN to Commercial equiv for the
semiconductors ?
Thanks
Les
Lester B Veenstra
M0YCM K1YCM
John Ackermann N8UR wrote:
I had a chance to measure a TADD-1 using an HP-3048 phase noise system
last year. I've attached a screen shot of the results; in short it was
below -140dBc/Hz from 100 Hz on out (by the way, I'm not sure I would
trust the noise floor shown in this test; I am not
Ulrich Bangert wrote:
Bruce,
I have seen this specs before but do you know how to find the
schematics?
Best regards
Ulric Bangert
Ulrich
NO, I'm still looking, I presume you mean the NIST amplifier schematics
and not the TADD-1 schematics at:
http://www.tapr.org/~n8ur/
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