Ulrich Bangert wrote:
Bruce,
I have seen this specs before but do you know how to find the
schematics?
Best regards
Ulric Bangert
Ulrich
Since the earlier NBS isolation/distribution amplifiers consisted of dc
coupled cascaded common base stages (according to Magnus who had looked
at
Christopher Hoover wrote:
The power supply noise may also limit the performance.
This is my major concern with the design.
Any noise on the supply rail goes into the first stage via the bias network,
and is transferred at whatever gain to the output.
I noticed that when I used a
Richard W. Solomon wrote:
I got a junker HP 5328A Counter and salvaged the Time Base and the
circuit board it is on. Does anyone have the schematic for it
Thanks,
73, Dick, W1KSZ
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Chris
Christopher Hoover wrote:
The TI regulators are, from my perspective extremely noisy, one can do
much better at least for higher output voltages.
They also don't have a high enough output for the TADD-1.
Agreed, that that regulator doesn't have sufficient margin for the entire
Christopher Hoover wrote:
Agreed, that that regulator doesn't have sufficient margin for the entire
TADD-1.
I was suggesting using the low-noise high PSRR linear reg only to establish
the bias level.
There are indeed better parts. This one looks pretty good for an
integration solution
://www.ko4bb.com/Test_Equipment/AvalanchePulser
Now, I just need a scope fast enough to take advantage of such a short
rise time. Back to eBay again :-)
Didier
Dr Bruce Griffiths wrote:
Didier
You can always build your own 100A avalanche transistor pulser using
several Zetex FMMT413s.
Bruce
Those who like tinkering with their rubidium standards may find the
following paper of interest
http://tf.nist.gov/timefreq/general/pdf/1013.pdf
You can potentially drop the Allan deviation of a rubidium package by a
factor of ten using the modification detailed in the paper.
Bruce
Christopher Hoover wrote:
Those who like tinkering with their rubidium standards
may find the following paper of interest
http://tf.nist.gov/timefreq/general/pdf/1013.pdf
This is very interesting, indeed, and a very nice practical, follow-on work
from the theory paper by
For those who would like to improve the phase noise of the output of a
digital divider or who would like a good reason to using DDS instead see:
http://tf.nist.gov/timefreq/general/pdf/1380.pdf
Bruce
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Those who maintain that its OK to use 75 ohm GPS antenna cable should read:
http://tf.nist.gov/timefreq/general/pdf/1380.pdf
Bruce
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Christopher Hoover wrote:
Those who maintain that its OK to use 75 ohm GPS antenna
cable should read:
http://tf.nist.gov/timefreq/general/pdf/1380.pdf
(I think you pasted the wrong URL.)
While I provided the quote from the Thunderbolt manual that said, according
to Trimble, that 75Z
Rob Kimberley wrote:
Interesting paper. I agree that for nanosecond timing applications then
antenna cable and matching are important. However, for frequency sync
applications and non-critical timing, then the effects of the 75 vs. 50 ohm
cable will not be noticeable.
Rob K
Those who
Steve1 Baillargeon wrote:
Is this link correct? I don't see refrences to antenna cables?
No a slight typo should have been
http://tf.nist.gov/timefreq/general/pdf/1384.pdf
Bruce
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Jeroen Bastemeijer wrote:
Dear Time-nuts,
New info on an old subject:
I opened the counter (5345A) to check what kind of oscillator was
inside. It was a 10544A instead of a 10811A!!!
I checked for a datasheet of the 10544 but I couldn't find it. Luckily I
ran across an article in HP
Didier Juges wrote:
does not have an OCXO, I think.
I remember seeing a number of postings on time-nuts (must have been
Bruce) advocating the increased performance of carrier phase tracking,
but I need to educate myself about what it is and what good it can do
for me :-)
Any feedback
Didier Juges wrote:
On a different subject, I just won a Novatel Superstar 2 GPS receiver
advertised to do carrier phase tracking. It's specification lists a
timing accuracy of 50nS typical, which is not bad at all for a GPS that
does not have an OCXO, I think.
I remember seeing a number
Brooke Clarke wrote:
Hi Didier:
Many GPS receivers output carrier phase data but it's usually used in
post processing to get survey grade position accuracy. Since the code
phase position accuracy is larger than a wavelength the receiver does
not know how many integer wavelengths to add.
Brooke Clarke wrote:
Hi Bruce:
Is there a paper describing the method?
Have Fun,
Brooke Clarke
Have Fun,
Brooke
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com
Dr Bruce Griffiths wrote:
Brooke
Yes I
Magnus Danielson wrote:
http://tycho.usno.navy.mil/ptti/ptti99/PTTI_1999_405.PDF
There is another paper just before it. There is also a patent for a
specific
form of implementation.
Note they used an Oncore VP, the Superstar has a better carrier phase
tracking.performance.
Hej Magnus
Magnus Danielson wrote:
An interesting product originating from Mitel (Mike and Terry's
lawnmowers later became MITEL - according to their local rep about 20
odd years ago)
Hehe... yeah, I know it was in the Mitel days they started this. I even
beleive
that the GPS
Magnus Danielson wrote:
From: Dr Bruce Griffiths [EMAIL PROTECTED]
Subject: Re: [time-nuts] 5370B on eBay, carrier phase tracking GPS receiver
Date: Mon, 19 Feb 2007 23:39:47 +1300
Message-ID: [EMAIL PROTECTED]
Hej Magnus
Hej Bruce,
Fuller version is that the later Mitel
Rob Kimberley wrote:
Interestingly, no one has mentioned the Augmentation systems like WAAS or
EGNOS where wide area correction data is transmitted down from INMARSAT to
improve nav accuracy. Primarily aimed at improved aircraft navigation
systems, it has a benefit for timing users. Zyfer have
Didier Juges wrote:
Magnus Danielson wrote:
You can acheive much greater speedup by a combined frequency/phase approach.
You will get a very accurate frequency error estimate, so you will very
quickly be close enought to go into phase lock. At least if your clock isn't
too noisy. So, the
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier
Typically with a good local oscillator you can do even better than that,
around 1E-11 in 1 sec is achievable and has been achieved.
Even with the on board TCXO typically 3E-11 or so in 1s is achieved.
Bruce
I don't
Didier
Didier Juges wrote:
Hi Bruce,
Dr Bruce Griffiths wrote:
Bon soir Didier
You are confusing the disciplining precision of the oscillator with
measurement of its short term stability via the GPS receiver in this case.
Bruce
Bon après midi to you, I believe, and if my
Didier Juges wrote:
This is somewhat off topic, but still a matter of precision timing.
A friend of mine wants to send a 3 GHz LO signal up a fiber optic cable.
I know there have been threads dealing with transmission of precise
timing signals over fiber optics, and I hope I can get some
Didier Juges wrote:
This is somewhat off topic, but still a matter of precision timing.
A friend of mine wants to send a 3 GHz LO signal up a fiber optic cable.
I know there have been threads dealing with transmission of precise
timing signals over fiber optics, and I hope I can get some
Didier Juges wrote:
This is somewhat off topic, but still a matter of precision timing.
A friend of mine wants to send a 3 GHz LO signal up a fiber optic cable.
I know there have been threads dealing with transmission of precise
timing signals over fiber optics, and I hope I can get some
Didier Juges wrote:
This is for a price sensitive commercial application, not a science
project and he is trying to minimize the amount of hardware at the far
end for cost and maintenance reasons.
A cleanup PLL becomes very costly when dealing with a frequency agile
system.
Thanks
for
the HP-Journal article.
Best regards, Jeroen
Dr Bruce Griffiths wrote:
Jeroen
This means that the revised specifications apply to your oscillator, The
1976 datasheet will be applicable as will the circuit diagram that is
available.
Bruce
Didier
Additional references
http://www.nt.hs-bremen.de/peik/rof/literatur/ROF-franz-presentation.pdf
http://www.plextek.eu/brochure/rffiber.pdf
http://www.opticalzonu.com/products/oz400TR.pdf
As you may glean from the above you wont be able to achieve anything
useful unless the laser is
Didier Juges wrote:
Bruce,
The more I read the specs, the more obvious it becomes. I did not
realize how jittery these things are.
I am still trying to get more info on how clean the LO has to be, but I
am pretty sure it will be close to telecom specs.
Thanks,
Didier
Didier
One
Didier Juges wrote:
Bruce,
I have read about this, noise performance also is not good for analog
transmissions, causing very limited dynamic range.
That's probably why they use either FM or digital coding in just about
all applications.
I just did not think the jitter would be so bad,
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Bruce,
I have read about this, noise performance also is not good for analog
transmissions, causing very limited dynamic range.
That's probably why they use either FM or digital coding in just about
all
Jared Morrisen wrote:
Interesting piece...
*Weak Enforcement of Corporate Governance and Lax Technical Controls Have
Enabled the Illegal Backdating of Stock Options*
*Conclusion*
The backdating fiasco demonstrates that the need for synchronized time is a
crucial business and technology
Magnus Danielson wrote:
I don't have the manuals (and particular the service manual) for the
SR620,
does anybody have them in electronics form?
Cheers,
Magnus
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[EMAIL PROTECTED] wrote:
I've done the self calibration. Nothing changes. I've let everything
warm-up and checked both channels A and B, same thing. I've swapped the
cables on the front and the back, same thing. I've tried a T-connector on
the ref input with 50ohm termination, same
Mike Fahmie wrote:
At 02:57 PM 2/21/2007, you wrote:
I have an SR620 counter that I set up with a Z3801A as an external
reference. If I put a bnc T connector at the output of the Z3801A and use
two equal length bnc cables, one to the ext. ref input on the back and the
other to channel
setup with my other counter and it read 10,000,000. or
thereabouts correctly. So rule out the GPSDO and the cables.
- Original Message -
From: Dr Bruce Griffiths [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Wednesday
[EMAIL PROTECTED] wrote:
...if my model is correct the apparent offset in the
mean will be increased by a factor of 10 over that for a a 1 second gate
time.
Bruce
Looks like you're right Bruce. I did both 1, 0.1 and 0.01 gate times and
the error increased by a factor of 10.
And
Jared Morrisen wrote:
And just how does this prevent someone altering the files's timestamp?
Not sure what your point is.
/jared
Jared
Just ensuring that the computer clock is accurate, doesn't prevent
anyone from tampering with the file timestamps as well as the
documentation
Didier Juges wrote:
Dr Bruce Griffiths wrote:
[EMAIL PROTECTED] wrote:
...if my model is correct the apparent offset in the
mean will be increased by a factor of 10 over that for a a 1 second gate
time.
Bruce
Looks like you're right Bruce. I did both
[EMAIL PROTECTED] wrote:
1. Same test with a Fluke 6680 yeilds 10MHz mean exactly.
2.Tried different length cables and swapping the cables. Same result.
3. Autocal was done (a few times)
- Original Message -
From: Tom Van Baak [EMAIL PROTECTED]
To: Discussion of precise time
John Miles wrote:
What do people observe on their 5370A/Bs? After warmup, I tend to see a
bias of about +0.0005 Hz, or 5E-11, when observing its own 10 MHz source.
There is some occasional random waffling on the order of about +/- 0.001 Hz
but for the most part it reads close to 10.000 000
Hal Murray wrote:
Every time I dig through the 5370 schematics, I think to myself
wouldn't it be nifty to build a replacement plug-in card with a
modern fast CPU to run the instrument, but I try and stop myself
there.
Suppose you start with an FPGA on a PCI card.
What sort of front
Hal Murray wrote:
Every time I dig through the 5370 schematics, I think to myself
wouldn't it be nifty to build a replacement plug-in card with a
modern fast CPU to run the instrument, but I try and stop myself
there.
Suppose you start with an FPGA on a PCI card.
What sort of front
[EMAIL PROTECTED] wrote:
Hi Bruce,
would you have some sample schematics for a more modern, faster version of
this than let's say the one used in the 5334A etc that you could share?
thanks,
Said
Said
The Attached GIF file illustrates one possible approach to a TAC using
discrete
[EMAIL PROTECTED] wrote:
Hi Bruce,
would you have some sample schematics for a more modern, faster version of
this than let's say the one used in the 5334A etc that you could share?
thanks,
Said
BRBRBR**BR AOL now offers free
email to everyone.
Hal Murray wrote:
If I understand things correctly, when a box like the 5334 takes a sequence
of frequency measurements, each measurement has a start time and a stop time.
For each measurement, you get out the number of ticks (including fraction)
on the input signal between those times
Angus wrote:
I don't know whether the outputs on a Jupiter exhibit any granularity
or not (I've not seen anything to suggest that they do), but I think
that with receivers that do, changing from 1PPS to a faster PPS output
would normally change the granularity effects that are seen - assuming
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Angus wrote:
Although that's not what I was talking about doing above, I think that
it's pretty much what some of the hardware GPSDO's actually do using
various types of oscillators (and to good
Larry Gadallah wrote:
Hello all:
I considering a do-it-yourself GPSDO, and I started by looking for a
good OCXO. I have been given a quote for a unit with the following
phase-noise numbers:
-120 dBc/Hz at 10 Hz
-145 dBc/Hz at 100 Hz
-155 dBc/Hz at 1 kHz
-160 dBc/Hz at 10 KHz
-160 dBc/Hz
Stephan Sandenbergh wrote:
Hi all,
How difficult is it to multiply a frequency standard from 10MHz to 100MHz?
I found the recent discussion about amplifying a 10MHz OCXO output from 5dBm
to 15dBm very interesting. Thanks Bruce for sending me that common base
circuit schematics - I
Larry Gadallah wrote:
On 2/28/07, [EMAIL PROTECTED] [EMAIL PROTECTED]
wrote:
Message: 6
Date: Thu, 01 Mar 2007 12:05:38 +1300
From: Dr Bruce Griffiths [EMAIL PROTECTED]
Subject: Re: [time-nuts] Good Phase-noise?
To: Discussion of precise time and frequency measurement
time-nuts
Larry Gadallah wrote:
Hello Bruce:
Larry
Obtaining a lower phase noise COTS OCXO in this price range is unlikely
unless Wenzel oscillators are unusually cheap.
http://www.wenzel.com/catalog.html#HF%20Oscillators
Is Wenzel the leader of the pack in this sort of technology? I know
that
Stephan Sandenbergh wrote:
Hi Bruce,
Thanks for explaining - the picture is starting to become clearer. I knew
there must be a reason why commercial multipliers are so expensive.
If I understand you correctly the variation in phase (or group delay) caused
by a variation in temperature
Pete wrote:
Bruce,
Can you please provide some references to phase noise problems/performance
of the passive components you mention?
Pete Rawson
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David I. Emery wrote:
On Fri, Mar 02, 2007 at 04:02:39AM +1300, Dr Bruce Griffiths wrote:
Its not just the temperature coefficients, real inductors and capacitors
have inherent phase noise.
Silver mica capacitors can be very bad as are ferrite core inductors.
Mylar capacitors are good
Ulrich Bangert wrote:
Hi foks,
I want to put forward a similar but slightly different question:
Suppose I need an clock running at around 50 Mhz for an DDS. Because of
the DDS it need not be exactly 50 MHz, can be 52 or 54 MHz too.
Basically this clock shall be derived from a 10 MHz source
Bilal Amin wrote:
Hi Everyone,
I am working on Jitter in Analog to Digital Converters(ADCs) for GPS receiver
front-end. I am trying to setup an experiment to see the effects of jitter in
real time ADCs. I have an ADC evaluation board with external clock input for
sampling (i.e Sampling
Bilal Amin wrote:
Hi Everyone,
I am working on Jitter in Analog to Digital Converters(ADCs) for GPS receiver
front-end. I am trying to setup an experiment to see the effects of jitter in
real time ADCs. I have an ADC evaluation board with external clock input for
sampling (i.e Sampling
Stephan Sandenbergh wrote:
Hi Said,
The DDS idea that you (and Ulrich) suggest sounds like a good plan.
However, to me your predictions sound overly optimistic.
Said wrote:
But let's say these are as good as advertised, and for me that would mean
say better than -95dBc/Hz at
Stephan Sandenbergh wrote:
Darn, the table is a mess. Here is the corrected one:
LVPECL Outputs
HzdBc/Hz
1 ?
10-127
100 -145
1k-153
10k -158
100k -158
1M-158
10MHz OCXO
HzdBc/Hz
1 -100
10-130
100 -152
1k-160
10k -165
100k
Bilal Amin wrote:
- Original Message -
From: Dr Bruce Griffiths [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Friday, March 02, 2007 6:10 PM
Subject: Re: [time-nuts] External clock for Analog to Digital Converter in
GPS Rx
Bilal Amin wrote:
Hi John,
Thank you for your email. I am also looking at the PM method to solve my
problem. I have a HP signal generator and I can use it to generate an RF
signal and then modulate it with noise from the modulating input of the
signal generator.
I need some suggestion
John Miles wrote:
You can easily add noise to a sinewave, for example a hybrid combiner
can be used to combine the output of a sinewave generator and a noise
source.
That's just going to create AM noise, isn't it? He wants jitter (phase
modulation), I believe.
-- john, KE5FX
John Miles wrote:
Well, sure, but it also causes all kinds of secondary distortion effects
(such as potential clipping at the rails of whatever you're feeding the
signal into). I don't think AM'ing the signal when you want PM is a good
idea, when it's so easy to apply PM by itself.
-- john,
Bilal Amin wrote:
Hi John and Bruce,
Thank you for your ideas. Now I have a much better picture for the
experiment using the comparator. Now, my only concern is a noise generator.
I have searched and found out that all the commercially available now
generators are very expensive and some
Bilal Amin wrote:
Hi John and Bruce,
Thank you for your ideas. Now I have a much better picture for the
experiment using the comparator. Now, my only concern is a noise generator.
I have searched and found out that all the commercially available now
generators are very expensive and some
Arnold Tibus wrote:
Hi,
HP was using in their 500MHz counter 5345A a noise generator
(zener diode with amplifier on PC board 'A8 PLL Multiplier Noise Generator
board') to modulate via a varactor and a tank circuit the 10 MHz
reference frequency coming from the ocxo 10811A.
4-126, As the
Tom Van Baak wrote:
Don,
Yes, using an oscilloscope in this way is a time-honored
trick to observe slow changes in relative phase over time.
It gets even better if you have access to a storage 'scope
or variable persistence because then you can get a rough
sense of short-term jitter as
Dr Bruce Griffiths wrote:
Tom Van Baak wrote:
Don,
Yes, using an oscilloscope in this way is a time-honored
trick to observe slow changes in relative phase over time.
It gets even better if you have access to a storage 'scope
or variable persistence because then you can get a rough
Arnold Tibus wrote:
Thanks Bruce,
'it generates poses some interesting challenges'
sounds interesting, could you give some little details
to get better idea of it?
many thanks,
Arnold, DK2WT
Arnold
As can be seen from the attached schematic, the 50X frequency multiplier
simplifies
Bill Janssen wrot
I built my own version of this scheme and it works OK but mine has some
issues
So I would like to have at least three of these.to replace my one.
Anyone willing to take on the job of designing a circuit board?
I log my results with a A-D converter and my Basic program
VK3YV wrote:
Hi, Tom and Bruce, many thanks for the help so far. Now I realise that I
will have to divide my 10MHZ reference down to match the 5MHZ from the
sulzers and also down to 1MHZ to use as an external ref. for the 5245L's.
How do I change the TTL from the dividers back to a Sine wave
Bill Janssen wrote:
I built my own version of this scheme and it works OK but mine has some
issues
So I would like to have at least three of these.to replace my one.
Anyone willing to take on the job of designing a circuit board?
I log my results with a A-D converter and my Basic
Hal Murray wrote:
I can design a suitable circuit but may need someone else to do the
layout as my PCB layout software is rather ancient.
I'll be willing to turn the crank on the board layout as long as a few people
are willing to double check whatever I do. (and nobody is in a
Robert Atkinson wrote:
Hi Bruce,
It's a while since I looked at the HP circuit and patent, but if I
recall correctly a lot of the performance relied on the input circuit.
This used a line receiver with feedback. When I looked there did not
seem to be an equivalent receiver chip available. I'm
The attached schematic depicts the logic circuitry for the revised phase
comparator
Each of the 2 phase outputs is low pass filtered and buffered by an opamp.
Specifications:
Max input frequency 20MHz
2 quadrature phase outputs.
nonlinearity 5nS at either end of range.
Input voltage (at
Jeroen Bastemeijer wrote:
Dear All,
I have problems accessing the 5370A manual on the Agilent website?!
Accessing the 5370B manual is nor problem. Any suggestions?
Thanks, Jeroen
Jeroen
Try
http://www.g8wrb.org/data/HP/HP5370A.pdf
Bruce
Robert Atkinson wrote:
Hi Bruce,
It's a while since I looked at the HP circuit and patent, but if I
recall correctly a lot of the performance relied on the input circuit.
This used a line receiver with feedback. When I looked there did not
seem to be an equivalent receiver chip available. I'm
Dr Bruce Griffiths wrote:
Lars Karlsson wrote:
Bruce-
There is a minor problem in the schematic. A capacitor have to be added
between R103 and R104. This will prevent the bias on pin 3 from
being shorted to the ground via R101 and R102. Also, C103 is not
required
as long as the diodes
The attached input circuit schematic has values for all components.
Bruce
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Brian Kirby wrote:
Can anybody recommend a low drop out voltage regulator that will work
with a 2 volt input differential, and a output of 22 volts at 2 amps ?
What I have in mind is a 28 volt DC power supply, and 24 volt batteries,
and a rubidium oscillator that will run at 22 volts.
Brian
Dr Bruce Griffiths wrote:
Brian Kirby wrote:
Can anybody recommend a low drop out voltage regulator that will work
with a 2 volt input differential, and a output of 22 volts at 2 amps ?
What I have in mind is a 28 volt DC power supply, and 24 volt batteries,
and a rubidium oscillator
Tim Shoppa wrote:
John Ackermann N8UR [EMAIL PROTECTED] wrote:
But we're time-nuts... we DO worry about those things. :-)
While we were at it with the network analyzer, we did FDR (frequency
domain reflectometry) to measure the cable delay to the antenna, and I
spent yesterday making
Tim Shoppa wrote:
Dr Bruce Griffiths [EMAIL PROTECTED] wrote:
At the lab I worked at in the 80's, all the cables hanging on
the wall-racks were calibrated and labeled in nanoseconds.
But... after the ECL signals got turned into TTL, we just didn't
care anymore :-).
Your
Hal Murray wrote:
So the cable delay should be a multiple of 317.375...ps.
What's the thermal coefficient of coax?
Typically around 50-100ppm/C depending on the coax.
High velocity cables have lower tempcos
Handwaving...
100 ft of cable is 70ns or 7ps.
100ppm
Tom Clark, K3IO wrote:
I just stumbled on an excellent tutorial on low-noise clocks --
National Semiconductors free downloadable [1]Clock Conditioner
Owner's Manual. This 88 page document is a 3.7 MB PDF.
73 de Tom, K3IO
References
1.
Matt Ettus wrote:
I was just investigating this very issue. It seems that every program
you use to compute these impedances comes up with different answers,
sometimes wildly different. Anyone have a free program they trust
with this sort of thing?
Matt
On 3/14/07, Dr Bruce Griffiths
Hal Murray wrote:
http://www.kvarz.com/pdf/05%20CH1-75A.pdf (Active MASER)
http://www.kvarz.com/pdf/06%20CH1-76A.pdf (Passive MASER)
What do active and passive mean wrt masers?
From the above data sheets, active means bigger and better. (and probably
more expensive)
Hal
Bilal Amin wrote:
Hi Everyone,
Some days back I emailed on the group regarding the jitter in the sampling
clock of ADC. I have tried the phase modulation method for producing the
jitter.
I used the HP 8648B Signal generator for this experiment. I modulated the RF
wave (at 10 MHz) with
Didier Juges wrote:
Even though you may have to be careful about noise, and assuming the
operating voltages are not exotic, you can probably find an
off-the-shelf switching supply that will fit where the transformer and
linear supplies were, with lots of room to spare, and significantly
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier Juges wrote:
Even though you may have to be careful about noise, and assuming the
operating voltages are not exotic, you can probably find an
off-the-shelf switching supply that will fit where the transformer and
linear
Didier Juges wrote:
Dr Bruce Griffiths wrote:
Didier
Try using a Murata BNX002 filter between the switching supply output and
the linear regulator input.
These should eliminate the High frequency noise (0.5MHz - 1GHz) from the
switching regulator output leaving the linear regulator
Hal Murray wrote:
How do modern pendulum clock geeks measure what their pendulum is doing? I'm
picturing a magnet on the bottom of the pendulum and a coil or hall effect
sensor.
A variation on this would be optical as in CD reader technology. Put a
pattern on the bottom of the
Hal Murray wrot
The hardware used for bar code scanners might be a useful starting place. I
assume you would have to hack the firmware/whatever to output time/position
info rather than bar code data.
My initial thought was that you would put one read head directly under the
middle of
[EMAIL PROTECTED] wrote:
In a message dated 3/29/2007 21:33:44 Pacific Daylight Time,
[EMAIL PROTECTED] writes:
_http://arxiv.org/PS_cache/physics/pdf/0503/0503015.pdf_
(http://arxiv.org/PS_cache/physics/pdf/0503/0503015.pdf)
Hi Bruce,
Isn't a -200dBc/Hz floor below the thermal
Mike Feher wrote:
Well, I must admit I did not read the referenced article, but, he is talking
about dBc, or relative to the carrier and not kT. So, if the carrier power
is high enough I suppose it could be done. Even suppose you could measure
it, what would it take to generate such a pure
The following papers may be of some interest to anyone contemplating
building a low noise low frequency (dc -100kHz) amplifier.
Such an amplifier would be useful, for example, after a double balanced
mixer in a conventional phase noise measurement system.
201 - 300 of 465 matches
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