Just brainstorming here, but how about this un-conventional approach:
Use a CSAC as a precise frequency reference for the LEA-6T. CSAC should
operate at 0.12W, I know, that's a lot, but maybe just worth a try.
To make the CSAC work, multiply the 10MHz up to the 26MHz the LEA uses.
Then
Hi Wolfgang,
one of the easiest and very accurate ways to do this is simply to measure
the drift of the two 10MHz signals on an oscilloscope. Adjust the OCXO so
that this drift between the two traces is as slow as you can get it. Then
simply measure it over time. Use one signal for
Depends on the scope..
if your scope has 100ps A-to-B measurement resolution, then waiting 5
minutes in this scenario would give 0.83ns drift, with 100ps uncertainty IF
your
oscillators were synced to ~3ppt which is very tough to do with a
free-running OCXO (It would be unrealistic to get
Haven't run into that battery problem.. but rented the 51717 from an Ebay
offerer for low $$ in the past.
I simply sent him an email saying, I see you are selling that unit in your
ebay store, can I rent it from you for a week?
And he did..
I did have a power supply go bad, and simply
Hi guys,
I am very partial to the HP Denali 54720D scope which is available on Ebay
in varius forms for around $1500.
This $50K+ when-new scope is very easy to use, has many low cost plug ins,
8GS/s with up to 2GHz Bandwidth plug ins available, and the amazing 54701A
FET probe. Support
Hello guys,
the cat is out of the bag, most of the Jackson Labs Technologies GPSDO
units and oscillators are now available from Symmetricom as well:
_http://www.sacbee.com/2012/04/12/v-print/4408812/symmetricom-now-offers-gps
-disciplined.html_
Hi Attila,
if I remember correctly, the issue is that the ground at the house is
not a real ground when the earth is frozen, as the resistance of frozen
earth goes up substantially over non-frozen earth. So it's like not having
grounded the wires at all.
This is a real issue for cables
Hi Bjoern,
Possibly, I am just reciting what I read in the Nordig requirements a
looong time ago. Maybe they are worried about far north permafrost scenarios
that go deeper? The requirements for receiver RF input surge protection were
much higher than the usual US requirements..
bye,
Paul,
there is a large unit-to-unit performance variation on these type of
products, you may have a very good 10811 OCXO in the HP unit, and a so-so OCXO
in the Thunderbolt.
This is normal, see Tom's measurements of different Z3801 units against
each other, some are way better than
Hi Ed,
no problem. It's an issue when some companies claim 2ns, when it's really
5ns. Or show phase noise plots that seem to be measurements of just the
oscillator removed from the board and measured in a clean-room environment,
not measurements of the module with all the digital control
Here is a trick or two that may work:
feed a very small AC voltage with say 1KHz and 10mV into the bad power
rail. It won't hurt anything.
Then use an old cassette players' magnetic pickup and amplifier to follow
the signal to the short. No need for expensive hall effect meters.
Another
Shouldn't be too bad, a 10uF cap would have 15 Ohms impedance at 1KHz, 150
Ohms at 100Hz, and one could inject at different places on the trace...
away from the big bypass caps.
Doing the same with DC and a simple multimeter should work too.
bye,
Said
In a message dated 3/23/2012
Jim Williams wrote an appnote on how to do this with ~100ps resolution with
a small number of parts.
I think it was mentioned before and should be in the time nuts archives..
His circuit can be modified without much effort for higher resolution.
bye,
Said
In a message dated 3/21/2012
Two suggestions:
How about using an off-the-shelf Wavecrest counter?
These have a 0.8ps resolution, and typically have a noise floor of around
3ps when averaging. They certainly can do 10ps single shot. There is a
DTS-2050 on Ebay now for $700: item number 120647180882
You can't get much
Hello guys,
looking for a very good oscillator (OSA 8607 BVA or similar) with
known-good STS from 0.1s to 100s and longer of a couple of parts in the E-13's.
Does anyone have anything for sale? I would take a Hydrogen maser too if
that's priced right :)
Would prefer 10MHz, but 5MHz
Forgot to mention:
please contact me off-list so we don't bother the rest of the lot here.
Thanks,
Said
In a message dated 3/9/2012 12:30:47 Pacific Standard Time,
saidj...@aol.com writes:
Hello guys,
looking for a very good oscillator (OSA 8607 BVA or similar) with
known-good STS
Sorry for my language, I was quite upset when I read his letter.
If it really was trivial and very low cost to upgrade GPS receivers, then
he should not worry too much about loosing much revenue. This sounds more
like he made major investments in either Lightsquared itself, or into
I'm sorry, but Mr. Javad is on crack.
A simple WAAS upgrade on a GENERAL AVIATION aircraft already costs about
$8000 fully installed.
This includes an antenna upgrade that I remember to be about $3000
installed for the antenna itself.
$500 per plane to fix the issue? Yeah right. In what
All the chip vendors sell parts in China in quantity for about 30% to 50%
less than quantity pricing in the US.
When asking distributors in China how this is possible they say we Chinese
expect this pricing, otherwise we wouldn't use these parts
This is why it's so hard to compete with
Cool!
That part looks like it will do the job, thanks very much Eric.
On the I2C driver, I ported the NXP I2C library from 8051 to NXP ARM a
very long time ago, it was quite a bit of work to make it work properly. Lot's
of bugs I had to fix.. and could only do that with a Philips I2C
Nowadays you can simply download the design software for free from the fab
houses.
Try PCB 123 from sunstone.com
Good shop, reasonable prices for quick protos.
bye,
Said
In a message dated 2/23/2012 16:39:12 Pacific Standard Time, j...@jxh.com
writes:
What do people use these days
Hello Bill,
this is potentially possible with the small M9108 or the Jackson Labs
Technologies GPSTCXO.
Some caveats:
1) The Trimble Resolution-T May work, but the above stated units have a 50
channel WAAS/EGNOS/MSAS GPS receiver and are also GPS Disciplined
Oscillators not just timing
In a message dated 2/19/2012 21:21:35 Pacific Standard Time, wb6...@cox.net
writes:
Doing a few fixes for 30 minutes will, under best conditions, get you
somewhere on a circumference around your location with a radius of 15 meters
(50 feet). For GPS to get a useful coordinate result with
Hi Bill,
the good news is that industrial units are becoming as inexpensive as hobby
type units..
bye,
Said
In a message dated 2/19/2012 21:48:36 Pacific Standard Time, wb6...@cox.net
writes:
Hi Said,
That may be, but I think he indicated he was using the common hobby type
units.
Hi Bill,
should have added a disclaimer, I am involved with Jackson Labs Tech..
The Trimble part with oscillator looks interesting, probably an NCO not a
GPSDO I would think. They are as usually not putting any real data in their
specsheets.. The TCXO they are using will determine
Hello team,
I am trying to get an HP 3048A system up and running, and I am having
problems with enabling spec limit lines on the graph.
I can enter the spec line data under the manipulate results then spec
lines menu, but the lines I entered are not visible. There are the standard
spec
Simple:
the ublox will just work when you apply power and have a good antenna. The
Motorola units have all sorts of idiosyncrasies, such as sometimes taking a
very long time to achieve a lock, having the Almanac get corrupted and not
lock when the battery backup is getting low, having
Hello Tom,
haven't tried the raw data capture yet. It would be nice if they would have
added support for USB thumb drives to store this type of data, and plots
etc.
But it does have internal RAM, they could have allocated a Mbyte or so for
data-storage..
BTW: my unit used to reset
Will try it John!
Thanks,
Said
In a message dated 1/4/2012 21:35:00 Pacific Standard Time, jmi...@pop.net
writes:
Grab the latest release from www.miles.io/timelab/readme.htm if you like --
it will acquire from the TSC 5125A for as many hours/days as the TSC's
Ethernet connection will
These Conner Winfield (Navsync) parts are not GPS Disciplined Oscillators,
many folks are initially fooled by this.
They use digital phase hopping techniques to generate something close to
10MHz. You can see the 10MHz 100ns phase jump around on a scope.
I believe their FTS250 and 125
Hello Azelio,
we looked at one here ordered from Digikey, and it had two VCXO's/TCXOs.
They did not use any OCXO's.
Lot's of folks ask us why the CW parts are lower cost than real GPSDO's, I
guess now we know..
bye,
Said
In a message dated 1/4/2012 12:33:34 Pacific Standard Time,
Hi Ed,
sorry to hear that, contact me off-list and I will try to solve your
problem. I tried sending you an email, but my mails must be getting filtered by
your spam filter..
bye,
Said
In a message dated 1/4/2012 11:33:14 Pacific Standard Time,
ed_pal...@sasktel.net writes:
On
yes, see that now, looks like the OCXO option about doubles the price of
the unit on Digikey..
In a message dated 1/4/2012 13:56:59 Pacific Standard Time,
azelio.bori...@screen.it writes:
It depends on the option ordered: the FTS125s we have are FTS125-COO
(double OCXO) the -CTV option
Hi Graham,
the TSC5125A has auto-scaled the plot to 2E-04Hz fractional frequency from
10MHz, or in other words one vertical division is 2E-011 at 10MHz, or 20
parts per trillion, or 0.0002Hz error.
I also don't like the way the TSC shows the frequency, and the fact that
you can only
Yes, it is the most amazing time nut tool! The older TSC5115A is also
amazing.
I consider myself very lucky...
bye,
Said
In a message dated 1/4/2012 14:17:48 Pacific Standard Time,
azelio.bori...@screen.it writes:
Wow, have you a TSC5125A? Lucky you...
On Wed, Jan 4, 2012 at 11:12 PM,
Yes, and the new uBlox timing GPS have a software jamming sensor and
indicator which the Motorola/iLotus products do not have, and they are much
easier to get to work at a users' site than the Motorola parts, and much more
robust against jamming than the Motorola timing GPS. We have done
Running it at 5V with a Ref out at 4.8V would seem too close. Maybe it's a
12V part?
If nothing else this could be a very stable, ovenized 4.8V lab reference
source..
Is anyone planning to monitor the aging/stability/noise of this reference?
bye,
Said
In a message dated 12/23/2011
Hi there,
maybe this has already been discussed here.. There is a small hole on the
side of the unit with a small trim-pot visible through the hole. Does anyone
know if this is an analog frequency adjustment?
If it is, maybe that trimpot connection can be used as disciplining input..
Hi Attila,
I like 2MHz switchers because they use small components (inductors and
capacitors) and are easier to filter out at our usual frequencies of interest.
The LT3502A for example works at 2.2MHz, which gives harmonics at 8.8MHz
and 11MHz, far enough away from 10.0MHz to avoid
Were getting of off the original thread about Electrolytics versus other
caps a bit..
A switcher at 2.2MHz does not have single frequency spikes in its power
spectrum, but a rather wideband distribution.
Yes, that's Fourier 101 basics.
But what matters to Time nuts is if the switcher is
Electrolytic caps have an extremely poor lifetime (MTBF). Sanyo on their
website state 50K Hrs at 50C.
This means only 6250 MTBF hours at 80C for one single cap. MTBF gets worse
the more caps are being used of course. I have seen some Panasonic
electrolytics state only 2000 hours MTBF at
As Bob Pease used to say: Spice plots are good for padding bird cages, not
much else :)
Hittite has a fantastic new ultra low noise LDO for VCO's. Haven't had a
chance to check that out, but it looks very promising. Has anyone tried that
part here?
Also, remember that those caps are
Hi Attila,
please share the document with us.
Thanks,
Said
In a message dated 10/20/2011 22:28:19 Pacific Daylight Time,
att...@kinali.ch writes:
That's also my impression. It was only after i had a longer
discussion with one of the user support guys about the exact
specs of the 6T
Hi Tom,
I am very eager to see lab reports of low-cost combined
GPS+GLONASS receivers. I bet Said has good info on
the u-blox 4T vs. 5T vs. 6T but now that he's selling to us
instead of sharing with us, you've noticed how quiet he
is about all this.
Sorry, haven't posted as much info as
Bert,
one would typically limit the loop bandwidth to something much lower than
10KHz. Say 100Hz.
This way at 10KHz the ADF4001 would have no effect on phase noise, it would
be almost entirely determined by the TCXO itself.
This is because a 10MHz reference would have to have to be
Hi Rick,
In my experience the 53132 is not good for ADEV measurements below 100s. It
is just way too noisy.
You can try longer measurement gate and averaging times, but theoretically
the SD value should be similar for 100s or 1000s SD measurements if what
you are measuring is actually
Hi John,
use gravity.
Turn the unit upside down, and see if it makes the error go away. Try all 6
faces.
Maybe you find one where the g-sensitivity of the crystal brings the efc
to below 90% again.
Easy and non-invasive to do. You may see a couple of ppb change in crystal
frequency as
Hi Dan,
the CSAC has been discussed here a couple of months ago. I will use your
post as a shameless plug of our CSAC GPSDO that we did in cooperation with
Symmetricom, as we are now allowed to talk about the product.
Here is a brochure, press release, user manual and other resources for
Hi Doc,
the CSAC GPSDO is still about 2x the price of Fury. The CSAC Oscillator as
a component is priced at $1500 from Symmetricom. This is comparable to the
Fury with accessories.
The Fury has better short term stability, and better phase noise. It is
designed for base-station
I think Bob died out of grief for Jim Williams. Jim's death came as a shock
alredy. now Bob. I don't think Bob could stand it.
I had the great fortune to meet Jim about a year ago and to work with him
since then, and he was such a joy to be around. A mentor and teacher par
excellence. Both
AMEN!
May this thread die now please.
In a message dated 5/21/2011 15:07:39 Pacific Daylight Time,
mi...@flatsurface.com writes:
I know it's kind of a tangent, but when people were talking about
phones radio broadcasting the time.. It just happened to be the
same time I was browsing
Hello Richard,
customer support is very dear to us, and we hope to be doing a better job
than some of the other companies out there.. We will do our best to support
our products long into the future.
Unfortunately with the CSAC being a brand new bleeding-edge technology it
may take some
Hi Chris,
as this is a brand new product, pricing depends on quantity and ordering
options.
Please contact Giovanni at _giovanni@jackson-labs.com_
(mailto:giova...@jackson-labs.com) to discuss details if you like.
I can say however that it's about half the price of a typical 19 inch
Hi guys,
fyi, this morning we announced the brand new CSAC GPSDO by Jackson Labs
Technologies and Symmetricom.
_http://money.msn.com/business-news/article.aspx?Feed=BWDate=20110315ID=13
141583Symbol=US:SYMM_
Hi Tom, Kevin,
the JLT DROR GPSDO mentioned by Kevin in the original email may be
overkill for this application, as it is designed to provide very low phase
noise
under extreme vibration conditions, and it is state-of-the-art technology
and priced accordingly. It is designed to interface
Hi guys,
need some help with a cal on my SR-620 counter.
In frequency measurement mode the unit always has an offset of up to
+/-2E-010 after auto-cal when feeding the same 10MHz to the (A) input and to
the
external reference. It should not have any offset of course.
Stanford says the
Hi Bob, John,
Yeah, getting a we take $500 no matter if we fix the issue or not
response is not what I had hoped for..
I don't have the time to learn about and tweak registers myself
unfortunately, but at least there seems to be some hope now that this can be
improved..
bye,
Said
Hi Ed,
excellent email. You raise the SNR of this forum!
I have tried to measure the CW-12 output myself with phase noise and Allan
Deviation equipment, and the constant cycle jumps prevent these from giving
sensible results. Both PN and ADEV plots look awful, many orders of
magnitude
Hello Raj,
our ULN-1100 and ULN-2550 GPSDO's use a 100MHz VCXO locked to the 10MHz
OCXO via an ADF4002 PLL with less than 40Hz bandwidth. After careful
optimization of the layout and the loop filter, the phase noise results are
quite
excellent at 100MHz, see the attached plot. The plot
Hi Fred,
I like the Crystek CVHD parts, and MtronPTI also has a number of good ones.
bye,
Said
In a message dated 2/2/2011 19:50:10 Pacific Standard Time,
tijddin...@yahoo.com writes:
Hello Said,
Low Noise 100MHz VCXO's are readily available at mouser and digikey (so
are 80MHz
Hi John,
I only have the two plots unfortunately, I will have to convert them to GIF
as they are too big to post.. will look into doing that sometime this
week.
bye,
Said
In a message dated 1/16/2011 17:04:41 Pacific Standard Time, jmi...@pop.net
writes:
Is the raw data for the
Hi Jerry,
I have the same unit, the power supply works just fine as it is for me.
Make sure you do a survey-in for your new antenna position...
Send command:
:gps:pos:surv once
bye,
Said
In a message dated 11/30/2010 20:51:55 Pacific Standard Time,
jreed...@cox.net writes:
Just
Hi Eugene,
the extra channels usually come on more modern GPS receivers that also give
you sometimes much higher sensitivity, much faster lock time, less 1PPS
jitter, sometimes WAAS/SBAS capability, and last but not least more
redundancy and better performance in environments with
Not necessarily so..
My HP Z3815A here (desktop unit) has horrible phase noise and massive
spurs. Really to cry over since I know what the internal OCXO (1938A type) is
capable of generating.
See the attached plot.
bye,
Said
In a message dated 11/26/2010 16:37:26 Pacific Standard
Hello Dave,
as some folks have already mentioned here, the best solution for you will
depend on your specific requirements in terms of how much warmup time you
have before GPS is gone, and how much drift your solution can handle.
The PRS-10 is a good unit, but requires cooling, a large
Hi Dave,
forgot to mention:
The PRS-10 also has a limited temperature range only up to +65C, so
military applications are a no-go. A good DOCXO will have +75C or even +85C
capability.
Also, the spec for the PRS-10 is 1.18E-012 per Degree C temperature change,
and the units I mentioned
Hi Paul,
good enough is in the eye of the beholder..
The M12M receiver can achieve 2ns rms. So 300ns seems very bad.
Some early units had up to 1000ns error, so 300ns is quite good in that
context.
Anything below 30ns from the GPS (with sawtooth correction) should be
excellent by
Hi there,
how can the nominal frequency be 1E+11 Hertz (in other words 0.1
TeraHertz)??
For the 10811A it should be set to 1E+7.
Also, what instrument are you using that gives you xE-13 resolution on
33ms sample rate (30 samples per second at 0.5 parts per trillion resolution)?
bye,
Hi Jason,
yes, we use uBlox among others. We have a very high opinion of these in
mobile applications.
We add dynamic GPS filter parameter configuration in our software, the
units with default configuration are not really usable in mobile applications
above walking speed. We did numerous
Hi Jason,
one more product line: all of our Jackson Labs Technologies, Inc.
FireFly-1A and FireFly-IIA based GPSDO Timing products use WAAS by default.
Actually they use WAAS in the Americas, Egnos in Europe and other SBAS
signals around the world.
We have shown significantly better
Hello Ladies, and Gents,
for those of you who may be interested, and at the risk of spaming
everyone else, we completely revised our Jackson Labs Technologies, Inc.
FireFly-xx user manuals, with proper indexing, firmware upgrade instructions,
etc
etc. Better late than never...
The new
Hello Bernd,
That's good PN for 1KHz and above on the AXIS10LN. How about the 1Hz, 10Hz,
and 100Hz noise?
Can -95dBc/Hz. 128dBc/Hz, and 135dBc/Hz be achieved in a VCXO?
How does the high power drive (which I assume is needed to achieve these PN
numbers) affect long term (10+ Year) aging
Off topic.
Some time ago we talked about what would happen if a legally-flown 4lbs
weather balloon was being hit by an airplane.. I think this is a similar,
albeit somewhat more funny story, but it does show what would happen due to
the momentum during such an impact, keeping in mind that
Hi Attila,
note that manufacturers are kind of cheating when they say things like
0.2ps rms jitter - see the N.S. appnotes below for example.
This is mostly calculated from phase noise, with typical bandwidth limits
of 20Hz to 20MHz or less.
So what happens below 20Hz or above 20MHz
Hi Bob,
Agreed that at a minimum the instrument will restrict the bandwidth due to
it's own bandwidth limitations, and some (like the Wavecrest units) go up
to 1GHz or more.
But many vendors claim sub 1ps jitter on low cost oscillators, and don't
specify what bandwidth was used to
Hi Scott,
a cool thing to try is to put the unit into manual holdover by issuing the
command
sync:holdover:init
The unit will act as if the GPS antenna has been removed, but GPSCon will
continue to show the 1PPS phase drift against GPS. Thus you can see how
stable your LPRO is over
Hi Don,
sorry about the hassle, please see the attached image of a Fury GPSDO PCB.
C67 is on the bottom side of the PCB. The hole is one of the five mounting
holes of the OCXO, close to the edge of the PCB, next to one of the SMA
connectors. I drew a white circle around it.
You can
Hi Bob,
do we know the resolution of that change for different Rb units?
Ergo, will a say 10 microvolt change in EFC voltage actually make a
difference in the output frequency or be lost in hysterisis?
Thanks,
Said
In a message dated 7/28/2010 04:23:34 Pacific Daylight Time,
That's an average accuracy of 6.6E-013 over 19 hours.
Impressive.
bye,
Said
In a message dated 7/28/2010 18:21:12 Pacific Daylight Time, sm...@intt.net
writes:
After about 19hours of holdover, only ~45ns. Now let's see how well it
recovers.
Scott
On 07/28/2010 01:02 AM,
Hi guys,
it may help to increase DAC gain to get faster recovery times from bumps
etc.
On an OCXO, the frequency recovery from an upset should happen within a
couple of minutes, definitely less than 15 minutes to achieve frequency lock.
The phase recovery (to 0ns offset) may take a
Hi Brian,
based on your measurements, it seems that your unit has a swing of about
0.00566 Hertz per Volt EFC, which is very little.
This compares to about 8Hz per volt for the standard DOCXO's we use.
That's a 1413 to 1 difference in EFC sensitivity between the Rb and the
standard OCXO.
Hi John,
on the Fury, the proportional part you describe is roughly the same as EFC
Scale. The integral part is PHASECO.
Fury can happily run with correct frequency output with PHASECO set to 0,
but the phase offset would be large, and slowly changing over time.
The EFCS (proportional
Hi Scott,
yes the pads are there, you can use the through-hole pad right next to C67
and a standard ground pad for the Thermistor. There will be 10.5V across
the thermistor. Connect the thermistor to your Rb case.
You should be able to connect two 10K Thermistors in parallel to get a good
Hi John, Brian,
actually we set D to 0, and use P and I gains.
Yes, the DACGAIN is an overall gain of the loop output - to normalize for
different oscillator voltage/frequency sensitivities.
I forgot that the DACGAIN is limited to 10,000, so instead of setting it to
20,000 one can set it
Hi Scott,
this one has about 3K at 60C and 10K at room temp. We used it before with
success. The only problem is having sufficient current go through it to be
above the cut-off threshold of the current sensor. You may have to put
something in parallel to this thermistor, or use a couple in
Hi Scott,
yes, Rb's tend to have many orders of magnitude smaller control ranges than
OCXO's, so it takes longer to phase lock. What's even worse is hysterisis,
eg. we have seen units that jump back and forth between two control
voltage values. This tends to happen in TCXO's and Rbs from
Hi guys,
for those of you that have Jackson Labs Technologies, Inc. products we
have placed the latest firmware updates onto our web-site under the support
tab:
_http://www.jackson-labs.com/support.html_
(http://www.jackson-labs.com/support.html)
This has been the first update since
Hi Magnus,
Just read up on their website, they cannot disable the WAAS signal because
it would disable all GPS WAAS landing approaches in the USA. A very big
deal. When it fails, they will be landing aircraft with only one GPS bird for
a while, and no backup!
So it will continue to
Hi Norm,
not sure if someone discussed this before, but he M12+ and M12M timing
receivers do not support NMEA output, just Motorola binary format.
Motorola disabled this feature on the timing versions of the receivers,
presumably for marketing reasons, or maybe to make firmware regression
Hi,
The FAA may not care, but a 4 pound chunk of metal being hit by a plane
travelling 400KM/H or more will take out the pilot, and likely cause a small
plane to crash. If a 747 is hit in the right spot, even that may come down..
Single engine aircraft windshields are tested to withstand
Hi Magnus, Life speed,
what does accuracy mean? Average (rms, 1-Sigma) frequency accuracy? If yes,
over what time frame is the average?
Or is this the peak to peak allowable deviation? Over what temperature
range, and after how long of a warmup?
To give you an example, a typical Fury
point of trivia:
can you count how many vertical wires are strung across a Trinitron
monitors' shadow mask??
I used to work at Sony for a long time, we had a TV assembly line next door
:)
If you can see the vertical wires, you still have very good eyesight...
bye,
Said
In a
Hi Dave, et. al.,
thanks for all the tips everyone!
I am going to try a couple of recommended approaches and parts. Will let
you know on Monday how it works.
bye,
Said
In a message dated 4/14/2010 01:01:41 Pacific Daylight Time,
d...@uk-ar.co.uk writes:
The injection stick is a
Hi there,
I do have space on the PCB, but I am worried that the ceramic as well as
ferrite cores both are sensitive to vibration.
I will try Joe's idea of using a doorbell buzzer to introduce vibration.
It's not easy to generate 1KHz vibration without professional (and heavy)
equipment
That is a big concern of ours of course!
It's a massive voice coil in the shaker..
bye,
Said
In a message dated 4/13/2010 11:20:16 Pacific Daylight Time,
n...@gruending.net writes:
True enough, but don't forget that a shaker table is a big moving
electromagnet right next to the device
Hi Magnus,
they did get the data from the scopes into NI Labview, not an easy task by
itself!
With my HP 54720D scope I can get down to 200ps or so resolution, with
about 60ps jitter from the scope, so for what they were trying to do a scope
should be ok (getting around 1ns resolution I
Hello guys,
need some help please:
I am looking for suggestions on a problem I have with a 20MHz LPF. This
part is used to reduce harmonics when generating an nice 10MHz sine-wave. Any
help is appreciated.
We are using a ceramic 560nH 0603 inductor, and believe that this part is
Hi Joe/Bob,
the board is mounted extremely rigidly into the enclosure, so I don't think
it's flexing. But even if there were flexing I wonder what components
would give the best results. I am also sure the caps are COG as specified,
this
is from a small proto-run. Low values anyway (47pF
I see other problems in the paper as well, for example why did they just
plot a time-domain plot of before and after which doesn't really say much. It
looks less noisy, but that doesn't mean anything. The peak to peak is
very similar.
Instead they should have put that data into the freeware
Back in the days (around 1985 or so) Caltech in Pasadena used to have a
surplus store on campus. I spent a good time in that store, and still have
some of those treasures. Lot's of JPL stuff.
Does anyone know if that still exists??
bye,
Said
In a message dated 3/31/2010 21:23:59
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