Team Nutters,
GPSDO's are often specified for stability as so many parts per x. Using a
Symmetricom 8040C as an example, this has a quoted accuracy of typically
5E^-11 at shipment. Ageing (monthly and yearly) and ADEV stability rates
for 1, 10 100 seconds are also given. This particular
In message 595D85DC050442D88D7AC80A4476610B@dd09, Kit Scally writes:
The question - is this accuracy with respect to 1Hz - or 10MHz ?
Both, because it's a relative measure:
Your 1Hz will be between 0.999 and 1.001 Hz
Your 10MHz will be 999. and 1000.0001 Hz.
--
Hi Kit,
The value of 5E^-11 refers to the resolution that the precision can be
relied upon after taking into account all the factors that influence
it. It means that there is an error that can be as much as +/-5 parts
per e^-11.
At 10 MHz that is +/- 0.0005 Hertz error. At 5 MHz that is
The value of 5E^-11 refers to the resolution that the precision can be
relied upon after taking into account all the factors that influence
it. It means that there is an error that can be as much as +/-5 parts
per e^-11.
No, it can be way more. A 5e-11 spec value is likely just RMS, or
1) When I fly I often use my iPhone while on the ground, before take-off or
after landing.
2) I sometimes carry a GPS receiver. When permitted (varies by airline), it's
fun to log NMEA data for a flight and later plot the flight path and duration
with UTC accuracy.
3) On occasion I also bring
Did they make any announcements regarding this? Most people aren't going
to care about GPS, but many people are used to using their cell phones
while waiting for the door to close and/or as soon as the wheels touch
the ground when landing. If this doesn't work in a 787 I would think
that they
In message BB41DBA7E336413BB9D643DF4D4F613D@pc52, Tom Van Baak writes:
I know, because my Geiger counter was wonderfully close to 60 CPM
(= 1 CPS) in a hotel near NIST. Yes, I have the 1PPS ADEV plot for
this and, yes, background radiation makes the world's worst atomic
clock.
Only for short
Hi Kit,
For convenience, accuracy is often given as a relative, unit-less value. Think
of values like 1%, or 20 ppm, or 5e-11. These are all are unit-less numbers. To
translate to absolute units just multiply:
50 Hz times 1% is 0.5 Hz.
1 meter times 20 ppm is 20 microns.
10 MHz times 5e-11 is
On 6/2/14, 1:55 AM, Tom Van Baak wrote:
Has anyone else noticed this? Or know about this? Please respond only if you
have real information. I can speculate as well as anyone; so it's solid
technical, RF, EMF, or composite carbon fiber engineering info I'm looking for.
I haven't noticed it
Hi Tom,
My experience is the manufacturer's, of hp or fluke quality, reported
error band (their spec sheet) is the worst case (or at least 3 sigma)
provided that the device is operated according to the recommended
environment, etc.
Nonetheless, my statement you quoted is still accurate as
On 6/2/14, 2:27 AM, Poul-Henning Kamp wrote:
It would be trivial to add a passive GPS repeater to the plane, but
the airtraffic industry has never been happy about people being
able to receive navigation signals inside planes, worrying that
somebody might try to blow up the plane at some
On Mon, Jun 2, 2014 at 8:57 AM, Jim Lux jim...@earthlink.net wrote:
On 6/2/14, 2:27 AM, Poul-Henning Kamp wrote:
It would be trivial to add a passive GPS repeater to the plane, but
the airtraffic industry has never been happy about people being
able to receive navigation signals inside
Hi,
I know this is not exactly a time-nut question, but i guess this is
the best place i know to ask about this stuff.
I recently got introduced into the usefullness of a VNA. But these
things are horribly expensive for home use, even if bought from ebay
(before you say anything, remember i live
There is a popular DIY VNA designed by N2PK, boards are available from a fellow
in Ontario Canada, a quick google search should find the information for you.
Also, Sam Wettlerlin has published much on his web site with respect to
Scotty's Spectrum Analyzer project, VNA, return loss bridges,
Attila
You might want to look at the N2PK and DG8SAQ vector network analyzer projects
there are also some commercial USB based 'personal' network analyzers out there
starting about 6K
As for directional couplers. I would suggest buying vs building Mini Circuits
has a line of high quality
I build and fly large model rockets. Many use carbon fiber in their
construction. I can tell you that carbon fiber does conduct electricity...
not quite as well as pure metals, but pretty darn good... and the conduction
is anisotropic (better conduction along the fibers than across their
Today you can do most of the processing in software. All you need is A/D
and D/A converters that can handle the required bandwidth and get the raw
numbers into the computer. Look up SDR type radios and search on the
combination of SDR and VNA and you'll find a few. Then with the same
On Mon, Jun 2, 2014 at 1:55 AM, Tom Van Baak t...@leapsecond.com wrote:
But last week I flew the new composite Boeing 787 Dreamliner and noticed
something quite different. From the second I entered the plane, I lost both
cell and GPS reception. It didn't matter how close I was to a window or
In message 538c82b8.5020...@earthlink.net, Jim Lux writes:
The reason for radio receiver ban originally [...]
Actually, there was a very specific incident where somebody brought
a television on a plane in order to see something important. We're
talking 1950-1960 timeframe and and a
There's a DIY project to build a spectrum analyzer at
http://scottyspectrumanalyzer.com . Since it's modular, one version of
the project is to add a couple of modules that change it into a network
analyzer.
If you search ebay for directional couplers, I can almost guarantee that
you will
Wonderful. It also means cell phones will crank up their power searching for a
signal, and the passengers are sitting inside a microwave oven since the RF
energy can't escape.
Thankfully there are alternative ways to fly.
Bye,
Said
Sent From iPhone
On Jun 2, 2014, at 8:45, Chris Albertson
On 6/2/2014 7:43 AM, Attila Kinali wrote:
Also, any good resource on how to build a directional coupler that
does 10-3000MHz without going to exotic materials would be much
I once had the opportunity to discuss directional couplers with
Julius Botka, then with HP/Agilent. Specifically, a
On 2 Jun 2014 10:03, Tom Van Baak t...@leapsecond.com wrote:
Now I have never had a problem with reception in the terminal, walkway,
or even while seated inside a plane. I figured the aluminum frame of the
plane was thin enough that photons at cell, GPS, and gamma frequencies
easily pass through
Said Jackson saidj...@aol.com wrote:
Wonderful. It also means cell phones will crank up their power
searching for a signal [...]
At least with GSM, a mobile station needs to receive a base station
signal before it transmits anything at all. If no cell network signals
are received at all, the
On Mon, 2 Jun 2014 11:09:55 -0400
Scott McGrath scmcgr...@gmail.com wrote:
You might want to look at the N2PK and DG8SAQ vector network analyzer
projects there are also some commercial USB based 'personal' network
analyzers out there starting about 6K
I've seen both and looked at their
The design of an VNA is an interesting thing. It requires quite high focus
on good RF practices and screening.
In the range 0-3GHz there is no low cost devices avaible, not counting the
copper mountain tech boxes ( http://www.coppermountaintech.com/ ). Up to
1.3GHz there is the DG8SAQ VNWA
On Mon, 02 Jun 2014 09:46:38 -0600
Ed Palmer ed_pal...@sasktel.net wrote:
There's a DIY project to build a spectrum analyzer at
http://scottyspectrumanalyzer.com . Since it's modular, one version of
the project is to add a couple of modules that change it into a network
analyzer.
That
On Mon, 2 Jun 2014 09:01:37 -0700
Chris Albertson albertson.ch...@gmail.com wrote:
Today you can do most of the processing in software. All you need is A/D
and D/A converters that can handle the required bandwidth and get the raw
numbers into the computer. Look up SDR type radios and search
On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote:
I recently got introduced into the usefullness of a VNA. But these
things are horribly expensive for home use, even if bought from ebay
(before you say anything, remember i live in europe, where every
boat anchor hast to travel a long
On Mon, 02 Jun 2014 09:35:41 -0700
Richard (Rick) Karlquist rich...@karlquist.com wrote:
Julius said that he designed it before
the era of cheap calibration. Now that everyone has calibration,
you don't need a good directional coupler. You can get away
with a MiniCircuits coupler.
How
On 2 Jun 2014 17:33, Ed Palmer ed_pal...@sasktel.net wrote:
There's a DIY project to build a spectrum analyzer at
http://scottyspectrumanalyzer.com . Since it's modular, one version of the
project is to add a couple of modules that change it into a network
analyzer.
But I think a VNA is an
I've flown on 787s three times before, and am about to do so again later today.
The prior times I used my cell phone as normal and didn't give it any thought.
This time I'll pay particular attention and report back. Twice for me have
been Ethiopian Air, once London-Addis, once Dulles-Addis.
On 2 Jun 2014 18:14, Thomas S. Knutsen la3...@gmail.com wrote:
The design of an VNA is an interesting thing. It requires quite high focus
on good RF practices and screening.
In the range 0-3GHz there is no low cost devices avaible, not counting the
copper mountain tech boxes (
One which is, IMHO, good value for money is this one. I've been very
pleased with mine.
http://sdr-kits.net/VNWA3_Description.html
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Those interested might look at RedPitaya.com for a new piece of hardware that
might be used. Less than $500 without a box
Don
Dr. David Kirkby
On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote:
I recently got introduced into the usefullness of a VNA. But these
things are horribly
Also, a convenient signal source with built-in attenuator:
http://www.rf-consultant.com/calibrated-signal-generator/
Don
Dr. David Kirkby
On 2 Jun 2014 15:50, Attila Kinali att...@kinali.ch wrote:
I recently got introduced into the usefullness of a VNA. But these
things are horribly expensive
Hello!
Most of the time I do not anything of significance to contribute, but VNA's
are near dear to me. I currently have a grad student working on a poor
mans VNA that will go to 2700 MHz. The issue is phase measurement over that
range, which, even though there are a bunch of chips that
I do not wanted to discourage any body, but building the hardware of a
network analyzer is not a simple task, and requires substantial
instrumentation, software could solve hardware problems to certain limit
only
73
KJ6UHN
On 6/2/2014 10:38 AM, Dr. David Kirkby wrote:
On 2 Jun 2014 17:33, Ed
I'm posting this from inside an Ethiopian 787, on the ground, with the doors
closed. I just completed a fifteen-minute voice call initiated from inside the
plane, with reasonable reception and no drops, while the doors were open. And
I was able to get a new GPS location in less than two
Hi:
I started with the HP 8410 and added an external computer.
Since it can be used manually I think it's an excellent way to learn about VNAs.
http://www.prc68.com/I/MWTE.shtml#NA
It turns out that when automating a VNA the same frequency is measured many
times during cal and device testing.
On 2 Jun 2014 19:07, Alexander Pummer alex...@ieee.org wrote:
I do not wanted to discourage any body, but building the hardware of a
network analyzer is not a simple task, and requires substantial
instrumentation, software could solve hardware problems to certain limit
only
73
KJ6UHN
VERY
Now that my TIC is working with Bert's board, I'm considering taking the next
step of designing a GPSDO from scratch. There are several projects I'd like to
do with a dsPIC33, so that was a natural choice. But I now understand that it
has an audio DAC and is not recommended for process
In message 1401742940.44103.yahoomail...@web142705.mail.bf1.yahoo.com, Bob
Stewart writ
es:
Could someone explain to me how such an audio DAC differs from a non
-audio DAC and why it's not suitable for this application?=A0 Is this just
a disclaimer from microchip to avoid liability or is there
On 6/2/2014 12:41 PM, Brooke Clarke wrote:
Hi:
I started with the HP 8410 and added an external computer.
Since it can be used manually I think it's an excellent way to learn
about VNAs.
http://www.prc68.com/I/MWTE.shtml#NA
For my last 8 years at Agilent before retiring in March, I
was doing
On 06/02/2014 10:51 AM, Tom Van Baak wrote:
The value of 5E^-11 refers to the resolution that the precision can be
relied upon after taking into account all the factors that influence
it. It means that there is an error that can be as much as +/-5 parts
per e^-11.
No, it can be way more. A
To the learned audience:
I agree that the 8410 is an excellent place to start to learn about VNA
architecture and issues. I, as well, learned the HP 8410, first as manual
system, then we did the automation ourselves (Westinghouse was too cheap to
buy a bundled system) using a 9825 desktop
Although I used to work for one of the competitor, I still do have a
complete working 8410, Rick is right, it is a very nice teaching tool
73
KJ6UHN
On 6/2/2014 2:36 PM, Richard (Rick) Karlquist wrote:
On 6/2/2014 12:41 PM, Brooke Clarke wrote:
Hi:
I started with the HP 8410 and added an
Hi Poul,
I've been reviewing microchips literature and the way I read it is that the DAC
isn't sensitive to staying at a fixed value. If it's on, the FIFO is fed to
the DAC. If the FIFO is drained, then the user-settable default value is fed
to the DAC. When the output amp is turned off, it
I think these kinds of DACs are meant to be clocked out at some fixed
sample rate, like 44.1KHz and your software has to stuff a FIFO so
there is some milliseconds of delay in the queue. Before you use
these write some pseudo-code and see if you can make it work.
One idea is to never write to
Jeff:
Was really great to see you yesterday at BreezeShooters! Hope to see
you again soon, maybe better yet, chat on the air!
73,
Jim
wb4...@amsat.org
On 6/2/2014 6:11 PM, k...@aol.com wrote:
To the learned audience:
I agree that the 8410 is an excellent place to start to learn about VNA
Hi
There are several reasons why they don’t recommend the typical MCU DAC for
control applications:
1) They are noisy at low frequency (1/f noise corner). That impacts their
hitting their INL and DNL specs.
2) They have constant current leakage at DC. That makes their “center” value
wander
Hi Bob,
I decided to look at Mouser for 16-bit DACs, and found the MAX541CCPA for
$12.47. On the one hand, it's an extra $12.47 for the project. On the other,
the dsPIC is a 3.3V device. I'll have to give some thought as to whether I
want to lose that much output range between the DAC and
Hi
The DAC noise is likely “outside the loop” in a GPSDO. It’s not reduced by
feedback. You can indeed find some of these parts that are noisy enough to
degrade the ADEV or phase noise of an OCXO.
Bob
On Jun 2, 2014, at 10:13 PM, Bob Stewart b...@evoria.net wrote:
Hi Bob,
I decided to
On 6/2/14, 7:16 AM, Brian Lloyd wrote:
On Mon, Jun 2, 2014 at 8:57 AM, Jim Lux jim...@earthlink.net wrote:
O, and since navigation using the ADF and tuning to a AM
broadcast station wasn't unusual.
Well, it is quite unusual for IFR (instrument flight rules) operation. But
VFR pilots would
Hi,
I have an HP 8412B and an HP 8413A, which go with the HP 8410, for $ 30.00
( maybe less) each plus actual shipping.
They look good but I have no way to test then since I have no mainframe.
Contact offline if interested. I can email pictures.
They will be at the Huntsville Hamfest later
On Mon, Jun 2, 2014 at 10:36 PM, Jim Lux jim...@earthlink.net wrote:
On 6/2/14, 7:16 AM, Brian Lloyd wrote:
On Mon, Jun 2, 2014 at 8:57 AM, Jim Lux jim...@earthlink.net wrote:
O, and since navigation using the ADF and tuning to a AM
broadcast station wasn't unusual.
Well, it is quite
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