On 9/9/13 8:08 AM, Paul wrote:
Although the inexpensive yet high sensitivity units are nice I'm not
sure why someone would choose a positioning MTK (e.g. Adafruit) over a
timing Ublox (or even an old Motorola style timing receiver).
Sometimes, continuing availability is a bigger design
On 9/9/13 8:36 AM, Bob Smither wrote:
On 09/09/2013 07:59 AM, J. Forster wrote:
FYI:
http://thunderstorm.vaisala.com/explorer.html
Here is another one:
http://www.strikestarus.com/
That uses an ad-hoc network of Boltek detectors, which work ok. I had
one in 1999-2000 at work..
On 9/9/13 1:20 PM, Mark Sims wrote:
A cute little lightning detector based upon the AS3935 lightning detector chip:
http://www.embeddedadventures.com/as3935_lightning_sensor_module_mod-1016.html
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On 9/9/13 2:21 PM, Mark C. Stephens wrote:
Is 200 amperes @ 2v not lethal?
Not particularly.. any more than putting your fingers across a 1.5 or 3V
battery is lethal.
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On 9/9/13 2:38 PM, Mark C. Stephens wrote:
I have seen a 12v car battery and a wire frame bed to torture victims on
television twice now.
Are you telling me that's bunk?! (pardon the pun)
As someone who used to make their living doing just such physical
effects for film and TV..
It's a
On 9/9/13 3:52 PM, Mark Sims wrote:
The AS3935 has an INT output pin that signals a detection. You could monitor
that. The AS3935 is based upon an internal DSP processing the receiver output.
No telling how long between when the strike occurs and when INT is activated.
On 9/9/13 4:08 PM, Jim Lux wrote:
On 9/9/13 3:52 PM, Mark Sims wrote:
The AS3935 has an INT output pin that signals a detection. You could
In an interesting coincidence, Charles Wenzel (yes, that Wenzel) has a
design for a lightning detector:
http://www.techlib.com/electronics
On 9/6/13 8:36 PM, John C. Westmoreland, P.E. wrote:
Fellow Time Nuts:
Is this a site to be trusted?:
http://adn.agi.com/SatelliteOutageCalendar/SOFCalendar.aspx
Regards,
John W.
AGI are the folks who make and sell STK (Satellite Took Kit, I believe)
which has a dominant position in the
On 9/6/13 4:00 AM, Bob Camp wrote:
Hi
A truck jammer isn't what you would use to take out a large area,
you would need 100,000 of that sort of jammer. Since the truckers
that use them get fired, there's a limited number of them in use….
Considering they cost $30, and they're not that easy to
On 9/2/13 7:21 PM, John Seamons wrote:
Somewhat off-topic but it might help someone out: I've had a tough time finding, and
using, files on the net containing raw GPS signal samples to be used with the various
software-only (or software-mostly) GPS receivers out there. I finally got a file of
On 9/4/13 7:35 AM, Didier Juges wrote:
Jim,
You should be able to piggyback a second serial port in parallel with the one
used by NTP (just the Rx line and ground) and use any NMEA decoder.
It does not even have to be the same computer.
I have a quick NMEA decoder for Windows I wrote some
On 9/3/13 7:07 AM, Poul-Henning Kamp wrote:
It is very rare to see courts deal with time precisions less
than minutes, but it seems to have happened in this case:
Interesting (and of course, this case has been in the news recently)..
In this case, all the messages were presumably handled by
On 9/2/13 7:50 PM, Bill Hawkins wrote:
Why do we hardly ever talk about synthesizers - those boxes that
turn 10 MHz into other frequencies?
We do.. there's a fair amount of talk about boxes like the PTS
synthesizers. And there's been talk about 866x series synths, and
perhaps the 3325,
On 9/3/13 10:20 AM, Said Jackson wrote:
Hi guys,
Thanks for the heads up, all should be well now. The auto-renew did not work
because we moved and they had an old CC address. Domains that expire stay
locked for 36+ days to the old owner, so no risk there..
This brings up a good point, we
On 9/3/13 11:21 AM, Poul-Henning Kamp wrote:
In message 5225f8af.60...@earthlink.net, Jim Lux writes:
In this case, all the messages were presumably handled by the same
carrier, so the issue of skew in timestamps is negligible;
Anything but.
The text-messages are likely stamped by the SS7
On 9/3/13 2:47 PM, Tom Van Baak wrote:
Nowhere does the opinion mention if the timestamps were taken on
the same clock or if the two clocks were synchronized.
PHK,
Correct. This is an age-old problem, whether its minutes or
nanoseconds. Time-stamps are inherently relative to a local
where it is).
It's not like ntpd or ntpq have some handy switch that says display
current lat/lon (which makes sense, because NTP is fundamentally time
source agnostic).
All of this with Windows 7.
Jim
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On 9/3/13 5:35 PM, Jim Lux wrote:
I'm looking for an easy way to get current lat lon, when you've got a
GPS-18 hooked up for NTP. That is, the GPS receiver is there doing it's
NTP thing, so presumably it knows where it is.
If NTP is decoding the GPRMC message, it has the lat/lon in it, so how
On 9/3/13 6:47 PM, brent evers wrote:
Wouldn't turning off ntp drive it nuts?
At the risk of throwing out the bone head answer and assuming this isn't
going on your next space craft, you could just split the GPS serial (my
quick google showed the 18 to be the serial unit vs usb) signal and run
On 9/3/13 7:14 PM, Pete Lancashire wrote:
Ah the 8660's
Image 22 8660A's in two racks, was an fun tax payer, paid project :-)
We where never told what the master clock was.
Have S/N suffix 0009 in the garage.
For you time nuts, a side hobby should be frequency nuts. How to
produce the
On 8/28/13 9:00 AM, Steven Kluck wrote:
It might appear that the
Torr-Kolen Experiment, which had similar results to de Witte, had similar
temperature compensation and control problems. I think it
would be interesting to run for a year with an east-west coax run, and a
separate north-south
On 8/20/13 8:20 AM, Brian Inglis wrote:
On 2013-08-20 02:45, Björn wrote:
b...@lysator.liu.se said:
The PTTI 1PPS is defined in
http://www.navcen.uscg.gov/pdf/gps/ICD-GPS-060B.pdf
It is 20us long and common in some applications. However the voltage
levels
are a bit high...
The section
Design so that when that module is no longer available, you've got pins and
software switches to use something else. Lots of one off projects depend on
something surplus or cheap, and rapidly become non-duplicate-able when the
parts supply ends.
On Aug 5, 2013, at 1:18, M. Simon
Did you /increase/ the elevation mask?
Jim
wb4...@amsat.org
On 8/5/2013 8:06 PM, gandal...@aol.com wrote:
Many thanks to those who commented on this and apologies for the delayed
response, having spent a few days in an internet free zone I've also had to
contend with a couple of power failures
, with
trees in the distance.
Jim
On 8/2/2013 9:24 AM, Bob Camp wrote:
Hi
Either a blown receiver (likely the SAW filter) or antenna multi path.
Bob
On Aug 1, 2013, at 8:45 PM, Jim Sanford wb4...@wb4gcs.org wrote:
I am seeing the same thing -- big jumps every single time a satellite is
counted
I am seeing the same thing -- big jumps every single time a satellite is
counted or not. Elevation mask 10 degrees, which should be very good
and stable for my location. The unit also insists on converging to a
bat altitude, then after a while declares stored position bad . .. then
declares
Yes.. You put a gain antenna on the space craft, so for the same tx power, you
get the same flux density on the ground. The gps height was chosen for a
variety of reasons. It is out of the debris band, for one. There's also a
tradeoffs on launch costs, etc. GPS world magazine had a great
or collided with another ship from spending too much time
looking out the window. Way too easy to get their heads stuck in the
radar or the GPS map.
73,
Jim
wb4...@amsat.org
On 7/27/2013 9:43 AM, Scott McGrath wrote:
Key here is how does the captain know that GPS is no longer providing
On 7/26/13 4:41 AM, briana wrote:
Ever since WINxp arrived on the scene hams who send code via computer
to radios via parallel, serial or usb ports (with serial port converters
following) have seen the latency issue in spades. We're talking about
effective baud rates less that 50. 3-4
On 7/26/13 8:46 AM, Brian Alsop wrote:
Hi Jim,
You mean to imply no commercial programs ever use quick fixes?
heavens no.. Plenty of quick fixes..
It's difference between seat-of-the-pants field engineering and a
theoretical pursuit. There are no humanitarian costs associated with
failure
On 7/26/13 12:50 PM, Didier Juges wrote:
There is a difference between managing the latency (as in ensuring that sound
and video are synchronized, but latency itself is acceptable) and minimizing
the latency as in a Morse code keyer where the operator has to manually control
the generation of
On 7/26/13 8:45 PM, J. Forster wrote:
I gather from the article, the GPS position was spoofed and the autopilot,
in bringing it back to where it was supposed to be, actually took it off
course.
There are places where a few hundred feet makes a big difference, viz. the
Costa Concordia.
IMO,
On 7/23/13 11:03 PM, Chris Albertson wrote:
You can prototype a system with off the shelf parts get a few
computers, old notebook computers, Raspburry pI' or repurposed
routers, what ever you have. Connect a Trimble Thunderbolt GPS to
each one. Each one runs NTP. Connect them all to a
On 7/23/13 4:51 AM, Scott McGrath wrote:
Thanks Jim
Was not aware that 10 Ghz signals could penetrate so deeply. I work for a
enterprise wifi company on the RF side and one of our key challenges is signal
attenuation/distortion by building materials
Any pointers to papers on this?
there's
requirement comes from being able to find the same heartbeat in
multiple data streams.
Jim,
That's a fascinating application. Ok, one last comment then. As much
as GPS is an obvious solution, did you consider the use of multiple
homebrew timing pulse pseudolites instead? If one placed a couple
Starting a new thread...
Brian wrote:
Have you considered WWVB? Works fine within structures.
Even though the carrier today is phase modulated one can probably glean
1 ms accuracy from it or the data transmitted.
-- disasters occur world wide, any time day or night, so depending on
WWVB
On 7/23/13 9:15 AM, Chris Albertson wrote:
I don't think those requirements are hard. You can build a system
that works in three cases
1) GPS is available full time
2) GPS is available intermittently.
3) there is not GPS system, world war III has destroyed it.
or you're in an urban canyon
or
On 7/21/13 6:42 PM, Chris Albertson wrote:
I think the way to keep the sensors in sync is to use the same method
they use to keep cell towers in sync. Basically each tower has a GPS
receiver and also a good local oscillator. The GPS disciplines the
oscillator and the timing is taken from that
On 7/22/13 5:48 AM, Scott McGrath wrote:
You might want to look at what these guys have done for 40 years or so.
Www.geophysical.com
ground penetrating radar doesn't work very well in the typical disaster
rubble enviroment which has uneven surfaces and a lot of random
scattering in the
On 7/22/13 10:39 AM, Scott McGrath wrote:
Moles are a bit small it would probably work better for woodchucks. who are in
the process of undermining all lawns in neighborhood now.
In a more serious vein most ground penetrating radar is low frequency and I was
not aware that THz waves could
I don't have a GPS-18 in front of me, and I'm modifying some software
remotely, and I ran across an issue that someone on this list probably
knows off the top of their head.
Does the GPS-18 put out 1pps pulses even if it hasn't got a fix yet?
That is, when you apply power, does it just start
On 7/21/13 7:15 AM, David McGaw wrote:
The GPS-18 does NOT output 1PPS until it acquires lock. Then the 1PPS
stays on even if lock is lost, running from the internal crystal. I
have not checked, but once it reacquires lock I presume it jumps to the
correct second. All outputs including 1PPS
On 7/21/13 6:59 AM, David J Taylor wrote:
My own notes on the GPS-18 LVC are here:
http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm
You may be able to gather something about the electrical characteristics
from that note - the device will happily feed to PC RS-232 ports
connected in parallel
On 7/21/13 9:28 AM, David J Taylor wrote:
From: Jim Lux
[]
Oh, I didn't actually think it would be 10% off.. more like a few ppm,
depending on temperature. I was wondering more what would happen if you
were indoors for a couple days, then went back out, what the box does.
realistically, I don't
accuracy
in an absolute sense: I just need to tag the data all with the same
time tag within a few seconds.
Jim,
If the requirement is just a couple of seconds, did you consider one
of the high-accuracy Dallas RTC chips? That might be a simpler
solution than a GPS receiver (knowing when and when
expect, with a 300' error in elevation.
Jim
On 7/13/2013 9:04 AM, Bob Camp wrote:
Hi
I believe what you have here is a Trimble / Nortel box rather than a TBolt - is
this correct?
If so there are a number of differences in what you can and can't do with LH.
Also since it's a different design
, so it never converges
to small variation like I see when I look at the KE5FX site -- what is
this telling me?
Thanks,
Jim
On 7/13/2013 8:44 PM, Bob Camp wrote:
Hi
On mine, I did a full reset and let them start from a survey. After they
figured out where they were, I did the normal stuff
, or stay locked, when it is seeing good sat signals?
Thanks!
Jim
wb4...@amsat.org
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On 7/11/13 12:45 AM, Stefan Heinzmann wrote:
Jim Lux wrote:
On 7/10/13 12:29 PM, Didier Juges wrote:
Jim said:
Now you're confusing me. As far as I am aware, there was the 8663A which
appeared in the early eighties. And much later came the E8663B, and
subsequently the E8663D. I've never
On 7/11/13 3:36 AM, Bob Camp wrote:
Hi
The pseudo random spreading / looks like noise / buried signal thing is the
most common way people piggyback low level signals on a bent pipe.
Assuming that the bent pipe isn't running saturated, which I'm not sure
is a valid assumption. Running TWTAs
On 7/10/13 2:15 PM, Max Robinson wrote:
I think that luminous dial watches still contain a little tritium to
keep them glowing for many hours after the atoms that were excited by
visible photons have all decayed. Without the tritium the glow would
completely go dark after most of the atoms have
On 7/10/13 12:29 PM, Didier Juges wrote:
Jim said:
It's like a HP 8663B (not the modern Agilent E8663).. very low noise,
The Agilent E8663 has similar SSB phase noise spec as the older HP 8662A
(-144dBc/Hz @ 10 kHz with option UNY, versus -143 for the 8662). You seem
to imply
On 7/9/13 7:01 AM, Burt I. Weiner wrote:
John,
Unfortunately, there's a lot of money in fear. Being in broadcast
engineering I learned as long time ago to never use the words,
radiation or radiate a signal when referring to a station's signal.
Instead, I refer to it as, Launch or Launched a
On 7/6/13 8:10 AM, jmfranke wrote:
http://www.navipedia.net/index.php/WAAS_Signal_Structure
Doppler Shift: The Doppler shift, as perceived by a stationary user, on
the signal broadcast by WAAS GEOs is less than 40 meters per second
(?210 Hz at L1) in the worst case (at the end of life of the
On 7/6/13 7:50 AM, Joseph Gwinn wrote:
Re: time-nuts Digest, Vol 108, Issue 29
On Fri, 05 Jul 2013 19:55:42 -0400, time-nuts-requ...@febo.com wrote:
OK. Given that the birds WAAS uses were built for communications
purposes, not timing purposes, I'g guess that their frequency reference
is a
.
No matter what I do, Lady Heather reports no serial communications on
comm/x.
/Thanks 73,
Jim
wb4...@amsat.org
/
/
On 7/6/2013 10:44 AM, Ed Palmer wrote:
Certainly if you need a full implementation with various control leads
you might have to dig out the breakout box and figure it out. But the
volts
or RS232 levels. It might put out some kind of
startup message on powerup.
Ed
On 7/6/2013 10:56 AM, Jim Sanford wrote:
All:
This is still not going well.
I have tried 3 different computers, 2 running Win7 and one running
XP. the XP machine successfully controls an Icom radio on the same
the problem was
caused by the internal com cable which had a factory reversed
connector that was unnoticed before. I had put the full story
recently on this list.
Regards,
Ignacio EB4APL
On 06/07/2013 18:56, Jim Sanford wrote:
All:
This is still not going well.
I have tried 3 different
On 7/6/13 9:29 AM, Joseph Gwinn wrote:
Code/Carrier Frequency Coherence: The lack of coherence between the
broadcast carrier phase and the code phase shall be limited. The short
term (10sec) fractional frequency difference between the code phase
rate and the carrier frequency shall be less than
OPEN.
Thanks for all the help!
73,
Jim
wb4...@amsat.org
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On 7/6/13 2:39 PM, Mark C. Stephens wrote:
How Does that Work Robert?
I mean why out of phase?
Then the voltage on the secondary of the buck transformer is subtracted
from the line voltage.
This is a very common thing commercially where you have what's called a
buck/boost transformer to
On 7/6/13 2:46 PM, Mark C. Stephens wrote:
Hopefully HP Voltage Derated the Cap as well so it can handle our
250V here.. We are across the road from the main transformer for the
area so the voltage is highest at our place, I checked the meter box
this morning - it is 255-258V on all 3 phases,
On 7/6/13 5:26 PM, Mark C. Stephens wrote:
The elephant in the room thing with me is SAFETY :)
I mean, can this be a fire hazard, what about the insulation breakdown on the
secondary winding etc..
Most transformers have a voltage rating on ALL windings that is greater
than several times
On 7/6/13 7:23 PM, Bob Camp wrote:
Hi
Ok, lets *assume* there is some uber secret gizmo in the sat that makes the
unsupervised signal absolutely perfect when transmitted from the sat.
The sat still moves relative to the ground. It's speed is a vector in three
dimensions (up / down , north /
All:
I purchased and am about to hook up the Nortel device.
Someone on this list expressed an interest in my old Z3801, but I lost
the email. If still interested, please contact me off list.
Thanks 73,
Jim
wb4...@amsat.org
On 6/28/2013 9:45 AM, Jim Sanford wrote:
All:
My Z3801
On 7/5/13 8:44 AM, Bob Stewart wrote:
Wouldn't a Cs or Rb clock in orbit be slow due to relativistic effects? I'm
pretty sure there is a relativistic correction to the GPS clocks.
Bob - AE6RV
I believe that the original WAAS repurposed transponders intended for
other L-band satellite
a few minutes, the green LOCK LED came on. It appears
that the Nortel is working.
Is there something I'm missing about making these two play nicely together??
Thanks 73,
Jim
wb4...@amsat.org
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Just opened it up . . . there is no cable. Only one board; the DB-9
connector is on the board.
Jim
On 7/5/2013 4:46 PM, Mark Sims wrote:
Most likely the cable to that front panel board is connected wrong. The people
that laid out the boards messed up the keying. Connecting it the
obvious
On 7/5/13 11:37 AM, Attila Kinali wrote:
On Fri, 5 Jul 2013 12:14:20 -0400
Bob Camp li...@rtty.us wrote:
Indeed the atomic clocks on sats are set up so they can tune far
enough to take out the relativistic effects. That (and a bunch of other
things) makes them somewhat more expensive than
An ION paper by Nagle, et al.
Nagle, J. R., Van Dierendonck, A. J., Hua, Q. D., INMARSAT-3 NAVIGATION
SIGNAL C/A CODE SELECTION AND INTERFERENCE ANALYSIS, NAVIGATION,
Journal of The Institute of Navigation, Vol. 39, No. 4, Winter
1992-1993, pp. 445-462.
Inmarsat-3, the next generation of
On 7/3/13 12:42 PM, Azelio Boriani wrote:
Sure about the bent pipe? If so it seems that much power is required
at the transmitting ground station...
Much equivalent power is required. If you have a 20 meter or so
antenna, it doesn't take much to get a pretty high EIRP.
On 7/3/13 2:21 PM, Dennis Ferguson wrote:
On 3 Jul, 2013, at 11:47 , Bob Camp li...@rtty.us wrote:
The pipe in this case is up on one frequency and down on another. The
conversion oscillator on satellite that's the weak link, no matter how good the
signal from the ground happens to be.
On 7/4/13 7:33 AM, Didier Juges wrote:
That works well for transponders with o LY one signal. On commercial
satellites, each transponder is shared among multiple signals, so that would
not work.
Ah, yes.. if it's a linear transponder/translator..
On 7/3/13 6:58 AM, Bob Camp wrote:
Hi
Since the LEA6-T will do conventional RINEX dumps, I suspect that all they are
doing is very long averaging on the data. I doubt the LEA6-T is the magic part
of the setup.
or sending the RINEX files to JPL for processing...If you don't need
real time
On 7/2/13 7:41 AM, J. Forster wrote:
A few years back, some Group Owners, especially of ham lists, outlawed the
mention of eBay, because the concept of selling something to the highest
bidder somehow offended 'the ham ethic' that stuff should go to the 'most
needy or deserving' as measured by
I had a chance to go through the Time and Navigation exhibit at the
National Air and Space Museum last week. From a time standpoint,
there's probably not much there that time-nuts don't know already, but
it's kind of cool to see cleaned up examples of equipment from days gone
by. (there's an
On 6/30/13 7:43 AM, Charles P. Steinmetz wrote:
A three-terminal regulator (3TR) comprises (i) a voltage reference, (ii)
an error amp, and (iii) a current amplifier. There is no need to
duplicate the voltage reference or the error amp just because you need
more current. In fact, they can only
On 6/30/13 8:48 AM, Brian Alsop wrote:
Maybe I read the original posting wrong but I think this thread has
departed greatly from the original posting.
What I thought the posting said:
1) The already present transformer can produce ~20 V DC unregulated at
sufficient current.
2) The desire was to
On 6/30/13 12:35 PM, Bob Stewart wrote:
I believe the original problem was that the raw unregulated voltage may
be marginally too high for a conventional three-terminal to take safely
Hi Ed,
Not really. The voltage is in line with the product specs for a 7812 (35V
max), as is the current I
NTBW50AA, a
Symmetricom, NTBW50AA, and another Nortel.
Does anybody have experience with these? I'm particularly interested
in the best phase noise I can get. This will be station master
frequency reference, and will ultimately lock stations up to 10 GHz.
Thanks 73,
Jim
wb4...@amsat.org
and then
from there to 2Ghz, 3Ghz, and 5. Haven't decided about 10 Ghz yet.
Appreciate the info. The units on ebay are cheaper than the VCXO I was
considering (first time I looked, they were more), so will probably just
do that.
Thanks again,
Jim
wb4...@amsat.org
On 6/28/2013 10:07 AM, Bob Camp wrote
Oh dear. Please go metric US. Please.
We will help you.
Jim
On 27 June 2013 11:33, Hal Murray hmur...@megapathdsl.net wrote:
j...@quikus.com said:
There WERE (past tense) a number of definitions of the inch, ranging from
lines on bars of PtIr to a string of grain kernels.
Now
On 6/24/13 6:48 PM, Tom Miller wrote:
I wonder what the actual distance is using current GPS survey processes?
Tom
SLightly different, because there are some faults running across there
and there have been some earthquakes with displacement.
On 6/23/13 10:48 PM, DaveH wrote:
Something a bit similar was first published by Nick Hood in 2007.
Here is a copy:
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p056.
shtml
Here is Nick's website:
http://cullaloe.com/
Some people use marshmallows.
Dave
the only
On 6/24/13 10:08 AM, Chris Albertson wrote:
Using only moderately accurate equipment, like mechanical clocks and
meter sticks Albert Michelson has able to measure the speed of light and
determine it was a constant in all directions. It was this work the
prompted Albert Einstein to think about
On 6/24/13 5:21 AM, Brian Alsop wrote:
The time issue was effectively eliminated by the Michaelson-Morley
interferometer. One used a monochromatic light and an array of mirrors
which split the light in opposite directions around the track. The two
beams were recombined and an interference
On 6/24/13 2:26 PM, Chris Albertson wrote:
On Mon, Jun 24, 2013 at 1:55 PM, Jim Lux jim...@earthlink.net wrote:
On 6/24/13 10:08 AM, Chris Albertson wrote:
Isn't that the Fizeau technique, which antedates Michelson's?
Michelson got the precision good enough that it finally put
On 6/24/13 3:01 PM, Bob Camp wrote:
Hi
I'm not so sure that slow would work. With all the sat's moving various
directions all the time, I suspect you need to do a solution fairly quickly. If you don't
the stale data messes up the solution. Also you need the correlators to work fast enough
to
On 6/24/13 4:16 PM, jmfranke wrote:
The tuning fork was used with a clock. The clock was checked against
astronomical measurements.
http://www.schoolphysics.co.uk/age16-19/Wave%20properties/Wave%20properties/text/Speed_of%20light/index.html
Hi all,
With a 3325B, a 5370B, and other time-nut miscellany, what's the quickest
way you can come up with to measure the speed of light OR reproduce the
metre.
I've got some ideas, but I'd like others' thoughts.
Jim
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My actual application is as a quick cool demo showing what I can do with
this gear in my garage when people go why?
:-)
On 24 June 2013 09:22, Magnus Danielson mag...@rubidium.dyndns.org wrote:
Hi Jim,
On 06/24/2013 01:03 AM, Jim Palfreyman wrote:
Hi all,
With a 3325B, a 5370B
On 6/23/13 10:47 AM, Chris Albertson wrote:
Magnetic cores were not invented until the 1950's and realy cam into use as
tubes were beibg replaced by SS. But there isnot reason yu can't build a
tube computer with core memory. I have actually seen and used a computer
that had one megabyte of
On 6/23/13 2:50 PM, Paul Berger wrote:
Hi:
The SAGE computers, which I had the pleasure of seeing the last two
operating, had an all vacuum tube array of core that consisted of 33
planes of 64 x64 cores for about 16K worth of memory.
I was wondering about the Q7.. it was all vacuum tube, but
I think that doing the PN code and correlator is something that could be
done with tubes (especially if you didn't want to go P-code).
I suppose you could use a counter to record the changes in code phase as
you scan for the correlation peak, so that gets you your numeric code phase.
Getting
On 6/22/13 3:28 PM, Magnus Danielson wrote:
On 06/23/2013 12:04 AM, Jim Lux wrote:
I think that doing the PN code and correlator is something that could be
done with tubes (especially if you didn't want to go P-code).
I suppose you could use a counter to record the changes in code phase as
you
On 6/22/13 4:38 PM, Magnus Danielson wrote:
electromechanical.. like omega receivers. rotary transformers can do
very high quality trig functions, but do you actually need trig
functions assuming you're just solving for X,Y,Z,T.
Oh yes. Check IS-GPS-200F, clause 20.3.3.4.3 User Algorithm for
On 6/22/13 5:35 PM, Bob Camp wrote:
Hi
How stable a 1.023 oscillator? How much pull range on that oscillator? H…..
Doppler is the big component..several kHz..
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On 6/20/13 4:57 PM, Gary wrote:
A common scheme in metal deposition measurement is to measure the frequency of
a crystal prior to starting the deposition process, then monitoring the
frequency shift of the crystal as the metal is sputtered.
I was told crystals are tuned this way at the
On 6/17/13 5:33 AM, Peter Gottlieb wrote:
The current distortion from simple transformer-rectifier-capacitor power
supplies contains a lot of third harmonic content. In a 3 phase system
(as are all distribution systems for commercial and industrial) the
third harmonic ADDS in the neutral, or
On 6/17/13 10:39 AM, Poul-Henning Kamp wrote:
In message 51bf15a8.40...@earthlink.net, Jim Lux writes:
The issue also arises with fluorescent [...]
As folks transitioned to the newer ballasts, the non-sinusoidal
current problem probably got worse.
I don't know about US, but in EU
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