James Lux, P.E.
Task Manager, SOMD Software Defined Radios
Flight Communications Systems Section
Jet Propulsion Laboratory
4800 Oak Grove Drive, Mail Stop 161-213
Pasadena, CA, 91109
+1(818)354-2075 phone
+1(818)393-6875 fax
-Original Message-
From: time-nuts-boun...@febo.com
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Thursday, January 08, 2009 11:19 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPSDO time constant
Poul-Henning Kamp
Google Leaf blower hovercraft and you'll get dozens of useful hits.
Here's a real old link: http://amasci.com/amateur/hovercft.html
-Original Message-
James,
Do you have any web sites that show such a contration using leaf
blowers ?
thanks,
BillWB6BNQ
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp
Sent: Thursday, January 08, 2009 3:27 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPSDO TC
And timekeeping lends itself
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Thursday, January 08, 2009 4:15 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPSDO TC
If someone gives me a good RF
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Matt Ettus
Sent: Monday, January 05, 2009 11:31 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Common sky pps errors for any GPSDOs?
I am working
, Jan 5, 2009 at 12:13 PM, Lux, James P
james.p@jpl.nasa.gov wrote:
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Matt Ettus
Sent: Monday, January 05, 2009 11:31 AM
To: Discussion of precise time and frequency measurement
On 1/5/09 9:27 PM, saidj...@aol.com saidj...@aol.com wrote:
Hi Matt,
having 140ps matching of the 1PPS between units is the equivalent of knowing
your antenna position to within ~0.14 feet total error max.
Thats less than one inch error per antenna!
That would require some serious
On 1/3/09 1:34 PM, James Cloos cl...@jhcloos.com wrote:
Warner Yet another hazard of high precision time keeping that few
Warner people get right
Part of what makes this list's name so appropriate is just how hard
it is, all things considered. That is also what makes it enjoyable.
And,
On 12/31/08 6:06 PM, Steve Rooke sar10...@gmail.com wrote:
2009/1/1 Mark Sims hol...@hotmail.com:
Note that there is an error in the first column heading in Lady Heather's
Leap Log. It says UTC... should be GPS. The three line hour timestamp
comment is correct (UTC). The distributed
On 1/1/09 8:37 AM, Chuck Harris cfhar...@erols.com wrote:
Lux, James P wrote:
The fault was in the thinking that there would never be more than one or
two terminal types used as consoles and I/O devices, so the applications
programs should handle I/O directly.
That fault was fixed
On 1/1/09 10:32 AM, Didier did...@cox.net wrote:
The reason for CR/LF is that CR takes a while on a teletype, while LF is
fast, so sending both allowed enough time for the paper/print head to be in
the right place before printing the next char. If you sent LF/CR on a
teletype instead of
On 12/24/08 6:04 AM, Didier did...@cox.net wrote:
-Original Message-
On Behalf Of Magnus Danielson
Specifically, John was suggesting adding the two 5MHz signals, instead of
locking them, that's why I added statistically independent.
So as when you average n signals, the noise
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR
Sent: Tuesday, December 23, 2008 8:41 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] New topics (was Re: He is a Time-Nut
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson
Sent: Tuesday, December 23, 2008 9:26 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] New topics (was Re: He is a Time-Nut
Several DDS parts from Analog Devices (e.g. AD9854, which runs quite warm) are
dual quadrature.. And have adjustable phase offsets as well.
I think the single DDS parts also have a programmable phase offset of 14-16
bits. You have to be careful with the configuration bits, so that writing the
[mailto:time-nuts-boun...@febo.com] On Behalf Of John Ackermann N8UR
Sent: Tuesday, December 23, 2008 12:29 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] New topics (was Re: He is a Time-Nut
Troublemaker)
Hal Murray said the following on
On 12/21/08 1:11 PM, Bill Hawkins b...@iaxs.net wrote:
The passage grave at New Grange, Ireland, is one of those astronomical
wonders where the rising sun at winter solstice shines down a relatively
long tunnel to shine on carved stone at the far wall of a chamber.
We know that solstice
On 12/21/08 6:27 PM, Steve Rooke sar10...@gmail.com wrote:
2008/12/22 Mike Monett xde-l...@myamail.com:
Right now, you don't have enough clocks. The only real solution to
your problem, is to get another TBolt:)
But which one of them is going to be right...
73, Steve - JAKDTNW
On 12/20/08 4:44 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
Edwin B. Walker skrev:
I wonder if companies don't junk equipment because electrolytic capacitors
last years not decades Does this make sense?
No. Details like that does not comes into play. If the quality of the
I read only the abstract. I have access to the database only from the
University computers,
and my comment was sent at midnight , local time, from home.
From the abstract I understood that they want to improve oscillators
by using multiple units
Yes.. You're right. But, they do mention a
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Predrag Dukic
Sent: Thursday, December 18, 2008 12:20 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Is oscillator sync always bad?
Hi, Time
-Original Message-
From: Lux, James P
Sent: Thursday, December 18, 2008 1:04 PM
To: 'Discussion of precise time and frequency measurement'
Subject: RE: [time-nuts] Is oscillator sync always bad?
Allan, et al., did a thing with 8 small oscillators in a
ring. I don't recall
Lux,
It is one more confimation that my assumption is valid.
In fact, they comment about the potential problem of injection locking..
Allan, et al., did a thing with 8 small oscillators in a
ring. I
don't recall if they deliberately tried to have them mutually
couple, or if it
How close to you want to be.
I always just use the 365.25 year length, so the time of birth rotates by 6
hours earlier each year; except in a leap year or the year after, depending on
if your birthday is before or after 28 Feb, when it moves 18 hours the other
way (back to actual time). We
David C. Partridge wrote:
Sort of related, but only just - however the signal to noise ratio here
is
so good that I feel impelled to ask.
For 'scope calibration I'm considering building a levelled sine wave
generator.
Ideally the specs I'm looking for are:
o Close to DC (10kHz or
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Björn Gabrielsson
Sent: Friday, December 12, 2008 1:55 PM
To: bro...@pacific.net; Discussion of precise time and
frequency measurement
Subject: Re: [time-nuts] time-nuts Digest, Vol
One of those things that I've always wanted to do was to lash together a
liquid air plant from, say, refrigeration parts. Never had the time and the
funds at the same time.
Looked at that 10-15 years ago when in the SFX business and we used a lot of
LN2. You need a real high pressure
On 12/5/08 9:47 PM, WarrenS [EMAIL PROTECTED] wrote:
James
Question
So if the antenna is rotated in any and all of its axes, it does not should
like from what you are saying there is really just a single point in it like
you get for say 'center of mass'. that stays at a known spot.
It
On 12/5/08 3:32 AM, Neon John [EMAIL PROTECTED] wrote:
On Sun, 23 Nov 2008 20:26:52 -0800, Lux, James P [EMAIL PROTECTED]
wrote:
There's a fair amount of F/OSS software from JPL available to do this sort of
calibration. It's used to calibrate cameras used on Mars rovers, among other
On 12/5/08 3:48 AM, Neon John [EMAIL PROTECTED] wrote:
On Mon, 24 Nov 2008 17:33:25 -0800, Tom Van Baak [EMAIL PROTECTED] wrote:
Yes. I know of several commecial systems. If you only need to do a short
jump, then using fairly basic E/O-O/E equipment should work well
enought. It all
On 12/5/08 8:55 PM, WarrenS [EMAIL PROTECTED] wrote:
To Björn
wow, neat, mm accurate antennas,
That means the RF way still has some hope.
How does it get the information down the cable without unacceptable loss of
accuracy?
Anyone know how they make these antennas, and can it be
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of pablo alvarez
Sent: Wednesday, December 03, 2008 7:50 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] DMTD mixer question
Hi,
I have been looking at several Dual
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Wednesday, December 03, 2008 10:34 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Wenzel Associates 100 Mhz osc
I have some drive time so I might give Wenzel a call and see
Cheers
Pablo
Pablo
Flipflop mixers tend to produce glitches at the beat
frequency transitions.
A digital PFD in a PLL doesnt produce a beat frequency output
when locked so such glitches arent a problem,
I don't know that this is the case with modern PLL PFDs.. If only because
On 12/1/08 10:58 PM, Bruce Griffiths [EMAIL PROTECTED] wrote:
Thus it may well be worthwhile doing this as one then (in principle)
only needs 3 mixers (plus 3 simultaneously sampled sound card input
channels) and no offset source, however the maximum achievable offset
will probably result
So offset each DUT to prevent injection lock within the 20 Hz
range, and get relaxed spec on mixers and buffers. The retail
was about 12 US$ for the surface mount and 50 US$ for the BNC
mini-circuit mixers. Home made buffer amps and mixers sounds
possible for me.
Get the mixers with SMA,
You will need to use high end sound cards like the M-Audio
AP192 for good performance.
If you're using that particular card , I'd definitely build a new cable for it.
You can probably do better than 1/4 TRS phone plugs.
Dont forget to have an individual isolation amplifiers
between
You can certainly start with a cheap no name card although
the noise floor will be somewhat higher (typically a 16 bit
motherboard sound system is at least 10x noiser than the
AP192, some have lots of spurs others are quieter). For a
long enough averaging time the system noise level even
Real AD cards with adequate performance are usually far more
expensive than $300.
In principle, one could build an ADC card with adequate
performance using 4 AD7760 ADCs.
Bruce
The AD7760 eval board is $150, and I think you need another board to hook it up
to a computer.
-Original Message-
From: Gretchen Baxter
very true!
but looking for a basic feature set.
Single most important thing.. Is there an accurate description of what the
hardware does, what its performance is, and how that is verified? That's what
separates real gear from consumer
Just send Wenzel an email and ask them. Yes, the part # indicates it's a
custom, but they probably can tell you what performance it has. Not all the
pins might be connected (e.g. Wenzel uses a standard package for these things).
James Lux, P.E.
Task Manager, SOMD Software Defined Radios
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Dan Rae
Sent: Monday, December 01, 2008 2:55 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Wenzel Associates 100 Mhz osc
Lux, James P wrote:
Just send Wenzel
Exactly.. I'm sure I'm not the only one on this list that has contemplated home
use of liquid helium or even making the stuff. Hey, if Onnes could do it 100
years ago, so can we.
I assume the cryogen isn't being used for superconductivity in this case, but
for just being cold. In which case,
On 11/30/08 4:27 PM, M. Warner Losh [EMAIL PROTECTED] wrote:
The thing that got me was the word 'really' in Bruce's statement. It
read like someone who had tried it, had limited success, but in the
end wound up believing that while possible, it wasn't really
practical. After thinking
On 11/30/08 5:29 PM, Brian Kirby [EMAIL PROTECTED] wrote:
A cryo may be hard to put togather (and maintain - from experience)
but there are plenty of peltier junctions/devices out there...
Brian KD4FM
Lux, James P wrote:
Cost wise, I like the snippet I read in Scientific American
On 11/28/08 11:27 AM, Bill Hawkins [EMAIL PROTECTED] wrote:
Has any work been done on temperature compensation of quartz or other
oscillators to avoid the expense, space, and power of ovens? The
oscillating material must have a repeatable temperature curve, of
course.
Look at MCXOs, a very
On 11/27/08 12:42 AM, Robert Atkinson [EMAIL PROTECTED] wrote:
One reasion why many US dealers will not ship otside the USA is the ITAR
export regulations (Google it!). These are very hard to follow and the
penalties are heavy. I know a couple of dealers have been warned and have just
I'm looking into something similar: transmitting an H-Maser signal
(probably 10MHz) over some 34km using CWDM SFPs. At first
glance this
seems fairly uncomplicated: get some SFPs, and SFP
connector + cage.
Use a fast opamp/differential driver to drive the transmitting SFP,
and use a
We do lots of this sort of thing at JPL. But the high precision does come at a
cost..
Here's a paper from Bob Tjoelker and colleagues..
http://ipnpr.jpl.nasa.gov/progress_report/42-167/167C.pdf
There are various off the shelf products too, (you could buy a receiver and
transmitter module from
There's a fair amount of F/OSS software from JPL available to do this sort of
calibration. It's used to calibrate cameras used on Mars rovers, among other
things. The target pattern for calibration is a bunch of big circular dots on a
background.
On 11/23/08 7:56 PM, Bruce Griffiths [EMAIL
On 11/17/08 7:55 PM, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
Who said 10Mhz was a standard? If it was all ham radios would have a 10 Mhz
input to replace the internal reference.
Ham radios (or radio boxes in general) aren't test equipment, and don't
have external reference inputs in
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray
Sent: Tuesday, November 11, 2008 10:10 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Checking the Frequency of a Rubidium
Oscillator
All the
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Tuesday, November 11, 2008 9:28 AM
To: time-nuts@febo.com
Subject: [time-nuts] Checking the Frequency of a Rubidium Oscillator
I have an EIP Model 548 counter with a
On 11/11/08 2:55 AM, Brian Kirby [EMAIL PROTECTED] wrote:
Somewhere out there is the specs that GPS was designed to. It list some
of what they had to do, to make the rubidiums and cesiums work in the
environment they put them in. Believe they are called ICD-GPS-200 or
something like that
I'd suggest giving the GPS folks at JPL a call. They've probably looked into
all the issues you're interested in, and can make suitable suggestions where to
go for answers (subject to the usual export control restrictions).Jim Zumberge
is the Section Manager of the Tracking Systems and
On 11/1/08 2:28 PM, Bruce Griffiths [EMAIL PROTECTED] wrote:
Hal Murray wrote:
One can, of course, observe meridian passage for a variety of stars at
night, and from that determine the time (given a calendar and the
appropriate almanac data), so you could directly observe midnight.
What
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris
Sent: Thursday, October 30, 2008 12:09 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Time-zones and World time..
As I recall, Local Solar Time is
As I recall, the lunar gravity force is on the order of a few ppm of g (and I
assume solar force is comparable).
So, the period of a pendulum does vary according to the time of day and phase
of moon. (about a ppm or so)
I seem to recall that acceleration sensitivity of a crystals is on the
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray
Sent: Thursday, October 30, 2008 4:35 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] What's the time Mr Wolf...
Thanks for your understanding and
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Tom Van Baak
Sent: Thursday, October 30, 2008 5:06 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] What's the time Mr Wolf...
This may not directly answer any of
On 10/26/08 5:34 PM, Jim Palfreyman [EMAIL PROTECTED] wrote:
If the Earth were a snooker ball you would not be able to tell it is not a
sphere...
Perhaps after consuming an ale or two..
Let's see.. It's out of round by 1 part in 300. Human visual acuity is
about 1 minute of arc, 1/60th of
Consider a country like India, which is a around 15 degrees of longitude
wide. If you make the time zone on the half hour, then the entire country
can be on one time zone without sunrise/sunset times being too far out of
whack.
It IS nice to have noon occur roughly at solar noon.
On 10/25/08
On 10/26/08 9:45 AM, Burt I. Weiner [EMAIL PROTECTED] wrote:
Except for the flat or pointy places.
Burt, K6OQK
At 05:00 AM 10/26/2008, [EMAIL PROTECTED] wrote
At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
I went to http://www.timeanddate.com/worldclock/
I saw that it was 10:35 in
On 10/21/08 9:31 PM, Chuck Harris [EMAIL PROTECTED] wrote:
Tom Van Baak wrote:
Both the Trimble and Motorola modules use active antennae with 5V power
- what I don't know is whether they are the same polarity.
all my trimbles and oncores have +5 on center, ground on shield...
I'd be
On 10/22/08 6:04 AM, Chuck Harris [EMAIL PROTECTED] wrote:
Matthew Smith wrote:
Quoth Chuck Harris at 2008-10-22 15:01...
I'd be interested to know if any antennas are in fact the other
way around. Never even considered that.
It would have been fairly trivial for them to put a bridge
On 10/22/08 7:20 AM, Chuck Harris [EMAIL PROTECTED] wrote:
Lux, James P wrote:
On 10/21/08 9:31 PM, Chuck Harris [EMAIL PROTECTED] wrote:
Tom Van Baak wrote:
Both the Trimble and Motorola modules use active antennae with 5V power
- what I don't know is whether they are the same
There IS a mini-TNC as I recall. My ancient (80s vintage) cellphone had such a
thing on the antenna. There's also something referred to as a mini-UHF
(presumably a small PL-259), but the amphenol catalog pitures show the serrated
top of the female, and yours are smooth. The thread was 3/8 -24
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Tim Shoppa
Sent: Friday, October 17, 2008 4:15 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] problem with Efratom FRS-C from eBay
[EMAIL PROTECTED] wrote:
My question: I was told by people
Well, no, proper domain synchronization doesn't just give you
an incremental advantage. The use of flip-flops between
clock domains is done to trade latency for guaranteed
stability. The idea is to isolate the effects of
metastability to a single clock edge that won't be used to
clock
PROTECTED] On Behalf Of Mike Monett
Sent: Thursday, October 16, 2008 3:51 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T
Lux, James P [EMAIL PROTECTED] wrote:
[...]
Even without TMR or other similar schemes, the probability of
upset
If it absolutely, positively can't take any hit, then some
more work
is involved
I would say that the first step is to put a number on
absolutely, positively.
There are lots of systems where you can't put a real number on it, for one
reason or another. Either there's too many
http://www.heavens-above.com/
On 10/14/08 11:12 AM, Mike Feher [EMAIL PROTECTED] wrote:
Well, no one jumped in to answer my question regarding frequency accuracy
that I asked on here a week or so ago. Maybe I'll get some answers to this
simpler question. Does anyone know of a web site that
http://en.wikipedia.org/wiki/Wikipedia:Featured_picture_candidates/Animated_representation_of_the_orbit_of_the_GPS_system
Might give you some ways to start.
There's a raft of GPS surveying planning applications out there that are
designed to tell you which s/v are where at what time. It was a
On 10/13/08 8:54 PM, Mike Monett [EMAIL PROTECTED] wrote:
Mike,
So where did the 1ns granularity come in?
For example, Motorola receivers output the sawtooth correction as
an 8-bit signed binary field in the @@En/Hn TRAIM message. The
range of said byte is -128 to +127; the
Ferrite circulator.
Black insert is ferrite
If one of the three ports is terminated, it¹s hooked up as an isolator.
Jim
On 10/3/08 1:43 AM, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
I don't know a whole bunch about microwave gear, so I need a little help. I
came across a small box in a
When does the phase of the timebase input mean anything?
Most test equipment is happy to have a stable external frequency
input; the phase is immaterial, no? Can someone give me an example
when relative phase among various random pieces of test
equipment is
important?
/tvb
Hi
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jeffrey Okamitsu
Sent: Friday, October 03, 2008 2:46 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] AC Connector On HP 5061B
For an interferometric application,
On 10/1/08 10:18 PM, Steve Rooke [EMAIL PROTECTED] wrote:
2008/10/2 Bruce Griffiths [EMAIL PROTECTED]:
Save yourself a counter and just divide the frequency down to about 1Hz
and time stamp the 1Hz transitions with the Linux box.
As long as you know the division factor its easy enough to
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of David C. Partridge
Sent: Thursday, October 02, 2008 9:31 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] AC Connector On HP 5061B
That critically depends what
Lux, James P wrote:
In the U.S., depending on where the installation is (residential vs
industrial), the neutral (groundED conductor) is bonded
(code-speak
for permanently connected) to the earth ground at the
service entrance panel. The safety ground (groundING
conductor aka green
On 9/26/08 2:36 PM, Gerhard Hoffmann [EMAIL PROTECTED]
wrote:
On Fri, 26 Sep 2008 16:21:49 -0400, you wrote:
For maximum phase stability the BNC connectors should replaced by
threaded connectors such as TNC, SMA , N etc.
The next iteration will have to live with BNC because RS smpd,
Well.. Non standards conforming RS-232 devices are hardly new..
But.. The standard just says -3 to +3 is a no defined behavior zone, and that
the receiver should be able to accept +/- 15 V, with a damage threshold of +/-
25V. (bear in mind, also, RS232C is in 1969, the latest is TIA-232-F, in
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Predrag Dukic
Sent: Wednesday, September 24, 2008 1:23 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] TBOLT communication
Lux,
my hardware experiences
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Monday, September 22, 2008 10:52 AM
To: [EMAIL PROTECTED]; time-nuts@febo.com
Subject: Re: [time-nuts] signal from DirecTV
Hello Andrew,
unfortunately I am not sure what you
On 9/14/08 12:57 AM, Jim Palfreyman [EMAIL PROTECTED] wrote:
Well let me be the devil's advocate and also put the cat amongst the pigeons
here...
With GPS, what actually is the use of a SW time signal?
Jim
---
Some off the cuff, before that first cup of coffee, answers:
WWV provides
On 9/14/08 1:01 AM, Brooke Clarke [EMAIL PROTECTED] wrote:
Hi Jim:
The HF and LF time signals are the only broadcast time signals that have
daylight savings time bits.
So, maybe if we do away with radio time signals, we can do away with DST?
Cool deal!
Jim Lux
APL..
Maybe they're talking about things like the famous 6000 lines of ECAP in
FORTRAN IV done in APL in 600 lines by a grad student, etc.
(not surprising.. ECAP is lots of matrix math, which is VERY dense in APL..
Mind you, today Matlab would do almost the same)
See
In a message dated 05/09/2008 05:23:56 GMT Daylight Time, [EMAIL PROTECTED]
writes:
Trivia: The engineer who designed that chip for HP 35 years ago has the
cubicle next to me at Agilent Labs! It was considered very advanced at the
time.
--
The cubicle?
-
Think of it
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Murray Greenman
Sent: Thursday, September 04, 2008 2:30 PM
To: time-nuts@febo.com
Subject: [time-nuts] Driving clocks from 1pps
In the light of the latest posts on driving clocks from 1pps, it sounds as
Jim L...There is a handful of Amateurs that have quite successfully detected
the Telemetry Signals from both NASA and ESA space probes currently roaming
space, the idea is to simply detect these feebly weak signals, that's the aim,
trying to copy telemetry and things like pictures is a long
From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of Clint Jeffrey - VK3CSJ
[EMAIL PROTECTED]
Sent: Saturday, August 30, 2008 10:52 PM
To: time-nuts@febo.com
Subject: [time-nuts] New to the list...Hello from Melbourne
As for me now, there are a couple
More on building low noise 8.4 GHz synthesizers:
http://ipnpr.jpl.nasa.gov/progress_report/42-166/166A.pdf
You can probably put one together using eval boards from the mfrs for $500
(1 board for the VCO/PLL, 1 for the loop filter, 1 for the DDS)
___
From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of Stan, W1LE [EMAIL
PROTECTED]
Sent: Sunday, August 31, 2008 5:58 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] New to the list...Hello from Melbourne
Hello
101 - 194 of 194 matches
Mail list logo
