In a message dated 09/09/2010 02:34:59 GMT Daylight Time,
eb4...@cembreros.jazztel.es writes:
Thank you very much for your efforts. And BTW, any PTS 040 manual around?
-
Hi Ignacio
I presume you've found the PTS160, PTS310, etc manuals on Didier's site?
I've not seen a
Brings back memories- I was on the west coast of the south island in 1990,
leaning against a large log on the beach very close to the water line at
sunset, when a quake hit. Being from California, it was fun because I was used
to experiencing quakes in buildings, cars, etc; but I had never felt
EADS is a bit more than test equipment. see
http://www.eads.com/eads/int/en.html#/story-2
Robert G8RPI.
--- On Thu, 9/9/10, David C. Partridge david.partri...@perdrix.co.uk wrote:
From: David C. Partridge david.partri...@perdrix.co.uk
Subject: Re: [time-nuts] Possibly OT: Maintenance manual
On 9/9/2010 7:03 AM, p...@pseng.org.uk wrote:
I'll second the thanks to EADS (and David). I too used too look for
support for older equipment when buying for day job.
Currently struggling with opt55M ie the miltary coding CIL/MATE etc
for a stack of 6 1991's for TI use. Any pointers on using
We have a requirement for approximately ten radio sites to be synchronized
to within 30 ns of each other. Ordinarily you could throw in an
appropriate GPSDO and be done with it. However, we also have the
reqirement to be able to operate independent of GPS for up to six days. If
we were able to
Symmetricom makes GPS based NTP time servers with excellent holdover
capability. I think our SyncServer with an OXCO is good for +/- 0.5
second holdover over something like 60 days. They have options for Rb
oscillators installed that will make that much much better and it might fall
inside of
How widely spread is your network?
Sent from my BlackBerry Wireless thingy while I do other things...
-Original Message-
From: Ralph Smith ra...@ralphsmith.org
Sender: time-nuts-boun...@febo.com
Date: Thu, 9 Sep 2010 11:37:46
To: time-nuts@febo.com
Reply-To:
Hi FL:
Thanks for the link to the book on escapements.
Maybe it contains an explanation for the Self Winding Clock escapement:
http://www.prc68.com/I/SWCC.shtml#Esc
Have Fun,
Brooke Clarke
http://www.PRC68.com
Flemming Larsen wrote:
When I was a kid, I loved to watch the pendulum swing back
The requirement is 30 nanoseconds, so individual rubidium holdover over
six days won't cut it.
Ralph
On Thu, September 9, 2010 11:58 am, Robert Darlington wrote:
Symmetricom makes GPS based NTP time servers with excellent holdover
capability. I think our SyncServer with an OXCO is good for
The network is spread over about 250-300 US miles.
Ralph
On Thu, September 9, 2010 12:01 pm, Didier Juges wrote:
How widely spread is your network?
Sent from my BlackBerry Wireless thingy while I do other things...
-Original Message-
From: Ralph Smith
On 9/9/2010 8:37 AM, Ralph Smith wrote:
We have a requirement for approximately ten radio sites to be synchronized
to within 30 ns of each other.
30 ns seems a little closer than most radio site applications need...
what drives this requirement?
Ordinarily you could throw in an
appropriate
Does the GPS backup include other sats ? As long as all sites could see the
same
sat then using it as a standard they would drift together.
Stanley
- Original Message
From: Ralph Smith ra...@ralphsmith.org
To: Discussion of precise time and frequency measurement time-nuts@febo.com
If you need that kind of timing accuracy in the absence of GPS then Cs is
probably the only answer. Dark fiber would also work but the infrastructure
and fiber leasing costs would probably be much more expensive than local Cs
Sent from my Verizon Wireless BlackBerry
-Original Message-
On Thu, September 9, 2010 1:10 pm, Matthew Kaufman wrote:
On 9/9/2010 8:37 AM, Ralph Smith wrote:
We have a requirement for approximately ten radio sites to be
synchronized
to within 30 ns of each other.
30 ns seems a little closer than most radio site applications need...
what drives this
Ralph--
As far as getting a signal through mountainous terrain, look at NVIS antennas
for HF -- we use them for Field Day for just that kind of communications, 200 -
300 miles in mountainous terrain. Figuring out propagation delays is going to
be interesting with NVIS though.
73 de Bob
On 9/9/2010 10:42 AM, Ralph Smith wrote:
On Thu, September 9, 2010 1:10 pm, Matthew Kaufman wrote:
On 9/9/2010 8:37 AM, Ralph Smith wrote:
We have a requirement for approximately ten radio sites to be
synchronized
to within 30 ns of each other.
30 ns seems a little closer than most radio
What about Symmetricom XPRO Rubidium? It says on the data sheet they have a low
aging rate option (1e-11 / month).
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and
Nigel,
Yes, I have downloaded them for the PTS 160, 500, 3200 and X10 and you
are correct, all those synthesizers share the same basic principles and
maybe some modules, but I found that the frequencies involved are not
the same. The problem with mine is that it shows frequency errors at
On Sep 9, 2010, at 10:42, Ralph Smith ra...@ralphsmith.org wrote:
Paranoia. People making the requirements are concerned with GPS going away
due to solar flare or some other reason.
Hmm... So the decision makers think that after a solar flare or some other
reason (hostile destruction of the
On Thu, September 9, 2010 1:55 pm, Matthew Kaufman wrote:
On 9/9/2010 10:42 AM, Ralph Smith wrote:
On Thu, September 9, 2010 1:10 pm, Matthew Kaufman wrote:
On 9/9/2010 8:37 AM, Ralph Smith wrote:
We have a requirement for approximately ten radio sites to be
synchronized
to within 30 ns
1e-11 only buys you 3000 seconds of drift before blowing the 30 ns budget.
Without going to cesium we will most likely need some form of mutually
visible synchronization.
Ralph
On Thu, September 9, 2010 2:01 pm, Jason Rabel wrote:
What about Symmetricom XPRO Rubidium? It says on the data sheet
On 9/9/2010 11:57 AM, Ralph Smith wrote:
You're making the mistake of applying logic. ;) Actually, aircraft can
continue to fly VFR or navigate using VOR/DME and inertial navigation.
The radios are part of an ADS-B installation.
Yes, and they can make routine position reports and ATC can
Hmmm...I design such timing systems for Moto data radios, and 30nS sync is
going to be very hard to achieve in reality. Over a few hundred miles you're
going to have OTA time of flight issues, temperature dependencies, etc. Over
the years this has been tried, usually with dismal success in
Does anybody know about using the same Peltier junction for both heating and
cooling?
I'm concerned about thermal/mechanical shock when changing the polarity
back-n-forth between hot and cold. Maybe there needs to be a controlled ramp,
if so then how do I figure out the rate?
Why:
I'm in the
On Thu, September 9, 2010 3:17 pm, John Anderson wrote:
Hmmm...I design such timing systems for Moto data radios, and 30nS sync is
going to be very hard to achieve in reality. Over a few hundred miles
you're going to have OTA time of flight issues, temperature dependencies,
etc. Over the
For this temp range, thermal shock or reversal should not be a problem.
Neither is reversal, just use a (relatively) cheap h-bridge off epay...
working out the water temp might be a problem? There will be no problem
with h-bridges, as the Peltier junction has very small L-C values, ie not
like a
Jerome,
All of the modern temperature calibration dry-wells that support both
lower-than-ambient and higher-than-ambient set points, within the same well
cavity, do so by changing the current direction through (typically) several
Peltier junctions attached to a massive aluminum block. See Hart
1) Your own LORAN?
2) MASERS!
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and follow the instructions there.
Peltier devices have been used as temperature control elements for
decades. I've never heard of fatigue failures, but, if I were designing a
chamber as you suggest, I'd try to keep the temperature differential
across the TE element under maybe 15 to 20F. The harder you push it, the
greater the
I would agree with the many comments.
Loran first choice in europe. Oooops we killed it here.
30ns speed of light issues. Think you need a synchronized RB or CS.
But what on earth needs 30ns in a radio.
On Thu, Sep 9, 2010 at 5:11 PM, Chris Howard ch...@elfpen.com wrote:
1) Your own LORAN?
There is a reference to thermomechanical fatigue in Peltier devices with
respect to the effect of peltier device ripple current on the longevity
of the Peltier devices in the HP Journal article on an optical power meter.
Bruce
J. Forster wrote:
Peltier devices have been used as temperature
Can you just close the system and let the item self heat.
Then you only ever have a cooling problem.
Seems I am familiar with a very large computer manufacture who does it that
way.
On Thu, Sep 9, 2010 at 5:14 PM, J. Forster j...@quik.com wrote:
Peltier devices have been used as temperature
On Sep 9, 2010, at 12:03 PM, Ralph Smith wrote:
1e-11 only buys you 3000 seconds of drift before blowing the 30 ns budget.
Without going to cesium we will most likely need some form of mutually
visible synchronization.
How about a rubidium or cesium standard at each site for holdover, with an
Wow, So many people have helped - Thanks!
I see your point, it can be done without changing the polarity, just control
how much heat is carried away... very interesting.
Regards,
Jerome
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
In a message dated 09/09/2010 20:05:14 GMT Daylight Time,
eb4...@cembreros.jazztel.es writes:
Yes, I have downloaded them for the PTS 160, 500, 3200 and X10 and you
are correct, all those synthesizers share the same basic principles and
maybe some modules, but I found that the frequencies
Ralph,
so you're talking about 5.8E-14, right?
I'd think no off the shelf caesium, even when run in a temperature
controlled environment, will get you there.
Well, at a first glance, a 5071A with high performance tube would, if
you keep any environmental effects out.
So you'll likely need to
Adrian wrote:
Ralph,
so you're talking about 5.8E-14, right?
I'd think no off the shelf caesium, even when run in a temperature
controlled environment, will get you there.
Well, at a first glance, a 5071A with high performance tube would, if
you keep any environmental effects out.
So
See TVB's site for an experiment with moving CS standards around...
Adrian
Ralph,
so you're talking about 5.8E-14, right?
I'd think no off the shelf caesium, even when run in a temperature
controlled environment, will get you there.
Well, at a first glance, a 5071A with high performance
It's kind of important for the heating and cooling systems to be
able to overlap. I think you will get much tighter control if you
use a simple resistance heater and the Peltier cooler.
-Chuck Harris
Jerome Peters wrote:
Does anybody know about using the same Peltier junction for both heating
Some form of low frequency broadcast system might work as a GPS backup.
This paper provides a comparison of Loran C vs GPS for time transfers. While
Loran C is history in the US, this might give some indication of what could be
expected from a low frequency broadcast system.
Nigel,
I have the pictures but it is 02:30 LT here and I have to go to bed.
Tomorrow I'll send you the pictures and I' give you a more extensive
description of the symptoms. I believe now that the 7th DM module is
not working well when the input is at one of its band limits.
Thank for
Oops, I intended to send it only to Nigel.
Sorry for the BW
Ignacio, EB4APL
EB4APL escribió:
Nigel,
I have the pictures but it is 02:30 LT here and I have to go to bed.
Tomorrow I'll send you the pictures and I' give you a more extensive
description of the symptoms. I believe now that
Hi
If 30 ns is the system goal, then you have a lot more to budget for than simple
clock error. You could easily be below 10 ns for just the clock portion of the
budget. I suspect that multiple 5071's and a maser or two at each site will be
the ultimate solution if each must stand alone for 6
Radar calibration:
You could do a clock calibration if you knew some fixed reference
points to
sweep.
Put some towers up on a few of the taller peaks in the area. Measure
them
while the GPS is running and use them for reference to keep the clocks
right when GPS is down.
But masers sound
On Sep 9, 2010, at 9:27 PM, Bob Camp wrote:
Hi
If 30 ns is the system goal, then you have a lot more to budget for than
simple clock error. You could easily be below 10 ns for just the clock
portion of the budget. I suspect that multiple 5071's and a maser or two at
each site will be
On Sep 9, 2010, at 8:01 PM, Rick Karlquist wrote:
I would like to point out that the environmental sensitivities of
the 5071A are unmeasureable, and the measurement threshold is
far below 5.8E-14. I would estimate that the 5071A (and ONLY the 5071A
among commercial clocks) could get the job
We should start seeing used Loran transmitters on ebay pretty soon (!), and it
should not be too hard to build a timing receiver using this signal. If you
just want timing, one transmitter may be enough to cover the area of interest.
The low frequency Loran signals do go relatively well over
Loran?
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mark J. Blair
Sent: Thursday, September 09, 2010 1:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Timing Distribution in Mountainous
Loran?
What was the stability of Loran when used to distribute time? (I'm assuming
I can use something like GPS for calibration.)
Wikipedia says:
The absolute accuracy of LORAN-C varies from 0.10-0.25-nautical-mile (185-463
m). Repeatable accuracy is much greater, typically from 60-300-foot
On Fri, Sep 10, 2010 at 06:17, Mark J. Blair n...@nf6x.net wrote:
Or, a specially-equipped aircraft which is periodically flown along paths
visible to multiple antenna sites during an extended holdover in order to
adjust out drift based on measured round-trip times between the sites and
Ralph Smith wrote:
On Thu, September 9, 2010 1:10 pm, Matthew Kaufman wrote:
On 9/9/2010 8:37 AM, Ralph Smith wrote:
We have a requirement for approximately ten radio sites to be
synchronized
to within 30 ns of each other.
30 ns seems a little closer than most radio site applications
Ralph Smith wrote:
O
We are not syncing time slots for communications. The timing requirement
is for determining aircraft position by multilateration. Timing errors
translate into position uncertainty.
What's your carrier freq? In mountainous regions you'll probably have
better luck at the
Ralph Smith wrote:
On Sep 9, 2010, at 8:01 PM, Rick Karlquist wrote:
I would like to point out that the environmental sensitivities of
the 5071A are unmeasureable, and the measurement threshold is
far below 5.8E-14. I would estimate that the 5071A (and ONLY the 5071A
among commercial clocks)
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