Effect of medium term loss of GPS or power
What is the effect of a medium term loss of
a) GPS signal on a GPS locked source?
b) Power loss to a GPS locked source?
By 'medium term', I am meaning 30 minutes to 1 hour?
I will be locking two sources:
-
PRS10 Rubidium from Stanford
-
10811A or 10811-60111 using the Brooks Shera board.
and are considering doing some comparisons with someone perhaps about
half an hour to an hours drive away with his GPS locked source.
I could keep power on my sources, but not keep a GPS (certainly not in
position mode anyway!).
I assume if power is removed from the Brook Shera design, it would
suffer badly, as there would be no record of the last ADC voltage and
you would expect to wait about 5x the time constant for the DAC voltage
to get back close to the correct value.
In contrast, power outages with the PRS10 would not be such as issue,
as the last DAC voltage will be stored in EPROM.
Obviously the rubidium should keep more stable than a crystal if power
is removed, but I'm more interested in the effect on the phase locking
systems, than of the actual sources themselves.
Soon I should be in a position to measure these effects myself, which is
obviously the best way. But I suspect others have done these sorts of
tests and I'd be interested in what they observed.
--
David Kirkby,
G8WRB
Please check out http://www.g8wrb.org/
of if you live in Essex http://www.southminster-branch-line.org.uk/
In message 42A2904E.4070800@onetel.net, David Kirkby writes:
What is the effect of a medium term loss of
a) GPS signal on a GPS locked source?
The it should continue to coast on the last frequency it was steered
to. If you do a 3rd order PLL it would continue to correct for drift.
b) Power loss to a GPS locked source?
You will loose anything of interest because of the "power-cycle retrace"
being anything but perfect.
Find two small 12V lead acid battries and use that to keep the PRS10
powered.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Forwarded from the HP/Agilent Yahoo group. Please respond to Dave
Cunningham at dcunningham@agilent.com if you're interested in helping out
with any of these.
I have hosted a copy of his spreadsheet in .html format at:
http://www.speakeasy.net/~jmiles1/ke5fx/manuals_needed.htm
-----snip original message-----
From: hp_agilent_equipment@yahoogroups.com
[mailto:hp_agilent_equipment@yahoogroups.com]On Behalf Of Dave
Cunningham
Sent: Wednesday, June 08, 2005 2:58 PM
To: hp_agilent_equipment@yahoogroups.com
Subject: [hp_agilent_equipment] I'm Ready for Your Manuals!
Hi, friends. I've gotten a thumbs-up from Thomas, the group
founder, to begin my manual search here. With the enthusiasm you've
shown me, there's no time like the present....
This is my initial request for your help in sharing manuals. Here's
how you can help, and what you can expect from me:
-
I've posted a file containing the top 500 products I'd like to
find manuals on. You'll find the file in the Files area of the
group. -
I'm like you - limited time and limited resources. I'm most
interested in the top 200 products at first, and PDF files are my
favorite! ;-) -
If you have a manual or a file, and you'd like to share it:
--Files: either email them to me at
dcunningham (at) agilent.com
or tell me how I can find and download the file.
--Hardcopy Manuals: Email me with details on what you have.
What will I do? I will review every file and email, and will
determine whether we can use the manual. I'm doing similar things
within Agilent (yes, we have manuals we've forgotten about lying
around!), so it's possible I'll already have a copy available. If
what you have is not on this first list, I'd still be excited to
look at it; resource constraints may force me to put off loading it
onto our site until later than the higher-priority products.
I don't have the scanning process complete yet, and I'm also working
to line up resources to load whatever materials we're sent. That
means I can't promise to load things immediately. I will commit to
responding to each submitter individually, and I will keep the group
aware of the products we're adding. I will eventually have a place
on the Agilent website to continue tracking what we've done.
Thanks for embarking on this experiment with me. I'm not certain
where this will lead us, but I sure enjoy the support and
encouragement you've provided. So...send those manuals, continue
commenting in the group, and I'll make sure to keep you all updated
on what's happening.
Thanks a ton!
Dave dcunningham (at) agilent.com
------end snip------
-- john, KE5FX
As usual, one hand doesn't know what the other hand is doing. Agilent had
virtually every single hardcopy manual ever made in its Tech Support library in
Colorado, at least when I spoke to them two years ago.
I thought it was interesting that several items on the list were among HP's
most popular instruments ever, like the 8640B. It's hard to believe that
they don't have that one in their magazine rack in the lobby. :)
-- john KE5FX
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of Jeffrey Pawlan
Sent: Wednesday, June 08, 2005 7:06 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: [time-nuts] Re: Agilent rep looking for manuals
As usual, one hand doesn't know what the other hand is doing. Agilent had
virtually every single hardcopy manual ever made in its Tech
Support library in
Colorado, at least when I spoke to them two years ago.
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
I remember in the late 90's when HP/Agilent's call center was just getting up
and running, that they were looking for a lot of the older manuals.
And the reason for that is that I distinctly remember in the early 90's there
was an edict that came down from corporate that we didn't need all those
complete sets of manuals in all the sales offices any more, and to get rid of
them.
Needless to say, this really made me cringe, being the pack rat that I am. Our
local office manager told me that they were going in the dumpster in the next
few days, but if I wanted them I had to get them out immediately. So one of my
friends and I frantically threw as many manuals as we could in our cars and made
several trips to my place where we put them in my pole barn. The bad news is
that in the haste to get them out, any semblance of organization was lost! Of
course there has never been enough time to try to tackle that huge task of
sorting them, and I fear that, although I still have them, spending over 10
years in an uncontrolled environment didn't do them any good. I'm still hoping
that one of these days I'll be able to pull together a bunch of my friends and
get them organized! If that ever happens, and they haven't been ruined, I may
be able to scan and supply some of them. (any volunteers?)
Daun
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of John Miles
Sent: Wednesday, June 08, 2005 10:18 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: RE: [time-nuts] Re: Agilent rep looking for manuals
I thought it was interesting that several items on the list were among HP's
most popular instruments ever, like the 8640B. It's hard to believe that
they don't have that one in their magazine rack in the lobby. :)
-- john KE5FX
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of Jeffrey Pawlan
Sent: Wednesday, June 08, 2005 7:06 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: [time-nuts] Re: Agilent rep looking for manuals
As usual, one hand doesn't know what the other hand is doing. Agilent had
virtually every single hardcopy manual ever made in its Tech
Support library in
Colorado, at least when I spoke to them two years ago.
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
I'm still hoping that one of these days I'll be able to pull together
a bunch of my friends and get them organized! If that ever happens,
and they haven't been ruined, I may be able to scan and supply some
of them. (any volunteers?)
What city do you live in Daun?
Regards,
Bill Powell af4jg
Cary, NC
-------- Original Message --------
Subject: RE: [time-nuts] Re: Agilent rep looking for manuals
Date: Wed, 8 Jun 2005 22:33:28 -0400
From: Daun Yeagley daun@yeagley.net
Reply-To: daun@yeagley.net, Discussion of precise time and frequency
measurement time-nuts@febo.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
I remember in the late 90's when HP/Agilent's call center was just getting up
and running, that they were looking for a lot of the older manuals.
And the reason for that is that I distinctly remember in the early 90's there
was an edict that came down from corporate that we didn't need all those
complete sets of manuals in all the sales offices any more, and to get rid of
them.
Needless to say, this really made me cringe, being the pack rat that I am. Our
local office manager told me that they were going in the dumpster in the next
few days, but if I wanted them I had to get them out immediately. So one of my
friends and I frantically threw as many manuals as we could in our cars and made
several trips to my place where we put them in my pole barn. The bad news is
that in the haste to get them out, any semblance of organization was lost! Of
course there has never been enough time to try to tackle that huge task of
sorting them, and I fear that, although I still have them, spending over 10
years in an uncontrolled environment didn't do them any good. I'm still hoping
that one of these days I'll be able to pull together a bunch of my friends and
get them organized! If that ever happens, and they haven't been ruined, I may
be able to scan and supply some of them. (any volunteers?)
Daun
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of John Miles
Sent: Wednesday, June 08, 2005 10:18 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: RE: [time-nuts] Re: Agilent rep looking for manuals
I thought it was interesting that several items on the list were among HP's
most popular instruments ever, like the 8640B. It's hard to believe that
they don't have that one in their magazine rack in the lobby. :)
-- john KE5FX
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of Jeffrey Pawlan
Sent: Wednesday, June 08, 2005 7:06 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: [time-nuts] Re: Agilent rep looking for manuals
As usual, one hand doesn't know what the other hand is doing. Agilent had
virtually every single hardcopy manual ever made in its Tech
Support library in
Colorado, at least when I spoke to them two years ago.
John Miles wrote:
Forwarded from the HP/Agilent Yahoo group. Please respond to Dave
Cunningham at dcunningham (at) agilent DOT com if you're interested in helping out
with any of these.
I have hosted a copy of his spreadsheet in .html format at:
http://www.speakeasy.net/~jmiles1/ke5fx/manuals_needed.htm
Great to see its in HTML, not some propietry thing like Excel.
The HP5370B time interval counter is on his list, but not the HP5370A, which I assume some of you own.
I've suggested he add the A, and perhaps subtract the B, since I have done the HP5370B
http://www.g8wrb.org.uk/useful-stuff/time/HP-5370B/
although I guess HP could do a better job than me.
Others who have the A might want suggest that too. I've not no idea of how many own the A. I guess the
most serious amounst you probably own several A's, several B's and several of the Stanford SR 620's too!!
I'm not considering myself serious, but what thinking the other day a second HP5370B would be nice.
However, I will get my pendulum clocked to a 10811A (or perhaps a Stanford PRS10) first, before
worrying about anything else.
--
Dr. David Kirkby PhD CEng MIEE,
Senior Research Fellow,
Department of Medical Physics,
Mallet Place Engineering Building,
Gower St,
University College London,
London WC1E 6BT.
They may still have the manuals.
This sounds like a great way to cut down on the cost of scanning.
Bill Hawkins
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com]On
Behalf Of Jeffrey Pawlan
Sent: Wednesday, June 08, 2005 9:06 PM
To: Discussion of precise time and frequency measurement;
dcunningham@agilent.com
Subject: [time-nuts] Re: Agilent rep looking for manuals
As usual, one hand doesn't know what the other hand is doing. Agilent had
virtually every single hardcopy manual ever made in its Tech Support library
in
Colorado, at least when I spoke to them two years ago.