Yeah, the TruePosition website is quite interesting. It seems they do a bit
more than 911 service. ;-)
Feel free to change the #3 in the file name to whatever for more shots of the
interior.
-Original Message-
From: Dennis Ferguson
Sender: time-nuts-boun...@febo.com
Date: Sat, 15 De
On 15 Dec, 2012, at 22:38 , Hal Murray wrote:
>
>> GSM cell sites in the US have GPS because it is required to support E911
>> positioning. I'm not sure if it is used for anything other than this, but
>> it doesn't have to be.
>
> So it's cheaper to install and maintain GPS rather than make
On 15 Dec, 2012, at 21:30 , gary wrote:
> This is a shot of the GPS timing rack in an AT&T shack.
>> http://www.lazygranch.com/images/att/att_3.jpg
Yes, the TruePosition box helps compute handset locations for
E911 and whomever else wants to know where your phone is. This
isn't a unit you would
Hi all,
Thanks for pointing this out, I have fixed the plots and the units now read
"us" for micro-second.
The original intention was to use Latex to generate a beautiful $\mu$ greek
letter, but urgent work got the best of me. I did apply a quick fix and will
improve things with our next serie
> GSM cell sites in the US have GPS because it is required to support E911
> positioning. I'm not sure if it is used for anything other than this, but
> it doesn't have to be.
So it's cheaper to install and maintain GPS rather than make one measurement
and tell the setup where it is?
--
The
My Starloc was a pull from a wireless shack. We should have DGPSOs up to
our armpits, but I guess most were crushed.
This is a shot of the GPS timing rack in an AT&T shack.
http://www.lazygranch.com/images/att/att_3.jpg
___
time-nuts mailing list --
GSM sites do indeed have GPS antennas. But Dennis is correct; all of them
use GPS for E911 compliance, the GSM standard wasn't up to that task so
sites have an outboard box (LMU - Location Messaging Unit) which provides
E911 Location independent of the actual cell site base station.
By the way
I thought the networks did that deliberately to frustrate automated
time shifting.
On Sat, 15 Dec 2012 19:04:05 -0500, Joe Leikhim
wrote:
>I have to wonder how seriously these network designers are with respect
>to timing.
>
>For example we have Brighthouse cable. The time on the cable box cloc
GSM cell sites in the US have GPS because it is required to
support E911 positioning. I'm not sure if it is used for anything
other than this, but it doesn't have to be.
In some other parts of the world it has been considered bad taste
to let the operation of telecommunications infrastructure bec
On 12/16/2012 12:59 AM, li...@lazygranch.com wrote:
I can assure you the GSM shacks have GPS timing in them. I can dig up the
photos if you want.
Depens on how the network was built. GSM does not need anything but +/-
50 ppb timing. The PDH backhaul will provide that usually. The time that
t
I have to wonder how seriously these network designers are with respect
to timing.
For example we have Brighthouse cable. The time on the cable box clock
is correct to WWV, however the program material is consistently 30
seconds or so late meaning the end of the program is cut off. Since my
w
I can assure you the GSM shacks have GPS timing in them. I can dig up the
photos if you want.
-Original Message-
From: "Joseph Orsak"
Sender: time-nuts-boun...@febo.com
Date: Sat, 15 Dec 2012 18:24:20
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of preci
Burt -
On the scope I see 950mv RMS with 50 ohm termination, 1.5V RMS with 1M. This is
on a 9390-6000 OCXO with the default timing output configuration, 10MHz on J7.
Hope this helps.
Paul - K9MR
On Dec 15, 2012, at 4:21 PM, Burt I. Weiner wrote:
Gang,
Does anyone have a DATUM 9390 series GPS
Hi
There are a *lot* of layers between the base station and the phone it's self
when it comes to the time that's displayed. There also are a *lot* of
opportunities for error as each layer is linked together. Often when you see
"Verizon" you are actually connected to "Bob's Cell Phone Tower".
AT&T uses UMTS in most areas which is a "self-synchronizing" modulation
scheme. Supposedly one of the selling points is "no dependence on GPS". All
the extra sync channels and sync messaging is a capacity hog, not a very
spectrally efficient standard in my opinion.
About 85 maximum simultaneou
On 12/15/12 2:16 PM, Scott McGrath wrote:
In a prior life we had a CDMA timing receiver for NTP which used VZ for its
source
On Dec 15, 2012, at 12:18 PM, Graham / KE9H wrote:
You should switch to Verizon.
They are inherently accurate to milliseconds.
Sub micro-seconds inside the base statio
In a prior life we had a CDMA timing receiver for NTP which used VZ for its
source
Sent from my iPhone
On Dec 15, 2012, at 12:18 PM, Graham / KE9H wrote:
> Greg:
>
> You should switch to Verizon.
> They are inherently accurate to milliseconds.
> Sub micro-seconds inside the base stations.
>
Gang,
Does anyone have a DATUM 9390 series GPS receiver that can tell me
what the (50 Ohm) terminated output level of the 10 MHz spigot
is. One of mine started spurring and the other one is clean, but
seems way to high in output level.
Thanks,
Burt, K6OQK
Burt I. Weiner Associates
Broadca
Greg:
You should switch to Verizon.
They are inherently accurate to milliseconds.
Sub micro-seconds inside the base stations.
--- Graham / KE9H
==
On 12/15/2012 12:51 PM, Greg Troxel wrote:
In central mass, AT&T and tracfone (? carrier) are showing phone times
very close to 1 min slow. Virgi
David thats what I was looking for thanks. At 4 watts that is impressive.
Regards
Paul
WB8TSL
On Sat, Dec 15, 2012 at 2:07 AM, David J Taylor <
david-tay...@blueyonder.co.uk> wrote:
> From: paul swed
>
>
> Thanks.
> I really like the idea that a Rassberry Pi could be a time server. Maybe
> enough
In central mass, AT&T and tracfone (? carrier) are showing phone times
very close to 1 min slow. Virgin/sprint is ok. I've never seen this
before - usually it's a few s slow.
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Hi
Unless you have a very fancy receiver, the cabling should not matter much. The
antenna is a bigger issue, but again it depends on just how fancy you are
getting and how good the antenna is. Right now, I would not worry about either
one. Use good quality RG-6 quad shield satellite TV coax and
Thank you all for the advices.
I will prepare the setup for a longer logging session,
using an inverter and a battery for power backup.
Now I'm starting building of a clock shaper
and a divider for the 10MHz signal, I will use
7AC gates for both the squarer and divider, since I
have many of them
c...@omen.com said:
> Does this provide 10 MHz or 1pps?
None of the low-cost units that I know about provide 10 MHz.
Most of them provide crappy timing via NMEA over a serial port.
The ones I mentioned include PPS.
--
These are my opinions. I hate spam.
_
On 12/15/2012 12:19 AM, Hal Murray wrote:
gha...@gmail.com said:
You mention "low cost units which require you to add a power connector,
etc". Could you recommend any that can be bought online? With RS-232,
please?
There are two obvious choices. A bit of googling may find more details
and/or
gha...@gmail.com said:
> You mention "low cost units which require you to add a power connector,
> etc". Could you recommend any that can be bought online? With RS-232,
> please?
There are two obvious choices. A bit of googling may find more details
and/or other boards.
--
The new f
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