NIST-Verizon Time Difference
 

Hello, All:

I bought a so-called "atomic clock" two days ago, and it receives the
radio signals from NIST (National Institute of Standards and
Technology) to automatically adjust its time. And it works fine.

Meanwhile, I called the Verion telephone number [(757)622-9311 in
southern Virginia] which gives current time. To my surprise, I found
that the Verizon time is about four (4) seconds faster than the NIST
time.

What is the cause of this difference? Is it due to telephone
transmission delay? Or does Verizon use an independent clock that is
not synchronized with NIST?

Thanks for reading the replying.

Roland

IMHO: Telephone time services have never been exact to NIST. I have no idea
if any of them had ever tried to be.

Many years ago, (the mid 70's), during "nothing to do" time at work I would
dial the time services in NY, Boston, Philadelphia and a few other places.
There was usually a difference of 4-10 seconds between them. Using NYC as
the standard, Philly would be 7 seconds behind and Boston 4 seconds early.
From week to week the difference between them might also change. NY was
about 2 seconds off the top of hour chime on CBS radio, but once it went 15
seconds slow to the radio.

FWIW; I also learned that you couldn't dial the time service in another time
zone.

"qquito" wrote in message
ups.com...
Hello, All:

I bought a so-called "atomic clock" two days ago, and it receives the
radio signals from NIST (National Institute of Standards and
Technology) to automatically adjust its time. And it works fine.

Meanwhile, I called the Verion telephone number [(757)622-9311 in
southern Virginia] which gives current time. To my surprise, I found
that the Verizon time is about four (4) seconds faster than the NIST
time.

What is the cause of this difference? Is it due to telephone
transmission delay? Or does Verizon use an independent clock that is
not synchronized with NIST?

Thanks for reading the replying.

Roland

Out of curiosity, several times I've called the WWV and USNO time
signal phone numbers via Nextel while simultaneously listening to WWV
time ticks on shortwave radio. In all cases the cell phone audio was
noticeably delayed, but only by a split second (less than 1/4 second).

Phone numbers:
http://www.bldrdoc.gov/timefreq/stations/sig.html
http://tycho.usno.navy.mil/phones.html

--

Paul Hirose
To reply by email delete INVALID from address.

On 23 Feb 2005 17:45:09 -0800, "qquito" wrote:

Hello, All:

I bought a so-called "atomic clock" two days ago, and it receives the
radio signals from NIST (National Institute of Standards and
Technology) to automatically adjust its time. And it works fine.

Meanwhile, I called the Verion telephone number [(757)622-9311 in
southern Virginia] which gives current time. To my surprise, I found
that the Verizon time is about four (4) seconds faster than the NIST
time.

What is the cause of this difference? Is it due to telephone
transmission delay? Or does Verizon use an independent clock that is
not synchronized with NIST?

At one point, I noticed that the time signal on KGO in San Francisco
was time delayed just like the talk shows. I complained that they
should either provide the exact time or stop making the appearance of
providing the exact time. (not have a time signal but just an
announcement)

Of course, time signals on RealAudio are never accurate - if nothing
else, and there almost always is, there's always a few seconds of
buffering.

How do XP internet-adjusted clocks compare to WWV, CHU, et alia?

How do XP internet-adjusted clocks compare to WWV, CHU, et alia?

As I understand it, they measure the ping time and compensate for the
network delays when setting the clock.
I have used XP to set the clock then gone into other clock setting programs
(Satscape, WSJT etc) and compared favourably.

Nana

Joel Rubin wrote:
At one point, I noticed that the time signal on KGO in San Francisco
was time delayed just like the talk shows. I complained that they
should either provide the exact time or stop making the appearance of
providing the exact time. (not have a time signal but just an
announcement)

Some years back I noticed that WLS was no more accurate than to get the
beep within sixty seconds of the appointed time; forty seconds after
the hour, or thirty-five before, weren't unusual. Eventually they quit
doing the beep altogether.

On the other hand, WBBM has always been spot-on accurate. I guess a lot
depends on the professionalism of the station and staff.