On Mar 23, 8:29�pm, Phil Kane wrote:
On Sun, 23 Mar 2008 22:53:54 EDT, Klystron wrote:
� Wouldn't it make more sense to include WWV and WWVH along with
WWVB?
Are you familiar with the Internet-based ntp system? Then, there is the
matter of GPS, which has a time capability that is incidental to its
navigation function.

Want some fun? �Compare the time ticks received from �WWVB
, WWV,
NIST-on-line, and GPS. �What, they are not all simultaneous? ï
¿½Welcome
to the real world. �GPS time does not correlate with UTC by any me
ans
(several seconds difference).

In one of the first digital military command and control system that I
was involved in during the early 1960s, we used rubidium standards at
our switching centers to get accurate time synchronization, and even
then it was rather crude because the line delays varied so much. �
HF
propagation (WWV/WWVH) is even worse in that regard.

I've compared each of our three radio-set clocks at this residence (in
Los Angeles) and find excellent correlation between their one-second
changes and both WWV and WWVH. Don't have any GPS receiver
to try the same.

In 1960, while working in the Standards Lab of Ramo-Wooldridge Corp.
in Canoga Park, CA, I got to pull some OT on Saturdays to measure
the difference between east coast transmissions of WWV and the
local General Radio frequency standard. Just a plain old quartz
crystal standard oscillator driving divider chains to the built-in
clock.
I would record the microseconds of difference between local clock
ticks and WWV ticks from the east coast. Not much variation in a
week's time, don't remember just how much (it was 48 years ago).

Yes, propagation on HF does vary but it is sometimes exaggerated.
Before R-W went into a business tailspin, the Standards Lab was
ready to get a low-frequency HP receiver for 20 KHz to improve on
establishing a local, secondary frequency standard. No joy on that
corporation which was eventually sold off. All I ever got to see was
the 'diurnal shift' of 20 KHz phase recordings at sunrise and sunset.
:-)

73, Len AF6AY

On Mon, 24 Mar 2008 00:09:24 EDT, AF6AY wrote:

In 1960, while working in the Standards Lab of Ramo-Wooldridge Corp.
in Canoga Park, CA,

Errrr, Len, the Ramo-Wooldridge Corporation went out of existence in
1958 when it merged with Thompson Products to become Thompson Ramo
Wooldridge, Inc. Remember that I started with the "original" R-W in
1957 and was employed by them at the time of the merger at the former
El Segundo Boulevard facilities (I never did get to work at the Arbor
Vitae Street facilities which were the headquarters of the Air Force
Ballistic Missile Division). They didn't move to Canoga Park until
the late fall of 1959, and I was laid off (for the second time) in
June of 1960. Thompson Ramo Wooldridge, Inc - later TRW, Inc. - went
on an acquisitions binge and itself went out of existence in 2002 when
the electronics and aerospace parts were acquired by Grumman (now
Northrop Grumman) and the automotive parts mostly by Goodyear.

In context - RW was always friendly to ham radio, and the pre-merger
RW Corp. actually let us scrounge both new and recycled parts for ham
rigs and audio projects which became our property as long as we signed
a register/release stating what we were building.

I got to pull some OT on Saturdays to measure
the difference between east coast transmissions of WWV and the
local General Radio frequency standard. Just a plain old quartz
crystal standard oscillator driving divider chains to the built-in
clock.

While at the El Segundo Blvd. facility we had a project of measuring
distance to a transmitter using the time delay of HF transmissions
received at different sites with a calibrated link between them
(azimuth was easy using standard DF techniques) and we used the GR
frequency standard referenced above. Using WWV was too error-prone.

I would record the microseconds of difference between local clock
ticks and WWV ticks from the east coast. Not much variation in a
week's time, don't remember just how much (it was 48 years ago).

My references about time differences, BTW, was to the time of day, i.e
the time of the tick, not the interval between the ticks. GPS has a
very noticeable offset compared to NIST.

I guess that it's only nuts like me that care about that. My early
training as a broadcast studio engineer while I was in engineering
school required timing of program starts and endings to the second.
"Dead air" was not permitted. Three o'clock did not mean three
o'clock plus 1 second - the Western Union clock reset pulse on the
hour was broadcast as a "beep".

From my other hobby, "railroad accuracy" of watches (which are
compared with a master clock at the start of a shift) requires one
second per day, 30 seconds per month. Easy to do with quartz watches
nowadays. There even used to be a SP Railroad dial-up number (now
long gone) where the "time man" would announce the time "Southern
Pacific Standard Time is ...." as contrasted to Ma Bell's "time lady"
who would announce "Pacific Standard Time is ..."
--

73 de K2ASP - Phil Kane

From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon

e-mail: k2asp [at] arrl [dot] net