Frnak McKenney wrote:


Hm. Wonder if anyone has built an antenna whose polarization shifts
to "best match" the incoming signal? (No, not _this_ weekend!
grin!)


Yes, such things have been built. There are some French researchers who
built an adaptive combiner that combined multiple polarizations, and
also did the processing to allow using both the ordinary and
extraordinary ray, and substantially improved link reliability on 1000km
skywave paths.



A minor update: It seems that I was _mis_tuning my antenna,
adjusting it for the strongest signal (highest stack of LEDs lit).
Over the past two days either I've finally tuned it _correctly_ or
I've done that _and_ the signal has improved. Whatever the
cause(s), I can now -- at times, in fact for an hour at a time --
hear the tocks fairly clearly and even understand the voice. (Who
knew the announcer's phrase for UTC "Coordinated Universal Time"?).

UTC is not an acronym. It's a madeup identifier that matches neither
the English (Coordinated Universal Time) or the French (T U C.. I won't
even attempt to figure out what it is..).

These sorts of international metrology things have all sorts of such
negotiated compromises in them, stemming all the way back to the Prime
Meridian being in Greenwich, but measuring in meters.

On Mon, 15 Oct 2007 09:06:49 -0700, Jim Lux
wrote:

hear the tocks fairly clearly and even understand the voice. (Who
knew the announcer's phrase for UTC "Coordinated Universal Time"?).

UTC is not an acronym. It's a madeup identifier that matches neither
the English (Coordinated Universal Time) or the French (T U C.. I won't
even attempt to figure out what it is..).

Hi All,

In fact, UTC is an acronym (already anticipated by Frnak and
explicitly stated every minute). It is but one of several, this one
being rather genericized (because any longer would force a lot of
talking, and minute passes by pretty quickly). The others would
include: UTC(NIST), UT1; and the academic UT0, and UT2.

The reason for the initials order is that there is an hidden comma.
Universal Time, Coordinated. Wikipedia reports this as an erroneous
expansion, but Wikipedia wasn't there in my Metrology classes (a
couple dozen miles from NBS) where we worked with these NBS standards.
It wasn't there when (1974) I performed the second leap second on my
Cesium Beam Standard which was calibrated through WWVB (taking about
half an hour, part of which was waiting during the roughly 15 minute
intervals between TOCs). My antenna was so far away (on the fantail
of the ship in another "time zone"), that I had to slip the time by
100nS.

Knowing that Arthur only reads his own threads, I won't have to
anticipate his rejection of the following efficiency reports for a
non-gaussian antenna. From NIST (the people who know efficiency)
about their 60KHz antenna system:

"Each antenna is a top loaded monopole consisting of
four 122-m towers arranged in a diamond shape.
A system of cables, often called a capacitance hat or
top hat, is suspended between the four towers.
This top hat is electrically isolated from the towers,
and is electrically connected to a downlead suspended
from the center of the top hat. The downlead serves
as the radiating element.

"Ideally, an efficient antenna system requires a
radiating element that is at least one-quarter wavelength
long. At 60 kHz, this becomes difficult. The wavelength is
5000 m, so a one-quarter wavelength antenna would be
1250 m tall, or about 10 times the height of the WWVB
antenna towers. As a compromise, some of the missing
length was added horizontally to the top hats of this
vertical dipole, and the downlead of each antenna is
terminated at its own helix house under the top hats.
Each helix house contains a large inductor to cancel
the capacitance of the short antenna and a
variometer (variable inductor) to tune the antenna
system.

"Using two transmitters and two antennas allows the
station to be more efficient. As mentioned earlier, the
WWVB antennas are physically much smaller than
one quarter wavelength. As the length of a vertical
radiator becomes shorter compared to wavelength,
the efficiency of the antenna goes down. In other words,
it requires more and more transmitter power to increase
the effective radiated power. The north antenna system
at WWVB has an efficiency of about 50.6%, and the
south antenna has an efficiency of about 57.5%.
However, the combined efficiency of the two antennas
is about 65%. As a result, each transmitter only has to
produce a forward power of about 38 kW for WWVB to
produce its effective radiated power of 50 kW."

73's
Richard Clark, KB7QHC

Richard Clark wrote:


Knowing that Arthur only reads his own threads, I won't have to
anticipate his rejection of the following efficiency reports for a
non-gaussian antenna. From NIST (the people who know efficiency)
about their 60KHz antenna system:

"Each antenna is a top loaded monopole consisting of
four 122-m towers arranged in a diamond shape.
A system of cables, often called a capacitance hat or
top hat, is suspended between the four towers.
This top hat is electrically isolated from the towers,
and is electrically connected to a downlead suspended
from the center of the top hat. The downlead serves
as the radiating element.

"Ideally, an efficient antenna system requires a
radiating element that is at least one-quarter wavelength
long. At 60 kHz, this becomes difficult. The wavelength is
5000 m, so a one-quarter wavelength antenna would be
1250 m tall, or about 10 times the height of the WWVB
antenna towers. As a compromise, some of the missing
length was added horizontally to the top hats of this
vertical dipole, and the downlead of each antenna is
terminated at its own helix house under the top hats.
Each helix house contains a large inductor to cancel
the capacitance of the short antenna and a
variometer (variable inductor) to tune the antenna
system.

"Using two transmitters and two antennas allows the
station to be more efficient. As mentioned earlier, the
WWVB antennas are physically much smaller than
one quarter wavelength. As the length of a vertical
radiator becomes shorter compared to wavelength,
the efficiency of the antenna goes down. In other words,
it requires more and more transmitter power to increase
the effective radiated power. The north antenna system
at WWVB has an efficiency of about 50.6%, and the
south antenna has an efficiency of about 57.5%.
However, the combined efficiency of the two antennas
is about 65%. As a result, each transmitter only has to
produce a forward power of about 38 kW for WWVB to
produce its effective radiated power of 50 kW."

73's
Richard Clark, KB7QHC

The NIST folks could probably increase the efficiency to greater than
90% if they dug a large pit to temporarily store the decaying electrons.
All of those dying electrons lying on the ground tend to discourage the
active electrons from working as hard as they could.

The efficiency could be raised to nearly 100% if the two helices were
wound in opposite directions. That would provide the best shot at
equilibrium.

73,
Gene
W4SZ

On Mon, 15 Oct 2007 19:48:48 GMT, Gene Fuller
wrote:

However, the combined efficiency of the two antennas
is about 65%. As a result, each transmitter only has to
produce a forward power of about 38 kW for WWVB to
produce its effective radiated power of 50 kW."

The NIST folks could probably increase the efficiency to greater than
90% if they dug a large pit to temporarily store the decaying electrons.
All of those dying electrons lying on the ground tend to discourage the
active electrons from working as hard as they could.

The efficiency could be raised to nearly 100% if the two helices were
wound in opposite directions. That would provide the best shot at
equilibrium.

Hi Gene,

You shave points too close. They could achieve 130% efficiency if
they simply tapped into the current return on the inside of the wire.

Arthur's 3dB here and 3dB there, if you use enough wire, then you are
beginning to talk about GAIN!

Also, Fort Collins is a higher altitude than Podunk Illinois, so
impedance is less than 377 Ohms too! High gain, maybe 129% efficient.

***** irony mode off ********

Load resistance seen by the transmitters is roughly 0.85 Ohm
transformed to 50 Ohms.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Mon, 15 Oct 2007 09:06:49 -0700, Jim Lux
wrote:


hear the tocks fairly clearly and even understand the voice. (Who
knew the announcer's phrase for UTC "Coordinated Universal Time"?).

UTC is not an acronym. It's a madeup identifier that matches neither
the English (Coordinated Universal Time) or the French (T U C.. I won't
even attempt to figure out what it is..).


Hi All,

In fact, UTC is an acronym (already anticipated by Frnak and
explicitly stated every minute). It is but one of several, this one
being rather genericized (because any longer would force a lot of
talking, and minute passes by pretty quickly). The others would
include: UTC(NIST), UT1; and the academic UT0, and UT2.

Au contraire...
while UT1, UT0, and UT2 are, in fact, acronyms of a sort, primarily
based on astronomical time, this is not the case for UTC..

the coordination has to do with matching up UT and TAI (atomic) time..
all those leap seconds, etc.

As one online source puts it:
The (Bureau Internationale de l'Heure) BIH was charged with the task of
monitoring and maintaining the program and introduced the term Temps
Universel Coordinné or Coordinated Universal Time for the coordinated
time scale in 1964.

BIH is the predecessor of the current BIPM (who seem to have a problem
with the standard kilo losing mass) http://www.bipm.org/


or, for more information:
http://syrte.obspm.fr/journees2004/PDF/Arias2.pdf

which says: The name of Coordinated Universal Time UTC appeared in CCIR
documents in the early 60s.

One might also seek a paper from 1964, by Guinot. (who was a time guy at
the BIH back then)

A paper by Dennis McCarthy at USNO on "Evolution of Time Scales"
mentions in Section 6 that: the term "Coordinated Universal Time" was
introduced in the 1950s to designate a time scale in which the
adjustments to quartz crystal clocks were coordinated among
participating laboratories in the US and UK.


A more recent paper by Guinot says:
"Until 1965, the more or less common scale for emission of signals,
which had received spontaneously the name of Coordinated Universal Time
(UTC), had not been strictly defined."



The reason for the initials order is that there is an hidden comma.
Universal Time, Coordinated.

Funny, thing, though, that if one searches the literature of the time
for that particular sequence of words, it never occurs..

Given that Coordinated Universal Time existed well before UTC, I suspect
that the comma thing is a post hoc creation.


Wikipedia reports this as an erroneous
expansion, but Wikipedia wasn't there in my Metrology classes (a
couple dozen miles from NBS) where we worked with these NBS standards.
It wasn't there when (1974) I performed the second leap second on my
Cesium Beam Standard which was calibrated through WWVB (taking about
half an hour, part of which was waiting during the roughly 15 minute
intervals between TOCs). My antenna was so far away (on the fantail
of the ship in another "time zone"), that I had to slip the time by
100nS.

Jim Lux wrote:
Richard Clark wrote:

The reason for the initials order is that there is an hidden comma.
Universal Time, Coordinated.

Funny, thing, though, that if one searches the literature of the time
for that particular sequence of words, it never occurs..

Given that Coordinated Universal Time existed well before UTC, I suspect
that the comma thing is a post hoc creation.

Not everything is English, folks. UTC is for Universale Temps
Coordinaire. No comma is implied or needed because in French, an
adjective follows the word it modifies, with very few exceptions.

Roy Lewallen, W7EL

Roy Lewallen wrote in
:

Not everything is English, folks. UTC is for Universale Temps
Coordinaire. No comma is implied or needed because in French, an
adjective follows the word it modifies, with very few exceptions.

Then wouldn't it be Temps Universale Coordinaire?

Owen

Owen Duffy wrote:
Roy Lewallen wrote in
:

Not everything is English, folks. UTC is for Universale Temps
Coordinaire. No comma is implied or needed because in French, an
adjective follows the word it modifies, with very few exceptions.

Then wouldn't it be Temps Universale Coordinaire?

Good point. This should be reported to the French language police!

Roy Lewallen, W7EL

Roy Lewallen wrote in
:

Owen Duffy wrote:
Roy Lewallen wrote in
:

Not everything is English, folks. UTC is for Universale Temps
Coordinaire. No comma is implied or needed because in French, an
adjective follows the word it modifies, with very few exceptions.

Then wouldn't it be Temps Universale Coordinaire?

Good point. This should be reported to the French language police!

Roy Lewallen, W7EL


Roy, I think that as others have posted, it is neither English nor
French, but a *******isation that doesn't concede either language to be
the better for expressing the meaning. The diplomacy aspect of striking
standards no doubt!

Owen

On Mon, 15 Oct 2007 16:43:53 -0700, Jim Lux
wrote:

The reason for the initials order is that there is an hidden comma.
Universal Time, Coordinated.

Funny, thing, though, that if one searches the literature of the time
for that particular sequence of words, it never occurs..

You are writing to one who read the literature - at that time. My
experience is not from arm chair history 101. UTC was arrived at as a
compromise between the French (naturally) and the "rest of the world"
(what else?). My bona fides are documented too: two diplomas from the
only Metrology school in the United States - at that time. Time in
service: with training in calibration and maintenance of the HP Cesium
Beam standard, and VLF subsystem - at that time. I also lived through
the great switch-over from cycles to hertz, and GMT to Zulu - at that
time (or slightly before... I wasn't looking at the clock that day).

I can flood this page with 250 references that employ the strict usage
of "Universal Time Coordinated" "Universal Time, Coordinated" or
"Universal Time (Coordinated)" and specifically 35 of them printed
before 1967. With google it takes more time to cut and paste than
actually find them. A short list includes:

Title 15 1971 Code of Federal Regulations By United States Office of
the Federal Register (1971)
"... the Universal Time Coordinated (UTC)
system' as recommended by the Bureau
International de l'Heure (bill).
The carrier offset currently is minus 300 ..."

Meteorological and Geoastrophysical Abstracts By American
Meteorological Society (1960)

International Aerospace Abstracts
By American Institute of Aeronautics and Astronautics Technical
Information Service, United States National Aeronautics and Space
Administration, Institute of the Aerospace Sciences Technical
Information Service (1961)

Proceedings of the IEEE. By Institute of Electrical and Electronics
Engineers (1963)

Scientific and Technical Aerospace Reports
By United States. National Aeronautics and Space Administration.
Scientific and Technical Information Division, United States National
Aeronautics and Space Administration. Scientific and Technical
Information Office, NASA Scientific and Technical Information
Facility, United States National Aeronautics and Space Administration.
Scientific and Technical Information Branch, NASA Center for AeroSpace
Information, United States. National Aeronautics and Space
Administration. Office of Scientific and Technical Information (1963)

Navigation Dictionary By United States Naval Oceanographic Office
(1969)

New Scientist By EBSCO Publishing (1971)

Basic Electronic Instrument Handbook By Clyde F. Coombs (1972)

Newer titles:

UPI Style Book & Guide to Newswriting By Harold Martin, Bruce Cook

Dictionnaire des sciences et techniques du pétrole By Magdeleine
Moureau, Gerald Brace

Acronyms, Initialisms & Abbreviations Dictionary By Ellen T. Crowley

GPS Satellite Surveying By Alfred Leick

All of 10 minutes (give or take).

Familiar with any service acronyms like BFD?

73's
Richard Clark, KB7QHC