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April 1958 Radio-Electronics
 [Table
of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
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WWV is
the oldest continuously-operating radio station in the U.S. since first going on
the air from Washington, D.C. in May 1920. It moved around an area near D.C. for
a few years before being relocated to its current location in Boulder, Colorado,
in 1966. WWVB, another
time standard transmitter, had already been established in Boulder a few years earlier.
Sister station WWVH
is located in Hawaii.
 The National Bureau of Standards (NBS) was renamed National
Institute of Standards and Technology (NIST) in 1988,
nearly a century after its inception in 1890. Having grown up not too far from Beltsville,
Maryland, I remember driving by their main campus when the NBS sign was still on
the lawn. The decision to change the name never did make sense, but then most of
what government bureaucrats do perplex me. Rank and file employees, the ones
who do the amazing work that comes from NIST, NASA, NIH, NSA, NSF, NOAA, et al,
are pawns in the process.
1The Department of Commerce's Boulder
Labs were dedicated on September 14, 1954. The Boulder Labs have evolved from the
National Bureau of Standards' Central Radio Propagation Laboratory to today's National
Institute of Standards and Technology, National Oceanic and Atmospheric Administration,
and National Telecommunications and Information Administration's Institute for Telecommunication
Sciences.
WWV Offers Additional Services
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NIST radio station WWV broadcasts time and frequency information
24 hours per day, 7 days per week to millions of listeners worldwide. WWV is located
in Fort Collins, Colorado, about 100 kilometers north of Denver. The broadcast information
includes time announcements, standard time intervals, standard frequencies, UT1
time corrections, a BCD time code, geophysical alerts and marine storm warnings.
Broadcast Frequencies WWV operates in the high frequency (HF) portion of the radio
spectrum. The station radiates 10,000 W on 5, 10, and 15 MHz; and 2500 W on 2.5
and 20 MHz. Each frequency is broadcast from a separate transmitter. Although each
frequency carries the same information, multiple frequencies are used because the
quality of HF reception depends on many factors such as location, time of year,
time of day, the frequency being used, and atmospheric and ionospheric propagation
conditions. The variety of frequencies makes it likely that at least one frequency
will be usable at all times.
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WWV Calls Attention to the fact that, besides providing correct time, it offers
a number .of less well known services. For example, a standard musical pitch, 440
cycles, is broadcast by the National Bureau of Standards over its shortwave stations
WWV (Beltsville, Md.) and WWVH (Maui, Hawaii). These broadcasts make a standard
pitch available day and night throughout the United States and much of the world.
A 600-cycle note is also broadcast. This together with the 440-cycle tone is used
by scientists, electronic engineers and manufacturers in the measurement of short
intervals of time and for calibrating instruments and devices that operate in the
audio and ultrasonic frequency ranges. Both the 440- and 600-cycle tones are obtained
from an electronic, crystal-controlled oscillator and are accurate as transmitted
to better than 1 part in 100 million.
The two frequencies are broadcast alternately, starting with 600 cycles on the
hour for 3 minutes, interrupted 2 minutes, followed by 440 cycles for 3 minutes
and interrupted for 2 minutes. Each 10-minute period is the same except that WWV
is off the air for 4 minutes beginning at 45 minutes after each hour, and WWVH is
silent, in addition, for a 34-minute period each day beginning at 1900 Universal
time or 1400 Eastern standard time. WWV broadcasts simultaneously on 2.5, 5, 10,
15, 20 and 25 mc. WWVH broadcasts on 5, 10 and 15 mc.
During the announcement intervals (19 1/2 and 49 1/2 minutes after the hour from
WWV and 9 and 39 minutes after the hour from WWVH) these stations transmit propagation
notices applying to transmission paths over the North Atlantic and North Pacific,
respectively. The notices, in International Morse code, consist of the letter W,
U or N followed by digits 1 to 9. W indicates ionospheric disturbance in progress
or expected; U means unstable conditions with communication possible with high power
and N means no warning.
The numbers indicate the propagation conditions expected during the next 12 hours.
They have the following meanings: 1 - Impossible, 2 - Very Poor, 3 - Poor, 4 - Fair
to Poor, 5 - Fair, 6 - Fair to Good, 7 - Good, 8 - Very Good, 9 - Excellent.
1 -
Significant
Papers from the First 50 Years of the Boulder Labs
Posted September 24, 2020
(updated from original post on 6/3/2014)
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