KDKA - PITTSBURGH

The first commercial radio station KDKA made its debut on Nov. 2, 1920 when it aired the presidential election that year. After technological advancements made in WWI, radio companies could sell and build ready-made machines.

The Westinghouse Electric Corp. wanted to build a broadcast station at their plant to increase sales of receivers and promote good publicity, and brought Frank Conrad (an engineer) onto their project since he was familiar with the equipment.

Thus, modern radio broadcasting was born, and the “Golden Age of Radio” began. Conrad built a 100-watt transmitter for air programming from Westinghouse, which involved knowledge of wiring and circuitry.

The first advertisement launched on a radio station was in 1922, and it was for a real estate developer in New York City. The radio was now a way to advertise, obtain news quickly (no waiting for newspapers), hear the same songs across the country, and listen to guest speakers/heroes.

Link to source

RADIO ARLINGTON

Photo: Smithsonian Institution
"Three Sisters" - Towers at Radio Arlington outside Washington, D.C.

Photo: engineeringhistory.tumblr.com 

Operator's desk at Navy Wireless Station NAA in Arlington, Virginia, 1915 

"Radio" was the nickname of  a residential neighborhood in Arlington County, Virginia, near U.S. Navy Wireless Station NAA. There was even a streetcar stop called "Radio." A trio of radio antennas – known to locals as ``The Three Sisters’’ – towered over the neighborhood. In their day, the towers were the world’s tallest. One was 45 feet taller than the Washington Monument. The station went on the air in 1913. Radio Arlington’s firsts included a transoceanic radiotelephone circuit with the Eiffel Tower in 1915 and regular broadcasts of time signals for ships at sea to calibrate navigational equipment.

HINDENBURG

Chief Operator Willy Speck in the radio room of the zeppelin Hindenburg in photo courtesy of the Luftschiffbau Zeppelin GmBH Archive. Speck died of injuries sustained in the May 6, 1937, explosion of the airship at Lakehurst, New Jersey. 

Hindenburg's radio room - located in the hull just above the control car - was equipped with both long wave and short wave radios capable of transmitting at 200 watts. The zeppelin's radio call sign was DEKKA.

CLEAR CHANNEL AM

On Nov. 11, 1928, the U.S. implemented General Order 40, classifying AM allocations as local, regional or clear channel. Radio fans refer to clear channel stations as "flamethrowers" or "blowtorches" because of their high power -- 50,000 watts.

LIST AS OF 2013:

(*) designates full power stations on same frequency
(Class B) denotes lower power station on same frequency

540 CBK, Watrous, Saskatchewan, Canada
640 KFI, Los Angeles, CA
650 WSM, Nashville, TN
*660 WFAN, New York, NY
*660 CFFR, Calgary, Alberta Canada
670 WMAQ, Chicago, IL (KBOI, Boise, Idaho: Class B) 
*680 KNBR, San Francisco, CA
*680 CJOB, Winnipeg, Alberta Canada
*680 CFTR, Toronto, Ontario, Canada
700 WLW, Cincinatti, OH
710 WOR, New York, NY
710 KIRO, Seattle, WA
720 WGN, Chicago, IL (KDWN, Las Vegas, NV: Class B) 
730 CKAC, Montreal Quebec, Canada
750 WSB, Atlanta, GA
760 WJR, Detroit, MI
*770 WABC, New York, NY (KKOB, Albuquerque, NM: Class B) 
*770 CHQR, Calgara, Alberta, Canada
*780 WBBM, Chicago, IL (KKOH, Reno, NV: Class B)
*780 CFDR Dartmouth, Nova Scoia, Canada
810 KGO, San Francisco, CA 
810 WGY, Schenectady, NY
820 WBAP, Fort Worth, TX
830 WCCO, Minneapolis, MN
840 WHAS, Louisville, KY
850 KOA, Denver, CO
860 CJBC, Toronto Ontario, Canada
870 WWL, New Orleans, LA
*880 WCBS, New York, NY (KRVN, Lexington, NE: Class B) 
*880 CHQT, Edmonton, Alberta, Canada
890 WLS, Chicago, IL (KDXU, St. George, UT: Class B)
990 CBW, Winnipeg, Manitoba, Canada 
*1000 WLUP, Chicago, IL
*1000 KOMO, Seattle, WA
1010 CBR, Calgary, Alberta, Canada
1020 KDKA, Pittsburgh, PA (KCKN, Roswell, NM Class B)
1030 WBZ, Boston, MA (KTWO, Casper, WY: Class B) 
1040 WHO, Des Moines, IA
*1060 KYW, Philadelphia, PA
*1060 CKMX Calgary, Alberta, Canada
*1070 KNX, Los Angeles, CA
*1070 CBA Moncton, New Brunswick, Canada
*1080 WTIC, Hartford, CT
*1080 KRLD, Dallas, TX
*1090 KAAY, Little Rock, AR
*1090 WBAL, Baltimore, MD
1100 WTAM, Cleveland, OH (KNZZ, Grand Junction, CO: Class B) 
*1110 WBT, Charlotte, NC
*1110 KFAB, Omaha, NE
1120 KMOX, St. Louis, MO (KPNW, Eugene, OR: Class B) 
*1130 KWKH, Shreveport, LA
*1130 WBBR, New York, NY
*1130 CKWX, Vancouver, British Columbia, Canada
1140 WRVA, Richmond, VA 
1160 KSL, Salt Lake City, UT
*1170 KVOO, Tulsa, OK
*1170 WWVA, Wheeling, WV
1180 WHAM, Rochester, NY (KOFI, Kalispell, MT: Class B) 
1190 KEX, Portland, OR
*1200 WOAI, San Antonio, TX
*1200 CFGO, Ottawa, Ontario, Canada
1210 WPHT, Philadelphia, PA (KGYN, Guymon, OK: Class B) 
*1500 WFED, Washington, DC
*1500 KSTP, St. Paul, MN
*1510 WLAC, Nashville, TN
*1510 KGA, Spokane, WA
*1520 WWKB, Buffalo, NY
*1520 KOMA, Oklahoma City, OK
*1530 KFBK, Sacramento, CA
*1530 WCKY, Cincinatti, OH
1540 KXEL, Waterloo, IA
*1560 KNZR, Bakersfield, CA
*1560 WQEW, New York, NY

TITANIC RADIO LOG

News of the disaster was sent by wireless

Titantic's SOS as copied by SS Birma

Photo of Titanic wireless station

Following is a log of wireless traffic between the HMS Titanic and ships steaming to her rescue on April 15, 1912. All times are by the ship's clock.

12-15 a.m

CQD (6 times) DE (this is) MGY (6 times) position 41.44 N. 50.24 W

La Provence and Frankfurt receive Titanic's first distress signals.

Titanic sends position to Frankfurt. Frankfurt says "OK: stand by"

12-15 a.m

Mount Temple heard Titanic sending CQD Says require assistance. Gives position. Cannot hear me (sic). Advise my Captain (sic) his position at 41.46 N. 50.24 W.

12-15 a.m.

Cape Race coast station hears Titanic giving position on CQD 41.44 N. 50.24 W.

12-18 a.m.

Ypiranga hears CQD from Titanic.   Titanic gives CQD here (sic).  Position 41.44 N. 50.24 W. Require assistance (calls about 10 times).

12-25 a.m.

Carpathia calls Titanic and says "do you know that Cape Cod is sending a batch of messages for you ?"

Titanic says "Come at once. We have struck a berg.

It's a CQD OM (it's a distress situation old man) Position 41.46 N. 50.14 W."

Carpathia says "Shall I tell my Captain ?. Do you require assistance ?"

Titanic says "yes, come quick"

12-25 a.m.

Cape Race hears MGY (Titanic) give corrected position 41.46 N. 50.14 W. Calling him, no answer.

12-25 a.m.

MGY (Titanic) says CQD, Here (is my) corrected position 41.46 N. 50.14 W. Require immediate assistance. We have collision with iceberg. Sinking. Can hear nothing for noise of steam (engineers releasing excess steam pressure from boilers to minimise risk of explosion) Sent about 15 to 20 times to Ypiranga.

12-26 a.m.

DKF (Prinz Friedrich Wilhelm) calls MGY (Titanic) and gives position at 12 a.m. 39.47 N. 50.10 W.

MGY (Titanic) says, "Are you coming to our ?" "We have collision with iceberg. Sinking. Please tell Captain to come." DKF says, "O.K. will tell"

12-27 a.m.

Titanic sends following: "I require assistance immediately. Struck by iceberg in 41.46 N. 50.14 W."

12-30 a.m.

Caronia sent CQ message (message addressed to all ships) to MBC Baltic and CQD (ie: a distress relay message): MGY(Titanic)  struck iceberg, require immediate assistance

12-30 a.m.

Mount Temple hears MGY (Titanic) still calling CQD. Our (sic) Captain reverses ship. We are about 50 miles off.

12-34 a.m.

Mount Temple hears Frankfurt give MGY (Titanic) his position 39.47 N. 52.10 W.

Titanic says (to Frankfurt) " are you coming to our

assistance ?"

Frankfurt says : "what is the matter with you ?"

Titanic says "We have struck an iceberg and sinking. Please tell Captain to come"

Frankfurt replies "O.K. Will tell the bridge right away"

Titanic says "O.K., yes, quick."

12-45 a.m.

Titanic calls Olympic (Olympic is Titanic's sister ship - 500 miles away en route to England) SOS.

12-50 a.m.

Titanic calls CQD and says, "I require immediate assistance. Position 41.46 N. 50.14 W." Received by Celtic.

12-53 a.m.

Caronia to MBC (Baltic) and SOS,"MGY (Titanic) CQD in 41.46 N. 40.14 W. Wants immediate assistance."

1-0 a.m.

MGY gives distress signal. DDC (Cincinnati) replies. MGY's position 41.46 N. 50.14 W. Assistance from DDC (Cincinnati) not necessary as MKC (Olympic) shortly afterwards answers distress call.

1-0 a.m.

Titanic replies to Olympic and gives his position as 41.46 N. 50.14 W., and says, "We have struck an iceberg."

1-2 a.m.

Titanic calls Asian and said, "Want immediate assistance" Asian answered at once and received Titanic's position as 41.46 N. 50.14 W., which he immediately takes to the bridge. Captain instructs operator to have Titanic's position repeated.

1-2 a.m.

Virginian calls Titanic but gets no response. Cape Race tells Virginian to report to his Captain the Titanic has struck iceberg and requires immediate assistance.

1-10 a.m.

Titanic to MKC (Olympic), "We are in collision with berg. Sinking Head down. 41.46 N. 50.14 W. Come soon as possible."

1-10 a.m.

Titanic to MKC (Olympic), Captain says, "Get your boats ready. What is your position?"

1-15 a.m.

Baltic to Caronia, "Please tell Titanic we are making towards her."

1-20 a.m

Virginian hears MCE (Cape Race) inform MGY (Titanic) "that we are going to his assistance. Our position 170 miles N. of Titanic."

1-25 a.m.

Caronia tells Titanic, "Baltic coming to your assistance"

1-25 a.m

Olympic sends position to Titanic 4-24 a.m. G.M.T. 40.52 N. 61.18 W, and asks "Are you steering southerly to meet us?" Titanic replies, "We are putting the women off in the boats."

1-27 a.m

Titanic says, "We are putting the women off in the boats."

1-30 a.m

Titanic tells Olympic, "We are putting passengers off in small boats." "Women and Children in boats, can not last much longer"

1-35 a.m.

Olympic asks Titanic what weather he had. Titanic replies, "Clear and calm."

1-35 a.m

Baltic hears Titanic say "Engine room getting flooded." 

1-35 a.m.

Mount Temple hears DFT (Frankfurt) ask "are there any boats around you already?" No reply

1-37 a.m.

Baltic tells Titanic, "We are rushing to you."

1-40 a.m.

Olympic to Titanic "Am lighting up all possible boilers as fast as (we) can."

1-40 a.m.

Cape Race says to Virginia: "Please tell your Captain this: "The Olympic is making all speed for Titanic, but his (Olympic's) position is 40.32 N. 61.18 W. You are much nearer to Titanic. The Titanic is already putting women off in the boats, and he says the weather there is calm and clear. The Olympic is the only ship we have heard say, "Going to the assistance of Titanic.  The others must be a long way from Titanic

1-45 a.m.

Last signals heard from Titanic by Carpathia, "Come as quickly as possible old man: the engine-room is filling up to the boilers"

1-45 a.m.

Mount Temple hears Frankfurt calling Titanic. No reply.

1-47 a.m.

Caronia hears Titanic though signals unreadable still. Virginia hears Titanic calling very faintly, his power being greatly reduced.

1-48 a.m.

Asian heard Titanic call SOS Asian answers Titanic but receives no answer.

DFT (Frankfurt) calls Titanic and says, "What is the matter with u ?"

1-50 a.m.

Titanic says to Frankfurt "You fool, stdbi and keep out"

Caronia hears Frankfurt working to Titanic.  Frankfurt according to position 172 miles from MGY (Titanic) at time first SOS sent out.

1-55 a.m.

Cape Race says to Virginian "we have not heard Titanic  for about half an hour. His power may be gone."

2-10 a.m.

Virginian hears 2 v's signalled faintly in spark similar to Titanic's.

2-17 a.m.

Virginian hears Titanic call CQ (call to all ships) , but unable to read him. Titanic's signals end very abruptly as (if) power suddenly switched off. His spark rather blurred or ragged...

2-17 a.m.

Virginian Called Titanic and suggested he should try emergency set, but heard no response.

2-20 a.m.

Virginian to Olympic,"have you heard anything about Titanic"   Olympic says, "No. Keeping strict watch, but hear nothing more from Titanic. No reply from him"

[2-20 a.m. was the official time the ship foundered in 41.46 N. 50.14 W. as given by the Carpathia in message to the Olympic.]

2-35 a.m.

Mount Temple hears MPA (Carpathia) send, "If you are there we are firing rockets."

2-40 a.m.

MPA (Carpathia) calling MGY (Titanic).

2-58 a.m.

SBA (Birma) thinks he hears Titanic so sends, "Steaming full speed for you. Shall arrive you
6-0 in morning. Hope you are safe. We are only 50 miles now."

3-0 a.m.

MPA (Carpathia) calling MGY (Titanic)

3-28 a.m.

La Provence to Celtic, "Nobody has heard the Titanic for about 2 hours."

4-24 a.m.

SBA (Birma) says "we are 30 miles S.W. off Titanic".

6-40 a.m.

Parisian hears weak signals from MPA (Carpathia) or some station saying Titanic struck iceberg. Carpathia has passengers from lifeboats

6-40 a.m.

Asian, with German oil tank in tow for Halifax asked what news of MGY (Titanic). Sends service (message) later saying heard MGY (Titanic) v. faint working. C. Race up to 10.0 p.m., local time. Finished calling SOS midnight.

7-40 a.m.

6-45 a.m. Mount Temple hears MPA (Carpathia) report rescued 20 boat loads.

8-07 a.m.

Baltic sends following to Carpathia: "Can I be of any assistance to you as regards taking some of the passengers from you? Will be in position about 4-30. Let me know if you alter your position."

8-10 a.m.

Baltic in communication with MPA. (Carpathia). Exchanged traffic re passengers, and get instructions to proceed to Liverpool

8-15 a.m.

Baltic turns round for Liverpool, having steamed 134 miles W. towards Titanic

8-40 a.m.

Mount Temple hears MPA (Carpathia) call CQ and say, no need to std. Bi (stand by) him. Advise my Captain (sic), who has been cruising round the icefield with no result. Ship reversed.

8-45 a.m.

Olympic sent MSG (message) to Owners, New York via Sable Island saying, "Have not communicated with Titanic since midnight."

8-55 a.m.

Carpathia replies to Baltic, "Am proceeding to Halifax or New York full speed. You had better proceed to Liverpool. Have about 800 passengers on board."

9-0 a.m.

Carpathia to Virginian: "We are leaving here with all on board about 800 passengers. Please return to your Northern course."

EKKO STAMPS

In the 1920's, EKKO stamps were a staple of the DX hobby.

Radio stations awarded EKKO stamps in exchange for reception reports and DXers collected the stamps in specially designed EKKO albums. 

The EKKO Company of Chicago made a tidy profit selling the stamps to the stations and the albums to the DXers.

Business was so good that the PM Bryant Company, also of Chicago, went into competition with EKKO.

Hundreds of broadcasters participated in the stamp programs.
For more information, click here.

PEACE AND PROGRESS

Photo: Glenn Hauser's World of Radio

Radio Station "Peace and Progress" broadcast from the Soviet Union during the Cold War, supplementing Radio Moscow's programming with Soviet "public opinion." The station took to the airwaves in 1964, establishing a harsher tone than Radio Moscow even though it pledged to promote "mutual understanding, trust and friendship." Peace and Progress utilized Radio Moscow's shortwave transmitters. Its signal faded with the demise of the Soviet Union, representing genuine "Peace and Progress."

SHORT WAVE CRAFT

Hugo Gernsback

Short Wave Craft was one of a stable of magazines published by Hugo Gernsback, who made significant contributions to the growth of early broadcasting.

The magazine was published in the 1930's and sponsored an organization called the Short Wave League. It featured construction projects, articles on the future of communications, station logs, reader correspondence - and colorful cover art.  

Gernsback's other publications included:

• Radio and Television
• Radio-Craft — July 1929 to June 1948 — became Radio-Electronics
• Radio Electronics — July 1948 to January 2003
• Radio Electronics Weekly Business Letter
• Radio Listeners Guide and Call Book 
• Radio News — July 1919 (as Radio Amateur News) to July 1948
• Radio Program Weekly
• Radio Review
• Science and Invention — formerly Electrical Experimenter. Published August 1920 to August 1931.
• Science and Mechanics — originally Everyday Mechanics. Changed to Everyday Science and Mechanics in 1931. "Everyday" dropped as March 1937 issue. Published as Science and Mechanics until 1976.

He also started WRNY, a New York City radio station that operated from 1925 to 1934. It was one of the first stations to have regularly scheduled experimental television broadcast starting in August 1928, according to Wikipedia.

However, Gernsback is best remembered as a science fiction writer and publisher of the magazines Amazing Stories and Wonder Stories. Today, the World Science Fiction Convention's annual awards are named "The Hugos" in Gernsback's honor.

For more Short Wave Craft covers, click here.

ALBANIA

The little county roared on 41 meters.

Radio Tirana, from the capital of Albania, was a major player in international shortwave radio during the Cold War.

The Balkan country was ruled by Stalinist dictator Enver Hoxha, who broke with the Soviet Union and allied with China.

China supplied Radio Tirana powerful shortwave transmitters that beamed programming to North America.

The transmitters also relayed Radio Peking.

Programming included "Leafing Through Our Listeners' Letters" and "Culture and Art in Socialist Albania."

At sign-off Radio Tirana played the communist anthem "Internationale." 

Radio Tirana QSL Card from 1970s

For information on Radio Tirana today, click here.

AT&T HIGH SEAS

The AT&T High Seas Service operated a ship-to-shore HF radio network consisting of stations WOO in New Jersey, WOM in Florida and KMI in California (photo).

The High Seas Service ceased operations on Nov. 9, 1999.

Today, WLO in Mobile, Alabama, is the only full service ship-to-shore provider of voice, data and e-mail services in the continental U.S.

WLO is operated by ShipCom, LLC.

For frequencies and other information , click here.

RADIO CAROLINE

Pirate station "Radio Caroline" went on the air in March 1964. It was anchored in waters off the United Kingdom. The station broadcast from a variety of vessels into the 1980s on medium wave. Transmitter strength over the years ranged from 10 kilowatts to 50 kilowatts. Its initial frequency was 199 meters (1485/1520 kHz). Broadcasts later moved to 259 meters (1169/1187 kHz).

VOA

President Dwight D. Eisenhower broadcasts from the Voice of America on its fifteenth anniversary in February 1957. VOA - the official government shortwave service - went on the air during World War Two with programming to Germany and Japan. Today, VOA broadcasts in 46 languages. Its transmitter site in the U.S. is located near Greenville, North Carolina.

TOKYO ROSE

Iva Ikuko Toguri D'Aquino, an American, was the woman most identified with the moniker "Tokyo Rose" - the name given to any of a dozen English-speaking female broadcasters of Japanese propaganda during World War II. She was convited of treason in 1949 and pardoned by President Ford in 1977 after evidence emerged a witness had lied at her trial. - Wikipedia

AUSTRALIA CALLING

Photo: Doug Garlinger

In 1939, Australia's prime minister, Robert Menzies, inaugurated the shortwave service at the Australian Broadcasting Corp. in an effort to counter Japanese propaganda at the outbreak of World War II. In the 1940s, the station was remaned Radio Australia.

RADIO MOSCOW

Your editor listened to Radio Moscow on his Lafayette receiver

Moscow calling.

Radio Moscow started beaming its English Service to the U.S. by shortwave in the early 1950's. 

Moscow Mailbag, hosted by Joe Adamov, was a popular feature that answered listeners' questions.

The program continued after the fall of the Soviet Union in 1991, when Radio Moscow was renamed Voice of Russia.

Adamov presented Moscow Mailbag from 1957 until 2005.

Radio Moscow's interval signal was "My Country's Vast."

Radio broadcasting in the Soviet Union commenced in the Moscow region in 1922.

A second station went on the air in Leningrad in 1924.

By 1939, Radio Moscow was broadcasting in English, French, German, Italian and Arabic via medium wave and short wave.

At its peak, Moscow broadcast in over 70 languages via transmitters in the Soviet Union, Eastern Europe and Cuba.

RADIO PRAGUE

Photos: Radio Prague
International shortwave broadcasts from Prague went on the air on Aug. 31, 1936 from the government telegraph office. The Technical Director of Czechoslovak Radio, Eduard Svoboda, hosted the first program in English.

RADIO RSA

Radio RSA - the Voice of South Africa - went on the air in 1966 and signed off at the end of the apartheid era in 1992. ``Radio RSA broadcast news and opinion programming, which was often propaganda aimed at defending the apartheid regime and demonizing its opponents, like the African National Congress,'' according to Wikipedia. Radio RSA was operated by the South African Broadcasting Corp.

AT THE TONE

In May 1920, WWV went on the air from Washington, D.C., transmitting time interval signals. It moved to Fort Collins, Colorado, on Dec. 1, 1966, enabling better reception of its signal throughout the continental U.S. - Wikipedia

From the National Institute of Standards and Technology

WWV has a long and storied history that dates back to the very beginning of radio broadcasting. The call letters WWV were assigned to NIST (then called the National Bureau of Standards) in October 1919. Although the call letters WWV are now synonymous with the broadcasting of time signals, it is unknown why those particular call letters were chosen or assigned. Testing of the station began from Washington, D.C. in May 1920, with the broadcast of Friday evening music concerts that lasted from 8:30 to 11 p.m. The 50 W transmissions used a wavelength of 500 m (about 600 kHz, or near the low end of today’s commercial AM broadcast band), and could be heard out to about 40 kilometers. A news release dated May 28, 1920 hinted at the significance of this event:

This means that music can be performed at any place, radiated into the air by means of an ordinary radio set, and received at any other place even though hundreds of miles away. The music received can be made as loud as desired by suitable operation of the receiving apparatus. Such concerts are sometimes sent out by the radio laboratory of the Bureau of Standards in connection with trials of experimental apparatus. This music can be heard by anyone in the states near the District of Columbia having a simple amateur receiving outfit. The pleasant evenings which have been experienced by persons at a number of such receiving stations suggest interesting possibilities of the future.

Interesting possibilities, indeed! Keep in mind that KDKA of Pittsburgh, generally acknowledged as the first commercial broadcast station, did not go on the air until November 2, 1920.

On December 15, 1920 the station began assisting the Department of Agriculture in the distribution of market news to farm bureaus and agricultural organizations. A 2 kW spark transmitter was used to broadcast 500 word reports, called the Daily Market Marketgram, on 750 kHz. The operating radius was about 300 kilometers out of Washington. These broadcasts continued until April 15, 1921.

By December 1922, it was decided that the station’s purpose would be the transmission of standard frequency signals. The first tests were conducted on January 29th and 30th of 1923, and included the broadcast of frequencies from 200 to 545 kHz. By May of 1923, WWV was broadcasting frequencies from 75 to 2000 kHz on a weekly schedule. The accuracy of the transmitted frequency was quoted as being “better than three-tenths of one per cent.” The output power of the station was 1 kW.

There were numerous changes in both the broadcast schedule, format, and frequency of WWV throughout the 1920’s. In January 1931, the station was moved from Washington to the nearby city of College Park, Maryland. A 150 W transmitter operating at 5 MHz was initially used, but the power was increased back to 1 kW by the following year. A new device, the quartz oscillator, made it possible to dramatically improve the output frequency of WWV. Quartz oscillators were first used at WWV in 1927, and by 1932 allowed the transmitted frequency to be controlled to less than 2 parts in 10⁷.

The station moved again in December 1932, this time to a 10 hectare (25 acre) Department of Agriculture site near Beltsville, Maryland. By April of 1933, the station was broadcasting 30 kW on 5 MHz, and 10 and 15 MHz broadcasts (20 kW output power) were added in 1935. The 5 MHz frequency was chosen for several reasons, including “its wide coverage, its relative freedom from previously assigned stations, and its convenient integral relation with most frequency standards." The 10 and 15 MHz frequencies were chosen as harmonics, or multiples of 5 MHz. WWV continues to use all of these frequencies today, as well as another harmonic (20 MHz), and a sub-harmonic (2.5 MHz).

The Beltsville area was the home of WWV until December 1966 (although the location name for the broadcast was changed to Greenbelt, Maryland in 1961). During the years in Beltsville, many interesting developments took place. A fire destroyed the station in November 1940, but the standard frequency equipment was salvaged and the station returned to the air just 5 days later using an adjacent building. An act of Congress in July 1941 provided $230,000 for the construction of a new station, which was built 5 kilometers south of the former site and went on the air in January 1943. The 2.5 MHz broadcasts began in February 1944, and are still used as a convenient way to reach the population nearest the radio station. Transmission on 20, 25, 30, and 35 MHz began in December 1946. The 30 and 35 MHz broadcasts were discontinued in January 1953 and the 25 MHz broadcast was stopped in 1977. With the exception of an almost 2-year interruption (1977-78), the 20 MHz broadcasts have continued to this day.

Much of the current broadcast format also took shape during the Beltsville years. The 440 Hz tone (A above middle C) was added to the broadcast in August 1936, at the request of several music organizations. The second pulses were added in June 1937, and the geophysical alert messages began in July 1957. And as quartz oscillator technology improved, so did the frequency control of the broadcast. The transmitted frequency was routinely kept within 2 parts in 10¹⁰ of the national standard by 1958.

WWV’s most well known feature, the announcement of time, also began during the Beltsville years. A standard time announcement in telegraphic code was added in October 1945, and voice announcements of time began on January 1, 1950. The original voice announcements were at 5-minute intervals. It is interesting to note that WWV continued to broadcast local time at the transmitter site until 1967.

In 1966, the decision was made to move WWV to its current location, near Fort Collins, Colorado. The LF station WWVB went on the air in July 1963 near Fort Collins, and it was decided that WWV would share the same 158 hectare (390 acre) site. The new site was about 80 kilometers from the Boulder laboratories where the national standards of time and frequency were kept. The proximity to Boulder and the use of atomic oscillators at the transmitter site would make it possible to control the transmitted frequency to within 2 parts in 10¹¹, a factor of ten improvement. Today, the station’s frequency is controlled to within 1 part in 10¹³.

At 0000 UTC on December 1, 1966 the Greenbelt, Maryland broadcast was turned off and the new transmitter at Fort Collins was turned on. In April 1967 the station began broadcasting Greenwich Mean Time (GMT) instead of local time, and began its current format of using Coordinated Universal Time (UTC) in December 1968. The time announcements were made every minute, instead of every 5 minutes, beginning in July 1971.