This airman doesn’t look particularly happy about being forced down in the middle of nowhere, but there’s a glimmer of hope in the form of the AN/CRN-16 radio beacon that he’s feverishly cranking. The set weighed in at only 2-1/2 pounds, a marked contrast to the famous “Gibson Girl” AN/CRT-3 from World War II. The CRT-3 had a range of over a thousand miles thanks to its 500 kHz signal and large antenna, but it was bulky, and there was always a possibility of it being lost at sea while trying to transfer it to a lifeboat. The new model operated on 140.58 MHz, which only covered line of sight. But a plane at 2000 feet would be able to pick up the signal 50 miles away. The main advantage of the VHF signal was the short antenna.
As with the original Gibson Girl, the hand crank served two purposes. First, it ran a generator to power the set. It also generated the Morse code message. The picture appeared on the cover of the August 1949 issue of Popular Mechanics.
Shown here in the June 1939 issue of Radio Craft is sixteen-year-old Kathryn Hutchinson of the famous Flying Hutchinsons. According to the magazine, she was an amateur radio operator, although her call sign was not specified. She is shown here working on part of the Amateur Radio display of the 1939 World’s Fair, which was part of the Westinghouse exhibit in cooperation with the ARRL.
The Flying Hutchinsons had earned their fame in 1931, when Kathryn was about eight, when they visited the capitals of all 48 states by air. The next year, when Kathryn was nine, the family achieved further fame in an attempted around-the-world flight. The attempt ended off Greenland when the plane crash landed and the family was stranded for several days before being picked up by a fishing trawler and taken to the U.K. Kathryn’s parents, George and Blanche, wrote two books detailing their adventures, The Flying Family in Greenland (1935) and Flying the States (1937).
You can see Kathryn and the rest of her family in this 1932 newsreel in which her father defends the flight:
You can hear Kathryn and the rest of the family at this 1939 radio program. More information is available at this link. I believe the program is actually a dramatization of the completion of a flight that never took place. Begun in 1939, the Hutchinsons made it as far as Mexico before the war broke out, making impossible a visit to all nations on earth.
Seventy five years ago this month, the April 1944 issue of Popular Science showed this illustration of the survival items that could be dropped to airmen who were forced to make an emergency landing in the Arctic.
For a larger image, click twice on the image above from most browsers.
Contrary to your first guess, no, this is not a picture of the Hindenburg. Instead, the picture appeared on the cover of Popular Science one hundred years ago this month, March 1919, a full 18 years before the Hindenburg’s crash on May 6, 1937. The picture is actually of an explosion during inflation of an observation balloon at Fort Sill, Oklahoma.
The article explained that this scene was a thing of the past thanks to the discovery of the element helium, and its great availability as a byproduct of the decay of radium in Kansas, Oklahoma, and Texas. But the article hints at the later disaster by asking how the first world war might have been different if the Germans had helium for their zeppelins.
As we previously wrote, despite the Roosevelt Administration’s eagerness to sell the strategic gas to Germany, Interior Secretary Harold Ickes nixed the idea, keeping helium out of the hands of the Germans.
Seventy-five years ago, a technically inclined high school student might have given serious consideration to the proposal contained in this ad, which appeared in the October 1943 issue of Popular Science for the Aero Industries Technical Institute, 5247 W. San Fernando Road, Los Angeles,
The ad starts out by reminding that students in technical training might be eligible for a draft deferment, and the school would give students a head start. They could complete their senior year of high school and at the same time gain a year of training in Aviation Mechanics or Engineering. High school courses were taught by state certified instructors, and the aviation instructors were approved by the CAA and military. Upon completion, the student would walk away with a California high school diploma and a certificate for completing the Master Mechanics Course.
Students lived in comfortable new dormitories where they would enjoy wholesome food and real companionship. Campus activities included a band, basketball, and baseball, and students had privileges at the nearby YMCA.
This sensible advice appeared in Life magazine 80 years ago today, August 22, 1938. If someone attempts to distract this Chicago air traffic controller by engaging in idle chit chat, he merely needs to point to the sign.
Shown here in the September 1927 issue of Popular Radio is Capt. Hawthorne C. Gray of the U.S. Army Air Service, preparing for the flight in which he achieved the record for the highest altitude from which radio broadcast reception had ever been made. According to the magazine, Capt. Gray’s balloon was equipped with an Atwater Kent Model 32, a seven-tube receiver with single dial control and loop antenna. During the flight, he was able to pull in stations KMOX and KSD, and he was able to determine bearings to the stations at all times during the flight. “Up to the time that the aviator became unconscious at 31,000 feet, the receiver was working satisfactorily, with a total lack of interference.”
The date of the flight is not stated in the magazine, but it appears to be the same flight that Capt. Gray recounted in the August 1927 issue of Popular Mechanics.
In that account, Capt. Gray notes that he was listening to a jazz orchestra playing in St. Louis, “the music coming in clear and loud on my radio, without a single trace of static.”
Gray made another attempt at an altitude record on November 4, 1927. On this attempt, his luck ran out. The barographs aboard the craft showed that he had reached an altitude of over 43,000 feet, but his lifeless body was found in the balloon basked in a tree near Sparta, Tennessee. He was posthumously awarded the Distinguished Flying Cross, and he is buried at Arlington National Cemetery.
It was a simpler time sixty years ago, and this electronics hobbyist and aviation enthusiast was able to walk out onto the tarmac with her suspicious electronic device, as shown on the cover of Popular Electronics, July 1957.
She is listening to aircraft traffic with a simple VHF receiver, and the plans are shown in the magazine. The set was a crystal set using a 1N82 diode, with one CK722 transistor for audio amplification and tuned 90-145 MHz. In addition to being useful for listening to aircraft, the magazine said that it could be used to zero in with bloodhound accuracy in a hidden transmitter hunt.
In testing the set at a local airport, the tower could be heard several hundred feet away and approaching planes could also be heard.
The war was over, and the American public was hungry for television. A handful of markets already had stations using the same format that would remain in use for seventy years. For example, the predecessor of WNBT-TV came on the air in New York in 1939. And the predecessor of WABD signed on in 1944. And starting in 1942, Los Angeles had the station that would become KTLA. But most of the nation was dark as far as television signals. To get signals to a significant proportion of the populations would require hundreds of stations. And getting network programs to those stations would require either hundreds of microwave relay stations, are a coaxial network estimated to cost a hundred million dollars.
Stratovision provided an alternative. The plan was proposed in 1945 by Westinghouse, and was the brainchild of engineer C.E. Nobles. Under the plan, fourteen aircraft would fly at the predetermined locations shown on the diagram at an altitude of 30,000 feet where they would continually orbit their designated location. They would transmit VHF and UHF television signals, as well as FM broadcasts. Because of the antenna height, each plane would provide a good broadcast signal to an area 422 miles in diameter. And because there would be no terrain that would need to be overcome, the transmitters could operate with much less power than ground-based stations.
The system also solved the problem of delivering network programming. Only eight planes would be required to link New York with Los Angeles. The planes would establish a reliable network whenever they were in flight, and the fourteen planes would provide broadcast television to 78% of the country’s population. The plan called for each plane to broadcast four television and five FM signals.
The plan may appear far fetched to some, but it is sound, and would result in a workable national network. The system was tested by Westinghouse in 1948 and 1949, as seen in this photo. In one 1949 test, the aircraft shown here, a B-29, relayed the signal of WMAR-TV in Baltimore on channel 6, using a 5 kW video and 1 kw aural transmitter. In June 1948, the same aircraft was used to rebroadcast the Republican National Convention in Philadelphia for one hour. As part of the test, a receiver was set up in Zanesville, Ohio, where it was used to demonstrate to the gathered newspaper reporters that the system was capable of reaching small town and farm homes.
Reception reports were solicited, and many were received. From the reports, Westinghouse confirmed that eight planes would provide the transcontinental relay.
There’s nothing technically unfeasible about Stratovision. The reason why it never took off (pardon the pun) was probably the mere fact that broadcast stations did spring up nationwide. They were initially provided with programs by kinescope recordings, but microwave and coaxial transmission quickly came into place. For example, by 1950, the Minneapolis/St. Paul market was getting the national networks live, by means of a coaxial cable from Des Moines, which was in turn linked to Chicago by microwave relay. Once the network signal was in place, there was no need for Stratovision’s relay services. And by this time, most major cities had multiple stations, and smaller markets had at least one. And for those far in the hinterlands, there were herculean efforts to get the distant terrestrial signals, such as those use in the tiny communities of Ellensburg, Washington and Marathon, Ontario.
But despite the fact that Stratovision was never adopted for its intended purpose, it did live on, and continues to do so, in some specialized niches. For example, between 1961 and 1968, educational programs were broadcast from two DC-6AB aircraft based at Purdue University by the Midwest Program on Airborne Television Instruction (MPATI). The MPATI aircraft would fly in a figure-8 pattern for six to eight hours at a time at 23,000 feet above a point just north of Muncie, Indiana. Prerecorded educational programs were broadcast on UHF channels 72 and 76, with call letters KS2XGA and KS2XGD. The transmission diameter was 200 miles, and covered both the Chicago and Detroit metropolitan areas.
Between 1966 and 1972, the U.S. Navy used Stratovision to broadcast two channels in the area surrounding Saigon, South Vietnam. One channel was intended for the Vietnamese audience, with the other providing information and entertainment programs to U.S. servicemen. Armed forces programs were carried on channel 11, with call letters NWB-TV, with the Vietnamese program on channel 9 with call letters THVN-TV. The aircraft also broadcast on 1000 kHz AM and 99.9 MHz FM. The Vietnamese program typically ran 1-1/2 hours per day, with the armed forces channel running three hours per day. American programs included Bonanza, Perry Mason, Ed Sullivan, and the Tonight Show.
Pennsylvania Air National Guard Commando Solo aircraft preparing to depart for emergency broadcasts to Haiti in 2010. Department of Defense photo.
The U.S. military continues to use EC-130 Commando Solo aircraft to provide PSYOPS broadcasts during war. Most recently, only radio programming has been used. But the aircraft is capable of television transmissions. For example, in 1999 in the former Yugoslavia, some television programming, using Yugoslavian broadcast format, was transmitted from aircraft. Typically, Commando Solo transmits an FM program, along with broadcasts on the standard AM band and short wave. For AM and short wave, the airborne transmitter has no particular advantage, other than providing a secure location to house the station. But on FM, the signal, like the original Stratovision concept, takes advantage of the aircraft’s altitude, and can provide a strong broadcast signal over a large area with a relatively low powered transmitter. The photo here shows a Pennsylvania Air National Guard Commando Solo aircraft preparing to depart for Haiti to make emergency broadcasts in the wake of the 2010 earthquake.
During the 2011 attack on Libya, Commando Solo aircraft broadcast information. Transcripts of the broadcasts are available at PsyWar.org. Since the Libyan broadcasts were carried on short wave as well as FM, they were heard by short wave listeners worldwide, including myself. A recording of the transmissions can be found at this video:
The plan may appear far fetched to some, but it is sound, and would result in a workable national network. The system was tested by Westinghouse in 1948 and 1949, as seen in this photo. In one 1949 test, the aircraft shown here, a B-29, relayed the signal of WMAR-TV in Baltimore on channel 6, using a 5 kW video and 1 kw aural transmitter. In June 1948, the same aircraft was used to rebroadcast the Republican National Convention in Philadelphia for one hour. As part of the test, a receiver was set up in Zanesville, Ohio, where it was used to demonstrate to the gathered newspaper reporters that the system was capable of reaching small town and farm homes.
