Military radio antenna kites facts for kids
Imagine a kite that helps you talk to people far away! Radio antenna kites are special kites used to lift a radio antenna high into the sky. This helps the radio signals travel further than they would from an antenna on a short pole.
These kites were often used with portable radio systems, especially before World War I. Navies also used them sometimes to send messages over longer distances from their ships. However, using kites for antennas had some challenges. The wind could be unpredictable, making it hard to keep the antenna at a steady height. Also, as radio technology got better, people found other ways to send and receive signals more reliably.
Later, during World War II and after, these kites became very important. They were used with survival radios given to pilots flying over oceans. If a plane crashed, the kite could help send a distress signal.
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Early Kite Antennas
The King Kite: A Big Helper
In 1905, a soldier named Sergeant Thomas I. King designed the first kite specifically for lifting a radio antenna. He was part of the United States Army Signal Corps at Fort Leavenworth, Kansas.
His "King" kite was quite large, about 7 feet tall and 5 feet wide. It was made from light Japanese silk and had a bamboo frame, weighing less than 2 pounds. The kite had a diamond shape with flat top and bottom edges, plus a special "keel" and a large hole in the middle. These features helped it fly steadily, a bit like a box kite. Sometimes, people used one King kite, or even a train of 2 to 4 kites together. On days with less wind, they might even add a balloon to help lift the antenna higher.
The King kite was used with small, portable radio transmitters. While it didn't greatly increase how far signals could be sent, it made a huge difference for receiving signals. People could hear messages from places as far away as Cuba!
Bell's Tetrahedral Kites
In 1906, Alexander Graham Bell, who invented the telephone, teamed up with Lee de Forest, another inventor. They experimented with Dr. Bell's special tetrahedral kites to lift radio antennas. Bell had been working on these kites, hoping they might lead to flying machines.
They used a very large kite with 230 cells to lift an antenna 400 feet into the air near Fort Myer, Virginia. They successfully sent and received radio messages with the Naval wireless station at the Washington Navy Yard.
Standard Military Kites
For a while, the United States Signal Corps kept three different models of antenna-lifting kites as standard equipment. These were still listed in their supply catalog as late as 1920.
- Kite KI-1: This kite was also called the "folding Malay kite". It was made of spruce wood rods and covered with cloth, measuring 60 by 60 inches. It was used with portable radio sets in the field.
- Kite KI-2 and KI-3: The original King kite was updated and became standard equipment, available in two sizes. The KI-2 was smaller, 6 feet tall and 6 feet wide. The KI-3 was larger, 7 1/2 feet tall and 7 1/2 feet wide. Both were made with spruce sticks and covered in a light gray cloth. They were meant to be used with the SCR-44 field radio set, which was a portable radio from before World War I.
Kites for Emergency Radios
Early Emergency Use
The United States Navy started looking into kites for emergency radios as early as 1922. They wanted a way for downed seaplanes to send out distress calls. At the time, aircraft radios only worked while the plane was flying.
Two different kites were made for this purpose: one for strong winds and one for lighter winds. Pilots also got a reel of light antenna wire and a small generator. This generator could be powered by a working engine to make the radio work.
Kites M-277-A and M-357-A
In 1941, the German military had an emergency radio called the NSG2. It came with a special winged box kite to raise its antenna. When the British captured one of these, they copied it to make their own "Dinghy Transmitter" T-1333.
The Americans also got an NSG2 from the British. They improved it and released it in 1942 as the SCR-578-A "Gibson Girl" survival radio. This radio was carried by United States Army Air Forces planes and was meant for use in life rafts.
The SCR-578-A included the M-277-A, a collapsible box kite designed to lift the antenna. This kite was similar to the German one but didn't have wings. It had a frame made of four aluminum rods that could fold out like an umbrella. The yellow cloth covering was waterproof, and part of it was filled with a material called kapok to help it float if it fell into the water. It was easy to put together and could fly in winds from 7 to 40 miles per hour. The instructions were even printed on the cardboard tube it came in!
The Kite M-357-A was almost the same as the M-277-A, but its frame could be separated into two pieces. This made it even smaller for storage. The instructions for putting it together were printed right on the cloth. The M-357-A was used with later versions of the SCR-578-B and the post-war AN/CRT-3 radio, which was still in use in the early 1970s.
Both kites had two places to attach the string, depending on how windy it was. This helped them fly well in different wind conditions. These radios also came with a small balloon and a hydrogen generator to lift the antenna if there was no wind. However, the kite was usually preferred because the hydrogen generator was dangerous to use.
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| M-277-A | M-357-A | Instructions for assembling M-357-A |
Images for kids
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King Kite, Fort Leavenworth, Kansas c. 1905
