The history of Radio Control

Written by Bob Noll How RC technology evolved in the US Education As seen in the August 2018 issue of Model Aviation.

Bonus video

It all started with Dr. Walter Good and his twin brother, Bill, in 1937. They could never have imagined what the hobby of RC model airplanes would be today. I’ll take you with me as we travel along the timeline of RC development since the Good brothers made their historic flights at the Kalamazoo, Michigan, airport. Those first flights were made with an 8-foot Free Flight (FF) model into which the brothers installed their primitive RC equipment. They designed and built their Big Guff airplane in 1938 specifically for RC.

That same year, Ross Hull, an avid modeler from Australia, flew a 13-foot RC glider at a famous glider site near Elmira, New York. As early as 1938, Leo Weiss was recognized as describing the first tone reed system, an eight-channel radio system. Raytheon developed its ultrasensitive RK-62 tube, which enabled the development of the single-tube receiver.

Howard McEntee published details with schematics for his twin-frequency transmitter in 1939. One of the earliest publications of a multifunction, single-channel RC system was by Thracey Petrides and Leon Hillman in 1941. The U.S. Army used RC airplanes called Radioplanes as artillery target drones during World War II.

FCC Order 130-C went into effect on March 1, 1946, and created the 6-meter band allocation for the amateur service as 50 to 54 MHz. Many modelers, such as I, quickly learned some radio theory and Morse code to be able to fly on the 6-meter band, which gave them an almost personalized frequency at local fields.

The Good brothers, Bill (L) and Walt, at the 1940 Nats. The pair won the RC Nats in 1938, 1939, and 1940. Photo by Ted Just.

The first examination-free frequency was provided by FCC in 1949. It was 465 mc and was limited to 5 watts. That same year, Ed Rockwood developed a multichannel system, which was the first commercial venture for an audio-frequency-modulated reed radio.

1952 was a big year for RC modelers when the FCC granted use of the 27.255 mc frequency as the first license-free and test-free band. The power output limit was 5 watts. In 1953, Frank Schmidt made and sold a complete five-channel reed set based on the Rockwood design. In 1954, Don Brown developed the Galloping Ghost system, which might have been the first multicontrol system. He called it the “crank system.”

During these years, transmitters were quite large with many tubes and heavy batteries. Bramco, Inc. introduced its Control Box Transmitter that was advertised as “the control box for controlling your model with the reflexes and coordination of a real pilot.”

Jack Albrecht built what is thought to be the first handheld transmitter in 1956. Bob Dunham started Orbit Electronics in 1958 and produced a popular reed system with a handheld transmitter. Before this, several top pilots were flying Bramco radios with ground-based transmitters. Bramco quickly saw the popularity of handheld transmitters and began producing its own.

This reproduction of the Good brothers’ radio was built by Wes DeLong using plans in the December 1940 issue of Air Trails magazine. The magazine covered building the Big Guff and the radio throughout several issues. Reproductions of both the airplane and radio can be seen in the National Model Aviation Museum.

1960 saw the first commercially available proportional system, Space Control, introduced by Zel Richie. Space Control was engineered by Hershel Toomim and produced by his company, Solidtronic, in Van Nuys, California.

Meanwhile, in 1960, Don Baisden submitted a proposed article to Grid Leaks magazine on his single-channel Galloping Ghost pulser and another for his rudder-only pulser that was later kitted by Ace RC.

Also in 1960, Howard McEntee came up with a simplified version of a pulse-proportional system that used only a single tone and added the feature of being able to vary the pulse rate of the tone, as well as achieve a second function with only one tone. Howard’s system was referred to as the “Kicken Duck” because the control surfaces flapped like a duck’s wings.

More advances were seen in 1961 as the Bonner relayless servo, the Transmite, became commercially available. The first jet model was flown with a Dyna Pulse Jet and a reed radio system. It had Jerry Nelson as the pilot. Don Brown built his first Quadraplex proportional RC system by hand as Carl Schwab, who designed the electronics, provided advice and assistance by telephone.

Don Baisden proposed an article to Grid Leaks magazine on his single-channel Galloping Ghost pulser and another for his rudder-only pulser, which was later kitted by Ace RC.

In the early 1960s, the move from reed systems to proportional systems was gaining ground. Three more significant advances in RC came in 1962. Airborne Control Labs introduced its pioneering feedback proportional system in April 1962, including incorporating the receiver and servos into an airborne “brick.”

The first commercial digital RC system was flown by Doug Spreng. The radio was named Digicon. 1962 also saw the first commercially produced four-stick proportional radio, the Astroguide, by Klinetronics.

In 1963, Howard Bonner’s name was in the news again when he introduced his eight-channel Digimite system. One of the most significant developments arrived in 1965 when the FCC granted five frequencies on 72 MHz band with 80 kHz spacing. In 1966, Proportional Control System’s (PCS) revolutionary low price of $299.95 for a complete proportional system with servos and batteries shook the RC world to its foundations and led to the demise of several competing manufacturers. Most of the systems at the time sold for approximately $500.

Phil Kraft introduced his Gold Medal Series proportional system in 1968 after winning the gold medal at the Corsica, Italy World Championships.

Toy company Mattel entered the RC hobby with its inexpensive, single-channel pulse-proportional system that sold for $29.95.

The first Controlaire three-channel proportional prototypes appeared and were built to explore the concept of a more affordable three-channel alternative to Controlaire’s full-house proportional system. Bob Elliot designed a servo amplifier that reduced the servo wires from six to three. In 1969, frequency-modulation and pulse-code-modulation receivers were introduced.

A few years later, in March 1975, Orbit Electronics displayed the Elite “super radio” in Westchester, New York, at the Westchester Radio Aero Modelers’ trade show. It had an LCD display panel. That same year, transmitter features included servo reversing, adjustable travel, and dual rates. A year later, toy company Mattel entered the RC hobby with its inexpensive, single-channel, pulse-proportional system that sold for $29.95.

Also in 1976, Kraft Systems introduced the first synthesized RC system. This radio system allowed the operator to change frequencies using the same transmitter and receiver. It had electronic circuits that generated a range of frequencies from a single reference frequency.

Here is an early Quadraplex. Don Brown hand-built his first transmitter and receiver. Carl Schwab, who designed the electronics, provided advice and assistance by telephone.

A major improvement to RC systems came in 1982 when JR Radios offered an array of programming features. These computer radios allowed pilots to program the transmitter for many different models. The programming started with naming the airplane, and then setting various parameters such as servo direction, servo travel limits, dual and triple rates, mixing of various controls, and exponential travel curves that could be customized for each pilot and model.

In 1987, the FCC granted additional channels on the 72 MHz band, and the following year granted more channels on the 72 MHz band, with 20 kHz spacing referred to as narrow band.

In 2004, the first commercial RC system using spread spectrum technology was introduced by Spektrum. It operated on 2.4 GHz. Paul Beard developed spread spectrum modulation (DSM) using 2.4 GHz.

PCS’s revolutionary low price of $299.95 shook the RC world to its foundations and led to the demise of several competing manufacturers.

In 2011, Futaba introduced Futaba Advanced Spread Spectrum Technology (FASST). The next year, Futaba introduced S.Bus protocol using one signal cable to control multiple servos. Improvements in reliability with lower costs have continued to the present.

I’m sure I missed some milestones along the road of RC development, but I believe that I captured enough to give you a picture of how our great RC model aircraft hobby has progressed since the Good brothers started it off in 1937.

Howard Bonner introduced this eight-channel Digimite system.

A timeline of radio control for model airplanes in the United States

• 1937: Twins Walt and Bill Good, only age 21, made their first flights at the Kalamazoo MI, airport after adding RC to their 8-foot gas FF model named KG-8.
• 1937: Australian Ross Hull went to Elmira NY, and flew a 13-foot glider with RC.
• 1938: Walt and Bill Good built the first airplane designed for radio control, the Big Guff, and placed first at the AMA Nats.
• 1938: Leo Weiss describes an eight-channel, audio-tone reed system for model airplane radio control he had under development.
• 1938: A new type of tube was introduced for radio control that enabled the development of an ultrasensitive single-tube receiver: the RK-62 by Raytheon.
• 1939: Howard McEntee published twin-frequency transmitter details with schematics.
• 1941: Early multifunction single channel published by Thracy Petrides and Leon Hillman.
• 1940: During WW II, the U.S. Army and Navy used RC airplanes called Radioplanes as artillery target drones.
• 1946: FCC Order 130-C went into effect on March 1, 1946, and created the 6-meter band allocation for the amateur service as 50–54 MHz.
• 1949: First examination-free frequency allowed—465 MHz and 5-watt maximum power.
• 1949: Ed Rockwood’s multichannel system was the first commercial venture for an audio-frequency-modulated reed radio.
• 1952: 27.255 MHz available with no test and a 5-watt maximum.
• 1953: Frank Schmidt made and sold a complete, five-channel reed set based on the Rockwood design.
• 1954: Don Brown developed a Galloping Ghost system that might have been the first single-channel multicontrol system called the “crank system.”

The National Model Aviation Museum displays many radios and visitors can leave Post-it notes detailing their recollections of these radios.

• 1955: Bramco Inc., in Detroit, entered the RC business with its Blue Chip reed system.
• 1956: Jack Albrecht built what is thought to be the first handheld transmitter.
• 1956: Bob Dunham started Orbit Electronics and produced a popular reed system.
• 1957: Walter Good published his TTPW transmitter for a dual-proportional system.
• 1957: Zel Ritchie built a handheld, solid-state version of Walt Good’s TTPW transmitter.
• 1958: FCC granted five additional frequencies at 50 kHz spacing on the 27 MHz band.
• 1959: Ken Willard flew indoor model using an .020 engine weighing only 33/4 oz.
• 1959: Al Doig introduced his Ulti Multi closed-loop, feedback, non-wiggling, multiproportional system.
• 1959: Relayless reed system was flown by Louie Scheel and Ken Oliver.
• 1960: Bramco, Inc. introduced its Control Box Transmitter, which was advertised as the control box for controlling a model with the reflexes and coordination of a real pilot.
• 1960: First commercially available proportional system, Space Control, introduced by Zel Richie. Space Control was engineered by Hershel Toomim and produced by his company, Solidtronic, in Van Nuys CA.
• 1960: Don Baisden submitted a proposed article to Grid Leaks magazine on his single-channel Galloping Ghost pulser and another for his rudder-only pulser, later kitted by Ace R/C.
• 1960: Howard McEntee came up with a simplified version of pulse proportional that used a single tone, and added the feature of being able to vary the pulse rate of the tone as well to get a second function with only one tone.
• 1961: Howard Bonner’s relayless servo, the Transmite, became commercially available.
• 1961: First jet model flown with Dyna Pulse Jet and a reed radio system had Jerry Nelson as pilot.
• 1961: The hand-built Quadraplex transmitter and receiver were by Don Brown. Carl Schwab, who designed the electronics, provided advice and assistance by phone.
• 1962: ACL introduced its pioneering feedback proportional system in April 1962, including its incorporation of receiver and servos into an airborne “brick.”
• 1962: The first commercial digital RC system flown by Doug Spreng. The radio was named Digicon.
• 1962: First commercially produced four-stick proportional radio, the Astroguide, by Klinetronics.
• 1963: Howard Bonner introduced this eight-channel Digimite system.
• 1964: Howard Bonner introduced the Transmite servo for relayless reed receivers.
• 1965: FCC granted five frequencies on the 72 MHz band with 40 kHz spacing.
• 1966: PCS’s revolutionary low price of $299.95 shook the RC world to its foundations and led to the demise of several competing manufacturers.
• 1968: Phil Kraft introduced his “Gold Medal Series” system after winning the gold medal at the Corsica, Italy, World Championship.
• 1968: The first Controlaire three-channel proportional prototypes were built to explore the concept of a more-affordable, three-channel alternative to Controlaire’s full-house proportional system.
• 1968: Bob Elliot designed a servo amplifier that reduced the servo wires from six to three wires.
• 1969: FM and PCM receivers were introduced.
• 1975: Orbit debuted the Elite “super radio” at the March 1975 WRAM Show. It had an LCD display panel.
• 1975: Transmitter features were increased to servo reversing, adjustable travel, and dual rates.
• 1976: Mattel, the toy company, entered the RC hobby with its inexpensive single-channel pulse-proportional system that sold for $29.95.
• 1976: Kraft Systems introduced the first synthesized RC system.
• 1982: The first computer transmitter was introduced by JR Radio.
• 1987: The FCC granted additional channels on the 72 MHz band.
• 1988: The FCC granted additional channels on the 72 MHz band with 20 kHz spacing referred to as narrow band.
• 2004: Paul Beard developed DSM using 2.4 GHz.
• 2011: Futaba introduced FASST.
• 2012: Futaba introduced S.Bus protocol using one cable to control multiple servos.

Credits: A brief summary of The History and Evolution of RC by Don Gray and Giuseppe Fascione, March 2006.
RC Hall of Fame
AMA Model Aviation Hall of Fame

—Bob Noll [email protected]

Sources:

Radio Control Hall of Fame

www.rchalloffame.org

AMA Model Aviation Hall of Fame

www.modelaircraft.org/museum/history-recognition/ama-model-aviation-hall-fame

AMA National Model Aviation Museum

www.modelaircraft.org/welcome-national-model-aviation-museum