Who invented Proportional?
#1
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Who invented Proportional?
I have been asked this question many times, in fact, when I first came to work in the R/C industry I too was curiouse as to how R/C systems came to be. This is an interesting question, but in a nutshell, it was not developed by the R/C hobby. For those who are curiouse about how we came to have such neat radios, I offer up the following as there are many people within our hobby who have erroniousely been credited with inventing proportional. The truth is they may have been intimatley involved in the radio control electronics business to include manufacturing, distribution, and sales of radios for hobby usage, but when it comes to where this technolgy came from it's quite a different story:
In the beginning, Proportional radio control was used for guiding full size vehicles like boats, planes, drones, and later, missles. One must remember, Colonel Sanders, and McDonalds did not invent fried chicken and the hamburger respectively, but they sure did popularize them. The original creators however are lost to history.
It can be said with some certainy however that the first versions of these control systems that were miniaturized for model planes were home built. One of the first home made proportional systems was constructed by the Good brothers, they used a well known technology and called it TTPW, for two tones that were each pulse width modulated. The basic theory is if the controls are pulsed fast enough, the would not respond, but if they were dithered to one side more than the other, then the craft would respond.
Walt Good was flying his miniature version before WW2, but after the war guys like Maynard Hill, Pappy DeBolt, and Zel Ritchie all built their own versions under the tutorship of Walt Good. By the mid-1950s, R/C proportional was well established with 2 proportional controls and incremental throttle. Due to weight and space considerations, more elaborate schemes for additional proportional functions was not possible.
Enter the transistor, and more importantly, the transistor radio craze of the late 1950s to early 1960s. This made small tuning coils and components readily availlable at low cost for use in AM radios, satellites, and aircraft communication systems. The space race which was going on concurrently along with the developement of the first solid state computers radically changed and influenced R/C as it introduced new technologies that led directly to the developement of the digital proportional radio as we know it. All the early analog designs quickly faded away as they were limited. By comparison the new digital technology offered almost a limitless amount of control fuctions, well at least more than the modeler could practically use.
Along the way, old technologies such as the Goods TTPW saw a renissance as miniature components made them more practical to produce, and several other innovations such as NiCad batteries also came along such that we saw Pulse Proportional, Galloping Ghost in particular enjoy renewed popularity. But this was short lived and largely cost driven as these systems had a low parts count and subsequently lower cost. Technological advancement in the commercial electronics world soon change this too, and these simpler systems became obsolete and due to costs and performance.
The futher developement of solid state devices, the integrated circuit, and ceramic and crystal filters in particular lead to low cost FM stereo radios and eventually this became availlable at low cost for use in R/C models as we saw many manufacturers offered FM radios. The home computer explosion of the 1980s led to those types of chips being used for our first PCM radios, and the cellular phone revolution has given us our latest 2.4 GHz spread spectrum radios.
Thus, it can be seen that all of the major advances in our R/C hobby are directly dependant on the developement of technologies from other areas such as government, military, and commercial projects, as the hobby in and of itself is not a big enough industry to support the required research it would take to develope the technology used. Just as before, even today we rely on spin-off technology from other large industries and as such that is what controls the sophistication and designs we use for controlling our models.
The real heros of proportional therefore are not from the R/C industry, but rather from the government/military think tanks, and commercial electronics companies where the research is done that makes this all possible.
In the beginning, Proportional radio control was used for guiding full size vehicles like boats, planes, drones, and later, missles. One must remember, Colonel Sanders, and McDonalds did not invent fried chicken and the hamburger respectively, but they sure did popularize them. The original creators however are lost to history.
It can be said with some certainy however that the first versions of these control systems that were miniaturized for model planes were home built. One of the first home made proportional systems was constructed by the Good brothers, they used a well known technology and called it TTPW, for two tones that were each pulse width modulated. The basic theory is if the controls are pulsed fast enough, the would not respond, but if they were dithered to one side more than the other, then the craft would respond.
Walt Good was flying his miniature version before WW2, but after the war guys like Maynard Hill, Pappy DeBolt, and Zel Ritchie all built their own versions under the tutorship of Walt Good. By the mid-1950s, R/C proportional was well established with 2 proportional controls and incremental throttle. Due to weight and space considerations, more elaborate schemes for additional proportional functions was not possible.
Enter the transistor, and more importantly, the transistor radio craze of the late 1950s to early 1960s. This made small tuning coils and components readily availlable at low cost for use in AM radios, satellites, and aircraft communication systems. The space race which was going on concurrently along with the developement of the first solid state computers radically changed and influenced R/C as it introduced new technologies that led directly to the developement of the digital proportional radio as we know it. All the early analog designs quickly faded away as they were limited. By comparison the new digital technology offered almost a limitless amount of control fuctions, well at least more than the modeler could practically use.
Along the way, old technologies such as the Goods TTPW saw a renissance as miniature components made them more practical to produce, and several other innovations such as NiCad batteries also came along such that we saw Pulse Proportional, Galloping Ghost in particular enjoy renewed popularity. But this was short lived and largely cost driven as these systems had a low parts count and subsequently lower cost. Technological advancement in the commercial electronics world soon change this too, and these simpler systems became obsolete and due to costs and performance.
The futher developement of solid state devices, the integrated circuit, and ceramic and crystal filters in particular lead to low cost FM stereo radios and eventually this became availlable at low cost for use in R/C models as we saw many manufacturers offered FM radios. The home computer explosion of the 1980s led to those types of chips being used for our first PCM radios, and the cellular phone revolution has given us our latest 2.4 GHz spread spectrum radios.
Thus, it can be seen that all of the major advances in our R/C hobby are directly dependant on the developement of technologies from other areas such as government, military, and commercial projects, as the hobby in and of itself is not a big enough industry to support the required research it would take to develope the technology used. Just as before, even today we rely on spin-off technology from other large industries and as such that is what controls the sophistication and designs we use for controlling our models.
The real heros of proportional therefore are not from the R/C industry, but rather from the government/military think tanks, and commercial electronics companies where the research is done that makes this all possible.
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RE: Who invented Proportional?
Doug Spreng and Don Mathes came out with their Digicon system in 1962.
Later they all ended up in California and by 1966 Phil Kraft had taken them in along with some others to form what was to become Kraft radio systems.
Later they all ended up in California and by 1966 Phil Kraft had taken them in along with some others to form what was to become Kraft radio systems.
#7
RE: Who invented Proportional?
I remember seeing films of Hellcats and Fire Bee's being flown by techs in chairs behind control panels with stick and rudder pedals that were most assuredly proportionally controlled.
It would be an interesting find to know who/which team perfected that Navy system in the 40's.
Chris...
It would be an interesting find to know who/which team perfected that Navy system in the 40's.
Chris...
#8
RE: Who invented Proportional?
There are some films from the Luftwaffe in WW II showing a crew member (maybe a JU-88 variant) guiding RC Glide bombs using a single stick box. It was a bit difficult to tell if he was pulsing the stick like people used to do when flying the old reed radios, getting proportional control through control of the average position of the control surface (Galloping Ghost and Kicken Duck also did this) or if he was smoothly moving the stick side to side as in a true proportional system. I saw at least one where the remote pilot was watching a small TV screen.
IIR, an editor for MAN actually had a chance to fly a Radioplane OQ-2 RC Drone. Described it as quite an experience. The RC system was bang-bang, not proportional. Had a four axis stick running in a cruciform slot. Could only activate one control movement at a time. A push button killed the engine and (hopefully) popped the recovery parachute.
IIR, an editor for MAN actually had a chance to fly a Radioplane OQ-2 RC Drone. Described it as quite an experience. The RC system was bang-bang, not proportional. Had a four axis stick running in a cruciform slot. Could only activate one control movement at a time. A push button killed the engine and (hopefully) popped the recovery parachute.
#9
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RE: Who invented Proportional?
The two previous posts show how hobby R/C systems came much later, and guys like Mathes, Spreng, and other well known R/C names were merely re-packaging this technology for use in model planes. Because the original proportional systems were developed for military purposes like guiding weapons, they were top secret and it is doubtful if we will ever be able to find out who designed them. Due to the originators being shrouded in secrecy, it makes it easy for others in the R/C field to be given credit for something that had actually been around for quite some time. In the case of the German rockets and glide bombs, most likely the scientists are dead, and the USA scientists, if they are still alive, probably cannot talk about what they did as they were sworn to secrecy, so they cannot claim credit either. Thus, the credit has been given, and/or claimed by default to the R/C hobby industry people, but it is not warranted.
#10
RE: Who invented Proportional?
Besides, like many inventions, the person who gets the publicity might not be the earliest inventor. Just the first to complete the patent process.
#11
RE: Who invented Proportional?
ORIGINAL: 50+AirYears
Besides, like many inventions, the person who gets the publicity might not be the earliest inventor. Just the first to complete the patent process.
Besides, like many inventions, the person who gets the publicity might not be the earliest inventor. Just the first to complete the patent process.
Or make the claim he did...
#12
RE: Who invented Proportional?
Jay,
I don't go all the way back with military type drones, but did have experience with stuff that dated back into the 1950's. The name that always seemed to come up when talking receivers and transmitters in drones was Babcock. I wonder whether they were a significant player back into WWII ?
By the way, I was in the Western Antique Aeroplane and Automobile Museum in Hood River, Oregon last week. Among the things on display was a WWII era target drone built by Jim Walker. All the ones I'd seen previously were by Radioplane. The Walker version was similar size, but more expensively built. It had tapered wings and empennage and a round fuselage. Sort of looked like a giant Custom Cavalier. The engine looked like the same Righter two cylinder with contra rotating props. From appearances it is likely that the Walker drone still has its radio gear inside, so it may be possible to learn who made the guidance.
It's a shame we're just now getting curious about this stuff. A few years back we could have just asked somebody. What should we be asking right now that somebody will be wondering about in another 25 years?
Dick Fischer
Dick Fischer
I don't go all the way back with military type drones, but did have experience with stuff that dated back into the 1950's. The name that always seemed to come up when talking receivers and transmitters in drones was Babcock. I wonder whether they were a significant player back into WWII ?
By the way, I was in the Western Antique Aeroplane and Automobile Museum in Hood River, Oregon last week. Among the things on display was a WWII era target drone built by Jim Walker. All the ones I'd seen previously were by Radioplane. The Walker version was similar size, but more expensively built. It had tapered wings and empennage and a round fuselage. Sort of looked like a giant Custom Cavalier. The engine looked like the same Righter two cylinder with contra rotating props. From appearances it is likely that the Walker drone still has its radio gear inside, so it may be possible to learn who made the guidance.
It's a shame we're just now getting curious about this stuff. A few years back we could have just asked somebody. What should we be asking right now that somebody will be wondering about in another 25 years?
Dick Fischer
Dick Fischer
#13
RE: Who invented Proportional?
Anybody notice that lately there's an old photo from the Radioplane ads showing a rather nice looking Brunette standing alongside on OQ-2 is getting into a lot of mags, including a recent Pop Mechanics? Norma Jean something? Later turned into a Blond movie star name of Marilyn Monroe?
I had a couple planes with Babcock SE-2 escapements. They were as dependable as the Bonner Varicomp, but a lot smaller and lighter.
I really miss escapements. NOT!!!
Somewhere in the house, I still have a Du-ac GG servo, a couple Rand GG servos, and maybe an Adams actuator. Also a Royal SC rudder servo, and an old KO compound escapement. 2 escapements on a single board with a couple arms to convert rotary to back and forth pushrod for rudder and elevator.
Also, just discovering something doesn't necessarily make you world famous for an application of your discovery. Tom Edison found an unexpected current flow during some of his expirements with light bulbs (which he only made practical, he didn't actually invent the light bulb) that he dismissed as useless. It later fell to DeForest (and a few others) to use this current to produce the vacuum tube that led to practical radios. That then led eventually to our favorite hobby/sport.
I had a couple planes with Babcock SE-2 escapements. They were as dependable as the Bonner Varicomp, but a lot smaller and lighter.
I really miss escapements. NOT!!!
Somewhere in the house, I still have a Du-ac GG servo, a couple Rand GG servos, and maybe an Adams actuator. Also a Royal SC rudder servo, and an old KO compound escapement. 2 escapements on a single board with a couple arms to convert rotary to back and forth pushrod for rudder and elevator.
Also, just discovering something doesn't necessarily make you world famous for an application of your discovery. Tom Edison found an unexpected current flow during some of his expirements with light bulbs (which he only made practical, he didn't actually invent the light bulb) that he dismissed as useless. It later fell to DeForest (and a few others) to use this current to produce the vacuum tube that led to practical radios. That then led eventually to our favorite hobby/sport.
#14
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RE: Who invented Proportional?
The concept of proportional control is fairly basic. There are two things that make the implementation difficult in model airplanes that were not limitations for military drones. The first limitation is gain, and the second is bandwidth.
Gain before transistors came at a high price in terms of weight and size. Which is why none of the early hobby radio systems were true proportional systems, since in just one servo amp you would require at least a half dozen tubes to build a simple feedback amplifier. It took almost 10 years for the transistor to go from invention (1947) to wide spread commercial usage. Even then, the limitations of early transistors prevented their use in receiver higher frequency circuits or transmitters high frequency high output circuits.
Bandwidth (how much radio spectrum you use to transfer information) was another limitation placed on hobby gear that the military could easily bypass. This was the greatest problem for people building analog radios, and the breakthrough that Doug Spreng is credited for solving with his digital servo coding scheme.
Gain before transistors came at a high price in terms of weight and size. Which is why none of the early hobby radio systems were true proportional systems, since in just one servo amp you would require at least a half dozen tubes to build a simple feedback amplifier. It took almost 10 years for the transistor to go from invention (1947) to wide spread commercial usage. Even then, the limitations of early transistors prevented their use in receiver higher frequency circuits or transmitters high frequency high output circuits.
Bandwidth (how much radio spectrum you use to transfer information) was another limitation placed on hobby gear that the military could easily bypass. This was the greatest problem for people building analog radios, and the breakthrough that Doug Spreng is credited for solving with his digital servo coding scheme.
#15
Thread Starter
RE: Who invented Proportional?
Great point about bandwidth, because at 27 MHZ, you cannot send very many tones with the channels only 50KHz apart.
So true about Doug Spreng, had he not learned about pulse width modulation/variable pulse width techniques being used for space craft control while he was at JPL, digital proportional for models may have been many more years in the making. In a round about way, Jerry Pullen was partly responsible as he got Doug into the door at JPL. The strange thing however is that Jerry failed to use the pulse width detection/feedback servo amplifier Doug had introduced and plowed away for many years trying to iron out an analog set with the financial aide of Phil Kraft, and they finally gave up on it and went digital in 1964. Why this happened, I don't know, but was there a clash of titans so to speak?
Nice mention of Babcock, yes, they did make radio controlled target drones, one of many makers. Radio Plane did employ Norma Jean, she assembled engines to the planes.
Jim Walker also made small rubber band sling launched balsa planes which were free-flight gligers, and scaled to be about the right size to give the proper sight picture for ariel gunnery practice, they were inexpensive so the gunners could hit them.
Most radio controlled drones were expensive, so they often towed a banner or flag for the gunners to aim at rather than hitting and destroying the drone. Of course, this did not always stop the gung-ho recruits from shooting them down anyway! I have a two cylinder McCulloch engine off a drone used here at camp Pendelton, it has a .50 cal round lodged in the engine case.
So true about Doug Spreng, had he not learned about pulse width modulation/variable pulse width techniques being used for space craft control while he was at JPL, digital proportional for models may have been many more years in the making. In a round about way, Jerry Pullen was partly responsible as he got Doug into the door at JPL. The strange thing however is that Jerry failed to use the pulse width detection/feedback servo amplifier Doug had introduced and plowed away for many years trying to iron out an analog set with the financial aide of Phil Kraft, and they finally gave up on it and went digital in 1964. Why this happened, I don't know, but was there a clash of titans so to speak?
Nice mention of Babcock, yes, they did make radio controlled target drones, one of many makers. Radio Plane did employ Norma Jean, she assembled engines to the planes.
Jim Walker also made small rubber band sling launched balsa planes which were free-flight gligers, and scaled to be about the right size to give the proper sight picture for ariel gunnery practice, they were inexpensive so the gunners could hit them.
Most radio controlled drones were expensive, so they often towed a banner or flag for the gunners to aim at rather than hitting and destroying the drone. Of course, this did not always stop the gung-ho recruits from shooting them down anyway! I have a two cylinder McCulloch engine off a drone used here at camp Pendelton, it has a .50 cal round lodged in the engine case.
#16
RE: Who invented Proportional?
I had quite a few of the commercial sized Walker Interceptors, as well as the 74 Gliders. I have one of the newer remakes of the Interceptors, but had some problems because the package wrapping shrank and set in some warps. Some of the Interceptors made for USAAF target practice got quite large, and used a custom designed launcher.
Not exactly RC, but for a while Walker experimented with a sound powered plane. Had a large speaker in the side to pick up the control sounds. Not very sucsessful, too sensitive to ambient noises.
Sometime in the early 50s, AT carried an article about Walker's RC lawnmower. An old reel type power mower. At some contest, I think possibly a NATS, he got hit by interferrence, and chewed up a couple models.
He also developed a means to allow a CL plane to perform axial rolls in flight, in spite of the wing leadouts connecting to the control cables.
He also frequently demonstrated solo flying 3 control lin models at the same tiome, and even sometimes flew 4. 3 and 4 separate independent planes, not 4 joined planes like bill Winter's Blue Angels.
Not exactly RC, but for a while Walker experimented with a sound powered plane. Had a large speaker in the side to pick up the control sounds. Not very sucsessful, too sensitive to ambient noises.
Sometime in the early 50s, AT carried an article about Walker's RC lawnmower. An old reel type power mower. At some contest, I think possibly a NATS, he got hit by interferrence, and chewed up a couple models.
He also developed a means to allow a CL plane to perform axial rolls in flight, in spite of the wing leadouts connecting to the control cables.
He also frequently demonstrated solo flying 3 control lin models at the same tiome, and even sometimes flew 4. 3 and 4 separate independent planes, not 4 joined planes like bill Winter's Blue Angels.
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RE: Who invented Proportional?
Well, You really have to figure out what constitutes "proportional" ... (and if it is modeling or military).
For the modeling public it was probably someone building boats. By 1958 we modelers had proportional control in boats. Anyone ever read "Radio Controlled Models" by F.J. Camm? (1958) It is a pretty good book if you are interested in learning about some of the schemes used for controling devices back in the day. They have a chapters on how to build a single channel super gen two tube reciever, mark space radio control (actually a mechanical digital signal I believe)...sending "on's and offs'...proportional steering..and also Reeds.
It is a british book and an interesting read.
Steve
For the modeling public it was probably someone building boats. By 1958 we modelers had proportional control in boats. Anyone ever read "Radio Controlled Models" by F.J. Camm? (1958) It is a pretty good book if you are interested in learning about some of the schemes used for controling devices back in the day. They have a chapters on how to build a single channel super gen two tube reciever, mark space radio control (actually a mechanical digital signal I believe)...sending "on's and offs'...proportional steering..and also Reeds.
It is a british book and an interesting read.
Steve
#18
RE: Who invented Proportional?
An early 50s Air Trails article on pulse proportional showed a mechanical pulser which used a wood dowel which was partially wrapped with a copper isosceles triangle. This was rotated by a small motor at a fixed speed. A movable wiper controlled the on-off time depending on where it touched the dowel. The end points were controlled by limiting the arc the wiper could be moved through.
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RE: Who invented Proportional?
So true about Doug Spreng, had he not learned about pulse width modulation/variable pulse width techniques being used for space craft control while he was at JPL
at 27 MHZ, you cannot send very many tones with the channels only 50KHz apart.
Not exactly RC, but for a while Walker experimented with a sound powered plane. Had a large speaker in the side to pick up the control sounds. Not very sucsessful, too sensitive to ambient noises.
mark space radio control (actually a mechanical digital signal I believe)...sending "on's and offs'...proportional steering
One of the first detailed articles on difficulties of a feedback proportional radio was by Al Doig who designed the "ULTI". He describes the circuit operation, making of servos from Bonner square box servo, and the transmitter control stick designed by Howard Bonner. These two articles were in the May and July 1959 issues of American Modeler.
One of the problems with his early design would have been inner-modulation distortion, so the frequencies for the control channels had to be carefully chosen to avoid spurious signals. He had 3 proportional and one positional control.
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RE: Who invented Proportional?
Good Morning 50+ AirYears,
You just triggered a long dormant memory - amazing. After two long stays in intensive care a lot of memories have lain dormant so it is nice to get one back. Anyway when I was a Senior in High School I was reading about proportional and had seen a project like your metal triangle wiper thing. I wanted to put a single channel rudder control in a hover craft I was working with, and used a mechanical pulser. I took a plexiglas bar and a piece of aluminum tubing of the same outside diameter.. I cut the aluminum in an angle and recessed the plastic to allow the aluminum to slide over. I ended up with the equivalent of what you were talking about.
It worked pretty well in the ground use but I did have trouble with contact integrity so I wouldn't trust it in flight. I can remember the sound of it grinding away in the wood box I put it in. This was in 1958.
Thanks for the memories,
Ben
You just triggered a long dormant memory - amazing. After two long stays in intensive care a lot of memories have lain dormant so it is nice to get one back. Anyway when I was a Senior in High School I was reading about proportional and had seen a project like your metal triangle wiper thing. I wanted to put a single channel rudder control in a hover craft I was working with, and used a mechanical pulser. I took a plexiglas bar and a piece of aluminum tubing of the same outside diameter.. I cut the aluminum in an angle and recessed the plastic to allow the aluminum to slide over. I ended up with the equivalent of what you were talking about.
It worked pretty well in the ground use but I did have trouble with contact integrity so I wouldn't trust it in flight. I can remember the sound of it grinding away in the wood box I put it in. This was in 1958.
Thanks for the memories,
Ben
#21
RE: Who invented Proportional?
You're very welcome. It's always nice to hear how something I only read about actually worked out. Hope you regain more pleasant memories. I know for myself being in intensive care is one I would gladly forget.
#22
Thread Starter
RE: Who invented Proportional?
Howard G McEntee has drawings of the Knuppel proportional joystick in his Radio Control Handbook dated 1954, and notes it was used by the Germans for proportional control of their Henschel HS 293 glide bomb in WW2, it was a rotating drum half covered with a triangle of silver foil. I think several others posters in their replies above are refering to this. It used a FuG 203b Khel transmitter by Telelfunken and a FuG 230b receiver made by Strassburg.