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Here is a bit of nostalgia for those who have been sailing at Sonstraal Dam since the start. While it is still uncertain when exactly the dam was built, we know that is was a “dam” as far back as the 1960’s.

We recently received this contribution from Ed Witney in the UK.

” I grew up on Louw street in Durbanville. I will see if I have any pictures of Sonstraal in the 60’s and 70’s. I still have all the motors that we ran in that era.”

And “that era” was when we still tolerated each other and allowed others to share the sunshine. It was the era of 10cc petrol driven Webra motors with tune pipes, and it sounded like a flock of chain saws when racing.

This is the “RC Boats” the guys used back in those days:

A remote controlled boat, in short, a “RC” boat is the scaled-down version of an actual boat, that is equipped with radio control equipment. The size of a RC boat is relatively smaller in comparison to a normal boat as it is neither purposed to transport passengers nor cargo. ARC boat may be controlled via a radio receiver and transmitter. It can be controlled by a user remotely or at a defined range. This range often varies from a few meters to a few hundred meters. The receiver is mounted on the boat and connected to the rudder and motor of the boat. The user can control the speed and direction of the boat remotely by sending radio signals through the transmitter. In some cases, an antenna is also usually installed onto the boat to increase the accuracy and range of the boat. RC boats are largely powered by rechargeable batteries and gasoline. In certain advanced models, the RC boats could also be solar powered.

The first RC boat was created in 1898 by Nikola Tesla. It was one of the earliest application of wireless control, even before the RC plane and RC car were invented. During his scientific Tour de France in New York’s Madison Square Garden, Tesla stunned the crowd by showing them the first-ever remote controlled vessel. Using a small radio transmitting device he was able to manoeuvre and flash the lights of a tiny boat on a pool of water without any visible connection between the boat and the controller[12,13]. When he first created the RC boat, he aimed to create an automation that could help reduce the laborious work of the human race. But the eyes of others, saw something much sinister: a war machine. Unfortunately, the significant parts of his ideas were however concealed. They were not even explained in his patent in fear that this invention would be “stolen” like many other of his inventions were in the past. Therefore the development of the remote control was severely delayed.

The first general use of radio control systems in models started in the early 1950s with single-channel self-built equipment; commercial equipment came later. The advent of transistors greatly reduced the battery requirements, since the current requirements at low voltage were greatly reduced and the high voltage battery was eliminated. In both tube and early transistor sets the model’s control surfaces were usually operated by an electromagnetic ‘escapement’ controlling the stored energy in a rubber-band loop, allowing simple on/off rudder control (right, left, and neutral) and sometimes other functions such as motor speed.

Crystal-controlled superheterodyne receivers with better selectivity and stability made control equipment more capable and at lower cost. Multi-channel developments were of particular use to aircraft, which really needed a minimum of three control dimensions (yaw, pitch and motor speed), as opposed to boats, which required only two or one.

As the electronics revolution took off, single-signal channel circuit design became redundant, and instead radios provided proportionally coded signal streams which a servomechanism could interpret, using pulse-width modulation (PWM).

More recently, high-end hobby systems using pulse-code modulation (PCM) features have come on the market that provide a computerized digital data bit-stream signal to the receiving device, instead of the earlier PWM encoding type. However, even with this coding, loss of transmission during flight has become more common, in part because of the ever more wireless society. Some more modern FM-signal receivers that still use “PWM” encoding instead can, thanks to the use of more advanced computer chips in them, be made to lock onto and use the individual signal characteristics of a particular PWM-type RC transmitter’s emissions alone, without needing a special “code” transmitted along with the control information as PCM encoding has always required.

In the early 21st century, 2.4 gigahertz spread spectrum RC control systems have become increasingly utilized in control of model vehicles and aircraft. Now, these 2.4 GHz systems are being made by most radio manufacturers. These radio systems range in price from almost R100 000, all the way down to under R800 for some. Some manufacturers even offer conversion kits for older digital 72 MHz or 35 MHz receivers and radios. As the emerging multitude of 2.4 GHz band spread spectrum RC systems usually use a “frequency-agile” mode of operations, like FHSS that do not stay on one set frequency any longer while in use, the older “exclusive use” provisions at model flying sites needed for VHF-band RC control systems’ frequency control, for VHF-band RC systems that only used one set frequency unless serviced to change it, are not as mandatory as before.