Electronics
John Marquette established
Silvertone in Australia in 1958. John’s company, Advance Radio Control, produced Silvertone single channel valve equipment and later multi channel reed equipment, again using valves. In 1963 Bob Young purchased the Silvertone radio manufacturing section and established Silvertone Electronics.
Thus
Silvertone may be considered the pioneers of radio control in Australia. From Single channel valve superregenerative receivers to 24 channel solid state superheterodyne digital proportional receivers has been a giant step and Silvertone has gathered a wealth of experience in the process.Amongst our list of Australian firsts are included the first commercial production of R/C gear which included single channel and reed, valve and transistor transmitter and receivers. In 1966 we produced the first Australian designed and built digital proportional system, the Silvertone Mark 1.
Could this be construed as sitting down on the job? A very young Bob Young (c 1969) with his "flying chair". Utilising a Silvertone Mark 1 proportional transmitter, the chair was actually a prototype dual control (buddy box) system with the chair control pots wired directly into the encoder. Uncomfortable and difficult to use at first, the chair proved to be quite successful eventually, especially on twin engine models. Note the dual throttle levers. The aircraft shown set the first Australian R/C speed record of 133mph.
In 1969 we introduced the Silvertone Mark VII system, a very advanced system for its time. It was the first Australian R/C system to be written up in International magazines. The Mark VII was particularly well received in the USA, receiving an excellent review in RCM magazine. The Mark VII was the first Australian R/C system to feature narrow band spacing, frequency interlock and dual control. The Mark VII ushered in a new era in Australian R/C operations. The narrow band feature presented clubs with some interesting problems and opportunities which they had never encountered before.
From a club point of view, the introduction of narrow band operations (from 50kHz down to 15kHz, increasing available frequencies from 6 to 18 frequency slots) completely revolutionised club R/C operations in Australia. The first problem was how to take advantage of the narrow band feature of the Mark VII, whilst maintaining safe operation for older and wider (40-50kHz) systems. The old peg-on-transmitter system proved to be totally inadequate and actually unsafe in this situation.
Silvertone's answer to this dilemma was to develop the
Silvertone Keyboard, a device that can safely control the simultaneous use of radio control systems of differing bandwidths. The Silvertone keyboard is to this day still used in almost every R/C club in Australia and has since been declared the Australian National Standard Frequency Control System. All MAAA sanctioned contests must use the Silvertone keyboard as the frequency control system. It is still to our knowledge the only variable bandwidth frequency control system available on the World market.The development of the Keyboard in turn led directly to the concept of frequency interlock to prevent accidental shoot-downs from transmitters left on in the pits. As each transmitter has it's own key in this system, the logical extension is to use that key to turn off the transmitter when the key is not in the Keyboard. Thus by plugging the key into the transmitter, power is removed from the electronics, thereby rendering the transmitter completely safe whilst in the transmitter pound. All Silvertone transmitters built since 1969 have featured Frequency Interlock.
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Silvertone 36MHz Keyboard showing 10kHz key on left and 20kHz key on right. |
Reverse side of key showing Interlock plug. Key plugs into TX when not in use cutting off all power to the transmitter, thus rendering it safe. |
In 1973 we began to investigate the use of R/C aircraft in military training applications. To this end we began the development of all fibreglass aircraft, such as the Silvertone Stingray shown below. This was intended as a proof of technology aircraft for a later, larger delta aircraft built for De Havilland Aircraft Australia. Silvertone supplied the glass airframes for this project.
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Wooden plug for Silvertone Stingray-A one of the world's first all fibreglass models. (c1974)
Glasswork by Alan Trinder, aircraft design by Bob Young. Model left the moulds in two pieces. Joined fuselage with integral tailplane and joined wing. Test-bed for all-glass RPVs.
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Finished Stingray-A ready to fly. |
Dawn Patrol. Single retract nosewheel with wheels in the tailplane tips left the underside of the wing perfectly clean. No disturbed air from wheel wells. Very fast aerobatic model |
Many Stingrays were sold to modellers throughout Australia. At the same time production commenced on the Silvertone Weightlifter RPV, designed as one component of a company funded missile training system. Many of these were sold to various Government departments performing a variety of chores including atmospheric sampling, missile training, weapons testing etc.
A series of small foam delta disposal target aircraft were also built in this period and used for small arms air-defence live-fire training. The final aircraft in this series was a 60 powered, live-fire target/trainer supplied to the Australian Army. All of the projects were the first of their kind in this country
We also pioneered such concepts as the first commercial model flying school. This scheme evolved into the RCAS (NSW State) instructors training system before finally growing into the Model Aeronautical Association of Australia (MAAA) National Flight Training system. We also fostered many records, helping
Silvertone customers to establish records that stood for many years.Along the way such projects as radio control full size cars and trucks, machines, target RPV’s, movie robots, radio controlled buildings etc have provided interesting diversions and added to our store of knowledge and experience.
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Alakazam the Robotic Puppet (Dummy on the left). Thirty-two channels, voice syncronous lips, blinking eyelids. Control tape was built up in layers, four channels at a time. All before computers. |
Model in a Box Silvertone Weightlifter prototype in |
However our first love has always been the radio control of model aircraft and now we have turned this wealth of age-old experience towards creating an absolutely unique radio control system, the Silvertone
Mark 22.|
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Mark 22-A TX left, Mark 22-C right |
Mark 22-SM showing internal modules |
The
Mark 22 has grown into something more exciting than we originally planned. The modular concept has virtually no limits and we are continuing to add new modules as time passes. The latest module is a dual control transmitter back. Thus fitting dual control to an existing transmitter is now merely a matter of purchasing a new back panel and plugging the leads onto the appropriate pins on the encoder PCB.System upgrades will be easy to fit and relatively inexpensive, thus the
Mark 22 with its robust construction, ease of maintenance and upgrade capacity will serve its owners well into the 21st century.All Mark 22 transmitters and receivers are now rated for 10kHz operation in preparation for the introduction of this frequency spacing in early 2002, thereby maintaining the long tradition of being in the forefront of developments in narrow band operations in Australia.
Silvertone Stingray Mark 2 (c2001)
For the complete
Mark 22 story activate the Data hyperlink.
