The Silvertone Keyboard System of Frequency Control is a tried and proven frequency control system. First introduced into club use in Australia in 1969, the system has been the Australian National system of frequency control for the past 20 years. Officially sanctioned by the MAAA (Model Aeronautical Association of Australia) under a nationally administered frequency management plan, almost every club in Australia now uses the Silvertone Keyboard. The MAAA management plan includes such programs a setting up approved testing stations to test and certify the bandwidth of transmitters. The issuing of bandwidth stickers to approved testing stations. The coordination of a national Frequency Sub-committee to investigate technical matters relating to frequency usage and negotiating with the local Government authorities in regards to frequency allocations and management. With nearly 100 frequency spots to administer, of which 59 are in one 600kHz block, frequency control in Australia is a complex but well developed art.

The Silvertone Frequency Control Keyboard system is essentially a graphic representation of a frequency band laid out on a grid of 0.1" = 1kHz. (1" = 10kHz) See Fig 1. This graphic layout provides the transmitter operator with the ability to reserve as much bandwidth as is required for the safe operation of his/her R/C system. The bandwidth reservation is made using a "Frequency Key" which is the exclusive property of the R/C system operator. Each R/C system in use has its own Frequency key. As a consequence of each transmitter having its own Frequency Key, it is now possible to carry frequency control through to its logical conclusion. By plugging the Frequency Key into the transmitter when the key is not in the keyboard, it is possible to render the transmitter completely inoperative. This then is a true Frequency Interlock system. When the Key is in the Keyboard it is safe to switch on. When the Key is in the transmitter it is impossible to switch on. Frequency Interlock is only a suggested option and the Keyboard system works as a pure Frequency Control System without it. All Silvertone Transmitters built since 1969 have been fitted with Frequency Interlock.

Briefly, the keyboard operates in this manner. Frequency keys are issued to all club members, one for each R/C system to be used. These keys are of a width proportional to the safe operating bandwidth of their respective R/C systems. Thus an R/C system rated as safe for operation at 10kHz spacing will be issued with a 10kHz (1") key and a 20kHz system a 2" key and so on. In operation these keys are slid into the appropriate slot on the keyboard in order to reserve the frequency block required by the operator for safe operation of his system and the TX must not be turned on until the key is in the keyboard. Only when the TX is turned off is the owner of the TX allowed to remove the key from the board. No other person except the operator of the transmitter is allowed to touch the key once it is in the keyboard.

In the mode of operation shown in Figure 1 the system is operating in the more complex "Variable Bandwidth Mode". In this mode keys of various bandwidths are mixed during operation. Operation is greatly simplified if the system is run in the "Fixed Bandwidth Mode" whereby all operators are issued with keys of the same width. These keys can be 1" for busy clubs or 2" for smaller conservative clubs who can afford to restrict the number of frequency spots in use in the name of safety. Also the 2" key is ideal for controlling the use of the "odd" or "even" systems of frequency spacing for two clubs in close proximity who need to "interleave" their frequencies..

1. As each operator has his/her own personal key, the risk of a missing peg or second peg is completely eliminated.
2. As each key carries the name of the operator it can be very quickly established who has reserved the frequency in the event of a key left in the keyboard.
3. Fixed or Variable bandwidth mode options on 10kHz or 20kHz spacing.
4. Controls the "Odd" or "Even" (20kHz) spacing systems very simply.
5. Frequency interlock option to completely eliminate the risk of transmitters accidently left on in the TX pound.
6. Suitable for use at club, State or National level.

1. All TX operators are issued with a key of the appropriate bandwidth, one for each transmitter to be used at the field.
2. All keys must be clearly marked with the operator's name and frequency number.
3. It must be clearly understood by EVERY person at the field that the ONLY person allowed to insert, touch or remove any frequency key, into, on or from the keyboard, is the operator of the transmitter associated with that key.
4. It must also be clearly understood by ALL operators that only frequency keys of the correct design and bandwidth are to be inserted into the keyboard. No rolled up bus tickets, bits of stick, cigarette butts etc are to be used.
5. It is recommended that a transmitter pound be set up in an area away from spectators and children and that all transmitters stay in the pound until required for use. This is also the recommended area in which to place the keyboard.
6. Before any transmitter can be turned ON the key for that transmitter must be inserted into the appropriate frequency slot on the keyboard.
7. When the key is inserted into the Keyboard always check to ensure that the number on the key agrees with the number that appears in the key window.
8. If it is not possible to insert the key into the keyboard because a key already in the Keyboard covers the required slot then the operator must wait until that key has been removed before turning on the transmitter.
9. The transmitter must be switched OFF before the key can be removed. Once the frequency key has been removed it must be replaced on the transmitter (It is usual to hang it on the throttle stick) and the transmitter returned to the transmitter pound. If the transmitter is fitted with Frequency Interlock, the key must be plugged into the Interlock socket as soon as it is removed from the Keyboard.

That is all there is to it. Once the Silvertone Keyboard System of Frequency Control is introduced, many of the problems that have plagued safety officers for years disappear immediately. Correctly used, and especially if used with the Frequency Interlock option, The Silvertone Keyboard will provide a level of safety unequalled by any other frequency control system.