Answer. No, the Mark 22 Transmitter does not use processor or volatile memory chips and therefore is completely immune to radiation from mobile telephones and such like.

Answer. Yes. When fitted with the F3B mixing module. Simply plugging this module into the transmitter immediately converts the Mark 22 TX into a fully configured F3B transmitter including snap flap, CROW, CAR, "V" tail etc. All either programmed in permanently or switchable from the front panel. All the operator needs to do is set the direction of travel on the servos and the throw adjustments. A very quick and simple way to move into F3B.

Answer. Silvertone has for many years supplied custom built R/C equipment to a wide variety of industries from Military to commercial to individual R/C modellers. The Mark 22 is designed to provide the utmost flexibility and in this it has succeeded admirably. The modular construction lends itself well to all sorts of applications. Mark 22 modules have found their way into full size sailing boats for the physically handicapped (set up like giant R/C sailing boats), military applications of many kinds, Film and TV sets and robots, along with a wide variety of 16 and 24 channel R/C models (mainly boats and trucks). To give one example, a film studio set up a full aircraft instrument panel using servo driven instruments via encoder/decoder modules connected using the hard wire facility (no radio link) provided in the Mark 22 modules. Obviously having 24 channels available is a plus in this type of application. The simple two-wire connection completely eliminates the noise problems often encountered in studios and reduces the cost significantly. The encoder module supplied in the standard 2 stick or single stick (3 axis) hobby transmitter is an 8 channel unit. The 24 channel expansion board is available as an option.

Answer. The receivers are fitted with a low dropout voltage regulator that allows the receiver to be run from higher voltages than 4.8V. Voltages of up to 15V are OK but the servos run off the unregulated supply at the servo pins so they will set the upper limit of the voltages to be used. The safe, low-level battery cut-off voltage is 3.4V.

Answer. No. The best approach here is to use the traditional approach of offset output arms on the servos. When we did our market research for the Mark 22, complexity of programming was one point often raised as criticism of the computer radio. Thus in the Mark 22 we strove from the outset for maximum simplicity in programming. We decided that wherever a suitable alternative existed, that feature would be left out of the program. The new servos with the finely splined output shafts make offsetting the output arm very simple indeed, and the offset technique works well, thus providing a viable alternative to differential programming.

Answer. No, but every channel is fitted with Adjustable Travel Volume (ATV) that can be used as a pseudo endpoint adjustment.

Answer. Yes. You may either use a "Y" lead if the servos are all required to travel in the same direction or alternatively, you may use one or more mixers. Use non-inverting mixers for the same direction of servo rotation or inverting mixers for opposite rotation. There are four free mixers in the standard 8 channel encoder module. A point to keep in mind with the Mark 22 system of programming is that the combinations of mixing are virtually unlimited for all 24 channels. The potential to combine any channel with any channel in a wide variety of formats is built into the Mark 22 hardware from the outset. And there are usually multiple choices as to how to achieve any given result. To come up with a computer program of this complexity would require a massive amount of (and in most cases) wasted or unused time and money. If we have not provided a particular facility, any competent electronic technician can quite often add it. The Mark 22 is a great radio for those who love adding their own touches to their R/C system. All systems come with a complete set of circuits and servicing instructions.

Answer. It simply means that programming the transmitter for either FM or AM operation can be done anywhere in less than one minute. There is no crystal change involved, nor is there any retuning or other adjustment. Simply reprogram the three micro-shunts (shorting links as used in computers) for AM, FM or CW operation.

Answer. This is a really useful and novel feature. Exclusive to the Silvertone Mark 22 transmitter, it allows an absolutely accurate frequency count to be taken on the crystal. When modulation is applied to a transmitter it is not possible to accurately establish the crystal frequency. By disabling the modulation, the carrier can be set to precisely the required frequency at the factory quickly and simply, and checking the frequency at contests can be done very accurately indeed. However the usefulness of this feature does not end there. By setting the transmitter to CW, a clean source of carrier is available when testing for, and demonstrating the effects of, Receiver Mixer Intermodulation (RMI) This phenomenon occurs when two transmitters are operated 450/460kHz apart as occurs in our 36MHz band. By removing the crystal from any receiver and using an unmodulated transmitter with another modulated transmitter (AM or FM) 450/460kHz removed, it is possible to demonstrate perfectly normal operation of the receiver from the modulated transmitter. In this manner we can very clearly demonstrate that the effect actually occurs and is not a figment of someone's over-active imagination. When this is done with two modulated transmitters the results are simply twitching, chattering servos due to the mixing of the two modulating signals. The CW feature of the Mark 22 TX has been invaluable during our RMI investigations at flying fields and was even more so during the 3.O.I. investigations. The unmodulated carriers provided very clean signal sources that were very easy to examine particularly at 10kHz spacing. It has allowed us to determine results with a degree of precision not available to most club modellers. One useful spin-off from the AM-FM programming is the fact that checking the PA current can be done simply by removing the CW micro-shunt and plugging in a multimeter. PA current (bias) in the Mark 22 TX plays an important part in reducing the third order intermodulation levels, so it is important that we can set this quickly and accurately at the factory and if required, during servicing. As you can see by the foregoing the Mark 22 TX is a very useful and versatile electronic instrument.

Answer. A question of cost I am afraid. The die-set for a plastic transmitter case costs upwards of $50,000 and in the small quantities that we produce sets, the amortisation of such a cost is not possible. However remember that the only reason that the other manufacturers went to plastic in the first place was to reduce costs. The aluminium case is more durable, easier to clean, provides a better ground-plane for the antenna and shields the internals from outside radiation from other nearby transmitters, thereby helping to reduce third order intermodulation via direct injection. It took the overseas manufacturers years and a lot of blood, sweat and tears to get a plastic transmitter to perform as well as a metal one and they still fall short on 3.O.I. I would be very loath to go to a plastic TX case even if costs were not a factor. True, plastic does give one more scope in shaping the external appearance but is this the measure of true worth? Remember also that the Mark 22 case is quite different from the traditional folded sheet unit. The welded seam construction gives the finished unit a very professional look. We can also offer the case in personalised colours for an additional fee of $49.00, something that cannot be done in plastic.

Answer. Exactly what it implies. It is an interlock that uses the frequency control element as the control key. In this case the frequency key issued for the transmitter by the testing stations, is fitted with a plug that mates with a socket in the Mark 22 TX.

When the key is inserted into the socket the power to the transmitter is cut off, thereby rendering it safe even if the transmitter is left switched on. In this manner it is not possible to shoot down another flier accidentally because there are only two places for that key. Either in the slot in the keyboard, in which case it is safe to switch on; or in the interlock socket in which case it is impossible to switch on. This system can only be used with the Silvertone Keyboard frequency control system because it is the only system that provides each flier with his own individual frequency key. Frequency Interlock has been fitted to all Silvertone transmitters built since 1969. The charge socket doubles as the interlock socket and has proven to be an extremely reliable approach to fitting interlock.