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. If we have not provided a particular facility, any competent electronic technician can quite often add it.
All systems come with a complete set of circuits and servicing instructions.
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. 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.