Mark,
The system I bought is capable of 16 different channels and there are even better systems than that. We shared the cost of the receiver and every pilot purchases their own transmitter. This way the pilots are responsible for their own receiver. I'm restricting the number to 16 pilots but you could have pilots share the channels. Most pilots purchase one transmitter and move it from aircraft to aircraft. To date we have recovered 5 lost aircraft. The recoveries are more than sufficient to pay for the cost of the Walston system. If you fly around a swamp or other areas that are difficult to locate your aircraft you won't regret purchasing this system.
Larry