The Fastlink/Multilink transmitters will remain keyed for a maximum of 5 sec. The transmitter will not transmit again until power is cycled. Once you cycle power, the transmitter can transmit again. The reason for not transmitting for more than 5 sec is to prevent a runaway transmitter from jamming the air ways. It is also a violation of FCC Part 90, which states that a transmitter cannot be on the air for longer than 3 min.