The first of the three new additions to the SM family is the SMD (SM-Dual) transmitter using two AA batteries and therefore doubling the battery life of the original unit. Next is the SMQ (SM Quarter Watt) transmitter which has been designed to deliver 250mW power for longer range and greater resistance to interference than the standard SM (100mW transmitter) - also using two AA batteries. Finally the RM (Remote unit) was created for programming and operation of the SM transmitter family, including the new SMD and SMQ units. The RM communicates with the transmitter via a proprietary audio signal through the transmitter's microphone so it does not rely on line of sight, as do infrared systems. This allows the transmitter to be buried in a costume and still respond to commands updating operating frequency, audio level, sleep, control surface lockout, etc. The RM is supplied with a lanyard and quick-release mechanism for ease of deployment in the field.
(Lee Baldock)
