The TPS-250 Portable Base Station is available with either the Model 91-DE or 90-6R transceivers. The system consists of a transceiver housed in a 5.5" (14cm) x 9.5" (23.5cm) x 15" (38cm) 24 lbs./11kg case which contains internal led acid sealed batteries, 120V power supply/charger and a 15W RF output power amplifier. Operating time is from 1.5 to 6 hours, depending on whether high (15W) or low (7W) output power is selected, for a 50% Tx/Rx duty cycle. Additional features include a remote/local operation switch, allowing remoting of audio input and output keying of the transceiver, adjustable external recording output jack and a battery charge indicator. In addition to the internal battery power, the unit can operate on external 24 Vdc or external 120 VAC (220 VAC optional) which is also used to charge the internal batteries.