This series of amplifiers is designed for 143 to 149 Mhz 2 meter band operation. The designs use the latest in micro-stripline techniques and highest quality state of the art transistors. Relay switching is automatic RF sensing. These units do not require any tuning. The boardband design offers the ultimate in flat input VSWR, 1.4:1 or less, and produces rated power output or better across the entire two meter band. This amplifier can be used for AM or SSB operation as well as FM and CW. The front panel switch on all models switches the amplifier in or out. With the switch “in”, the 13.5 VDC is supplied to the RF sensing and relay 'circuit inside the amplifier, however, the unit will not draw any current until the transceiver or transmitter.is keyed and RF is applied to the amplifier. At this point an audible click of the relay can be heard and the LED light on the front panel will light. The amplifier will now amplify the RF applied. In the “out” position, the amplifier will bypass the RF through the amplifier.