SCR-197

The SCR-197 was a ground mobile high frequency radio station used by the United States military prior to and during World War II, notably during the Battle of Wake Island in 1941.

The SCR-197 mobile station consisted of the BC-325 radio transmitter with a frequency coverage of 1.5 to 18 Mhz and an RF power output of 400 watts. Radio receivers consisted of three BC-342 and one Hallicrafters S-20R "Sky Champion". Also provisioned was a BC-119 control box. The complete set was housed in a K-18 truck and K-19 trailer combination. A 45 foot vertical antenna was used for sending and a 15 foot whip used for receiving. Power could be optionally supplied by power mains or portable generator units: one PTO driven GN-42-A generator for the transmitter and two small PE-75 skid mounted units for the receivers. The SCR-197 set was later replaced by the SCR-299.

...
Wikipedia