Wikipedia:SCR-197

The SCR-197 was a ground mobile high frequency radio station used by the U.S. Army Signal Corps prior to and during World War II, notably the Battle of Wake Island in 1941.

Specifications
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.

General references

 * TM 11-227 Radio Communications Equipment 1944
 * TM 11-487 Electrical Communication Systems Equipment 1944
 * TM 9-2800 Military vehicles 1943
 * TM 11-241 SCR-197 B through F
 * TM 11-805
 * TM 11-900 1942  PE-75A and PE-75B
 * SNL G517 K-19 trailer
 * TM 10-1702 GMC, 1$1/2$-ton, 4 × 2 (LC), COE, K-18, Model No. CF-351
 * SNL G620 K-18 truck