|Racal MA4224 voice scrambler for use with
TRA931 transceiver. (Photo by Paul Lusk via
Racal TRA931 Transceiver. (Photo by Paul Lusk via E-bay)
The 931 is a versatile HF Transceiver that operates over the range of 1.6-29.999 MHz, although the Rx section works into the long wave region but with much reduced performance. Operating modes are USB,LSB,AM, and CW. CW though is by means of a keyed 1 KHz tone( A2). RF output power is around 20 watts PEP on SSB and CW and about 5 W on low power setting.
Current consumption is about 4 amps (continuous) on transmit high power, and 250 ma on receive (approximately). The whole unit is mounted in a high impact plastic case and is waterproof. The front panel is of steel construction. The 931 has been designed to withstand very rough use. Frequency is changed by using 5 decade switches in 1 KHz increments. A sixth knob, marked "Search" provides continuous tuning in-between the 1 KHz increments. A small meter indicates battery voltage when receiving and RF current when transmitting.