| GENERAL CHARACTERISTICS ITEM DESCRIPTION | RECEIVER CONSISTS OF THREE MAJOR SUBASSEMBLIES; RF ASSEMBLY CONSISTS OF A PARABOLIC ANTENNA AND A SCHOTTKY DIODE DETECTOR; DEMODULATOR CIRCUIT BOARD; POWER SUPPLY BOARD; RECEIVED AUDIO SIGNAL IS AMPLIFIED BY AN AUTOMATIC GAIN CONTROL PREAMPLIFIER ENABLING THE OUTPUT TO BE HELD TO A CONSTANT LEVEL; PREAMPLIFIER OUTPUT IS APPLIED TO A PHASE-LOCKED LOOP DETECTOR WHICH OPERATES AS A NARROW BANDPASS FILTER AT ONE OF THE MODULATION FREQUENCIES |