Section IV. PRINCIPLES OF OPERATION

TM 11-5985-371-12&P

PRINCIPLES OF OPERATION

Section IV.

4-9. General. The AS-3577/GRC permits transmission or reception of rf energy

in the 2-30 MHz frequency range. It is an omnidirectional, broad band,

double delta antenna that can receive or transmit rf signals over.a distance

up to 380 miles. When used for transmission, it can handle power up to a

maximum of 1 kilowatt.

4-10. Circuit Description. Refer to the schematic diagram below. The letters A, B,

C, and D are terminal designations assigned during installation (para 2-5). They

are not equipment markings. During reception or transmission, rf energy is con-

ducted to or from the receiver or the transmitter, respectively, through the coaxial

rf cable(s). The rf cable(s) is connected to the balun. The balun transformer

matches the 50-ohm impedance of the rf cable to the 600-ohm input impedance of the

antenna. The antenna radiating and receiving device is formed by wires configured

into two delta arrangements. As configured, one half of one continuous antenna

wire, and one half of the other continuous antenna wire form one delta, and the

remaining halves form the other delta. The peaks of the two deltas are connected to

the 600-ohm terminating resistor box.

SCHEMATIC

DIAGRAM

ANTENNA

AS-3577/GRC

ORGANIZATIONAL

TROUBLESHOOTING

Section V.

4-11. General. Troubleshooting at the organizational category is limited to visual

checks and the use of a multimeter to isolate faults to the terminating resistor

box, the balun, antenna wire, and electrical cables.

4-12. Troubleshooting Table. The malfunctions listed in table 4-2 can show up

during operation of the radio, during scheduled PMCS (tables 2-1 and 4-1), during

assembly and preparation for use (para 2-5), during preparation for movement

(para 2-6) or during corrective maintenance.