Components of Direction Finder Set AN/ARN83

Receiver bandwidth:

Aural rf input sensitivity-Continued

Down 6 db at 200 kc . . Not less than 2.6 kc.

Antenna mode:

Down 60 db at 200 kc . Not more than 9.0 kc.

200 kc . ....... . . . . 50 microvolt per meter with

Down 6 db at 1,700 kc. Not less than 3.5 kc.

270-µµƒ capacitor on sense

Down 60 db at 1,700 kc. Not more than 11.0 kc.

antenna input, 40 microvolt

per meter with 150-µµƒ ca-

Receiver bfo . . . . . . . . . . . . . . Crystal oscillator.

pacitor on sense antenna in-

Frequency . . . . . . . . ...1425 kc (fixed).

put.

Audio output impedance .,600 ohms.

1,700 kc . . . . . . . ...22 microvolts per meter with

Audio output level . . . . Not less than 100 milliwatts

270-µµ capacitor on sense

into a 600-ohm load with an

antenna input, 18 microvolt

rf input signal of 1,000 micro-

per meter with 150-µµƒ ca-

volts per meter, modulated

pacitor on sense antenna in-

30 percent at 400 cps.

put.

Power requirements:

Loop mode:

Voltage . . . . . . . . . . . . . . .+27.5 ±1.0 volts dc.

200 kc . . . . . . . . . . . .100 microvolt per meter.

C u r r e n t . . . . . . . . . . ...2 amperes maximum,

1,700 kc . . . . . . . ...30 microvolts per meter.

Weight of complete

Receiver intermediate

equipment . . . . . . . . . . . . . . 18 pounds (less cabling).

frequency . . . . . . . . . . . . . . 1425 kc.

1-6. Components of Direction Finder Set AN/ARN83

1-9. Description of Receiver

1-7. Common Names

(fig. 1-2)

Listed below are nomenclature and assigned

a. The receiver is housed in a removable metal

common names for the equipment covered in this

dust cover provided with air vents. When the re-

manual.

ceiver is installed on its mount, it is secured at one

end by a hook and at the other end by a mating

electrical connector. A handle is provided for main-

Common Name

Nomenclature

tenance functions and transporting the receiver.

Connections to the loop and sense antennas are

Direction Finder Set

AN/ARN-83.

Direction finder set

made through keyed connectors at the front of the

Radio Receiver

receiver. Connections for power, signals, and re-

R-1391/ARN-83.

Receiver

mote control functions between the receiver and

Mounting MT-3605/ARN-83 . . . . Receiver mount

control unit are made through a connector at the

Direction Finder Control

rear of the receiver, which mates with another con-

C-6899/ARN-83.

Control unit

nector on the receiver mount.

Antenna AS-1863/ARN-83 . . . . . . Loop antenna

b. Physically, the receiver chassis is divided into

front and rear sections. The front section contains

rf circuitry and eight removable subassemblies. The

1-8. Description of Direction Finder Set

rear section contains synchros, motors, gear trains,

Direction Finder Set AN/ARN-83 consists of a

and a power supply and is hinged for access to these

receiver, receiver mount, control unit, and a loop

components. With the exception of power supply

antenna. The direction finder set is intended to be

transistors, all other transistors use sockets. The

used with a suitable sense antenna, a radiofrequency

internal regulated power supply is capable of sup-

(rf) inductance compensator, the necessary inter-

pressing power input voltage transients from -40

connecting cables, and a bearing indicator. Figure

to +80 volts direct current (de) about the nominal

1-1 shows all components of the direction finder set.

+27.5 volts dc required for operation.