Additional Equipment Required

at 400 cps. It is required for indicating the bearing

connector and rf inductance compensator (para

or azimuth of a radio station. Typical bearing indi-

l13d) to the receiver.

cators are the ID-637/ARN and ID-250/ARN-30.

1-13. Additional Equipment Required

c. Electrical Cables and Connectors. Cables and

The following items are not supplied as part of

connectors are required for interconnections be-

Direction Finder Set AN/ARN-83 but are required

tween the receiver mount, control unit, bearing in-

for use with the set.

dicator, sense antenna, loop antenna, aircraft inter-

phone system, and primary power. The cabling is

a. Sense Antenna. The sense antenna is usually

originally fabricated and installed by the aircraft

a flush-mounted type, built into the aircraft or a

manufacturer.

T-type antenna constructed of large diameter wire

or tubing mounted on stantoff insulators at the bot-

d. Rf Inductance Compensator. The rf induct-

tom of the fuselage, parallel with the aircraft longi-

ance compensator, connected between the loop

tudinal axis. It supplies a nondirectional sense radio

antenna and receiver, compensates for any electro-

signal to the receiver. This antenna is originally

magnetic field distortion introduced into the an-

installed by the aircraft manufacturer.

tenna by the engines, wings, or other metal parts of

b. Bearing Indicator. A radio magnetic bearing

the aircraft. This field distortion, introduced in. one

indicator or a type which displays both the adf

or more quadrants, causes radio station bearings to

hearing and other navigational aids, such as very

be displaced from their true direction. Quadrantal

error varies with the aircraft configuration so the

high frequency omnidirectional radio range, (vor)

rf inductance compensator is selected during the in-

or compass information. is required. The indicator

stallation phase.

must be a synchro receiver operating on 26 volts ac