TM 11-5826-225-35
CHAPTER 1
FUNCTIONING
Section 1. GENERAL FUNCTIONING OF DIRECTION FINDER SET AN/ARN-83
1-1. Scope
compensator (not supplied as part of direction finder
This manual contains direct support, general support
set) which corrects for any electromagnetic field distor-
and depot maintenance instructions for Direction
tion induced into the antenna by metal parts of the
Finder Set AN/ARN-83, It includes instructions ap-
Aircraft.
propriate to these levels of maintenance for
troubleshooting, testing, aligning, and repairing the
b. Radio Receiver R-1391/ARN-83 (CPN 522-
equipment. The manual also lists tools, materials, and
2587-000, -0150 ) receives directional radio signals
test equipment for maintenance. Detailed functions of
from Antenna .AS-l863/ARN-83 and nondirec-
the equipment are also covered.
tional radio signals from a sense antenna (not
1-1.1. Reporting
Equipment lmprove-
ment Recommendations (EIR)
EIR's wll be prepared using DA Form 2407, Mainte-
nance Request. Instructions for preparing EIR's are
provided in TM 38-750, The Army Maintenance
Management ( System. EIR's should be mailed direct to
Commander, US Army Communications and
Electronics Materiel Readiness Command, ATTN:
DRSEL-MA-Q, Fort Monmouth, N.J. 07703. A reply
c. Direction Finder Control C-6899 /ARN-83 con-
will be sent direct to you.
tains all the necessary controls for remotely selecting
NOTE
the receiver frequency ranges (190-400 kc, 400-850
For other applicable forms and records, see
kc, 850-1750 kc) and operating modes (adf, antenna,
paragraphs 1-2 and 1-3 in TM
or loop), tuning the receiver, adjusting gain, and con-
11-5826-225-12.
trolling power bfo operation.
1 - 2 . General System Block Diagram
d. Mounting MT-3605/ARN-83, serves as the
Functioning
receiver shockmount and distribution center for ac and
Direction Finder Set AN/ARN-83 includes the
U.
dc power, control signals, audio signal, and bearing
components shown in figure 1-1. The general direction
data, between the receiver and control unit and the
of ac power, dc power, and signal flow is also shown.
aircraft. Inverter, power, static CV-2128/ARN-83, a
Antenna AS- 1863/ARN-83 (fixed loop antenna) con-
dc-to-ac inverter in the receiver shockrnount, changes
tains two pairs of loop antennas displaced 90 degrees.
27.5-volts dc primary power into 26-volts, 400-cps
One pair of loops is sensitive to radio signals parallel to
power for synchro excitation.
the aircraft longitudinal axis, and the other pair of loops
1-3. Overall Functional Block Diagram
is sensitive to signals parallel to the aircraft lateral axis.
Analysis
The two-loop output signals are applied to Radio
T h e following is based upon the overall
Receiver R- 1391/ARN-83 through an RF inductance
Change 5
1-1
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