AN/ARN-89 Control Functions continued
Provides for operation as an receiver using the sense antenna.
Provides for receiver operation as a manual direction finder using only the loop antenna.
LOOP L-R control
Manually provides for left and right control of the loop when the mode selector switch is in the
LOOP position. This control knob is spring-loaded to return to center.
Adjusts audio volume for station identification.
100 KHz coarse
tune control knob
Tunes receiver in 100 KHz steps as indicated by first two digits of the KILOCYCLES
10 KHz fine tune
Tunes receiver in 10 KHz steps as indicated by last two digits of KILOCYCLES indicator.
CW, VOICE, TEST
CW (in the COMP
Enables the tone oscillator to provide an audible tone for tuning to a (CW) station when the
mode selector switch is at COMP.
CW (ANT or
Enables the beat frequency oscillator to permit tuning to a CW station when the mode
selector switch is at ANT or LOOP.
Permits (LF) receiver to operate as a receiver when the mode selector switch is at any
TEST (in the
Provides for slewing of the loop through 180 degrees to check operation of the receiver in the
COMP mode. This switch position is inoperative in LOOP and ANT modes.
Indicates relative signal strength while tuning the set to a specific radio signal.
Indicates operating frequency to which receiver is tuned.
3.12.3 Operating Procedures.
a. Starting Procedure.
1. Mode selector switch COMP, ANT or LOOP.
2. Frequency Select.
3. CW-VOICE-TEST switch CW or VOICE as de-
4. CSC panel NAV A receiver select switch ON.
5. Fine tune control Adjust for maximum upward
indication on the TUNE meter.
6. AUDIO control Adjust as desired.
b. COMP Mode Operation.
1. Mode selector switch COMP.
The horizontal situation indicator No. 2 bearing
pointer and the radio magnetic indicator bearing
pointer will display the magnetic bearing to the
ground station from the helicopter as read
against the integral compass card on each in-