Section VI. DIRECT AND GENERAL SUPPORT BENCH TESTS

TM 11-5826-258-24

(2) Set MEGACYCLES control to 110.10 MHz.

(6) Set NAV GS switch to GS.

(7) Set MICROVOLTS control to lK microvolt.

(3) Allow at least 15 minutes warmup, then adjust

(8) Set METER switch to CAR.

CARRIER SET control for redline indication on meter.

(9) Adjust CARRIER SET control for redline in-

(4) Set AUDIO SELECTOR switch to TONE LOC.

dication on meter.

(5) Set MICROVOLTS control to 10K microvolt.

(10) Set LOC-GS switch to DOWN.

(6) Set receiver frequency (in aircraft) to 110.10

MHz.

(11) Position the SG-13/ARN 50 feet directly in

(7) Set LOC-GS control to center (white line).

front of the aircraft center and move towards the air-

(8) The LOC deviation indicator in the aircraft

craft until the glideslope warning flag is driven out of

shall be within the center donut.

view.

(9) Set LOC-GS control to LEFT.

b. Glideslope Test Procedure.

(10) The LOC deviation indicator in the aircraft

(1) Set MICROVOLTS control to 10K microvolt.

shall deflect to the left,

(2) Set LOC-GS control to center (white line).

(11) Set LOC-GS control to RIGHT.

(3) The glidescope deviation indicator in the air-

craft shall be within the center donut.

(12) The LOC deviation indicator in the aircraft

shall deflect to the right,

(4) Set LOC-GS control to UP.

e. Marker Beacon Test Procedure. Flight line tests

(5) The glidescope deviation indicator in the air-

of the marker beacon receiver are performed using

craft shall deflect full scale upward.

Test Oscillator BC-376. The BC-376, with its antenna

(6) Set LOC-GS control to DOWN.

fully extended, must be placed 10 to 20 feet from the

(7) The glideslope deviation indicator in the air-

marker beacon receiver antenna. A headset can be

craft shall deflect full scale downward.

c. VOR Test Procedure.

used to monitor the marker beacon audio output.

(1) Turn the BC-376 on and move it toward the

(1) Perform the test setup procedures given in

paragraph 3-14a.

receiver antenna until a strong signal is heard in the

headset,

(2) Set MEGACYCLES control to 114.90 MHz.

(2) Set the BC-376 MODULATION switch to 400.

(3) Allow at least 15 minutes warmup. With

The OUTER marker lamp on the aircraft instrument

METER switch in CAR position, adjust CARRIER SET

panel must light, and the MIDDLE and AIRWAY

control for redline indication on meter.

lamps must not light.

(4) Set AUDIO SELECTOR switch to VOR.

(5) Set MICROVOLTS control to 10K microvolts.

(3) Set the BC-376 MODULATION switch to

1300. The MIDDLE marker lamp on the aircraft in-

(6) Set NAV GS switch to NAV.

strument panel must light, and the OUTER and AIR-

(7) Set receiver frequency (in aircraft) to 114.90

WAY lamps must not light.

MHz.

(8) Set VOR control to 0,

(4) Set the BC-376 MODULATION switch to

3000. The AIRWAY marker lamp on the aircraft in-

(9) Adjust the aircraft OBS control for zero devia-

strument panel must light, and the MIDDLE and

tion. The OBS dial shall indicate 0 5.0.

OUTER lamps must not light.

(10) Set VOR control to each of its other positions

and adjust the OBS control for zero at each position.

NOTE

The OBS dial shall indicate the same reading as the

Test must be performed with aircraft away

VOR control for each position (5.0).

from electromagnetic energy and reflecting

d. Localizer Test Procedure.

surfaces such as buildings or other aircraft.

(1) Perform the test setup procedures.

Section VI. DIRECT AND GENERAL SUPPORT BENCH TESTS

ment may be considered suitable for installation in an

3 - 1 6 . General

aircraft.

a. This section contains direct and general support

c. If either the receiver or the control fails to meet

bench testing procedures for the receiver and the con-

any requirement of the tests, no further testing is re-

trol. The test procedures specify the minimum per-

quired. The equipment is returned to the manufac-

formance limits within which the equipment may op-

turer for disposition under the terms of the equipment

crate and still be suitable for installation in an air-

Warranty.

craft. As such the tests may be used to check equip

ment removed from an aircraft or units removed from

NOTE

storage.

Personnel must be aware that any attempts

b. If the units test within the acceptable limits

at maintenance beyond the testing specified

given, no further testing is required and the equip

herein will void the manufacturer's warranty

3-5