VOR Bench Tests - TM-11-5826-258-240030

TM 11-5826-258-24

BRG

BEARING

d. Marker Beacon Sensitivity Switching.

Compass heading

(1) Place the MB SENS switch in the LO position

FLAG LOAD

and then check for continuity between rear connector

SENS

pins 12 and 14. There must not be continuity.

V/L RCVR

IND TEST

(2) Place the MBS SENS switch in the HI position

DEVIATION

V/L

AUDIO

and then check for continuity between rear connector

N(0)

OBS

pins 12 and 14. There must be continuity.

114.90 MHz

CONTROL frequency

e. VOR/Marker Beacon Test Switching.

Audio Output Meter TS-585/U:

(1) Place the VOR/MB TEST switch in the test

X1, 150

IMPEDANCE

(down) position and then check for continuity between

MULTIPLY BY

Modulator MD-83A/ARN:

rear connector pins 10 and 16. There must be continu-

POWER

ity.

OFF

TONE LOCALIZER

(2) With the VOR/MB TEST switch not in the test

PHASE ANGLE SELECTOR

position (up), check for continuity between rear con-

CAL

FUNCTION SELECTOR

nector pins 10 and 16. There must not be continuity.

30~VAR

SPECIFIC SIGNAL SELECTOR

Counterclockwise

MASTER ATTENUATOR

f. VOR/LOC Audio Volume Adjustment.

OFF

1000~

(1) Measure the resistance between rear connector

Power Supply PP-348/ARN:

pins 1 and 3. The resistance must be 750 to 1250

POWER

ohms.

NORMAL

INPUT VOLTAGE ADJUST

(2) Measure the resistance between rear connector

Signal Generator SG-1A/ARN:

114.90

FREQUENCY

pins 1 and 2 while rotating the NAV VOL knob from

OUTPUT LEVEL

the OFF position to its fully clockwise position. The re-

100%

MOD RANGE

sistance must increase smoothly from 0 ohm to be-

MOD

EXT

tween 900 and 1100 ohms with no intermittency.

114.9 MC

XTAL FREQ

g. Marker Beacon Audio Volume Adjustment.

XTAL

OSC SEL

NOTE

(1) Measure the resistance between rear connector

The FREQUENCY dial must be adjusted for

pins 17 and 19. The resistance must be 110 to 190

peak on RF MONITOR meter, and the RF

ohms.

LEVEL control must be set for a redline indi-

(2) Measure the resistance between rear connector

cation on RF MONITOR meter.

pins 17 and 18 while rotating the MB VOL knob from

c. VOR Test Signal. The VOR test signal is an rf car-

the OFF position to its fully clockwise position. The re-

rier, amplitude modulated simultaneously 30 percent

sistance must increase smoothly from 0 ohms to be-

by a 9960 Hz subcarrier which is in turn frequency

tween 135 and 165 ohms with no intermittency.

h. Panel Lighting Test.

modulated at a deviation ratio of 16 by a 30-Hz ref-

(1) Test equipment required. Hewlett-Packard

erence phase signal, and 30 percent by a 30-Hz vari-

Model 6266B Power Supply, or equivalent, is required.

able phase signal which can be varied in phase with

(2) General test conditions. The receiver control

respect to the 30 Hz reference phase signal. When the

test procedure calls for a VOR test signal, proceed as

chassis shall be grounded.

follows:

(3) Test. Apply 27.5 vdc power to the receiver

control rear connector (+ at pin 21, - at pin 10). Both

(1) Set Power Supply PP-348/ARN POWER

panel lamps must be fully illuminated.

switch to ON.

(2) Set Signal Generator SG-1A/ARN controls as

3-19. VOR Bench Tests

follows:

a. Test Setup. All VOR and LOC bench tests are per-

(a) FREQUENCY to 114.90.

formed with the test setup shown in figure 3-1. CO-

(b) OUTPUT LEVEL to 1K (1000 microvolts).

axial cables with 52 ohms characteristic impedance are

(c) MOD RANGE to 30%.

(d) MOD to EXT.

used for all rf and modulation interfaces. Test set cable

plugs P2, P3, and P7 mate with jacks J2, J3, and J7 on

(e) EXTAL FREQ to 114.9 MC.

Receiver Adapter Cable CX-13034/AR. Plugs P11001

(3) Set Modulator MD-83A/ARN controls as

and P12002 on the receiver adapter cable connect to

follows:

J11001 and J12002 on the receiver panel.

(a) POWER to ON.

b. Initial Switch Settings. Before performing the

(b) TONE LOCALIZER to 0.

VOR/LOC receiver section bench test procedures, set

(c) 1000~ to OFF.

the controls of all items of test equipment as follows:

(d) FUNCTION SELECTOR to CAL

Radio Test Set AN/ARM-92B:

(e) SPECIFIC SIGNAL SELECTOR to 30~VAR

PWR

OFF/PWR/TEST

400 Hz

MODE

3-8