Marker Beacon Bench Tests

TM 11-5826-258-24

(4) Set AN/ARM-69 FREQ

and

(1) Adjust the AN/ARM-5 ATTENUATOR to 700

AN/ARM-92B CONTROL frequency to each glide-

microvolt.

slope channel in table 3-5 and verify the

CAUTION

AN/ARM-92B DEVIATION meter reads 90 30 mi-

Disconnect Cables CG-409/U and CG-483/U

croampere right of zero at each setting.

from the AN/ARM-69 DEMOND and MOD

(5) Repeat the teat on all frequencies with the

jacks except while performing the warning

AN/ARM-5 MODULATION switch set to AMP

signal teat. Maintain approximately 22.5

The AN/ARM-92B DEVIATION meter must

percent modulation (each tone) on the

indicate 90 30 microampere left of zero at each set-

AN/ARM-5.

ting. Return the controls to 332.0 and 109.30.

(2) Set the AN/ARM-5 MODULATION switch to

e. Course Centering Test.

90~.

(1) Adjust the AN/ARM-5 ATTENUATOR to 700

(3) Adjust the AN/ARM-5 90~ MOD control for

microvolts.

22.5 on %M meter. The AN/ARM-92B FLAG meter

(2) Set the AN/ARM-5 MODULATION switch to

must indicate leas than 180 microampere.

AMP LO C

(5) Adjust the AN/ARM-5 150~ MOD control for

(3) The AN/ARM-92B DEVIATION meter must

22.5 on %M meter. The AN/ARM-92B FLAG meter

indicate 0 30 microampere.

must indicate less than 180 microampere.

(6) C o n n e c t C a b l e C G - 4 0 9 / U b e t w e e n

Table 3-5. Frequency Pairs for Glideslope Sensitivity Test

AN/ARM-5 DEMOD jack and AN/ARM-69 DEMOND

AN/ARM-92B

jack.

freq. sel.

Freq. sel.

Sig. gen.

freq. (mhz)

(mhz)

freq. (mhz)

(MHz)

( 7 ) Connect Cable

CG-433/U between

AN/ARM-5 EXT MOD terminals and AN/ARM-69

108.10

334.70

334.40

110.10

MOD jack.

108.30

334.10

335.00

110.30

(8) Set the AN/ARM-5 MODULATION switch to

108.50

329.90

329.60

110.50

108.70

330.50

110.70

330.20

AMP LOC

108.90

329.30

110.90

330.80

(9) Set the AN/ARM-5 DEMOD adjust (screw-

109.10

331.40

331.70

111.10

driver adjustment) for 80 on %M meter. The

109.30

332.00

332.30

111.30

AN/ARM-92B FLAG meter must indicate 220 micro-

109.50

332.60

332.90

111.50

ampere minimum.

109.70

333.50

333.20

111.70

109.90

333.80

111.90

331.10

3-22. Marker Beacon Bench Tests

f. Deflection Sensitivity Test.

a. Test Setup. The marker beacon bench tests are

(1) Adjust the AN/ARM-5 ATTENUATOR to 700

performed with test setup shown in figure 3-3.

microvolts.

b. Initial Switch Settings. Before performing the

(2) Set the AN/ARM-5 MODULATION switch to

marker beacon bench test procedures, set the controls

AMP LOC

of all items of teat equipment as follows

(3) The AN/ARM-92B DEVIATION meter must

Radio Test Set AN/ARM-92B

0FF/PWR/TEST

PWR

indicate 90 30 microampere right of zero.

400 HZ

MODE

(4) Set the AN/ARM-5 MODULATION switch to

BEARING control

AMP LOC

BRG

BEARING switch

(5) The AN/ARM-92B DEVIATION meter must

FLAG LOAD

indicate 90 30 microampere left of zero.

SENS

GS RCVR

IND TEST

g. Agc Response Test.

DEVIATION

(1) Adjust the AN/ARM-5 ATTENUATOR to 700

109.30

CONTROL frequency

microvolt.

AUDIO

(2) Set the AN/ARM-5 MODULATION switch to

Audio Oscillator AN/URM-127

AMP LOC

ATTENUATOR

Midrange

OUTPUT CONTROL

(3) Note the reading on the AN/ARM-92B

X10

FREQ. RANGE MULTIPLIER

DEVIATION meter. The indication must be 90 30

Frequency control dial

microamperes right of zero.

FREQ. METER switch

(4) Adjust the AN/ARM-5 ATTENUATOR slowly

POWER switch

between 100 and 10,000 microvolt. The

RF Signal Generator AN/USM-44

Power switch

AN/ARM-92B DEVIATION meter must indicate

ATTEN.

5 mv. (-33 dBm)

within 30 microampere of the previously noted read-

MOD SELECTOR

EXT MOD

ding throughout the entire output level range.

C (42-90 MHz)

FREQUENCY RANGE

h. Warning Signal Test.

Adjust to 75 MHz (using

FREQUENCY

3-14