Printed-Wiring Circuit Board (Card) Tests

C1, TM 11-6625-646-15

d. If no further tests are to be performed stop the

a. Turn the SAS amplifier selector switch to DC,

test set (para 4-20).

then to AC. Observe the SAS amplifier meter for the

required indication.

4-19. Calibration Card

b. Set the AXES METERS READ switch to

Test a calibration card as follows:

CLOSED LOOP.

c. Turn the SAS amplifier selector switch, inturn, to

NOTE

PITCH, ROLL, S/SLIP, and YAW. At each switch

The CALIBRATION TEST POINTS

position, operate the L-R switch to each position.

connect to the corresponding pins of

Observe the SAS amplifier meter for the required

the

CALIBRATION

CARD

test

indication.

receptacle.

Since the calibration

card does not include complete

4-15. Printed-Wiring Circuit Board (Card) Tests

functioning circuits, testing is limited

resistance

and

capacitance

4-16. To test a SAS amplifier card, perform the

measurements.

preliminary procedures (para 4-4). Then proceed as

directed below.

a. Plug the card into the CALIBRATION test

receptacle component-side down.

4-17. Demodulator-Modulator Card

Test a demodulator-modulator card as follows:

b. Refer to the SAS amplifier schematic diagram

for circuit points and component values. Calibration

a. Plug the card into the DEM/MOD CARD TES

card circuit configurations and component values are

TER receptacle, component-side down.

Turn the

not the same for all SAS amplifier models.

FUNCTION switch to DEM OUPT, Set the 115V 400~

POWER switch to on (up) position.

c. Adjust the multimeter to the appropriate

resistance range or adjust the C-I-R bridge to the

b. Adjust variable resistor R76 on the card until the

appropriate capacitance range. Connect the test leads

FUNCTION meter indicates 0.

to the CALIBRATION TEST POINTS to be measured.

c. Set the CARD TEST SIGNAL switch to L.

Observe the FUNCTION meter for the required

indication.

NOTE

The test of the ASE function of the

d. Set the CARD TEST SIGNAL switch to R.

calibration card is not applicable to

Observe the FUNCTION meter for the required

indication.

the CH-47 SAS amplifiers.

d. Remove the card from the test receptacle.

e. If no further tests are to be performed, stop the

test set (para 4-20).

e. If any measurements are not correct, repair or

install a new card as necessary.

4-18. Amplifier Card

f. Stop the test set (para 4-20).

Test an amplifier card as follows:

a. Turn the FUNCTION switch to AMPL OUPT.

4-20. Stopping Procedure

Plug the card into the AMPLIFIER CARD TESTER

receptacle, component-side down. Set the 115V 400

4-21. Stop the test set as follows:

POWER switch to on (up) position.

a. Set the 115V 400~POWER switch to off (down)

b. Set the CARD TEST SIGNAL switch to L.

position.

Observe the FUNCTION meter for the required

b. Disconnect all test and power cables from the

indication.

test set.

c. Set the CARD TEST SIGNAL switch to R.

c. Stow all cables and the adapter in the cover of

Observe the FUNCTION meter for the required

the test set.

indication.

d. Close the hinged door. Secure it with the

turnlock fasteners.