Mode 4 Reply Decoder Tests-CONT. - TM-11-6625-667-450207

Control Settings

Step

Performance Standard

No.

Test Procedure

Test Equipment

Equipment under test

AN/UPM-15A

TRIGGER SELECT: EXT

(Cont)

PULSE DELAY coarse

PULSE WIDTH coarse

POSITIVE AMPLITUDE: Fully

ccw.

ACCEPT indicator glows.

Depress transponder test set PUSH

FUNCTION: SYSTEM

TO TEST switch. ACCEPT

MODE: 4

indicator should glow.

DIR/RAD: RAD

ISLS: OFF.

a. ACCEPT indicator glows.

a. Set AN/TPM-25A GATING PASS

to 56 and GATING INHIB to 8.

Depress transponder test set

PUSH TO TEST switch. AC-

CEPT indicator should glow.

b. REJECT indicator glows.

b. Set AN/TPM-25A GATING PASS

to 55 and GATING INHIB to 9.

Depress transponder test set

P U S H TO TEST switch.

REJECT indicator should glow.

c. None

c. Set transponder test set DIR/RAD

switch to DIR.

d. ACCEPT indicatorglows.

d. Set AN/TPM-25A GATING PASS

(See note

to 16 and GATING INHIB to

48. Depress transponder test set

PUSH TO TEST switch. AC-

CEPT indicator should glow.

NOTE

If the ACCEPT lamp does not go on, it is possible that the mode 4 reply from the AN/TPM-25A is

arriving too late for-the timing-of the transponder test set. To check this, continue as above while

slowly turning 269

gate adjust A2R2 clockwise until the ACCCEPT lamp glows. If the ACCEPT

lamp glows, the performance standard, in 3d above, has been met. Perform the 269

gate ad

justment procedure given in paragraph 5.1-22.

e. REJECT indicator glows.

e. Set AN/'PM-25A GATING PASS

to 15 and GATING INHIB to

49. Depress transponder test set

PRESS TO TEST switch.

REJECT indicator should glow.

f. None

f. Set AN/TPM-25A GATING PASS

to 16 and GATING INHIB to

48.