Technical Characteristics

TM 11-6625-667-12/NAVAlR 16-30APM-123-1/TO 33A1-3-367-1

(2) Direct coupling to the transponder set by an

TEST . . . . . . . . . . . . . . . . . . . . . . . .6.5 usec 0.2.

RF cable and attenuator.

4 . . . . . . . . . . . . .Modulation from external

unit

(3) Direct coupling of the test set to Antenna

Side lobe suppression

AT-884/APX-44 by an antenna test hood, a fixed

pulse spacing (Pl

attenuator, and an RF cable.

and P2) . . . . . . . . . . . . . . . . .2.0 usec 0.15.

c. Modes 1,2, 3/A, C, TEST, or 4 can be selected, and

Receiver:

codes 0000 to 7777 can be selected. The TEST mode is

Frequency . . . . . . . . . . . . . . . . . . . 1.090 MHz 0.5%(center).

Bandwidth (3 deci-

used in conjunction with the corresponding trans-

bels down) . . . . . . . . . . . . . . 6.5 MHz l.0.

ponder set mode to allow testing when local

Sensitivity . . . . . . . . . . . . . . . .-9 dbm.

identification transmissions may interfere with the

Gating . . . . . . . . . . . . . . . . . . .Only for duration of

use of the normal modes.

replies.

d. Emergency or identity operation checks can be

Decoding . . . . . . . . . . . . . . . . .Codes 0000 to 7777 includ-

ing emergency and

selected and a three-pulse sidelobe suppression test

identity.

can be selected in all modes, except 4.

Power requirements:

e. A test set self-test can be performed, as a

Type . . . . . . . . . . . . . . . . . . . ..ac or dc

confidence level check, in all modes, except 4.

Ac. . . . . . . . . . . . . . . . . . . . . . .115 volts 10%, 50 through

f. Mode 4 tests may be performed by direct

420 Hz at 0.5 ampere.

Dc. . . . . . . . . . . . . . . . . . . .28 3 volts at 1.5 ampere.

coupling of the test set to an auxiliary interrogator

computer or by direct coupling with an RF cable and

attenuator.

1-6. Differences in Models

Official nomenclature, AN/APM-123(V), followed by

1-5. Technical Characteristics

the number 1, 2, or 3 identifies the type of power

Transmitter

cables supplied with the AN/APM-123(V) for use by

Frequency . . . . . . . . . . . . . . . .1,030 MHz 0.02% crystal

the Army, Navy, or Air Force. Number 1 designates

controlled.

that the components of the test set include power

Power output . . . . . . . . . . . . .-- 6 dbm at antenna terminal.

cables that can only be used by the Army. Number 2

Sidelobe suppression

type . . . . . . . . . . . . . . . . . . . 3 pulse.

designates that the components of the test set

Pulse repetition

include power cables that can only be used by the

frequency . . . . . . . . . . . . . 230 +5 - 10 pps

Navy. Number 3 designates that the components of

Pulse output group . . . . . . . 2 (P1 and P3) without side-

the test set include power cables that can only be

lobe suppression or) (P1,

used by the Air Force. Power cable connections for

P2, and P3) with sidelobe

suppression.

the AN/APM-123(V)l, AN/APM-123(V)2, and AN/

Pulse spacing (P1

APM-123(V)3 are given in paragraph 2-4. Except for

and P3):

the difference in power cables and test hood, the

Mode l. . . . . . . . . . . . . .3 usec 0.2.

components of the AN/APM-123(V)1, AN/APM-

Mode 2 . . . . . . . . . . . . . . .5usec 0.2.

123(V)2, and AN/APM-123(V)3 are mechanically and

Mode 3/A . . . . . . . . . . . . .8 usec 0.2.

Mode C. . . . . . . . . . . . . .21 usec 0.2.

electrically identical.

1-7. Items Comprising an Operable AN/APM-123(V)1, 2, or 3

Change 3 1-2.1