Receiver Frequency, Sensitivity, and Bandwidth Test

5.2-6. Receiver Frequency, Sensitivity, and Bandwidth Test

a. Test Equipment Required

(1) Test Set, Radar AN/TPM-25A.

(2) oscilloscope, AN/USM-281A.

(3) Generator, Pulse AN/UPM-15A.

b. Test connections and conditions. Perform the system timing setup as described in the chart in

paragraph 5.2-4c step (l). Then connect the equipment as shown in figure 5.2-4 receiver frequency and

bandwidth test setup.

c. Procedure.

Equipment under test

Performance standard

Test procedure

Test equipment

Step

a. Use

a. None.

AN/USM-281A

DIV

AN/TPM-25A

MODE: 1

DELAY dial to position the

REPLIES panel:

CODE (A,B,C,D) 0000

FUNCTION: SYSTEM

MODULATION SEL: SIF

center (1090 MHz) frequency

POWER: ON

PULSE WIDTH: 0.45

marker on the center vertical

PRESS-TO-TEST: LOCK

SIF REPLY CODE: 0000

graticule of the oscilloscope. Note

SUB PULSE SEL OFF

that the 1 MHz markers appear

RANGE DELAY SEL: SEC) 0100

on vertical lines two divisions

GATING PASS: 00

from the center. Each division on

M4 JAMMING: 0

the oscilloscope .5 MHz.

b. While observing the frequency

b. Test set ACCEPT lamp is lit.

PRT SEL (SEC) Immaterial

markers on B input and the reply

SIG GEN FUNCTION: SWP 5

video on A input, adjust

MHZ

AN/TPM-25A MEASUREME-

SUM ATTEN: -3 DB

NT FREQ MEAS dial to position

the reply video near the center

(1090 MHZ) frequency marker.

c. Observe the oscilloscope as in

c. None.

AN/USM-281A

b above,

and

adjust

Sweep display switch DELAYED

AN/TPM-25A MEASUREME-

DELAYED TIME/DIV: 20 s

NT FREQ MEAS dial coun

MAIN TIME/DIV: .5 MS

terclockwiee until test REJECT

INT AUTO/EXT/EXT10 AUTO

lamp lights and then clockwise

EXT10/EXT/lNT/LINE: EXT

until ACCEPT lamp lights. Note

MAIN - SLOPE +:+

position of the outside reply pulse

DIV DELAY 0.9

with respect to the 1090 MHz

DISPLAY: ALT

frequency marker. The frequency

A VOLTS/DIV: 1

is 0.5 MHz less than 1090 for each

B VOLT/DIV: 5

A and B, AC/G RND/DC: DC

oscilloscope division. Note this

frequency as F1.