Transmitter Pulse

TB 9-4920-358-35

(d) Menu 14 - PRF to 257 PPS, 0 TRIG to INTERNAL.

(e) Menu 16 - SOURCE to LOW PWR, RF to - 0.

(4) On Menu 16 on radar test set, highlight FREQUENCY and press ENTER to

start frequency measurement. Test may take up to 15-20 minutes.

(5) Radar test set frequency measurement will indicate TI output frequency

between 1029.8 and 1030.2 MHz.

b. Adjustments. No adjustments can be made.

13. Transmitter Pulse

a. Performance Check

(1) Connect equipment as shown in figure 3.

(2) Set TI switches as listed in (a) through (d) below:

(a)

MODE switch to 2.

(b)

REFERENCE CODE switches to 7700.

(c)

FUNCTION switch to FREQ/POWER.

(d)

SYSTEM TYPE switch to SINGLE CHANNEL.

(3) Select radar test set Menu 11, MODULATION to ON. Set TI MODE switch to

1, 2, 3/A, and C, and adjust oscilloscope to observe presence of complete interrogation pulse

trains (see fig. 4), making sure that TI ACCEPT lamp is lit in each mode.

(4) Set TI MODE switch to 1.

(5) Set oscilloscope for a convenient display of the first 3 pulses of the interrogation

pulse train.

Figure 4. Pulse train (example).

(6) Measure the pulse width of P1 and P3 pulses. Pulse width will be between 0.7

and 0.9 µs.

(7) Initialize radar test set by selecting FUNCTION and ENTER. Set radar test

set INTERROGATOR menus as listed below:

(a) Menu 3 - M2 to 7700, RANGE DELAY to 0 µs, SIF2 to OFF.

(b) Menu 4 - SIF CODE to 7700, DELAY to 3 µs, TRIG SOURCE to

EXTERN+.

CHANGE 1 11