Wavetek 3000 Instruction Manual page 64

PERFORMANCE TESTS
PROCEDURE 1 . Set the Signal Generator controls as follows :
4- 24
FREQUENCY selector
520 .000 MHz
MODULATION MODE FMx100
MODULATION FREQ EXT
MODULATION FM/AM 0 kHz
OUTPUT VERNIER +3 dBm reading on OUTPUT meter
OUTPUT step attenuator +10 dBm
2 . Connect the equipment as shown in Figure 4-6 .
Oscilloscope
TEE
Figure 4-6 . FM Bandwidth Setup
3 . Set the modulation meter to read FM deviation at 520
MHz . Set the RF input attenuation to 20 dB, the IF band-
width to ±400 kHz, the meter response to fast, the function
switch to +FM, the meter range switch to 300 and the filter
bandwidth to 75 kHz .
4 . Set the function generator for a 1 kHz sine wave out-
put and the attenuator controls for a 10 volt p-p sine wave
on the oscilloscope .
5 . Adjust the Signal Generator MODULATION FM/AM control for
a modulation meter reading of 0 dB (approximately 320 kHz
deviation) .
6 . Maintain the 10 volt p-p output level and slowly increase
the function generator frequency from 1
to 25 kHz
while
observing the dB scale on the modulation meter .
It should
read between +1 and -1 dB . Note the maximum change from the
0 dB calibration level .
7 . Repeat steps 4 through 6 with the modulation meter func-
tion switch set to -FM . Note the change from the 0 dB set-
ting as in step 6 .