Fm Deviation Accuracy Test - Wavetek 3000 Instruction Manual

PERFORMANCE TESTS
METHOD
4 .14
FM DEVIATION ACCURACY TEST
SPECIFICATION
the meter response to fast, the function switch to +AM, the
meter range switch to 100 and the filter bandwidth to 50 Hz
to 15 kHz .
4 . Adjust the Signal Generator MODULATION FM/AM control
for a modulation meter reading of 70% AM . Set the modulation
meter function switch to -AM, and observe the modulation
meter reading .
Readjust the MODULATION FM/AM control until
the average of the two modulation meter readings in +AM and
-AM positions of the modulation
meter function switch is
equal to 70% AM .
5 . Calibrate the distortion analyzer and measure the dis-
tortion . The distortion should be less than 3% . Record the
distortion on line 34 of the PTR .
6 .
Adjust the Signal Generator MODULATION FM/AM control as
in step 4 until the average of the modulation meter readings
in +AM and -AM positions of the modulation function switch
is equal to 90% AM .
7 . Calibrate the distortion
analyzer and measure the dis-
tortion . The distortion should
be less than 5% . Record
the distortion on line 35 of the PTR .
Deviation Accuracy ±250 Hz on FMx1 range
±35 kHz on FMx100 range
The deviation is measured in both FM modes using an internal
DC voltage equal to the peak of the internal sine wave
voltages .
A frequency counter is used to measure the maxi-
mum deviation in both FM modes .
EQUIPMENT
Frequency Counter HP5300B/5303B
PROCEDURE
1 . Set the Signal Generator controls as follows :
FREQUENCY selector
050 .000 MHz
MODULATION MODE FMx1
MODULATION FREQ VERNIER
MODULATION FM/AM 5 kHz on FM scale
OUTPUT VERNIER Fully Clockwise
OUTPUT step attenuator
+10 dBm
2 .
Connect the 50 ohm
input of the frequency counter to
the Signal Generator RF out connector .