Am Distortion Test - Wavetek 3000 Instruction Manual

4 .13 AM DISTORTION TEST
SPECIFICATION
Distortion
<3% distortion to 70% AM (<5% to 90% AM) at a frequency of
METHOD
EQUIPMENT
1 kHz (Typ <1 .5% to 30% AM)
Modulation Meter Radiometer AFM2
Distortion Analyzer HP334A
PERFORMANCE TESTS
This specification applies for output limits _<+3 dBm. AM
is possible above +3 dBm if the peak of the modulated output
does not exceed +13 dBm .
The measurement is made with a modulation meter and a dis-
tortion analyzer,
which measures the distortion of the de-
modulated AM from the modulation meter .
The measurement is
made at the minimum leveler point where the AM distortion is
normally worst-case .
PROCEDURE 1 . Set the Signal Generator controls as follows :
FREQUENCY selector 520 .000 MHz
MODULATION MODE AM
MODULATION FREQ
1 kHz
MODULATION FM/AM 0% AM
OUTPUT VERNIER -7 dBm reading on OUTPUT meter
OUTPUT step attenuator 0 dBm
2 . Connect the equipment as shown in Figure 4-5 .
Figure 4-5 . AM Distortion Setup
3 . Set the modulation meter to read %AM at 520 MHz . Set the
RF input attenuation to 10 dB, the IF bandwidth to ±400 kHz,
Model 3000
Signal Generator
Modulation Meter
Distortion Analyzer
Input
RF
AF O
RF Out
Input
Output
O