Table of Contents
Advertisement
3-2-6. Distortion Ratio Check
Equipment and Tools
DC power supply
DC output voltage: +3.0 ± 0.1 V dc
DC ammeter
Audio analyzer
Modulation analyzer
Oscilloscope
RF adjusting cable (Part No. J-6402-390-A)
RF conversion connector (Part No. J-6402-490-A)
AF input cable (Part No. J-6407-010-A)
Connections
(For connecting the DC power supply, refer to the "Prepara-
tions" on page 3-2.)
Modulation
analyzer
RF IN
AF OUT
Level meter
RF adjusting cable
RF conversion connector
RF-96 board
CN402
MB-914 board (A side)
Switch and Control Setting
First, Perform the same setting as described in "4. Switch and
Control Setting during Adjustment and Checking," on page 3-
3, then perform the following setting:
RF power setting:"H" (= 50 mW)
WRT-847A/847B
Oscilloscope
Audio
Distortion meter
analyzer
Oscillator
AF input cable
CN301
DP-341 board
Procedure
(1) Connect the audio analyzer to the AF OUT connector
on the modulation analyzer.
(2) Connect the modulation analyzer to the antenna connec-
tor (CN402) with RF adjusting cable (and RF conver-
sion connector).
Set the modulation analyzer as below;
MEASUREMENT:
MEASUREMENT RANGE: AUTO or ± 40 kHz
HPF:
LPF:
DE EMPHASIS:
(3) Set the audio analyzer to distortion measurement (dis-
tortion mode).
(4) Input 1 kHz, _55 dBV (_52.8 dBm) signal to the AF
input connector (CN301/MB-914 board) with AF input
cable from audio analyzer (oscillator).
(5) Check that the distortion analyzer reading is less than 1.0 %.
(6) Input 1 kHz, _22 dBV (_19.8 dBm) signal to the AF
input connector (CN301/MB-914 board) with AF input
cable).
(6) Check that the distortion analyzer reading is less than 1.5 %.
FM
(manual operation)
50 Hz
15 kHz or 20 kHz
50 us
3-7
Advertisement
Table of Contents
