3-10
WRT-808A (U)
3-2-9. S/N Check
Equipment and Tools
DC power supply
DC output Voltage:
+
3.0
±
0.1 V dc
DC ammeter
Audio analyzer
Modulation analyzer
MEASUREMENT:
FM
MEASUREMENT RANGE:
±
40 kHz
HPF:
50 Hz
LPF:
15 kHz for HEWLETT
PACKARD equipment
20 kHz for ANRITSU
equipment
DE EMPHASIS:
50
u
s
MM-SMA (J) connector (Part No. J-6402-480-A)
SMA-BNC (J) connector (Part No. J-6402-490-A)
Connections
Same as “3-2-6. Distortion Ratio Check”.
Switch and Control Setting
The following setting is to be perform with the channel se-
lect switches (S504 and S505).
Transmitting Channel setting:
U64 model: 65-01 channel (776.125 MHz)
U66 model: 67-01 channel (788.125 MHz)
U68 model: 69-01 channel (800.125 MHz)
RF power output switch (S401): 50 mW
Input LEVEL control (RV101): “
_
60” (0 dB attenuation)
Turn the RV101 clockwise
fully.
2
1
Short-circuit
XLR 3Pin (male)
- wiring side -
3
Procedure
(1) Connect the audio analyzer (level meter) to the AF OUT
connector on the modulation analyzer.
(2) Input 1 kHz,
_
60 dBV (
_
57.8 dBm) signal to the MIC
input connector (CN101) from audio analyzer (oscilla-
tor).
(3) Set the audio analyzer to S/N measurement (with A-
weighted filter).
(4) Check that the S/N reading is more than 32dB. (with
MIC input connector short-circuited).
