3-6
WRT-808A (U)
3-2-4. Reference Frequency Deviation
Adjustment
Equipment and Tools
DC power supply
DC output voltage:
+
3.0
±
0.1 Vdc
DC ammeter
Audio analyzer
Modulation analyzer
MEASUREMENT:
FM
MEASUREMENT RANGE: AUTO or
±
10 kHz
HPF:
50 Hz
LPF:
20 kHz or 15 kHz
DE EMPHASIS:
50
u
s
Adjustor (Part No. 7-721-052-81)
MM-SMA (J) connector (Part No. J-6402-480-A)
SMA-BNC (J) connector (Part No. J-6402-490-A)
Connections
(For connecting the DC power supply, refer to the “Preparations”
on page 3-2.)
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.
Procedure
(1) Input 1 kHz,
_
60 dBV (
_
57.8 dBm) signal to the MIC
input connector (CN101).
(2) Adjust
1
RV202 so that the frequency deviation for the
modulation analyzer reading meets the following speci-
fication.
Specification: Frequency deviation
=
±
5 kHz
±
0.1 kHz
Adjustment:
1
RV202/AF-27 Board (B side)
(3) After the adjustment has been completed, perform the
“3-2-5. Maximum Frequency Deviation Check”.
Modulation
analyzer
Oscilloscope
RF IN
AF OUT
MM-SMA (J) connector
with SMA-BNC (J) connector
CN402
MIC input
(CN101)
RF-90 Board
Audio analyzer
2
1
Oscillator
XLR 3Pin (male)
- wiring side -
3
Oscillator
Level meter
POWER/BATT (D502)
AF/PEAK (D503)
