3-7
WRT-808A (U)
3-2-5. Maximum Frequency Deviation Check
n
Be sure to perform this adjustment after “3-2-4. Reference
Frequency Deviation Adjustment” has been completed.
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: AUTO or
±
100 kHz
HPF:
50 Hz
LPF:
15 kHz or 20 kHz
DE EMPHASIS:
50
u
s
Oscilloscope
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
Same as “3-2-4. Reference Frequency Division adjustments”.
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,
_
24dBV (
_
21.8 dBm) signal to the MIC
input connector (CN101) with Mic input cable.
(2) Check that the frequency deviation for the modulation
analyzer reading meets the following specification.
Specification: Frequency deviation =
±
40 kHz
±
3 kHz
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
MEASUREMENT:
FM
MEASUREMENT RANGE: AUTO or
±
40 kHz
HPF:
50 Hz
LPF:
15 kHz or 20 kHz
DE EMPHASIS:
50
u
s
Oscilloscope
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.)
Modulation
analyzer
Audio
analyzer
Distortion
mode
RF IN
AF OUT
MM-SMA (J) connector
with SMA-BNC (J)
connector
CN402
MIC input
(CN101)
Oscilloscope
RF-90 Board
Audio analyzer
2
1
Oscillator
Oscillator
XLR 3Pin (male)
- wiring side -
Level meter
3