3-16
WRT-808A (U)
Procedure
(1) Set the spectrum analyzer as below:
CENTER FREQUENCY:
U64 model: 776.125 MHz
±
1 kHz
U66 model: 788.125 MHz
±
1 kHz
U68 model: 800.125 MHz
±
1 kHz
REFERENCE LEVEL:
17 dBm
FREQUENCY SPAN:
500 kHz (50 kHz/DIV)
RBW (resolution band width): 1 kHz
VBW (video band width):
1 kHz
ATT:
30 dB
(2) Set the carrier frequency level (the center frequency lev-
el of the spectrum analyzer) to the REFERENCE LEV-
EL (17 dBm) when no signals are input.
(3) Input 1 kHz,
_
24 dBV (
_
21.8 dBm) signal to the MIC
input connector (CN101) from audio analyzer (oscilla-
tor), and you can see the waveform which has some
bandwidth as shown below.
(4) At this time, check that the bandwidth at the level 23
dB lower than REFERENCE LEVEL is in specifica-
tion.
Specification: Bandwidth = 100 kHz or less
3-2-14. Occupied Band Width Check
Equipment and Tools
DC power supply
DC output Voltage:
+
3.0
±
0.1 Vdc
DC ammeter
Audio analyzer
Spectrum analyzer
MM-SMA (J) connector (Part No. J-6402-480-A)
SMA-BNC (J) connector (Part No. J-6402-490-A)
Connections
Switch and Control Setting
The following setting is to be perform with the channel
select 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.
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
Spectrum
analyzer
17 dBm
–23 dB
V : 10 dB/div
H : 50 kHz/div
fc
band width
100 kHz or less
carrier with no input signal
REFERENCE LEVEL
