Directional coupler test points, Bode equalization – Motorola BLE*/* User Manual
Page 29
3-8
Amplifier Setup
BLE*/* Installation and Operation Manual
Figure 3-4 illustrates BLE87* flatness and control ranges:
Figure 3-4
Typical flatness and control ranges
CH2 S21 /M log MAG
BLE87S/12/G
1 dB/ REF 30.49 dB
4: 30.757 dB
870.000 000 MHz
1: 30.434 dB
52 MHz
2: 30.306 dB
200 MHz
3: 30.394 dB
800 MHz
4
3
2
10:22:15
25 Jun 2001
1
PRm
C?
Del
14.7 dB P3-412 @870.0 MHz
START 52.000 000 MHz
STOP 900.000 000 MHz
Directional Coupler Test Points
Accurate
−20 dB directional-coupler test points are available at the input and at the output of
the BLE*/*. Because these test points are 75-ohm source impedance, they do not require special
test probes.
After the output hybrid, a second directional coupler provides signal to the optional ADU board.
This signal is used only when the ADU board is installed. It is not necessary to terminate this
port when the ADU is not installed.
Bode Equalization
The Bode board, which is an electronically controlled equalizer, receives its control input from
either the ADU or TDU control boards. The response of the Bode board compensates for cable
attenuation changes due to temperature. If necessary, you can control the Bode board manually
using the potentiometer labeled Manual Level (
MAN
) in Figure 2-8.