Directional coupler test points, Bode equalization – Motorola BT100 User Manual
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3-8
Amplifier Setup
BT100 Installation and Operation Manual
Figure 3-4
BDR-1G board – top (left), bottom (right)
To obtain maximum flatness:
1
On the main board, adjust the high-end flatness adjustment (C129) to minimum capacitance
to place the peak out of the bandwidth.
This should not need adjusting as it is properly set during manufacturing.
2
On the BDR-1G board adjust:
a. R5 and C6 for the response across the lower end of the mid-band.
b. C1 and L6 for the mid-band response.
c. C3 and R4 for more mid-band response adjustment; C2 and R3 for response around
100 MHz.
d. C7 and R2 for the response at Fmin.
e. C4, L4, and L5 for the response at the upper frequency range.
3
You may adjust tilt by changing the MEQ-100-* equalizer value.
If the module's response is up tilted, increase the MEQ-100-* value by l dB.
If the module's response is down tilted, decrease the MEQ-100-* value by 1 dB.
Directional Coupler Test Points
Accurate – 20 dB directional-coupler test points are available at the input and at the output of
the BT100. 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 or
QADU board. This signal is used only when the ADU or QADU board is installed. It is not
necessary to terminate this port when the ADU/QADU is not installed.
Do not remove the ADU pad (JXP ADU). Removing this pad affects the output test points.
Bode Equalization
The Bode board, which is an electronically controlled equalizer, receives its control input from
the ADU or QADU control boards. The response of the Bode board compensates for cable