Motorola BT100 operation manual Directional Coupler Test Points, Bode Equalization

3-8 Amplifier Setup

Figure 3-4

BDR-1G board – top (left), bottom (right)

To obtain maximum flatness:

1On 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.

2On 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.

3You may adjust tilt by changing the MEQ-100-* equalizer value.

ƒ If the module's response is up tilted, increase the MEQ-100-* value by l dB.

ƒ 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

BT100 Installation and Operation Manual