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Forward amplifier – Motorola Broadband House Amplifier BHA-100K/P-R User Manual

Page 14

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Overview 2-3

BHA-100* Broadband House Amplifier Installation Manual

Forward Amplifier

Figure 2-2 illustrates a functional block diagram of both the forward amplifier and the optional

return amplifier, and applies to all models.

Figure 2-2
BHA-100* functional block diagram

RF

output

Preamp

Postamp

Gain

Slope

Attenuator

(plug in)

Attenuator

(plug in)

Attenuator

(plug in)

Equalizer

(plug in)

Equalizer

(plug in)

-20dB

test point

+24Vdc

test point

-20dB

test point

-20dB

test point

Return amplifier

(plug in)

Switching

power

supply

+24Vdc

90-240Vac

2.5A/250V

5A/125V

H

L

H

L

RF

input

-20dB

test point

The forward amplifier consists of a low noise pre-amplifier followed by a power-doubled output

stage to achieve low distortion. Between the two stages there are gain and slope controls for

level adjustment.
The input signal level to the pre-amplifier is controlled by a vari-losser with a range of 6 dB.

The vari-losser is controlled by the

GAIN

potentiometer. A JXP-*B socket is also incorporated in

the signal path to further reduce input signal amplitude. SFE-100-* cable equalizers can be

installed in the socket to supplement the slope control network.
A –20 dB directional coupler test point at the amplifier input monitors forward input signal

levels. Directional coupler test points are also available to measure forward amplifier output,

return input, and return output signal levels.

This manual is related to the following products: