MB-750D-H and MB-750D-H/40 Installation Manual
Section 2
Overview
Product Description
The model MB-750D-H and MB-750D-H/40 Mini-Bridgers are dual output, high gain,
three-stage hybrid amplifiers designed to drive both a limited cascade as well as a local
distribution system. These amplifiers provide 110-channel capability utilizing a forward
bandpass of 50 to 750 MHz and a return path of either 5 to 30 MHz for model MB-750D-H and
5 to 40 MHz for model MB-750D-H/40. The high gain feature — 35 dB operational — makes the
amplifiers suitable for drop-in replacement of trunk amplifiers that were originally spaced for
22 dB at 300 MHz. Use of the mini-bridgers eliminates the need for intermediate amplifiers
normally required to modify a “tree-and-branch” system into a “fiber-to-the-feeder” architecture.
The attenuation of coaxial cable as used in CATV systems changes with variations in
temperature. To assist in compensating for these changes, the MB-750D-H and MB-750D-H/40
include manual thermal gain compensation. The degree of thermal compensation is selectable
by a plug-in jumper and can be set to 0, 17 or 26 dB of cable. Gain control through automatic
temperature compensation is an available option.
The basic amplifier is shipped in housing model MB-HSG/60 and includes all necessary
components for a fully functional one-way amplifier, with the exception of the forward cable
equalizer, model EQ-750-*.
The block diagram in Figure 1 shows the functional interconnections of all stages in both
amplifiers.
