Operating instructions

Overview 2-9
Factory installed 20-amp fuses, illustrated in Figure 2-9, provide power passing to additional
amplifiers.
Figure 2-9
Power passing fuse locations
Forward Path
The operational gain of the MBV3-100* amplifiers is 42 dB with 16 dB of return loss in the
forward path. The operating gain includes provisions for the insertion loss of the input cable
equalizer and required reserve gain to operate the Bode equalizer in the middle of its range.
The forward path’s electronics consist of two parallel three-stage paths consisting of:
(1) pre-amplifier (input hybrid), (2) intermediate amplifier (midstage hybrid), and
(3) power-doubling output hybrid stage. The first two stages are common to both paths. The
pre-amplifier stage provides a low noise figure while the output stage contributes the preferred
power at low distortion. The amplifier input provides a facility to install a cable equalizer and a
socket for a model JXP-*B attenuator. The attenuator and equalizer are customer installed
options.
Several circuits comprise the intermediate amplifier stages. A flatness control circuit enables
optimization of the frequency response. The Bode equalizer is a voltage-controlled device that
receives its input from the manual gain control, the vertical automatic drive unit (VADU-*), or
the VQAM automatic drive unit (VQADU-*).
Following the Bode board, a JXP-*B pad facility adjusts the RF level into the interstage hybrid
amplifier and the MDR/10/1G/* controls flatness and provides equalization. Because these
losses are located interstage, the noise figure is only significantly impacted by the insertion loss
of the forward cable equalizer or broadband cable simulator, and the input pad if its value is
increased from zero.
Following the interstage hybrid is a JXP-*B pad socket (or a splitter and two JXP-*B pad
sockets for dual output) leading into the power-doubling output stage.
MBV3-100* Installation and Operation Manual