Operating instructions

Amplifier Setup 3-3
 Field-sweep the entire bandwidth of the amplifier to correct frequency response for passive
signature and roll-off.
 Close the housing in accordance with the instructions in Section 5, “Installation.”
STARLINE Forward Equalizers
Select the appropriate model SFE-100-* to compensate for cable attenuation versus frequency
and to obtain the proper output tilt. The MBV3-100* is equipped with the MDR/10/1G/*
interstage equalizer and flatness board, which compensates for cable attenuation. Any cable or
passive slope beyond that of the MDR must be compensated for by selecting and installing the
appropriate SFE-100-* cable equalizer.
Equalizers are available in 1 dB increments from 0 dB through 22 dB. The following examples
describe how to choose the correct equalizer.
Example 1
The amplifier location includes 20 dB of cable (at 1 GHz) between its input and the preceding
amplifier. Consider cable loss only. Exclude any flat loss due to splitters or other passive
devices. The internal equalizer, model MDR/10/1G/*, compensates for approximately 18 dB of
cable. Subtract this cable length from the 20 dB of this example (20 − 18 = 2). The SFE-100-2 is
the proper equalizer in this case. With this equalizer installed, the amplifier reproduces the
output tilt of the last upstream amplifier.
When selecting an equalizer, choose the next lower value if the exact value is not available or in
cases where the calculated value makes two choices possible.
Example 2
The MBV3-100* is used in a link following a fiber node. The fiber receiver output is flat and
connects to the input of the amplifier through 18 dB of cable plus passive loss. Determine which
is the proper equalizer to achieve the 11 dB output tilt from the MBV3-100*.
Calculate the equalizer value using the following equation:
SLOPE
eq
= TILT
out
+ SIG
lo
– SIG
hi
– SLOPE
ieq
where: SLOPE
eq
= required SFE-100-* slope
TILT
out
= required amplifier output tilt
SIG
lo
= signal input level at 54 MHz (channel 2)
SIG
hi
= signal input level at 1 GHz
SLOPE
ieq
= interstage equalizer slope (14 dB)
From various references, such as manufacturer’s catalogs, you can determine that 18 dB of
cable, at the operating frequency of 1003 MHz, produces approximately 4.0 dB of loss at
54 MHz. This suggests that the channel 2 signal input to the MBV3-100* is 14.0 dB greater
(18 − 4.0 = 14.0) than it is at 1003 MHz. Our example assumes that the high-end frequency level
into the MBV3-100* is +12 dBmV.
MBV3-100* Installation and Operation Manual