Cisco GainMaker Optoelectronic Node 1GHz with 65 86 MHz Split Installation Guide
Chapter 3 Balancing and Setup
Specified port (station) input, per design = 19 dBmV
Injection test point loss = 20 dB
Port Input + Injection test point loss = Signal generator setting
19 dBmV + 20 dB = 39 dBmV
Set the signal generator output for + 39 dBmV. This signal, when injected
through the reverse injection point, is attenuated by 20 dB, simulating the 19
dBmV port input level specified per design.
Important:
If a CW signal generator is used, at least two carriers should be injected, one
at the low end and one at the high end of the reverse bandpass. In a reverse
system with a 5 MHz to 40 MHz bandpass, the low frequency carrier would
be in the 5 MHz to 10 MHz range, and the high frequency carrier would be in
the 35 MHz to 40 MHz range.
The amplitude of the signal generator output can be set higher or lower than
the level specified by the calculation above, but the difference between the
actual output level and the level calculated above must be known. If the
generator output is x dB higher (or lower) than the level calculated, then the
reference (desired) level received at the headend or hub should also be x dB
higher (or lower) than the original headend reference level.
3 The station reverse input pad(s), reverse output pad, and reverse transmitter
input pad are selected during the reverse system design and are based on the
services to be transported by the reverse system. DO NOT CHANGE ANY OF
THESE PADS FROM THEIR DESIGN VALUES! Reverse equalizer values may be
changed if needed to obtain flat receiver output levels across the reverse
frequency spectrum.
4 Have the technician in the headend refer to the headend system design and set
the output of the optical receiver to the specified output level. If using a sweep
system that is x dB below standard design levels, be sure to consider that your
receive level should also be x dB below the original design reference level.
See the instruction guide that was shipped with the optical receiver for setup
See the instruction guide that was shipped with the optical receiver for setup
procedures. It may be necessary to use an external attenuator at the RF output of
the optical receiver, if the receiver does not have an RF output level adjustment
control.
Note: If the required output level of the reverse receiver is not known, set up the
Note: If the required output level of the reverse receiver is not known, set up the
longest optical link first. Set the remaining receivers for the same RF output level
as that of the receiver connected to the longest optical link.
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