Cisco Model GS7000 4-Port Node 1 GHz with 42 54 Split Installation Guide
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Appendix
Forward Band Optimization
Typically the GS7000 node performance will be acceptable following a split upgrade
with no additional optimization. If performance optimization is required, the
following steps provide details on accomplishing this optimization.
Complete the following procedure for each output port on the RF Amp module.
Note: The High Pass Filter Trim modules near the top of the amplifier are active only
for higher orders of segmentation. The lower 2 modules are active for all modes of
segmentation.
1 While looking at the S21 frequency response trace, use a non-conductive tuning
with no additional optimization. If performance optimization is required, the
following steps provide details on accomplishing this optimization.
Complete the following procedure for each output port on the RF Amp module.
Note: The High Pass Filter Trim modules near the top of the amplifier are active only
for higher orders of segmentation. The lower 2 modules are active for all modes of
segmentation.
1 While looking at the S21 frequency response trace, use a non-conductive tuning
tool to tune each of the three variable capacitors on the High Pass Filter Trim
modules to optimize the forward band response for its respective port(s), as
follows:
modules to optimize the forward band response for its respective port(s), as
follows:
2 Adjustment of the crossover region is most easily adjusted while monitoring a
limited portion of the operating band. Generally a sweep of the region 50 MHz
below and 150 MHz above the high pass crossover frequency offers a suitable
view. Adjust the crossover cap for optimum response.
below and 150 MHz above the high pass crossover frequency offers a suitable
view. Adjust the crossover cap for optimum response.
The 2 additional adjustments on the High Pass Filter Trim Modules are intended for
optimizing the overall high frequency response.
optimizing the overall high frequency response.
Adjustment of the remaining 2 capacitors requires a full bandwidth
view. Adjust these 2 remaining capacitors as required to optimize for a
smooth response across the band.
view. Adjust these 2 remaining capacitors as required to optimize for a
smooth response across the band.
A rise in gain at frequencies between 1GHz and 1.5GHz may be
anticipated. This additional gain will be absorbed by losses between the
Forward Receiver Module and the RF Amplifier.
anticipated. This additional gain will be absorbed by losses between the
Forward Receiver Module and the RF Amplifier.
Note: Test and adjustment points vary depending on the FCM module being used.
For example: