Motorola BLE Series, Инструкция по установке и эксплуатации

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BLE */* Ins talla tion and Op eration Manual
Section 3
A m p l i f i e r S e t u p
This section provides instructions for fully configuring the BLE*/* and describes the proper
forward and return path alignment procedures.
F o r w a r d P a t h A l i g n m e n t
The following subsections describe the BLE*/* alignment procedures required for proper
performance in the forward path.
Before You Begin
Before you begin to set-up the amplifier and perform forward-path alignment, please read the
following instructions and recommendations.
For proper forward alignment obtain:
!
RF output levels and tilts of all BLE*/*s in the forward or return path
!
RF input level for the BLE*/* being set up (from system design or as-built map)
!
A carrier at the system’s highest frequency. It can be modulated or continuous wave (CW)
and should be inserted in the headend at standard video levels. This carrier is used to
simplify field set-up.
It is recommended that you:
!
Remove the input pad and/or the SFE-*-* before you install or remove the electronics
package (E-pack) or apply power to the BLE*/*
.
!
Do not use wire jumpers to bypass the SFE-*-* location.
!
Recognize that actual pad and SFE-*-* values may differ slightly from their design values.
This is caused by factors such as walkout errors, worst-case data utilization during design
and temperature variation from 70
°
F.
!
Secure the E-pack in the housing and torque to 18-22 in-lbs. to facilitate heat transfer and
avoid damage from overheating.
!
Subject the BLE*/* to a 24-hour heat cycle before performing bench alignment.
!
Do not daisy-chain power on burn-in racks.
!
Perform a bench alignment. Pre-distorting the BLE*/* response on the bench (Section 4,
“Bench Testing”) for a system signature simplifies field alignment.
!
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.”
Cable Equalizer
Select the appropriate Model SFE-*-* to compensate for cable attenuation versus frequency and
to obtain the proper output tilt. The BLE*/* is equipped with the *LDR/*/II interstage equalizer
and flatness board, which compensates for cable attenuation. Any cable or passive slope beyond