Operating instructions

Amplifier Setup 3-13
 Do not use wire jumpers to bypass the SRE-*-* location
 Perform the return optical link set up before performing amplifier set up
 Specify reverse alignment design levels for a single carrier
 Consider sweep equipment as a single carrier and operate at design levels
 Do not include injection point losses in reverse design levels
If JXP THERM devices (JXP-TH*C) are specified for level control, they should be installed in
the JXP THERM pad facility (illustrated in Figure 2-11).
Alignment Procedure
The return amplifier configuration includes one high-gain (30 dB) return amplifier hybrid, and
an appropriate SRE-*-* equalizer. All components are plug-in and are easily installed.
To align the return path:
1 If the MBV3-100* is powered, remove all fuses before you perform the following steps.
2 Install the design value pad in the return output pad location (JXP).
3 Install the design value return equalizer, SRE-*-*, in the RTN EQ location.
4 Verify that the return input pad locations (JXP 2 and JXP 3/4) have 0 dB pads
(or JXP-ZX jumpers) installed.
5 If you require ICSs, install them in the ICS locations illustrated in Figure 2-11. If you plan
to install the ICSs later, install JXP-2Bs to simulate the through-loss of the ICSs. This
eliminates the need to rebalance the return path if you install the ICS later.
6 Verify that the return pad (JXP COMMON) has a 0 dB pad (or JXP-ZX jumper) installed.
7 Verify that the return thermal pad socket (JXP THERM), located between the hybrid output
and the SRE-*-*, has a 0 dB pad (or JXP-ZX jumper) or JXP-TH*C installed.
8 Set the sweep equipment output level to the amplifier’s design input level. Add insertion
point loss.
9 If required, change the return output pad (JXP) and/or return equalizer to achieve, as close
as possible, a match of the reference level as compared to the node.
10 Verify the sweep response of all insertion points, if applicable.
11 Verify that the pad and equalizer values are similar to the map design values.
You can verify proper return alignment by injecting a carrier, at the design level, into any
amplifier at random. Proper alignment is achieved if you observe the reference level at the
headend optical receiver output.
Return levels used for alignment are not necessarily operational system levels. These levels
vary from system to system due to differences in equipment, architectures and design
philosophies. For an in-depth analysis and discussion of the return path, refer to Motorola
reference guide Return Path Level Selection, Setup and Alignment Procedure.
MBV3-100* Installation and Operation Manual