Motorola RF Amplifier - Manual (Page 7)

STARLINE 7
RF Amplifier Quick Start Guide
Alignment Procedure
To align the return path:
1 If the amplifier is powered, remove all fuses before you perform the following steps.
2 If necessary, carefully install a return hybrid amplifier.
3 Ensure that both hybrid screws are tight. Torque the screws to 10 to 12 in-lbs. Over torque
can damage the hybrid.
4 Install the design value pad in the return output pad location.
5 Install the design value SRE- *-*.
6 Verify that the return input pad locations have 0 dB pads (or JXP-ZX jumpers) installed.
If the optional ICS is ordered, verify that the switch(es) are installed in the ICS location(s).
Otherwise, leave the factory-installed jumpers in the ICS location(s).
7 Verify that any remaining return pad locations have 0 dB pads (or JXP-ZX jumpers)
installed.
8 Verify that the JXP THERM pad location has a 0 dB pad (or JXP-ZX jumper) or a JXP-TH *B
installed.
9 Set the sweep equipment output level to the amplifier’s design input level. Add insertion
point loss.
10 If required, change the return output pad and/or SRE- *-* to achieve, as close as possible, a
match of the reference level as compared to the node.
11 Verify the sweep response of all insertion points if applicable.
12 Verify that the pad and SRE- *-* 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’s Return Path
Level Selection, Setup and Alignment Procedure.
Closing the Housing
Before you close the housing:
1 Record all pertinent information as required.
2 Secure the electronics chassis in the housing and torque to 18 to 22 in-lbs. This facilitates
heat transfer and reduces damage caused by overheating.
3 Verify that the electronics chassis cover screws are torqued to 10 to 12 in-lbs.
4 Check the condition of the RF and weather gaskets and replace them if necessary.
5 If applicable, ensure that the electronics chassis handles are folded down and the cable
between the power pack and electronics chassis is not pinched.