User Manual

Table Of Contents
Maintenance RF-Orchestra!™ Transmitter Installation and Operation
6-56 6880493G02-C July 2000
Carrier Feedthrough Nulling
The carrier feedthrough (CFT) signal is an undesired by-product of the I/Q modulator circuit
of the exciter. This procedure is followed to minimize the CFT component, which may cause
degraded voice quality (pops and fades) in InFLEXion paging systems.
Perform this procedure whenever you replace a wattmeter power detector, an RF coupler, a
power amplifier, an OCM, an exciter, and during periodic maintenance routines:
1. Reaccess the RF-O! transmitter, if necessary:
DANGER
Before disconnecting the paging station from antenna RF output cable,
ensure there is no transmission.
CAUTION
The RF-O! transmitter must warm up (transmit) for a minimum of five minutes
before starting this procedure.
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