GE ApexPro TT, Technical Manual

Page: 72 / 192

4-10 ApexPro™ 2001989-351A
Maintenance
Calibration
WARNING
LOSS OF DATA—The manufacturer requires that calibration be
performed by service personnel as follows:
For 1395-1400 MHz systems calibrate the following every 2 years:
„
T14 transmitter
„
RIM 1400
„
Receiver subsystem
Determine and record the date of initial factory calibration of transmitters and
receivers from the removable calibration sticker that ships on these devices. Calibrate
within 30 months of the date shown on the manufacturer calibration sticker or 24
months after installation, whichever occurs first, and every 24 months thereafter.
Transmitter calibration
Required equipment
„ Spectrum analyzer
„
Rubber duck antenna
„ An external 10 MHz reference (accurate to 0.0083 ppm)
„
Laptop with HyperTerminal
Determine target frequency
Using the TTX number on the back of the transmitter, look up the target frequency in
the ApexPro Telemetry Frequency Chart Reference Manual and record it here:
Target frequency: _________________
Determine frequency offset
This checks the carrier frequency to verify that it is within the frequency tolerance of
the programmed value.
NOTE
The Rohde & Schwarz FSH3 spectrum analyzer is used for the following steps. If
a different spectrum analyzer is being used, the detailed sub-steps may be
different.
1. Connect a Rubber Duck antenna to the spectrum analyzer to view the transmitter.
2. Do one of the following:
„
Using a small paper clip, short pins 2 and 4 on either of the interface
connector ports as shown.