User's Manual

MAINTENANCE 5543A DIGITAL AGILE PAGE 14
ALIGNMENT PROCEDURES
GENERAL:
Due to the complex and delicate nature of this digital equipment, very few adjustments can be made in the
field. Do not attempt to make any adjustments without proper test equipment.
REQUIRED TEST EQUIPMENT
• DVM
• Frequency Counter
• Spectrum Analyzer
For settings other than those covered in this section, a network analyzer and other equipment is
required. If you have any questions on how to adjust your system contact Axcera Customer Service.
OSCILLATOR CALIBRATION:
The FCC requires that the transmitter carrier frequency should be checked once each month. If the carrier is
found to be off frequency, the following procedure should be performed. The data resulting from this
procedure should be logged for future reference. A frequency counter that is capable of 5 x 10
-9
stability and a
voltmeter are required.
CALCULATE CENTER CARRIER FREQUENCY.
(FOR FREQUENCY GENERATOR TRAY)
í Measure the VCXO frequency (f
(s)
) at the BNC connector on the front
panel (10 digits).
í Using a 10 digit calculator, perform the following calculation:
[ 16 x f
(s)
] + 539 MHz
(2
nd
L.O.) (1
st
L.O.)
The result should be the desired center carrier frequency, ±500 Hz (Axcera spec.) or ±1000
Hz (FCC spec.)
í In the event the frequency appears to be incorrect, check the agile upconverter
front panel VHF PLL indicator, if it is OFF contact Axcera Customer Service.