Harris Ranger Series, Commissioning Manual

Page: 99 / 162

12/24/07 888-2685-001 4-9
WARNING: Disconnect primary power prior to servicing.
Section 4 RF Testing
Ranger Commissioning Manual
4.2.11 Frequency Tolerance
4.2.11.1 Objective
To verify the Channel Center Frequency meets the tolerance requirements.
The transmitter will be operated in CW mode (719 MHz for U.S. applications and at
other frequencies to be defined by Qualcomm for international operation) while the
frequency is measured at the transmitter forward output directional coupler. Output
power must be adjusted to 375 or 500 watts +/- 10% (output level depends on power
level of transmitter).
4.2.11.2 Requirement(s)
The relative maximum frequency difference (|f-f
c
|/f
c
) between the mean actual transmit
carrier (f) frequency and the specified transmit frequency (f
c
) shall be less than 1 x 10
-9
with the external reference connected.
With external reference disconnected, the relative maximum frequency difference shall
be less than 1 x 10
-8
for at least 24 hours.
4.2.11.3 Setup and Test Equipment
Table 4-6 Frequency Tolerance Setup
Transmitter Exciter
Status 1 Active on Exciter A External GPS Active
Status 2 Standby on Exciter B External GPS Active
Table 4-7 Frequency Tolerance Test Equipment
Frequency Meter (error < +/- 0.72 Hz
RF Test Cables (with known and measured losses)