User's Manual

4-20 888-2687-001 10/19/07
WARNING: Disconnect primary power prior to servicing.
Ranger ™ Mobile Series
Section 4 Theory of Operation
d. Monitoring system reflected RF power
e. Maintaining hardware trip points for reject loads and forward and reflected power
sense ports to generate an exception on the transmitter parallel bus in the event of
a fault while in Life Support mode
f. Calculation of VSWR based on Forward and Reflected power samples (Not
applicable in Life Support mode)
While this board utilizes the micro module, the CPLD is responsible for all of the
critical power and VSWR overload protection. The micro module is basically just
responsible for communicating information to the Main Controller.
4.4.8.1 RF Detectors
There are 2 types of RF detectors used on the RF Monitor Board:
• Relative - Used to monitor the reject load power levels. These detectors are
very accurate at a calibrated power level, but are not linear across a wide
dynamic range.
• Precision - Used for metering of critical (metered) forward and reflected
power levels of the cabinet and the system. These are true RMS detectors
that are linear at all power levels, giving the accurate readings required for
metering and VSWR protection.
Parameters monitored by the RF detectors include:
a. PA Circulator Reject load #1 power (Relative)
b. PA Circulator Reject load #2 power (Relative)
c. PA Module Combiner Reject load #3 power (Relative)
d. PA Forward Power before filter (Precision)
e. #2 PA Reflected Power before filter (Precision)
f. #3 System Forward Power after filter (Precision)
g. #4 System Reflected Power after filter (Precision)
h. #5 Drive Chain Power exciter (Precision)