User's Manual

METERING AND INDICATORS
The following signals and voltages are indicated on the front panel HMS status meter, (a liquid crystal display).
The parameters to be monitored are selectable via the front panel momentary contact toggle switch. The status
meter has two lines of text. The top line indicates the parameter to be measured while the bottom line
indicates the measured value and its units. Refer to the front panel drawing in the illustrations section for the
location of the meter and switch. The following is a list of display positions and functions.
Display Position Function
HMS STATUS . . . . . . . . . . . . . . . . . Meter default position
FWD PWR . . . . . . . . . . . . . . . . . . . . Output RF Forward Power Level
RFL PWR . . . . . . . . . . . . . . . . . . . . Output RF Reverse (Reflected) Power Level
RF INPUT . . . . . . . . . . . . . . . . . . . . Input RF Power Level (Relative Reading Only)
DRIVER V . . . . . . . . . . . . . . . . . . . . DC Voltage, Driver Amplifier
FINAL V . . . . . . . . . . . . . . . . . . . . . . DC Voltage, Final Amplifier
A CURR . . . . . . . . . . . . . . . . . . . . . . Amplifier side “A” DC Current (Usually the driver stage)
B CURR . . . . . . . . . . . . . . . . . . . . . Amplifier side “B” DC Current (Usually the final stage)
TOT CURR . . . . . . . . . . . . . . . . . . . Total DC Current
The switch can be toggled in either direction. If the switch is not toggled for approximately three minutes the
display reverts to the HMS STATUS position.
The primary purpose for the front panel switch is to provide a tool for maintenance of the RF amplifier system. A
table for recording values for each parameter shown by the panel meter is included as
APPENDIX 1 of this manual. It is strongly recommended that these parameters be entered in the table upon
initial installation of the RF amplifier and at regularly scheduled intervals after that. In case of a system failure,
values can be recorded in the table and the table furnished to TPL Communications. This will greatly aid our
technical personnel to make any necessary repairs to the system.
In addition to the front panel metering, a visual system status
monitoring is provided by front panel indicators. Five indicators are used and have the following functions and
characteristics:
Indicator Functions/Characteristics
RF ON . . . . . . . . . . . . . . . . . . . . . . . Steady green LED indicating that adequate RF drive
power is being applied to the amplifier.
SWR . . . . . . . . . . . . . . . . . . . . . . . . Flashing red alarm LED when output load SWR exceed the
internally preset level.
OTEMP . . . . . . . . . . . . . . . . . . . . . . Flashing red alarm LED when amplifier heat sink
temperature is above an internally preset level.
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