User's Manual

14221-1200-4010, Rev. B
85
17.4 LOW BAND PA TRANSMITTING INTO A 50-OHM LOAD/TERMINATOR
17.4.1 For a 100 Watt Output Configuration
1. If it is not already, disconnect the LBPA antenna cable at the rear of the LBPA. Label this cable from
the antenna as the “LBPA Antenna” cable. This should be the cable from the lowest (vehicle trunk lid
mounted) antenna.
2. Using the Type N male to TNC male coaxial test cable, connect the ANTENNA connector at the rear
of the LBPA to the input of the 20 dB RF Attenuator.
3. Connect a Type N male to Type N male to the wattmeter’s input connector. See Figure 17-2.
Rear View of XG-100M
and XG-100LPA
DC Power
Cables
From 13.6-Volt Fused
Power Source
TNC Male-to-Type N Male
RF Coaxial Test Cable
CAN Cable and GPS
Antenna Cable connections
not are indicated.
Vehicle-Mounted
Antenna for
Multi-Band
(highest antenna)
RADIO ANTENNA
Antenna’s
Coaxial
Cable
For XG-100M Multi-Band coax cable
connection is made to MB ANT
(TNC) connector on rear of radio.
Vehicle-Mounted
Low Band Antenna
(lowest antenna)
Antenna’s
Coaxial Cable
IN OUT
Type N Male-to-
TNC Female
RF Adapter
Peak-
Reading
Wattmeter
50-Ohm RF Load/
Terminator
(“Dummy Load”)
Wattmeter Element
(shown positioned for forward
power measurements; see text)
For XG-100LPA Low Band coax cable
connection is made to ANTENNA
(TNC) connector on rear of Amplifier.
20 dB RF Attenuator
(Only Required for
50 and 100-Watt VHF Radios)
(For the 50 and 100-Watt VHF
Radios, see the Required Test
Equipment table for RF cable
requirements.)
Figure 17-2: Wattmeter Connections for LBPA Antenna Tests
4. Connect a 50-ohm RF load/terminator to the wattmeter’s output connector.
5. Insert a 5-watt element into the wattmeter and position the element to measure forward RF output
power. Rotate it as necessary. The arrow on the face of the element must point away from the LBPA
and towards the 50-ohm load/terminator for forward power measurements.
6. Set the wattmeter to measure peak RF power.