Bird Technologies 4201 Series - Manual (Page 20)

Zeroing Meters
Before any power measurements are made, be sure the pointer rests on the zero
mark. If not, adjust the zero adjustment screw clockwise or counterclockwise until
the pointer rests on the zero mark. The adjusting screw is located at the bottom
center of the meter bezel face. Perform this adjustment, if needed, on both meters.
Refer to figure 8.
Using The Wattmeter
Models 4201A501
and 4201A502
Operation of the Wattmeter using line sections and elements.
1. Make sure the Plug-In-Elements, in the line sections of the
transmission lines, are properly positioned and directed.
2. Turn the switch, or switches, to a channel that is connected
to the transmitter to be monitored. If applicable, press the
push button to enable.
3. Turn on the transmitter.
4. Read the actual power values directly on the meters. The
wattmeters have triple-range scales on both the forward and
reflected powers. The full scale value shown on the element
cap determines the power scale to be read.
Models 4201A503
and 4201A504
Operation of the Wattmeter using Power Sensors.
1. Make sure the power sensors are properly positioned and
directed in the transmission line
2. Turn the switch, or switches, to a channel that is connected
to the transmitter to be monitored. If applicable, press the
push button to enable.
3. Turn on the transmitter.
4. Read the actual power values directly on the meters. The
wattmeters have triple-range scales on both the forward and
reflected powers.
The Multi-Channel Wattmeter provides continuous, uninterrupted observation of the
RF transmission equipment’s performance. The advantage of simultaneous surveil-
lance of the meters is that the indication is always present without having to rotate
the Plug-In-Element to obtain forward or reflected power values. The forward/reverse
RF power ratio is readily calculated from the readings, and the VSWR may be
determined from figures 9 and 10.
Zero Adjust Screw Figure 8
Zero
Adjustment
Bird Series 4201 Multi-Channel RF Directional Wattmeter
10