Bird Technologies 4527 - Manual (Page 25)

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Chapter 4 Operating Instructions
The Bird 43 uses plug-in elements to make measurements. The element’s fre-
quency range and maximum power are listed on its label. The transmitter test
frequency should be within the band of the element used. See "Frequency
Response" on page 9 for information on using the elements outside of their
specified frequency range.
The arrow on the element indicates directional sensitivity; i.e., the direction of
power flow that the meter will read. Rotate the element to select forward or
reverse power measurement.
Combining the Thruline Wattmeter with a Bird Termaline Load Resistor creates an
accurate absorption wattmeter. With this combination, readings only need to be
taken in the forward direction because the reflected power will be negligible.
Normal Operation
1. Insert the appropriate element in the line section socket.
2. Turn the element so that the arrow points towards the load to measure for-
ward power and towards the source for reflected power.
3. Turn on the RF source.
4. Read the power using the scale whose full-scale marking matches the ele-
ment’s maximum power.
WARNING
When working with RF powers of 200 watts or more, the potential of the
center conductor of the line section will exceed 100 volts. Do not touch the
center conductor while RF power is on.