Bird Technologies 4304A - Manual (Page 24)

13
Chapter 4 Operating Instructions
Normal Operation
1. Turn the element so that the arrow points towards the load to measure for-
ward power.
2. Turn it so that the arrow points towards the source to measure reflected
power.
3. Set the range switch to 500 W.
4. Turn on the RF source.
5. Read the power using the scale with 500 W full-scale.
Note: For greater accuracy, after estimating the power with 500W full-
scale, set the range switch so the power is in the upper third of the scale.
Low Frequency
For frequencies below 100 MHz, a correction factor must be applied to the read-
ing. The correction table is located on the back cover plate of the unit. Multiply
the measured power by the correction factor to determine the actual power.
VSWR Measurements
For your convenience, a set of VSWR conversion nomographs in Figure 6 on
page 14 and Figure 7 on page 15. With these charts, VSWR may be determined
from the forward and reflected power readings. Find the intersection of the for-
ward and reflected power measurements. The slanted line passing closest to this
point indicates the VSWR.
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.
CAUTION
Above 800 MHz, do not exceed 150 W RF power.
CAUTION
RF power must not exceed range switch setting.