12
Chapter 4
Operating Instructions
Normal Operation
1.
Turn the element so that the arrow points towards the load to measure
forward 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
reading. 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
13
and
Figure
7 on page
14
. With these charts, VSWR may be determined
from the forward and reflected power readings. Find the intersection of the
forward 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.
