TB 9-6625-1916-24
(3) Adjust signal generator and RF amplifier amplitude controls for a full-scale
reading on the TI.
(4) If the RF power meter does not indicate within 5 percent of the full-scale
reading on the applicable power range of the TI, perform b (1) and (2) below. Record the
exact reading if the TI is within tolerance.
(5) Turn the TI RANGE switch to another range and then return it to the range
under test. The power meter will continue to indicate within 5 percent of the reading
recorded in (4) above. Repeat this technique two times.
(6) Turn the TI RANGE switch to its highest range and rotate the coupler detector
to measure reflected power; then rotate it back to its original position and turn the RANGE
switch back to the range under test. The power meter continues to indicate within 5
percent of the reading recorded in (4) above.
(7) Adjust the signal generator frequency controls to each of the remaining
computed frequencies. The power meter will continue to indicate within 5 percent of the
reading in (4) above.
(8) Repeat (2) through (6) above for the remaining ranges.
b. Adjustments
(1) Adjust signal generator and RF amplifier output until the RF power meter
indicates the reading that should read full-scale on the TI.
(2) Adjust the coupler detector adjustment screw for a full-scale indication on the TI
9. Calibration of Termination Wattmeters Using 100 Watt RF Source
a. Performance Check
(1) Connect the equipment as shown in figure 2.
CAUTION
Due to the possibility of RF power amplifier spikes which may
cause equipment damage in the steps below, reduce signal
generator and RF amplifier outputs to minimum when signal
generator output frequency is changed.
NOTE
RF power meter sensors must be selected according to the
frequency under test.
(2) Compute the 10, 30, 50, 70 and 90% points of the frequency range. Set the TI
range control to the lowest range.
step (2) above.
