Harris Atlas DVL1100, Техническое руководство

Страница: 154 / 180

5-8 888-2473-001 2/25/03
WARNING: Disconnect primary power prior to servicing.
Section 5 Maintenance and Alignments ATLAS Series™
5.5.1 Forward Power Calibration
This procedure is used to calibrate the output sample from the precision forward
power directional couplers to display the correct power level on the GUI.
STEP 1
Remove the sample cable from the directional coupler to be
calibrated.
STEP 2
Connect the digital power meter probe to the coupler and set the
offset to that printed on the coupler. Measure and write down the
power reading.
STEP 3
Go to the Output Setup screen shown in Figure 5-5. Press the button
for the coupler just measured in the previous step. The Total System
Forward power button is pressed in Figure 5-5.
STEP 4
Use the Calibration (+/-) buttons to set the GUI reading (to the left of
the on screen button) the same as the measured reading.
STEP 5
Press the SAVE button to store the calibration setting.
5.5.2 Reflected Power Calibration
The forward power calibration should be done before the reflected power is
calibrated, since the forward sample is used to calibrate this reading.
STEP 1
Drop the forward power to 80% of nominal.
STEP 2
Place a 10dB pad in series with the forward power sample. Make
sure the forward power reading drops to 10% or 1/10 of normal and
note this level.
STEP 3
On the Output Setup screen, press the button for the coupler to be
calibrated (PA Cabinet Reflected or Total Power Reflected)
STEP 4
Connect the reflected sample cable to the 10dB attenuator (which is
still attached to the forward sample).
STEP 5
Use the Calibration (+/-) buttons to set the GUI reading (to the left of
the on screen button) the same as the measured reading of 10% of
the forward power.
STEP 6
Press the SAVE button to store the calibration setting.
STEP 7
Remove the 10dB attenuator and replace the sample cables. The
forward power should read normal and the reflected should be very
low.
STEP 8
Raise the forward power back to the nominal level or 100%.