Boonton 4530 Series, Руководство по обслуживанию и калибровке

Страница: 19 / 38

BOONTON ELECTRONICS a WIRELESS TELECOM GROUP COMPANY
18
[Set Ref] means to place Meas4530 into reference (ratiometric) mode and load the current power level as
a reference. This process is detailed in step (j) below, and all other steps should use the same procedure.
Procedure Summary
The transfer calibration is performed in two steps. First, the variable output oscillator is calibrated. The
inherent linearity of the oscillator is quite good, so a two-point calibration is performed at a “full-scale”
point, and a “down-scale” point exactly 10dB below full-scale, which is the normal range switch point.
Then the step attenuator is calibrated with the oscillator at its full-scale level for each 10dB step. Each
point is calibrated using the reference transfer method, so final accuracy should be within several
thousandths of a dB for all but the lowest levels.
a. Connect the instruments as shown above, and allow 30 minutes warm up time with the cover installed
for the 4530 Unit Under Test ( UUT ), the 2520 and the optional reference 4530. All calibrator outputs
should be off.
b. Connect the test 4530 (
UUT
) and reference powermeter (
Meas4530
) to a terminal or host computer
using the serial port or GPIB interface, and verify proper communication. See 4530 Instruction
Manual for details on communication interfacing.
c. If a separate 4530 is used for the reference powermeter, AutoCal its 51075 CW sensor as follows:
Remove the sensor from the coaxial switch and connect it to the reference powermeter’s
calibrator output.
Pressing the
Zero/CAL key.
Select the appropriate channel by pressing < or > .
Select
AutoCal
and press
Enter
, and wait for the calibration sweep to complete.
Reconnect the sensor back to the output of the coaxial switch.
OR
Send “CAL1:INTERNAL:AUTOCAL” to the Meas4530 instead of the using the above keystrokes.
d. Configure the measurement and display settings on the Meas4530 :
Select
Main Menu > Channel 1 > Parameters > Filter time
4 secs
Select
Main Menu > Channel 1 > Parameters > Frequency
0.05GHz
Select Main Menu > Channel 1 > Display > Units Log-dBm
Select Main Menu > Channel 1 > Display > Display Source Sensor1
OR
Send “SENSE1:FILTER:TIME 4; CALC1:UNITS DBM” to the
Meas4530
Send “SENSE1:CORR:FREQ 0.05; CALC1:MODE CW; CALC1:MATH CH1” to the Meas4530
e. Display the current power reading (probably underrange) on Meas4530 as follows: Press the Text
key.
OR
Send “DISP:TXTB 1” to
Meas4530.
f. Send “SYSTEM:LANG BOON” to the
UUT.
g.
[Select UUT]
(select the Coaxial Switch Position for the UUT’s output).
h. Send “$CAL:DAC 50000; $CAL:ATTEN 0” to the
UUT. Meas4530
should display the output level of
the UUT s calibrator between 20.2 and 21.6 dBm. If no output is detected, the connections or one of
the configuration settings is most likely incorrect. Cycle power on the UUT and Meas4530 and begin
the procedure again. If there is output, but it is not within this range, the calibrator may require RF
alignment (see section above) or could be defective.
i. Set the 2520’s RF output to 0.0dBm & “ ON ”
Scans by Artekmedia => 2009