Boonton 4530 Peak Power Meter Service Manual - Manual (Page 16)

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500K.
e. Connect the 2510 output to the 4530’s Sensor 1 (or 2) input using a CW SENSOR DATA ADAPTER.
f. Zero the channel as follows:
Pressing the Zero/CAL key.
Select the appropriate channel by pressing < or >.
Select Zero Chan and press Enter, and wait for the zeroing process to complete.
g. Set the 2510 Range to 6B and set its Output to ON.
h. Send “$DCCAL:R1:C1” to the 4530, (“…C2” for channel 2). Look for any error messages on the
4530.
i.
Set the 2510 Range to 4.
j.
Send “$DCCAL:R0:C1” to the 4530, (“…C2” for channel 2). Look for any error messages on the
4530.
k. Repeat steps (d) through (j) for channel 2 if the instrument is a 4532 (2 channel unit).
l.
Send “$DCCAL:SAVE” to the 4530 to save the new gain calibration coefficients for both channels.
m. Disconnect the 2510, remove power from the 4530, and reinstall the cover.
6) 50MHz Calibrator Calibration
It is recommended that the 4530 be returned annually to Boonton Electronics for calibration. If that is not
possible, the calibration accuracy of the 4530’s calibrator should be checked annually by performing the
checkout at the end of this procedure, or by an equivalent method traceable to NIST standards. If
calibration errors are noted, or if the calibrator has been replaced, the following procedure should be used
to store new coefficients into the 4530’s calibration memory. This procedure should be attempted only by
personnel with a strong knowledge of interconnecting bus communications and RF Power Measurements,
and only after carefully reading this entire procedure. DC Gain Calibration and Input Offset adjustment
procedures must be completed prior to this procedure. The 4530 should have its cover installed and be at
a stable operating temperature (within one degree Celsius) for a minimum of 30 minutes before this
calibration is performed.
This procedure may require communication with two or more instruments. If RS232 is used, it will be
necessary to use separate ports, or alternatively to enter commands manually from the keyboard on the
reference powermeter. Both the bus commands and the menu keystrokes are shown below.
Overview
This calibration technique uses a reference calibrator to generate precise power levels and a reference
powermeter operating in relative (ratiometric) mode to resolve the difference in power between the
reference calibrator’s output and the UUT at each calibration point. A coaxial switch is used to switch a
single RF power sensor between the two sources, and the reference powermeter is used to first measure
the reference signal, then the test signal, and display the difference in dBr. Once the output error in the
UUT is know, a new gain coefficient may be calculated. This process is repeated iteratively until the test
level is exactly equal to the reference level. In this manner, the calibration of the reference calibrator
(which should be NIST traceable) can be transferred to the UUT.
Test Setup