Boonton 4530 Peak Power Meter Service Manual - Manual (Page 13)

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2) Calibrator Signal Check
a. Press ON/STBY key on front panel. The instrument should power up with the calibrator off.
b. With the calibrator output still off, connect a spectrum analyzer with a 50 ohm input impedance to the
Calibrator connector. Scan from 1MHz to 1GHz for any signals above –80dBm.
c. Set the spectrum analyzer input to accept a signal of +20dBm without overloading, then turn on
calibrator and set for a 20dBm output level using the following key sequence:
Select Main Menu > Calibrator > IntSignal ON.
Select Main Menu > Calibrator > Int Level +20dBm
(Once the current level is highlighted, press > key to position an edit cursor on the desired digit,
then use the UP and DOWN keys to set for 20dBm. Press Enter to set level.)
d. With the spectrum analyzer, scan for carrier harmonics from 49.5MHz to 1GHz. The main carrier
should be at approximately 20dBm at 50MHz, and all harmonics must be at least 60dB below the
carrier (-60dBc, or –40dBm).
e. Set the analyzer for a narrow bandwidth, and perform a very slow scan the calibrator’s output from
49.5 to 50.5 MHz. Look for low frequency components being mixed with the 50MHz signal. These
components must be at least 60dB below the 50MHz signal (-60dBc, or –40dBm).
f. Select Main Menu > Calibrator > IntStatus to view the calibrator’s internal AGC signal. The A-to-D
value should be fairly stable between 100 and 210 counts, and the bargraph should move no more
than 1 pixel.
g. Turn off the calibrator with the following key sequence:
Select Main Menu > Calibrator > IntSignal OFF.
h. If any of the preceding steps fail, the following RF alignment should be attempted on the calibrator. If
this alignment cannot bring the calibrator back into spec, the entire instrument should be returned for
service. There is no need to perform RF alignment if all the above steps were completed
successfully.