Anritsu 683XXB, 682XXB manual Calibration

	FM
CALIBRATION	CALIBRATION

4. Internal Unlocked Wide FM Mode Sensitivity calibration is accomplished by adjusting the FM Variable Gain Control DAC to obtain a 200 MHz FM deviation at frequencies of 5 GHz and

15 GHz. The modulating signal input is from the internal Function Generator.

Perform the calibration as follows:

a. At the $ prompt, type: calterm 143 and press <ENTER>.

The screen will display the following menu: 1) Toggle polarity (this lets you go from a

positive deviation to negative deviation.)

2) Change DAC value.

3) Quit.

b. On the Spectrum Analyzer, set the Span/Div to 50 MHz per division.

c. On the computer keyboard, enter 2 to begin calibration.

d. On the computer keyboard, use the ‘, 1, 2, and 3 keys to increment and the 7, 8, 9, and 0 keys to decrement the value of the DAC’s setting.

Start calibration by pressing the ‘ key.

e. While observing the Spectrum Analyzer dis- play, adjust the value of the DAC’s setting to obtain a 100 MHz change in frequency.

f. On the keyboard, press Q to return to the menu, then enter 1 to toggle the polarity.

g. Measure the change in frequency on the Spec- trum Analyzer. The change in frequency should be 200 MHz. If not, enter 2 and adjust the DAC.

h. Repeat steps 4.f and 4.g as necessary to obtain a 200 MHz frequency change. When finished adjusting the DAC, press Q to return to the menu.

i. On the Spectrum Analyzer, set the Span/Div to 5 MHz per division and adjust the center fre- quency control to position the high (or low) carrier at the center of the display. Note the frequency reading.

j. On the keyboard, enter 1 to toggle the polarity.

682XXB/683XXB MM 4-47