8.LO Distribution Amplifier Adjustment

15.On the HP 85623, press LCAL), MORE I OF 2, SERVICE CAL DATA, LO LEVELS, and

INT LO LEVEL. The message DRIVE FOR BAND# 1 will be displayed.

16.Note the “Bl INT Sense” voltage printed on the A7 LO distribution amp label. Use the knob or keypad, and press enter, to change the displayed DAC value so the DVM reading is 6 mV more negative than the label voltage. For example, if the “Bl INT Sense” voltage is -170 mV, change the displayed DAC value so the DVM reading is -176 mV.

17.Record the DAC value:

DAC value for 4.60 GHz =

18.To set the band 2 sense voltage, set the HP 85623 center frequency to 9.46 GHz.

19.On the HP 85623, press (CAL), MDRE I OF 2, SERVICE CAL DATA, LO LEVELS, and

INT LO LEVEL. The message DRIVE FOR BAND# 2 will be displayed.

20.Note the “B2 INT Sense” voltage printed on the A7 LO distribution amp label. Use the knob or keypad, and press enter, to change the displayed DAC value so the DVM reading is 6 mV more negative than the label voltage. For example, if the “B2 INT Sense” voltage is - 170 mV, change the displayed DAC value so the DVM reading is - 176 mV.

21.Set the “Sense EXT” value by pressing EXT LO LEVEL .

22.Use the knob or keypad to enter the DAC value for 1.45 GHz from the band 0 sense voltage adjustment above.

23.Save the adjustment values by pressing PREtV MENU, STORE DATA, and YES.

24.Move the jumper on A2J12 from WR ENA back to the WR PROT position.

2-42 Adjustment Procedures

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Agilent Technologies 856290216 service manual DAC value for 4.60 GHz =