Agilent Technologies 8360 L Series, Service Manual

Page: 117 / 603

7. External Lev eling
Description and Procedure
The syn thesizer is set up to externally lev el using a negative crystal detector. A D VM
measures the crystal detector DC output. A 1000 pf capacitor across the D VM input limits
the eect of an y small signals generated b y the D VM. The syn thesizer p o w er lev el is set to the
minimum allo w able limit and then is increased un til the p o w er output is lev eled. The external
lev eling v oltage is then measured and compared to the minimum sp ecication. Next, the
output p o w er is increased un til the maxim um lev eled p o w er is reac hed. The lev eling v oltage is
measured and compared to the sp ecication.
The v oltage , not the p o w er lev el , is what is imp ortant in p erforming this test.
If y ou ha v e problems ac hieving the sp ecied v oltages in this test, y ou may place a pad in the
RF path b efore the crystal detector or the coupling factors may b e c hanged to ac hiev e the
sp ecied v oltages.
Note
The syn thesizer m ust meet the p o w er atness sp ecication b efore pro ceeding
with this test.
1. Preset all instrumen ts sho wn in Figure 2-8 and let them w arm up for at least one hour.
Figure 2-8. External Lev eling T est Setup
Equipment
Digital V oltmeter HP/Agilent 3456A
Crystal Detector HP/Agilent 33330E (83640B /L and 83650B/L)
Crystal Detector HP/Agilent 33330D (83620B/22B/24B,
83623B/L, and 83630B/L)
Capacitor 1000 pf P/N 0160-4574
2. T o ac hiev e p eak p o w er, initiate auto tracking on the syn thesizer as follo ws: terminate the
RF output with a go o d 50 imp edance match suc h as a 10 dB attenuator or a p o w er
sensor (not necessary for syn thesizers with a step attenuator). Press:
4 USER CAL 5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
Tracking Menu
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
Auto Track (asterisk on)
W ait for the syn thesizer to complete auto tracking b efore con tinuing to the next step.
2-30 P erformance T ests
External Lev eling
Agilent 8360