HP 8753D Option 011 Service Manual page 124

How to Set Up the High/Low Band Transition Adjustments
1. ress
EQ X HBLBADJ
PRESET 5
2. Observe the VCO tuning trace:
If the left half of trace = 0 1000 mV and right half of the trace = 100 to 200 mV higher
(one to two divisions), no adjustment is necessary.
If the adjustment is necessary, follow these steps:
a. Remove the upper-rear bumpers and top cover, using a torx screwdriver.
b. Adjust the VCO tune (A12 C85) to position the left half of the trace to 0 125 mV.
This is a very sensitive adjustment where the trace could easily go o of the screen.
c. Adjust the HBLB (A12 R68) to position the right half of the trace 125 to 175 mV
(about 1 to 1.5 divisions) higher than the left half.
Refer to \Source Troubleshooting" if you cannot perform the adjustment.
How to Set Up the Fractional-N Spur Avoidance and FM Sideband
Adjustment
1. ress
EQUENCE X APIADJ
PRESET 5
2. Remove the upper-rear corner bumpers and the top cover, using a torx screwdriver.
3. Follow the directions on the analyzer display and make all of the A I adjustments.
Sequence Contents
Sequence for the High/Low Band Transition Adjustment
|Sequence HBLBADJ sets the hi-band to low-band switch point.|
RESET
SYSTEM
SERVICE MENU
ANALOG BUS ON
START 11 M/u
STO 21 M/u
MEAS
ANALOG IN 22 x1 (A12 GND)
DIS LAY
DATA MEM
>
DATA - MEM
MEAS
ANALOG IN 23 x1 (VCO TUNE)
MKR 11 M/u
RAFT
3/21/106 15:11
Artisan Scientific - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisan-scientific.com
(where X is the sequence number).
(where X is the sequence number).
Adjustments and Correction Constants 3-59