Fractional-N Spur Adjustment - Agilent Technologies 8711C Service Manual

Fractional-N Spur Adjustment

Note
he fractional-N spur adjustment is not normally required. If this board has
been replaced, the replacement board will have been adjusted at the factory.
his adjustment should only be performed if you have reason to believe that
the fractional-N VCO assembly is generating spurious responses.
his adjustment minimizes the spurs caused by the analog phase interpolators (APIs) on the
fractional-N board assembly. An external controller sets the source output frequencies on the
analyzer and sets up the spectrum analyzer to measure the spur. Afterwards, you can adjust
potentiometers to minimize the spur.
equired Equipment
Equipment
escription
HP B SIC controller w/B SIC 5.0
or higher
Test software
Spectrum analyzer
Type-N cable
Minimum loss pad
Service extender board
Note
Before performing this adjustment:
Check the voltage at A3 P11 as described in the previous adjustment
(\Fractional-N VCO Adjustment") and adjust as required.
Warmup Time
Allow the analyzer to warm up for one hour.
stimated Adjustment Time
his adjustment takes approximately fteen minutes to perform.
Procedure
1. If you already have the fractional-N board assembly out of the analyzer and attached to
the service board extender, continue with step 4. If not, continue with the next step.
Recommended Model or Part Number
50
HP 9000 series 200/300/700
08712-10017
HP 8560 Series or HP 8566B
any 50
N/
p/o service kit, 08712-60012
75
HP 9000 series 200/300/700
08712-10017
HP 8560 Series or HP 8566B
any 75
HP 11852B
p/o service kit, 08712-60012
Adjustments 2-7