HP 8559A GHz, 5-17. POWER SUPPLY CHECKS AND ADJUSTMENTS(SERIAL PREFIX 2236A)

ADJUSTMENTS

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5-17.POWER SUPPLY CHECKS AND ADJUSTMENTS(SERIAL PREFIX 2236A)

REFERENCE:

A7, A8, A9 Schematics

DESCRIPTION:

The + 14.5V and - 10Vsupplies on Frequency Control Assembly A7 are adjusted. The - 12.OV supply on A7 is checked for proper dc output with less than +50 mV variation when tuning the HP 8559Afrom 0 to 3 GHz. The + 10.OV supply on Sweep Generator/Bandwidth Control Assembly A9 is adjusted and the VO (Varactor Offset) voltage on Marker Assembly A8 is adjusted. The + 10.OV supply and VO voltage must be adjusted during the first five minutes after the spectrum analyzer is turned on (cold instrument). However, the + 14.5V and - 10.OV supplies must be adjusted first.

DISPLAY . DIGITAL VOLTMETER .

SPECTRUM

EXTENDER

ASSEMBLY

FIGURE51. POWER SUPPLYCHECKS ANDADJUSTMENTSTESTSETUP

EQUIPMENT:

Digital Voltmeter .................................................,...... HP 349OA

PROCEDURE:

1.Connect equipment as shown in Figure 5-1. Install Frequency Control Assembly A7 on extender board and connect digital voltmeter to A7TP3 + 14.5y

2.Adjust A7R52 + 14.5Vadjustment for a voltmeter indication of + 14.500 k 0.002 volts.

3.Connect digital voltmeter to A7TP2 and adjust A7R55 - 10V adjustment for a voltmeter indication of

-10.000 *0.005 volts.

4.Check for -12.0 *0.1V at collector (base)of A7Ql.

5.Select FREQUENCY BAND GHz .01- 3 and tune from 0 to 3 while monitoring the -12V at collector of A7Q1. The -12V supply should not vary more than *50 mY