ADJUSTMENTS

5-25. FIRST CONVERTER ADJUSTMENTS(SERIAL PREFIX 2236A)

REFERENCE:

A3, A4, AS, A6, and A7 Schematics

DESCRIPTION:

The First LO (A6 YTO) is adjusted by monitoring the YTO output at the RF input connector (LO feedthrough) and the tuning voltage(TUNE)output of the A7 Frequency Control board and adjusting the YTO low-end frequency for 3 GHz at OV tuning voltage and 6 GHz at - 10Vtuning voltage.

The FM Driver is adjusted by inputting comb signals to the analyzer and adjusting for proper spacing (span linearity)of displayed signals on the CRT display.

 

 

 

 

 

 

COMB

DISPLAY

 

DIGITAL VOLTMETER

FREQUENCYCOUNTER

GENERATOR

 

 

 

 

 

INPUT I

I

 

 

 

 

P

 

OUTPUT

EXTENDER

Al6TPl

 

 

 

 

 

CABLE

LOCATED

 

 

A7TP4

 

 

ASSEMBLY

THROUGH

 

 

TUNE

 

 

HOLEIN

/ \

 

 

 

SIDE FRAME

.fq

 

 

 

HERE

-

:%?: SPECTRUM

 

 

 

 

;((9

io)'(i3 ANALYZER

 

 

 

 

, , , , o r ,

,,.,-*fd

 

 

INPUT

FIGURE511. FIRSTCONVERTER ADJUSTMENTSTEST SETUP

EQUIPMENT:

 

FrequencyCounter .......................................................

HP5340A

Digital Voltmeter (DVM) ..................................................

HP 3490A

Comb Generator ........................................................

HP 8406A

PROCEDURE:

1.Allow one-half hour warmup time of equipment with analyzer connected to mainframe with extender cable.

First LO Adjustments

2.Connect DVM to A7TP4TUNE.

3.Set analyzer controlsas follows:

INPUT ATTEN ..............................................................

0 dB

FREQ SPAN/DIV .........................................................

0 (zero)

ALTIF .................................................................

OFF(out)