Checks and Adjustments

15.Adjust Span/Div Magnifier Range (R38 and R37)

16.Adjust Intensified Zone Range (R61 and R36)

17.Adjust Vertical Gain (R176, R239, R240, and R232)

18.Adjust 2 dB/Div Position (R140)

19.Adjust 590 MHz Notch (C69)

Long Form Procedure

Figure 5-7 shows the 1705A Spectrum Monitor internal adjustment locations.

PRELIMINARY SETUP

Connect the 1705A ac power cord to the variable autotransformer. Turn the 1705A power on. Set the front-panel controls to start this procedure as shown in Table 5-2.

Table 5- 2: Preliminary Control Settings

POWER

ON

 

 

INTENSITY

Set to Preference

 

 

FOCUS

 

 

 

SCALE

 

 

 

VERTICAL POSITION

Set later

 

 

HORIZONTAL POSITION

 

 

 

INPUT

70 MHz

 

 

RESOLUTION

300 kHz

 

 

VIDEO

ON

 

 

SPAN/DIV

FULL

 

 

CENTER FREQUENCY

anywhere

 

 

SWEEP SPEED

 

 

 

A1 POWER SUPPLY BOARD

(Refer to Figure 5-7 for adjustment locations.)

1.Adjust +5 V

a.Connect the DMM negative lead to TP1 (GND) and the positive lead to W1 (+5V).

b. ADJUST - R99 (+5V ADJ) for +5.0 V 0.5V.

5- 18

1705A Spectrum Monitor

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Tektronix 1705A instruction manual Preliminary Setup, Video SPAN/DIV Full Center Frequency