Checks and Adjustments

7.Adjust Readout Position

Display the DAC test pattern by completing parts a. through c.

a.Press both the 1705A SPAN/DIV buttons simultaneously to display the Main Menu.

b.Press either SPAN/DIV button to move the cursor to TEST, then press the INPUT button to display the TEST menu.

c.Press either SPAN/DIV button to move the cursor to DAC, then press the INPUT button to display the DAC test pattern.

d.ADJUST - R27 and R29 (HORIZ and VERT POSN READOUT) for a display crossing at the crt center.

e.Exit the DAC test pattern by first pressing the INPUT button to display the TEST menu.

f.Press either SPAN/DIV button to move the cursor to EXIT, then press the INPUT button twice to return to a normal display.

8.Adjust 360/119.8 MHz L.O.

NOTE. Use an insulated tool for the following adjustments.

a.Adjust the VERTICAL POSITION control so that the crt trace is on the -70 graticule reference line.

b.Connect the signal generator to J11 (480 MHz IF Input). Set the output Frequency for 489.7 MHz and the Amplitude to -40 dBm.

c.Select 300 kHz RESOLUTION.

d.Set C55 to full mesh, C69 to 1/8 mesh, and L4 to the top of the coil (three slug threads visible).

e.ADJUST - FL1 for maximum signal (three screws beginning at the outside adjustment screw). If no signal is present, adjust L4 down a few turns and then adjust FL1.

f.ADJUST - C55 for maximum signal. (C55 should peak at about 1/8 to 1/2 mesh.)

g.ADJUST - FL1, center and inside screws (do not readjust the outside screw), for maximum signal. (Less than one turn should be required.)

h.ADJUST - FL2 for maximum signal (three screws beginning at the back screw).

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1705A Spectrum Monitor

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Tektronix instruction manual 1705A Spectrum Monitor