Checks and Adjustments
5- 22
1705A Spectrum Monitor
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).
Summary of Contents for 1705A
Page 13: ...Service Safety Summary xii 1705A Spectrum Monitor ...
Page 17: ...Preface xvi 1705A Spectrum Monitor ...
Page 18: ...Introduction ...
Page 19: ......
Page 38: ...Operating Instructions ...
Page 39: ......
Page 61: ......
Page 62: ...Installation ...
Page 63: ......
Page 72: ...Theory of Operation ...
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Page 93: ...Theory of Operation 4 20 1705A Spectrum Monitor ...
Page 94: ...Checks and Adjustments ...
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Page 123: ...Checks and Adjustments 5 28 1705A Spectrum Monitor ...
Page 124: ...Maintenance ...
Page 154: ...Options ...
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Page 158: ...Replaceable Electrical Parts ...
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Page 189: ...Replaceable Electrical Parts 8 30 1705A Spectrum Monitor ...
Page 190: ...Diagrams Circuit Board Illustrations ...
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Page 214: ...Replaceable Mechanical Parts ...
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