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Checks and Adjustments
1705A Spectrum Monitor
5- 27
e.
ADJUST
-- R239 (IF AGC) for maximum signal amplitude.
f.
ADJUST
-- R240 (RF AGC) so the signal is one major Division (
±
0.5
major Divisions) down from the top graticule line.
g.
ADJUST
-- R232 to its midpoint.
18. Adjust 2 dB/Div Position
a.
Disconnect the signal from the L--BAND INPUT.
b.
Turn VERTICAL POSITION fully clockwise.
c.
Hold the VIDEO push button down until 2 dB/Div appears on the crt
readout.
d. ADJUST
-- R140 to position the noise floor to center screen.
e.
Hold the VIDEO push button down again to exit the 2 dB/Div mode.
19. Adjust 590 MHz Notch
a.
Select L--BAND INPUT and set the SPAN/DIV to 10 MHz.
b.
Connect the signal generator to the L--BAND INPUT.
c.
Set the signal generator Frequency to 1200 MHz, and Amplitude to
--20 dBm.
d.
Use the HORIZONTAL POSITION control to place the 1200 MHz
signal at the extreme left graticule mark. A small spur should be visible
near the extreme right graticule mark. Note: R240, RF AGC, may be
adjusted to ease visibility of the spur. Be sure to reset R240 (step 17
part f.).
e.
ADJUST
-- C69 carefully until spur is minimized. Note: While
adjusting C69, note the 1200 MHz amplitude. The spur should be
minimized without reducing the 1200 MHz spike by more than 2 dB.
End of Adjustment Procedure
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 ...
Page 95: ......
Page 123: ...Checks and Adjustments 5 28 1705A Spectrum Monitor ...
Page 124: ...Maintenance ...
Page 154: ...Options ...
Page 155: ......
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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