Tektronix 1705A User Manual

Page 110

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Checks and Adjustments

1705A Spectrum Monitor

5- 15

s.

CHECK

-- that the readout still reads 1000,

±10.

t.

Set SPAN/DIV to 1 MHz.

u. CHECK

-- that the marker is on screen. Position the marker under the

caret with the CENTER FREQUENCY control.

v.

CHECK

-- that the readout still reads 1000,

±10.

w.

Set SPAN/DIV to 100 kHz.

x.

CHECK

-- that the marker is on screen.

y.

Repeat steps m. through x., substituting 1700 MHz.

12. Check L--Band Gain and Flatness

REQUIREMENT

-- Flatness:

±5 dB (± from center (1400 MHz)).

Relative Amplitude Accuracy

±3 dB/100 MHz. (Typically ±1 dB/100

MHz.)

a.

Set SPAN/DIV to FULL.

b.

Set the 1705A SWEEP SPEED fully counterclockwise.

c.

Set the UHF signal generator Frequency to 1400 MHz and Amplitude to
--30 dBm. Position the tip of the marker to the --10 graticule reference
line (vertical scale).

d.

Change the UHF signal generator Frequency to 950 MHz.

e.

CHECK

-- that the marker is on the same crt center line (vertically),

±0.5 Division.

f.

Change the UHF signal generator Frequency to 1700 MHz.

g.

CHECK

-- that the marker is on the same crt line (vertically),

±0.5

Division.

h.

Set the UHF signal generator Frequency to 1400 MHz.

i.

Position tip of marker to crt center.

j.

CHECK

-- that the marker tip is on the --10 graticule reference line,

±0.5 Division. Note: Make sure that the baseline is on the --70
graticule reference line.

13. Check Positioning Range

REQUIREMENT

-- Vertical: + and --3 Divisions, Horizontal: + and --2

Divisions.

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