Tektronix instruction manual 1705A Spectrum Monitor

Checks and Adjustments

6.Check Resolution Filter

REQUIREMENT - 300 kHz Filter Resolution 200 - 400 kHz. 10 kHz Filter Resolution 20 kHz or less. Filter through gain matches ±2 dB.

a.Adjust the leveled sine wave generator Amplitude for a 5 Division signal amplitude.

b.CHECK - that the marker width 0.6 Divisions down from the top of the signal is 3 Divisions, ±1 Division.

c.Change resolution to 10 kHz.

d.Set SWEEP SPEED fully counterclockwise.

e.CHECK - that the marker width 0.6 Divisions down from the top of the signal is ≤2 minor Divisions.

f.CHECK - that the 10 kHz marker amplitude matches the highest point of the 300 kHz marker amplitude within 1 minor Division, when switching between 300 KHZ and 10 KHZ RESOLUTION.

7.Check 70 MHz Gain and Flatness

REQUIREMENT - Incremental Amplitude Accuracy ±4 dB/70 MHz. Flatness ±1 minor Division from 70 MHz to either 50 or 90 MHz.

a.Set SPAN/DIV to FULL.

b.Set RESOLUTION to 300 kHz.

c.Set SWEEP SPEED fully clockwise.

d.Set the leveled sine wave generator Frequency to 70 MHz, the Ampli- tude Multiplier to X1, and the Amplitude to 0.5 (-2 dBm).

e.CHECK - for a marker amplitude change of 2 Divisions, ±2 minor Divisions when switching the leveled sine wave generator Amplitude Multiplier between 0.01 and 0.1 (a 20 dB change).

f.Set the leveled sine wave generator Amplitude Multiplier to 0.01 and Amplitude to 0.5 (-42 dBm).

g.Position the tip of the marker to exact crt center with the HORIZONTAL and VERTICAL POSITION controls.

h.Set the leveled sine wave generator Frequency to 50 MHz.

i.CHECK - that the tip of the marker is on the crt center line, ±1 minor Division (vertically).

j.Set the leveled sine wave generator Frequency to 90 MHz.

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