Tektronix 1L40, Instruction Manual

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Operating Instructions— Type 1L40
IF ATTEN dB
IF CENTER FREQ
FINE
POS
VIDEO FILTER
VERTICAL DISPLAY
G A IN
FINE RF CENTER FREQ
INT REF FREQ
MIXER PEAKING
All switches in OFF position
Centered (000)
Midrange
Centered
OFF
LIN
CCW
Centered
OFF OR EXT REF FREQ IN
CCW
Plug-in Oscilloscope
Time/Cm 5 ms
Triggering Adjusted for a free
running sweep
1. Turn the Intensity control clockwise until a trace is
visible, then adjust the Focus and Astigmatism controls for
optimum trace definition.
2. Position the trace to the horizontal center and to the
bottom line of the graticule with the Position controls.
3. Adjust the Scale Ilium control for the desired graticule
illumination.
4. Using a signal generator, apply a low amplitude
signal (between — 60 and— 30 dBm) within the frequency
range of the instrument to the Coaxial or W aveguide Mixer.
5. Adjust the G A IN control for a moderate noise level
(0.5 cm) on the display, then rotate the RF CENTER FREQ
control through the dial range. Note the rate and direction
of movement (left to right or right to left) of the signals
across the screen.
6. Tune the dial to the frequency of the applied input
RF signal.
7. Adjust the MIXER PEAKING control for optimum signal
amplitudes.
8. Adjust the G A IN a n d /o r IF ATTEN dB switches for a
signal amplitude on the display of approximately 4 centi­
meters.
9. Tune the signal to the extreme left graticule line with
the RF CENTER FREQ control. Note the dial reading. Tune
the signal to the extreme right graticule line and note the
dial reading. The difference between dial readings is the
total dispersion window for this 10 centimeter display. Tune
the signal to the center of the screen and switch th DISPER­
SION-COUPLED RESOLUTION selector to the 5M H z/cm
position. It should decrease to ’/ 2 the total dispersion
noted with the DISPERSION selector in the lO M H z/cm posi­
tion. Tune the signal to the center of the screen.
10. Tune the IF CENTER FREQ control through its range.
Note that all signals move across the screen in the same
direction and the same amount. This control w ill shift the
IF center frequency approximately
and —25 MHz with
the DISPERSION controls set to 5M H z/cm . Tune the IF
CENTER FREQ control to its centered (000) position.
11. Change the DISPERSION selector to .5M Hz/cm posi­
tion. Adjust the FINE IF CENTER FREQ control. Note the
frequency range of this control. This control w ill shift the
IF center frequency approximately -f- or — 1 MHz with the
DISPERSION selector set to ,5M H z/cm position.
12. Switch the plug-in oscilloscope Time/Cm switch
between the .1 s and .1 ms positions. Note the change in
signal amplitude and the resolution. Return the Time/Cm
selector to the 5 ms position
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