Tektronix 1L30, Instruction Manual

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Operating Instructions'— Type ;-..ZQ
A. Narrow pulse width produces wide spectrum lobes. Low pulse repetition frequency produces low repetition rote Sins density.
B. Wide pulse width produces narrow spectrum lobes.
C. High pulse repetition frequency produces high line density.
Fig. 2-17. Pulse width and PRF effects on pulse modulated spectrum.
change of the dial scale as the RF center frequency is
changed.
Higher order modulation or intermodulation produces
spurri that are tunable, but their rate and amount of move­
ment across the dispersion window, as the RF center frequency
is tuned, is nbt coincident'with the dial scale reading.
Most of the spurious signals described, with the exception
of intermodulation products, can be reduced or eliminated .by
the use of external bandpass filters.
APPLICATIONS
These basic applications for the Type 1L30 Spectrum An­
alyzer are a few examples of its use and are presented to
familiarize you with its operation.
Relative Amplitude Measurements
The relative amplitudes between signals are measured as
follows:
1. Center the IF CENTER FREQ controls, then type the
signal with the lowest amplitude to the center of the screen
with the RF CENTER FREQ control.
2. W ith no IF ATTEN switched on, adjust the G A IN con­
trol so the low amplitude signal establishes some reference
amplitude.
3. Tune the stronger signal to the center of the display.
Add IF attenuation by switching in combinations of IF ATTEN
dB switches; until the stronger signal amplitude decreases to’
the same reference amplitude established in step 2.
4. The total dB attenucfion switched on is the-relative am ­
plitude difference, in dB, between the two compared signals.
NO TE
For maximum accuracy, the signals should be refer­
enced and compared near the same location on the dis-
, play. Tune each signal to the reference with the RF
CENTER FREQ control.
The IF CENTER FREQ, the DISPERSION-COUPLED
RESOLUTION, th e FINE RF CENTER FREQ, and the
T im e/C m controls should not be adjusted when
measuring relative signal am plitud e.
Frequency Measurements
Frequency measurements taken from the RF CENTER FREQ
dial are accurate to within ± (2 M Hz - f 1 % of the dial
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