Tektronix 1L20, Инструкция по эксплуатации

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Performance Check— Type 1L20
TABLE 5 -3
DISPERSION/CM
M o d u la tio n
Signal
CRT D isplay in
D iv is io n s /M a rk e r
Maximum
Error Notes
10 MHz .1 [x S (10 MHz)
1
± 3%
At IF CENTER FREQ con­
trol center
5 MHz .1 n S (10 MHz) 2
± 3%
2 MHz .5 iiS (2 MHz) 1
± 5%
Over range of IF CENTER
FREQ control (± 2 5 MHz)
1 MHz 1 fiS (1 MHz) 1
± 7%
.5 MHz 1 n S (1 MHz) 2
± 1 0 %
.2 MHz 5 ix S (200 kHz) 1 ± 1 5 %
500 kHz 1 [xS (1 MHz) 2
± 3%
200 kHz
5 fx S (200 kHz)
1
100 kHz 10 JU.S (100 kHz) 1
50 kHz
10 fxS (100 kHz)
2
20 kHz 50 [xS (20 kHz) 1
10 kHz .1 mS (10 kHz) 1
5 kHz .1 mS (10 kHz) 2
2 kHz
.5 mS (2 kHz)
1
1 kHz 1 mS (1 kHz) 1
4. Set the Modulator's controls as follows: Modu Freq
2 to On, 60 MC Trap to Out, and the two Variable con­
trols to the settings giving the most readable display.
e. Adjust the Analyzer’s G A IN control for a display about
5 centimeters high.
f. Use Table 5-3 to check the dispersion accuracy at each
DISPERSION/CM setting. Position a modulation pip at the
first graticule line and check the ninth pip displacement from
the ninth graticule line for displays having 1 division/marker;
if the display has 2 divisions/marker, check the fifth marker
displacement from the ninth line (see Fig. 5-4).
g. If the dispersion accuracy is out of tolerance, the instru­
ment should be recalibrated as directed in Section 6.
b. Set the IF CENTER FREQ controls to midrange.
c. A t each DISPERSION/CM setting of Table 5-3, readjust
the DISP CAL adjustment to align the correct markers with
the first and ninth graticule lines (see Fig. 5-5). (The IF CEN­
TER FREQ controls may be moved slightly away from center
to position a marker at the first graticule line.)
d. All markers between the first and ninth graticule lines
should be within 2.4 millimeters of the appropriate graticule
lines.
13. Dynamic Range Check
a. Preset the controls of the Spectrum Analyzer as follows:
POS
IF ATTEN
IF CENTER FREQ
DISPERSION RANGE
DISPERSION-
COUPLED RESOLUTION
VIDEO FILTER
VERTICAL DISPLAY
RF INPUT
Position the trace to the
bottom of the graticule
ALL OFF
Midrange
M H z/C M
1
O ff (Down)
LOG
BANDS 2-5
b. A pply a —40 dBm 200 MHz signal from the UHF Signal
Generator to the BANDS 2-5 RF INPUT connector.
c. Adjust the G AIN control of the Analyzer for 6 centi­
meters of signal deflection.
Fig. 5-5. Display for Dispersion Linearity check (Step 1 2 ).
d. Add 40 dB of IF ATTEN. (Set the 20 dB, 16dB, and
4 dB switches to On.)
12. Dispersion Linearity Check
a. Set up the equipment as directed in Steps 11a through
1 I f (above).
e. Check that the signal is just discernible.
f. Set the VERTICAL DISPLAY switch to LIN and switch
all the IF ATTEN switches back to OFF.
5 -6