Performance Check— Type 1L30
the vertical location o f the —6d B points, switch in an ad
ditional 6 dB of IF ATTEN and note the position of the top
of the display. Then remove the 6d B of attenuation, and
note the points where the rising and falling portions of the
display cross the 6 dB level. The crossing points should be
separated horizontally by at least 2 cm, indicating —6 dB
resolution bandwidth of at least 100 kHz. See Fig. 5-3A.
f. Change the RESOLUTION control to the 1 kHz posi
tion (fully counterclockwise) and the DISPERSION to 1 kHz/
cm keeping the 200 M Hz signal centered on screen with the
IF CENTER FREQ controls.
g. Check the resolution bandwidth at the — 6dB ampli
tude point. Bandwidth must not exceed 1 kHz. See Fig.
5-3B.
Fig. 5-3. Display pattern when resolution is correctly adjusted.
h.
Return the RESOLUTION to the coupled position and
set the DISPERSION-COUPLED RESOLUTION controls to
500kHz/cm position.
4. Check Dispersion Accuracy of k H z/C M
Ranges
a. Requirement— Accuracy must equal or exceed ± 3 % .
b. Apply 10 ns and 1 /is markers from the Time-Mark Gen
erator through a 40 dB attenuator (2, 1 0 X Attenuators)
lo the RF INPUT connector.
5-4
c. Change the VERTICAL DISPLAY switch to the LIN posi
tion (Sweep rate 20 ms/cm or slower).
d. Check the range of the IF CENTER FREQ control. Fre
quency range must equal or exceed + and — 2.5 M H z from
its centered (000) position.
e. Center the IF CENTER FREQ controls. Set the DIS
PERSION selector to 50 kHz/cm.
f. Depress the 10 ns and 10 /is Marker Selector buttons
on the Time-Mark Generator.
g. Check the range of the IF CENTER FREQ-FINE con
trol. Frequency range must equal or exceed + and — 50
kHz from the centered position.
h. Set the DISPERSION selector to the 500 kHz position
and center the IF CENTER FREQ controls. Apply 10 ns and
1 /
as
time-markers to the RF INPUT.
i. Check dispersion accuracy over a + and — 2.5 M H z
change in the IF center frequency, at the DISPERSION se
lector positions listed in Table 5-2.
Dispersion accuracy must remain within ± 3 % (2.4 mm)
for all DISPERSION settings and through - f and — 2.5
M H z change in the IF center frequency.
As the dispersion is decreased, the sweep time should
be increased (slower sweep rate) to maintain optimum dis
play resolution. • Uncouple the RESOLUTION control and
adjust for optimum time-marker definition. Turn the VIDEO
FILTER switch to the O N position at the slower rates to
improve marker definition.
j. Turn the VIDEO FILTER switch to OFF.
TABLE 5 -2
DISPERSION
k H z/c m
T i m e - M a r k
G e n e r a t o r
M a r k e r S e l e c t o r
D i s p l a y s in
c e n t i m e t e r s
p e r m a r k e r
5 0 0
1 0 ns a n d 1 /
as
2
200
1 0 ns a n d 5 /
as
1
100
1 0 ns a n d 1 0 /
as
1
5 0
1 0 ns a n d 1 0 /
as
2
20
1 0 ns a n d 5 0 /
as
1
10
1 0 ns a n d .1 ms
1
5
1 0 ns a n d .1 ms
2
2
1 0 ns a n d .5 ms
1
1
1 0 ns a n d 1 ms
1
5. Check Operation of Video Filter
a. Requirement— Filter should restrict the video band
width and reduce high frequency video components such
as noise when viewing signals near minimum resolution
bandwidth.
b. Apply 10 ns and 1 0
/
a s
markers from the Time-Mark
Generator through a 40 dB attenuator to the RF INPUT
connector.
c. Set the front panel conrtols as follows:
©
Summary of Contents for 1L30
Page 48: ...si L i y n Maintenance Type 1L30 Fig 4 15 Honeycomb assembly drcui a n d component layout 4 n ...
Page 59: ...Fig 6 1 A Test equipment required for calibration ...
Page 60: ... Calibration Type 1130 ...
Page 120: ...T Y P E I L 3 0 S P E C T R U M A N A L Y Z E R ib i IF SYSTEM BLOCK DIAGRAM 9 1 9 2 ...
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