Fig. 6-26. Wide band IF am plifier and 1st mixer adjustments for
response flatness.
This procedure does not require a sweep generator to check
flatness; however, if a sweep generator such as the Kay Model
121C is available it may be used.
a. Equipment setup is shown in Fig. 6-25.
b. Disconnect the Sealectro connector from J120 on the
honeycomb assembly and apply a calibrated 65 M Hz sig-
nel (— 30 dBm] from the Signal Generator through a 20 dB
attenuator and Sealectro to GR adapter such as a P6040
cable to J120.
Calibration— Type 1L30
e. Remove the Signal Generator connection so the Seal
ectro connector on the honeycomb assembly. Reconnect the
honeycomb cable to J120.
f. Apply a frequency and amplitude calibrated signal
(— 30 dBm) within the frequency range of the Type 1L30
through a 20 dB attenuator to the RF INPUT connector.
g. Set the DISPERSION to lO M H z/cm . Tune the RF center
frequency to the applied signal frequency. Adjust the MIXER
PEAKING control for maximum signal amplitude. Adjust the
G A IN an d /o r the Variable Attenuator of the Signal G en
erator for a signal amplitude of 4 centimeters.
h. Check the response flatness over the 100 M Hz disper
sion by tuning the RF CENTER FREQ or the Signal Generator
frequency over the frequency width of the dispersion window.
Signal amplitude should not vary over ± 1 . 5 dB (3 dB total)
with a constant amplitude input signal to the RF INPUT con
nector.
i. If the response flatness is not within tolerance, adjust
C l 37 and L I34 (Fig. 6-26) for maximum sensitivity and an
alyzer response flatness. Adjusting C l37 will usually produce
a noticeable effect on the response slope. Adjust LI 34 for
optimum' sensitivity at the high frequency portion of the IF
response.
j. Check the display flatness over the frequency range of
the instrument as follows:
NOTE
Each time the Signal Generator frequency is
changed it will be necessary to recalibrate the
output amplitude and after each major change
(1 0 0 MHz or better) of the RF CENTER FREQ, it
will be necessary to readjust the MIXER PEAKING
for maximum signal amplitude.
(1) Set the front panel controls as follows:
RF CENTER FREQ
975 M Hz
DISPERSION RANGE
M Hz
DISPERSION-COUPLED
lO M H z/c m
RESOLUTION
IF ATTEN dB
20
VERTICAL DISPLAY
LIN
(2) Apply the signal frequency listed in Table 6-4 from
the Signal Generator through a 20 dB attenuator (Part No.
011-0086-00) to the RF INPUT connector.
NOTE
t
%
c-. Switch in the 20 dB ATTEN selector. Adjust the output
of the Signal Generator for an approximate vertical DC shift
of 1 cm in the trace.
Do not use the 1 0 X attenuator Part No. O i l -
0 0 5 9 -0 0 to check flatness or sensitivity at these
d. Adjust LI 47 (Fig. 6-26) the. 65 M Hz trap, for minimum
response to the 65 M H z signal. This will be indicated by a
decrease in the vertical displacement of the plug-in oscillo
scope trace.
(3) Tune the Type 1L30 to the frequency of the applied
signal and adjust the MIXER PEAKING control for maximum
signal amplitude, then adjust the Signal Generator output
control and the Type 1L30 G A IN control for a signal am-
©
6 -25
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I.
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Содержание 1L30
Страница 48: ...si L i y n Maintenance Type 1L30 Fig 4 15 Honeycomb assembly drcui a n d component layout 4 n ...
Страница 59: ...Fig 6 1 A Test equipment required for calibration ...
Страница 60: ... Calibration Type 1130 ...
Страница 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 ...
Страница 127: ......