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ALIGNMENT
I - F S E C T I O N
Alignment of the I-F
system consists of optimizing the input and output networls
and balancing the detector output.
The bandpass and center frequency are established
by quartz crystal filters and "peaki.g" the coils can result in bandpass ripple or poor sensi-
tivity. Field alignment should rot be necesqan- but the procedure is given for general information.
E O U I P ME N T N E E D E D
Oscilloscope
Sweep generator with 10.79, 10.80
and l0.BlmHz markers
l.
Connect sweep generator to TP-l through a lpf capacitor.
2.
Connect oscilloscope to TP-2.
3.
Maintain output of tO.BmHz sweep generator at a low level
to prevent distortion from overloading.
4.
Adjust Tf and T2 for maximum output, and minimum
ripple. See Figure 2.
t o . 8 l
Figure 2
Figure 3
Connect scope to ;in TP-2 and adjust T3 so that l0.BmHz
is in center of discriminator curve and for best linearitv.
See ligure 3.
-{LTER\ATE
METHOD:
I-F
alignment may be checked using a Measurements
\lodel 800 Generator or equivalent tuned to an operating frequency and swept
+ 25kc.
\larkers are not essential since eenter frequency is determined by the filter.
R _ F S E C TIO N
DO NOT ATTEMPT ALIGNMENT OR "PEAKING'' OF R-F MODULES.
The R-F alignment points are adjusted and sealed at the factory and should not be
disturbed. Factory alignment involves multi-frequency signal generation systems, add-on
test modules, output indicators and training beyond the scope of normal service activities.
The unique R-F system inclurles electronic tracking of R-F and oscillator circuits for
maximum performance over a wide range of frequencies. THIS PERFORMANCE CAN BE
DESTROYED BY AN ATTEMPT TO "PEAK UP'' OR "TWEAK'' OR "OPTIMIZE'. ETC.
l o . 8
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