Axcera INNOVATOR, Инструкция по эксплуатации

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UHF Analog Driver/Transmitter/ Chapter 5, Detailed Alignment Procedures
Translator
LX Series, Rev. 3 5-8
Figure 5-2. Bandpass Filter
5.4 (A10) UHF Trap Filter Assembly
The Traps on the output Trap Filter are
labeled with their Center Frequency
relative to the Frequency of the Carrier.
(For Example: The Traps labeled -4.5
MHz are tuned for a Center Frequency of
4.5 MHz Lower than the Frequency of
the Visual Carrier.) The first section of
the Trap Filter filters out the Visual
Carrier plus 9 MHz (f
v
+9 MHz). The
second and fourth sections work
together to filter out the lower spurious
product (f
v
-4.5 MHz). The third section
is tuned to remove the (f
v
+8.08). The
output of the Trap Filter is an "N" Type
Connector. The Trap Sections have
been factory tuned and should not need
major adjustments. The Trap Filter is
comprised of four trap sections
connected to the main transmission line.
The Trap Sections are Reflective
Notches, adjustable across the entire
UHF Frequency Band. The electrical
length of the Outer Sleeve and the
Center Rod of the Notch can be adjusted
to Tune the Notch Frequency. The
Depth of the Notch is set by the gap
between the Center Conductor of the
Trap Section and the Center Conductor
of the Main Line. Tight Coupling makes
a Deep Notch, while Loose Coupling
makes a Shallow Notch.
FINE TUNING
of the Notches Center
Frequency can be accomplished with the
Tuning Bolts located on the side of the
Filter Section. Loosen the nut locking the
Bolt in place and adjust the Bolt to
change the Frequency of the Notch.
Monitor the output of the Transmitter
with a Spectrum Analyzer and Null the
Distortion Product with the Bolt. Red
Field is a good Video Test Signal to use to
see the +8.08 MHz Product. Tighten the
nut when the tuning is completed. Hold
the bolt in place with a screwdriver as
the nut is tightened to prevent it from
slipping.