Data Sheet Chapter 5

10-kW UHF Transmitter with Chapter 5, Detailed Alignment Procedures
Feedforward Drive
840A, Rev. 0 5-18
Figure 5-2. Bandpass Filter
5.8 (Optional) (A14) One- or Two-
Section Trap Filter
The trap sections in the one- or two-
section trap filter have been factory
tuned and should not need major
adjustments. The trap filter is optional
and may not be part of this system.
The input to the one- or two-section trap
filter is the output of the coupler
assembly. The trap filter is comprised of
3-1/8" EIA standard transmission line
sections connected to the main
transmission line. The transmission line
assembly consists of 7/8" EIA standard
rigid coaxial components.
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 trap sections are reflective notches
and can be adjusted 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