Assembly Instructions Chapter 4

4-6 kW UHF Translator Chapter 4, Circuit Descriptions
837B, Rev. 0 4-47
4.9 Translator Output Assemblies
The outputs of the (A2 & A3) 2-3 kW
Amplifier Assemblies (+63.5-+65.2
dBm) connect through 1-5/8” hard-line
and (A5 or A6) 1-5/8” to 3-1/8”
Adapters to (A4) a Hybrid Combiner.
The combiner combines the output
from each Amplifier Assembly into a
single output. The Reject Output of the
Hybrid Combiner is connected through
(A12) a 1-5/8” to 3-1/8” Adapter to
(A7) a Directional Coupler (1016-1043)
that provides a Reject Sample from J3
to the Metering Panel located in the
UHF Exciter Assembly for monitoring
purposes. The output of the Directional
Coupler connects to (A8) a 2500 Watt
Reject Load which dissipates any reject
due to problems in one of the Amplifier
Arrays. Mounted on the 2500 Watt
Load is (A8-A1) a Thermal Switch that
connects to the Overtemperature Fault
circuit located on the Transmitter
Control Board in the UHF Exciter Tray.
If the temperature of the load reaches
155°F. the switch closes and causes an
Overtemperature Fault to occur which
shuts down the Translator.
The output of the Hybrid Combiner at
J3 is fed to (A9) a Bandpass Filter,
(A10) an Output Trap Filter Assembly,
then to (A11) the Output Coupler
Assembly and finally to the Antenna for
your System. The Bandpass Filter and
Trap Filter are tuned to provide high
out of band rejection of unwanted
generated products. The filtered signal
is connected to (A11) an Output
Coupler Assembly which provides a
Combined Forward and a Combined
Reflected Power Sample to the
Metering Panel located in the Single
UHF Exciter Assembly. The Forward
Sample is processed to provide peak
detected Visual and Aural Power Output
Samples to the front panel Meter of the
Metering Panel. The Reflected Power
Sample is also peak detected and wired
to the front panel Meter. A Sample of
the RF Output, for test purposes can be
taken from J5 on the Coupler, but a 20
dB Attenuator must be connected to J6
for the Sample port to operate. An
appropriate attenuator must be
connected to J5 to protect any test
equipment connected to it.
The RF output of the Coupler at J2
(+66 to + 67.7 dBm pk of sync) is the
RF output of the translator and is
connected to the Antenna for your
System.