System Description Chapter 2

4-6 kW UHF Translator Chapter 2, System Description
837B, Rev. 0 2-5
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.
2.2 Control and Status
The Control and Status of the Translator
are provided by the Meter indications on
the Metering Panel and the Variable
Phase/Gain Trays. There are also
Control, Status and LED Indications
located on the front panel of the UHF
Exciter Tray.
The switches and LED indicators, which
are mounted so that the switches and
LEDs are operated or viewed from the
front Panel of the UHF Exciter, are part of
the Transmitter Control Board
(1061195). On the UHF Exciter Tray,
switch (S1) is an Operate/Standby
Switch that provides the Operate
Command (Enable), when in Operate, to
the each of the Amplifier Arrays. The
Enable to each Amplifier Array Assembly
at J4-15 & 16 is split 4, 5 or 6 ways on
the terminal block A9-TB2, which are
then applied to each of the UHF Amplifier
Trays at J3-9. The Enable is needed to
turn on the Switching Power Supplies
located in each of the UHF Amplifier
Trays.
When the UHF Exciter is in Operate, the
Green LED (DS2) is On and when in
Standby the Amber LED (DS1) is On.
Note: If the Translator does not switch
to Operate when S1 is switched to
Operate, check that a dummy plug, with
a Jumper between Pins 1 & 2, is
connected to Jack J7 located on (A9) the
Remote Interface Assembly in the UHF
Exciter Assembly. This Jumper provides
the Interlock needed for the operation of
the Translator. If the Interlock is
present, the Green LED (DS5), located on
the Transmitter Control Board, should be
lit.
Operation of the Translator is controlled
by the front panel switches located on
the UHF Exciter Tray. During Normal
operation of the Translator, Switch S2
should be in the Auto position. The front
panel of the UHF Exciter also has LEDs
that indicate a Video Fault (Loss), Red
LED (DS9) and a VSWR Cutback, Amber
LED (DS7).