System Description Chapter 2

4-6 kW UHF Translator Chapter 2, System Description
837B, Rev. 0 2-7
Table 2-4. UHF Exciter Tray Switches
SWITCH FUNCTION
Translator S1
Operate/Standby
The momentary switch S1 applies a ground
to K1, a latching relay on the transmitter
control board. K1 will switch either to
Operate or to Standby depending on which
direction S1 is pushed. When switched to
Operate, the low, enable commands are
applied to the UHF amplifier trays. These
enables will turn on the UHF amplifier trays.
The opposite occurs when the switch is
turned to Standby.
Mode Select S2
Auto/Manual
The momentary switch S2 applies a ground
to K2, a latching relay on the transmitter
control board. K2 will switch the Translator
to Automatic or Manual depending on which
direction S2 is pushed. In Automatic, the
video fault command from the ALC board
will control the operation of the Translator.
The Translator will switch to Standby, after
a slight delay, if the input video is lost and
will switch back to Operate, quickly, when
the video is restored. In Manual, the
Translator is controlled by the operator
using the front panel Operate/Standby
switch or by remote control.
Power Adjust R1
The 5-k pot A20 sets the ALC level on the
ALC board to set the output power of the
translator.
Table 2-5. UHF Exciter Tray Fault Indicators
INDICATOR DESCRIPTION
Video Loss (DS9 Red)
Indicates that the input video to the
translator has been lost. The fault is
generated on the ALC board in the UHF
exciter tray.
VSWR Cutback (DS7 Amber)
Indicates that the reflected power level of
the translator has increased above 20%;
this automatically cuts back the output
power level to 20%. The fault is generated
on the transmitter control board in the UHF
exciter tray.