User's Manual

300-Watt Digital UHF Transmitter Chapter 3, Installation and Setup Procedures
DT830A, Rev. 1 3-6
of the cabinet and mounted behind the
rear door. On the UHF exciter tray,
switch the Operate/Standby switch to
Standby.
Move the Operate/Standby switch,
located on the UHF exciter tray, to
Operate. Observe the power supply
reading, +26.5 VDC, on the front panel
of the UHF amplifier trays.
Note: If the transmitter does not
switch to Operate when the
Operate/Standby switch is switched
to Operate, check that an external
interlock plug, with a jumper wired
from pins 23 to 24, is connected to
jack J11 on the rear of the UHF
exciter. Or, if (A17) the optional
input and remote interface assembly
is present in the system, the external
interlock plug, with a jumper wired
from pins 21 to 22, should be
connected to jack J9 on the
assembly.
Observe the front panel meter reading in
the % Output Power position on the UHF
exciter tray; after allowing several
minutes of warm-up time, it should read
100%. If necessary, readjust the
screwdriver adjust power pot on the front
panel of the UHF exciter for 100%. As
you are checking the power level, check
the meter reading in the % Reflected
Power position. If the % Reflected Power
is very high (above 10%), a problem
with the output coaxial lines is present
and needs to be checked. A center bullet
missing from the 7/8" rigid coax lines or
loose bolts on the connections can cause
this problem. Return the Operate/
Standby switch to Standby.
The gain and phase controls on the front
panel of the UHF amplifier tray were
adjusted at the factory to attain 100%
output of the transmitter and should not
need to be readjusted. Refer to the Test
Data Sheet for the transmitter to
compare the final reading from the
factory with the reading on the tray after
the setup. They should be very similar. If
a reading is off by a significant amount,
refer to the phasing and power
adjustment procedures for the UHF
amplifier tray in Chapter 5, Detailed
Alignment Procedures, of this manual
before trying to make any adjustments.
If a dummy load is connected to the
transmitter, switch the transmitter to
Standby and switch off the main AC
circuit breaker. Remove the dummy load
and make all of the connections needed
to connect the transmitter to the
antenna. Switch the main AC circuit
breaker on and the Operate/Standby
switch to operate. Adjust the output
power screwdriver pot to attain 100%
output.
If the transmitter is already connected to
the antenna, check that the output is
100%. If necessary, adjust the power
screwdriver pot.
If a problem occurred during the setup
and operation procedures, refer to
Chapter 5, Detailed Alignment
Procedures, of this manual for more
information.
This completes the setup and operation
procedures for the DT830A transmitter.
The transmitter can now be operated
normally.