User's Manual

Innovator CHV400BTD ATSC Transmitter System Description
Technical Manual, Rev. 0 38
A1) the VHF HB Pre-Driver Amplifier (1313899) and (A6-A2) the 100 Watt Amplifier
Pallet, Italmec (1313484). The assembly has approximately 36 dB of gain. The
amplified output at approximately +38 dBm connects to the (A7) Output Metering
Detector Board (1313747) which provides forward (2V=100%) and reflected (2V=25%)
power samples to the CX Control Board (1312543) for metering and monitoring
purposes. An output power sample is also supplied to the front panel sample jack J15,
which is a 50Ω BNC type. The typical sample value in a CHV200B is approximately 60dB
down from the output power level of the tray. The RF output is cabled to J2 the “N”
connector RF output jack on the rear panel of the tray. In CHV200B single tray systems
the output connects to a digital mask filter, low pass filter and then the antenna for your
system. In CHV400B and CHV500B systems, the RF output, from the driver tray, is
connected to J1 on the rear panel of the amplifier tray. The RF is cabled to J1 on the
Amplifier Heatsink Assembly in the amplifier tray. In CHV1000B and higher power
systems the RF is connected to a splitter and then to the inputs of the amplifier trays.
The CHV400B ATSC system is made up of a CHV20B Driver Tray and a 400 Watt ATSC
Amplifier Tray. The CHV20B is used as a driver that connects to the 400 Watt Amplifier
tray and supplies the needed drive level to produce the 400 Watts output of the system.
The control and operating parameters of the 400 Watt Amplifier Tray are displayed on
the LCD Screen on the Driver Tray. In the CHV400B amplifier tray, the RF input signal
to the tray is at J1 on the rear panel of the tray that is cabled to J1 on the two way
splitter and then to J1 on the two amplifier pallets. In a standard CHV400B amplifier
tray, a single +42VDC power supply provides the operating voltages, through the
current metering board, to the two amplifier pallets. In a N+1 CHV400B amplifier tray,
two +42VDC power supplies are diode-ord and provide the operating voltages, through
the current metering board, to the two amplifier pallets. If one power supply should
malfunction, the other power supply will maintain the necessary voltage to provide the
400 Watts output. The amplified output of the pallets, which have approximately 15 dB
gain, is connected to a two way combiner before it is cabled to J2 the 7/16” (1.1cm) Din
RF output jack of the tray. The two way combiner supplies a forward and a reflected
power sample to the amplifier control board for metering and monitoring purposes.
The CHV500B ATSC system is made up of a Driver Tray and a 500 Watt Amplifier Tray.
The CHV200B is used as a driver that connects to the CHV500 Amplifier tray and
supplies the needed drive level to produce the 500 Watts output of the system. The
control and operating parameters of the 500 Watt Amplifier Tray are displayed on the
LCD Screen on the driver Tray. In the CHV500, the input RF signal at J1, located on the
rear panel of the tray, is fed to J1 on the 4 Way Splitter Board, which supplies four
outputs, one to each amplifier pallet. Each amplifier pallet has approximately 14 dB
gain. The amplified outputs of the pallets are combined in the 4 Way combiner board
whose output is at J1. The RF is connected to J2 the 7/16” (1.1cm) Din RF output jack
located on the rear panel of the tray. The 4 way combiner board supplies a forward and
a reflected power sample to the amplifier control board for metering and monitoring
purposes. In a CHV500B, the typical sample value at J6, a 50Ω BNC jack located on the
front panel of the tray, is approximately 65dB down from the output power level of the
tray.
In higher power systems, multiple amplifier trays are used along with splitters and
combiners to produce the desired output. A System Metering Board (1312666) provides
forward, reflected, overtemperature and other parameters to the exciter/driver tray
from the external power amplifier chain. The CHV1000Bis made up of a driver tray, a
two way splitter, two CHV500B amplifier trays and a two way combiner with a 500W
reject load. The reject load provides isolation protection of the operating power
amplifier if the other amplifier fails. One–half the power of the operating amplifier tray