Axcera CHV400BTD, Technical Manual, Page: 41 / 87

Innovator CHV400BTD ATSC Transmitter System Description
Technical Manual, Rev. 0 37
System Description
The Innovator CHVB Series Systems are of two different types. They are either
Regenerative Translators, example: CHV200BRD, or DTV Transmitters, example:
CHV200BTD. The Regenerative Translator (BRD) accepts an RF On Channel signal (-79
to –8 dBm) and converts it to a DTV RF On Channel output signal. The DTV System
(BTD) takes a SMPTE-310 Input and converts it to a DTV RF On Channel output signal.
The SMPTE-310 input can be from an ASI to S310 converter, a KTECH Receiver Tray, an
Axciter Tray or any other SMPTE-310 source. The output power level of either
configuration is typically up to 200 Watts ATSC using a single tray, at 400 or 500 Watts
ATSC using an additional single amplifier tray, at 1000 or 1500 Watts ATSC with two
Amplifier trays, at 2000 Watts ATSC with three Amplifier trays, or at 3000 Watts ATSC
with four Amplifier trays. The Innovator CHVB Series system provides linear and
nonlinear correction capability for the transmission path as well as internal test sources
that are used during initial system installation.
The CHV200B systems and the driver tray for higher power systems contain the Digital
Modulator w/Power Conditioner (1309629) that is made up of (A2) the Digital Modulator
Board (1304883) and (A22) the Power Conditioner Board (1309404). The tray also
contains (A3) the IF Precorrector Board (1308796), (A4) the Frequency Agile
Upconverter (1309695), and (A6) the Amplifier Assembly. The (A7) Output Metering
Detector Board (1313747), (A8) the Innovator CX Control Board (1312543), (A9) the
+5V, ±12V Power Supply and (A10) the +28V/+42VDC Power Supply are also contained
in the tray. The BRD kit (1310182) supplies the (A1) 8 VSB Demodulator Board
(1308275) to the tray to make it a regenerative translator.
The type of (A6) Amplifier Assembly used in the tray changes as the output power of the
system changes. The Amplifier Assembly (1313959) is used in CHV20B systems and the
Amplifier Assembly (1313912) is used in CHV200B systems.
The (A10) Power Supply Assembly also changes as the output power of the system
changes. A +28V/300W Power Supply is used in CHV20B Systems and a +42V/1100W
Power Supply is used in CHV200B systems.
When configured as an ATSC Transmitter (BTD), the SMPTE-310 input at (J1), from an
ASI to S310 converter, a KETCH Receiver, an Axciter Tray or any other SMPTE-310
source, connects directly to the input jack (J42) on the (A2) Digital Modulator Board
(1304883). When configured to operate as a Regenerative Translator (BRD), the DTV
ON Channel RF Input at (J1), (-8 to -79 dBm) connects to the Tuner Input Jack on (A1)
the 8 VSB Modulator Board (1308275) supplied with the (BRD) kit. The 8 VSB
Modulator Board (1308275) converts the DTV input to a SMPTE-310 output at (J13) that
connects to the input jack (J42) on the (A2) Digital Modulator Board (1304883). The
rest of the tray operates the same for both the BRD and the BTD systems.
The IF output of the 8 VSB modulator board connects to J2 on the IF pre-corrector board
(1308796). The IF Pre-Corrector Board provides ALC, automatic or manual, gain control
of the IF level. The board also supplies pre-correction Response, In Phase and
Quadrature Non-Linear adjustments. The board has the circuitry for ALC Fault, Input
Fault and Modulation Fault monitoring and indications. The IF is connected to the digital
upconverter board (1309695) that takes the 44 MHz or 36 MHz IF signal and converts it
to a TV channel frequency in the range of 54-860 MHz. The RF on channel signal is fed
to the ALC Board, Innovator CXB Series (1308570), which is used to control the drive
power to the RF amplifier chain in the CHV200B Transmitter/Translators. In a CHV20B,
the RF is connected to the (A6) Amplifier Assembly (1313959) that is made up of (A6-