User's Manual

Innovator CU0TD-1/CU0RD-1 – CU4TD/CU4RD System Description
ATSC Transmitter/Regenerative Translator
Instruction Manual, Rev. 1 12
When configured as an ATSC Transmitter (TD), the SMPTE-310 input at (J1),
from an ASI to S310 converter, a KETCH Receiver, an Axciter Drawer 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 (RD), 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 (RD) 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) in systems without an
Axciter drawer. 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 from the IF precorrector board is connected to the digital
upconverter board (1309695) at J6.
In regenerative translator systems with an Axciter, 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). The SMPTE-310 output of the board at J13 is wired
to J2 on the rear panel of the drawer. The SMPTE-310 is cabled to the SMPTE-
310 input jack J27 on the Axciter drawer. The digital IF output of the Axciter at
J40 is cabled to J3 on the CU0RD-3 drawer that is wired to J6 on the digital
upconverter board. The rest of the drawer operates the same for both the RD
and the TD systems.
The digital upconverter 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 CX Series (1308570), which is used to control
the drive power to the RF amplifier chain in the CU0TD/RD-1, CU0TD/RD-2,
CU0TD/RD-3, CU0TD/RD-4 and CU0TD/RD-5 Transmitter/Translators. In a
CU0TD/RD-2 or CU0TD/RD-3, the RF is connected to the (A6) Amplifier Assembly
(1312566) that is made up of (A6-A1) the 2 Stage UHF Amplifier Board
(1308784) and (A6-A2) the RF Module Pallet w/Philips transistors (1300116).
The assembly has approximately 36 dB of gain. The amplified output at
approximately +38 dBm connects to the (A7) Output Detector Board (1308685 or
1312207) which provides forward (2V=100%) and reflected (2V=25%) power
samples to the CU 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 50 Ohm BNC type. The typical sample value in a CU50 is
approximately 60dB down from the output power level of the drawer. The RF
output is cabled to J2 the “N” connector RF output jack on the rear panel of the
drawer. In CU0TD/RD-1, CU0TD/RD-2, CU0TD/RD-3, CU0TD/RD-4 and
CU0TD/RD-5 systems the output connects to a digital mask filter, low pass filter
and then the antenna for your system. In CU1TD/RD-1, CU1TD/RD-2, and
CU1TD/RD-3 systems, the RF output, from the driver drawer, is connected to J1
on the rear panel of the amplifier drawer. The RF is cabled to J1 on the Amplifier
Heatsink Assembly in the amplifier drawer. In CU2TD/RD and higher power
systems the RF is connected to a splitter and then to the inputs of the amplifier
drawers.
The CU1TD/RD-1 ATSC system is made up of a Driver Drawer and a 250 Watt
ATSC Amplifier Drawer. The driver drawer connects to the 250 Watt Amplifier