User's Manual

Innovator CU0TD-1/CU0RD-1 – CU4TD/CU4RD Board Descriptions
ATSC Transmitter/Regenerative Translator
Instruction Manual, Rev. 1 66
supply connects to TB2 and TB4 on the board. The +42VDC from the (A9) power supply
connects to TB8 and TB10 on the board. The +42VDC input at the TB2 input senses the
current to the (A1) 878 output amplifier pallet through TB1 on the board. The +42VDC
input at the TB4 input senses the current to the (A2) 878 output amplifier pallet through
TB3 on the board. The +42VDC input at the TB8 input senses the current to the (A3)
878 output amplifier pallet through TB7 on the board. The +42VDC input at the TB10
input senses the current to the (A4) 878 output amplifier pallet through TB9 on the
board.
The two or four sensing circuits are identical therefore only one will be described. For
the (A1) 878 amplifier pallet, the +42VDC from the (A8) switching power supply
connects to TB2. R1 and R2 are the parallel .01Ω current sensing resistors which
supplies the voltage values to the U1 current sense amplifier IC. R11 is a gain adjust,
which is adjusted to eliminate any rSense Error and to place the OpAmp output at 2.61V
for 40Amps sense as measured at TP3. The current sense output at J1-1 connects to
the (A7) control board for metering purposes.
(A5) 2 Way Splitter Board (1313158), in Amplifier Drawer w/two Dual 888A
Pallets
The 2 way splitter board takes the RF Input at J1 (≈12.5 Watts ATSC) on the board and
splits it into two equal outputs (≈5Watts ATSC) that connect to the inputs of the two
878 amplifier pallets at J1.
(A5) 4 Way Splitter Board (1308933), in multiple pallet amplifier drawer
The 4 way splitter board takes the RF Input at J1 (≈11Watts ATSC) on the board and
splits it into four equal outputs (≈4.75Watts ATSC) that connect to the inputs of the four
878 amplifier pallets at J1.
(A1-A4) 878A Amplifier Pallets (1314098, 1313170 or 1310138)
There are two 878 Amplifier Pallets mounted on the two pallet Amplifier Heatsink
Assembly and there are four 878A Amplifier Pallets mounted on the four pallet Amplifier
Heatsink Assembly. Each of the 878A pallets has approximately +16dB of gain for the
UHF frequency range of 470 to 860 MHz. The pallets operate Class AB and generate 150
Watts ATSC with an input of 4.75 Watts ATSC.
Or (A1-A2) Dual 888A Amplifier Pallets (1314173) Used in two pallet Amplifier
Drawer (CB005715)
There are two 888A Amplifier Pallets mounted on the two pallet Amplifier Heatsink
Assembly. Each of the 888A pallets has approximately +16dB of gain for the UHF
frequency range of 470 to 860 MHz. The pallets operate Class AB.
(A1-A4) 888A Amplifier Pallets (1315347) Used in three pallet Amplifier
Drawers
There are four 888A Amplifier Pallets mounted on the Amplifier Heatsink Assembly.
Each of the 888A pallets has approximately +15dB of gain for the UHF frequency range