User's Manual

Innovator CU5-1800BTD/BRD ATSC Transmitter/ System Set Up Procedure
Regenerative Translator
Instruction Manual, Rev. 0 61
Refer to Figure 13A. Turn the output power down to 10% power with R62 on the
ALC Board. Remove the output RF connector from J2 on tray and calibrate the
reflected power to 10%, using R7, the Reflected Calibration pot, on the Output
Detector Board. Refer to Figure 14. Re-connect the RF output connector to the tray
and increase the power, in Manual gain using R62 on the ALC Board, to 115%.
Adjust the Overdrive pot R38 on the ALC Board, CCW until the overdrive threshold
just trips and the Overdrive Fault LED DS4 lights. Turn R38 slightly CW so that
power comes back up and DS4 goes out.
Switch S1 on the ALC Board to ALC. Turn the ALC Adjust pot R75 on the ALC Board
until the power is 100%. Switch S1 between ALC and Manual to verify smooth
switching, with minimal change in power. If necessary repeat the above procedure.
With the tray in ALC, use the ALC Adjust pot, R75, to decrease the power to 10%.
Remove the RF output connector from the tray. Verify that the VSWR Cutback LED,
DS6, comes on and the Reflected Power drops to approximately 6%. Reconnect the
RF output connector and increase the power back up to 100% using R75.
This completes the set up of the ALC board and the Forward and Reflected Power
Calibration.
Forward and Reflected Power Calibration of CU250 and Higher Power
Systems
NOTE: If your system is a CU5, CU30, CU50, CU100 or CU125, refer to the previous
section for the forward and reflected power calibration procedures.
Connect a calibrated coupler and average reading power meter to the output of the
DTV mask filter. On the ALC Board (1308570), mounted in the Driver Tray, set the
Switch S1, Auto/Manual ALC, to the Manual position. Refer to Figure 13A. Adjust
the Manual adjustment Pot, R62, for the desired output power level as indicated on
the average reading power meter. In the Amplifier Tray, on the Amplifier Control
Board (1309822), refer to Figure 15; adjust the Forward Calibration Adjustment pot,
R8, for a reading of 100% on the External Amplifier Forward Power screen of the LCD
display mounted on the Driver Tray.
Figure 15: (A5) Amplifier Control Board (1309822)
On the ALC Board (1308570), mounted in the Driver Tray, set the Switch S1,
Auto/Manual ALC, to the Auto position. Adjust the ALC adjustment Pot, R75, for a
reading of 100% on the External Amplifier Forward Power screen of the LCD display
mounted on the Driver Tray. This completes the forward power set up and
calibration adjustments.
On the ALC Board (1308570), mounted in the Driver Tray, adjust the ALC
adjustment Pot, R75, for a reading of 10% on the External Amplifier Forward Power
R8 FWD CAL ADJ R26 REFL CAL ADJ