Specifications

4-9. Composite Level Adjustment.
A.Connect a high impedance AC Voltmeter across the BTSC Composite Out line. The audio
equipment that will normally be connected to this line should remain connected while
performing this measurement; if for any reason the level must be set in the absence of the
connecting equipment, terminate the line with a precision 75Ω termination.
B.Have a 455 transmitter site send a continuous tone of 1 kHz on both channels as follows:
connect an audio signal generator to both the LEFT and RIGHT channel inputs of the BTSC
stereo generator. The flat (no pre-emphasis) inputs should be used. The output of the stereo
generator should be connected to the appropriate input of the 455. Set the signal generator to
provide a 1 kHz test signal at a 100% modulation level at both inputs. The pilot should be
switched off for this procedure, and the SAP and PRO channels should also be OFF.
C.Use the AUDIO screwdriver control on the front panel to adjust the receiver output to 342.5
mv rms (968.6 mv p-p).
4-10. TRANSMITTER INTERNAL OPTIONS.
There are no internal options on the 455 Transmitter.
4-11. RECEIVER INTERNAL OPTIONS.
The internal options are selected with jumper plugs on the internal printed circuit board, and
require removal of the top cover plate of the units.
___________
_ WARNING _
___________
Unplug the power cord from the equipment before removing any cover plates. Failure to do
so could result in a hazardous electrical shock, and/or damage to the equipment. Replace all
cover plates prior to restoring power to the equipment.
The top cover plate is held in place by 11 flat head phillips machine screws, 2 of which pass
through the top edge of the front panel. After removing these screws, carefully remove the top
cover plate by tilting the rear edge up slightly and sliding it out from under the top edge of the
front panel.
455 Operation Manual Page 32 6/23/98