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TABLE OF CONTENTS SAFETY INSTRUCTIONS...............................................................................2 UPC-21 FEATURES....................................................................................... 3 UPC-21 INSTALLATION................................................................................ 4 AUDIO & POWER CONNECTIONS............................................................... 5 PRELIMINARY LEVEL SETTINGS................................................................
1. Main Connector; consisting of the following: a. Pins 1 & 2: DC Power Input Terminals. Connect the output leads of the USL supplied 32VDC power supply to pins 1 and 2. Connect the red wire to pin 1. b. Pin 3: AC Ground Terminal. This terminal may be connect to an earth ground connection if required by local building codes. c. Pin 4: Audio System Ground. Connect to the shield of shielded-pair input cable. d. Pin 5 & 6: Audio Input Terminals. Balanced, differential input.
4. Audio Input level Adjustment. Adjust input level so that only the peaks of the audio signal light the LED “Signal Presence” indicator. If the LED is on constantly, the audio level is too high and the channel is clipping. 5. Compression Slope Adjustment. Adjusts compression from 1:1 to 3:1 with 2:1 at the approximate center of the range. Improves intelligibility of low level dialog. 6. RF Source Switch. Selects source of IR RF modulation to be radiated by this emitter panel.
CONNECT THE AUDIO INPUT LINE Connect the center channel speaker terminals to the + and - (ground) audio input terminals on the IRC-21 as in Fig C. If the center channel is bi-amped, you must construct a resistor network, as in Fig. D, that sums the high and low frequency signals, then feed the output of the network to the IRC-21 audio input. You also may connect the IRC-21 input to the output of a monitor or a processor.
PRELIMINARY LEVEL SETTING Run program material with HI audio. Set the compression slope to 2:1. Adjust the appropriate DIP switches and input level controls to cause the audio level LEDs to flash druing normal programming, but not to stay lit continuously. Try listening on IR headphones. If necessary, adjust compression to bring up low levels or reduce noise. Note: The IRC-20 has an automatic shutoff circuit. The unit will shut itself off after a thirty-minute absence of audio input.
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AN INSTALLATION USING TWO IRC-21S Connect an IRP-20 DC power supply to each of the IRC-21s. Connect a 75 ohm coaxial cable from the RF OUT connector on the unit being driven with audio (the master) to the RF IN connector on the slave unit. Additional slave panels may be similarly cascaded from the first slave panel. On the master panel, turn on the internal RF Source switch, and turn off the external RF Source switch.
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181 Bonetti Drive San Luis Obispo, CA 93401 ph: 805-549-0161 fax: 805-549-0163 e-mail:usl@uslinc.
