USL UPC-28C - Manual (Page 5)

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UPC-28C Instruction Manual Ultra Stereo Labs, Inc.
Introduction
The IRC-28C transmits two channels of audio plus closed captioning data
over infrared. Channel A is transmitted at 2.3MHz. Channel B is transmitted at
2.8MHz. Both carriers are frequency modulated. Channel A is normally used to
carry the Hearing Impaired audio, while channel B is normally used to carry the
Visually Impaired - Narrative audio.
1. Ethernet Connector
2. and 6. Input audio level range switches for channels A & B.
With both switch keys in the “up” position, the input range is 0.1 to 1.0
Volts RMS. In the down position, the range is 2 to 20 Volts RMS.
3. and 7. Input audio level adjustments for channels A & B.
4. and 8. LED audio level indicators for channels A & B.
5. and 9. Compressor slope adjustments for channels A & B.
Increasing compressor slope improves intelligibility of low level dialog.
10. Main Connector; consisting of the following:
a. Pins 1 & 2: DC Power Input Terminals.
Connects to the DC terminals of the 32VDC Power Pack
supplied with the IRC-28C. Red wire connects to + terminal (pin
1) connection.
b. Pin 3: Chassis Ground Terminal.
The DC power supply connects the AC safety ground to its nega-
tive output. No connection is required to this terminal.
c. Pin 4: Audio System Ground.