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General
The OS803R is a three channel Fibre to Video Receiving unit with Automatic Gain Control (AGC). This unit converts an optical signal received from the fibre into a composite video signal, which is transmitted out onto a BNC connector. When the optic signal is present, an led indicator will light up. Each card uses 3 Optic Receiver devices.
This unit is designed to fit into an OS800 19? sub-rack system. The card is standard Eurocard size.
This unit operates autonomously.
Basic System Description
The unit consists of 3 fibre to video receivers, and one voltage regulating circuit.
The unit is powered via an edge connector that is situated at the back of the card. This edge connector plugs into an OS800 card frame that is fitted with the correct back plane edge connectors.
All three receiver circuits operate identically, and are independent of each other. The basic operation is outlined below.
The optic receiver on the front of the card receives the optical signal from the fibre cable. This signal is then fed into the video signal-conditioning amplifier. The amplifier checks the sync-pulse amplitude of the video signal, and employs AGC to set the correct gain to obtain a sync-pulse level of 300mVp-p (sync to blank level), as per composite video signal standard. The sync to picture ratio will now be 3:7 with a standard colour bar test signal. This means that the remainder of the signal amplitude will be 700mVp-p (blank to white level). A jumper can be removed to override the AGC mode, and the gain can then be set manually via a variable resistor on the card. Finally, the video signal is fed out on a BNC connector on the back of the card, with an output impedance of 75 Ohm.
Features - Compatible with standard composite video signals.
- Compact design allows large concentration of video signals.
- Up to 3 channels per card.
- Multiple cards fit into OS800 - 19" rack system (up to 12 per rack).
- Interface directly to the OS801 Single channel video transmitter on fibre.
Uses - Security systems.
- Long distance noise free video transmission.
Indications
Power - Indicates unit is powered
Video signal - Indicates video signal presence
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