Pro Intercom AD903 2 to 4 Wire Active Transceiver Adapter The AD903 has many functions for getting various levels of audio into an intercom circuit, or getting the intercom audio "traffic" out to an amplifier or recorder. It is also useful as a 2-to-4 wire adaptor for connecting 4-wire communications into and out of a standard intercom circuit. The 'Null' control allows you to minimize or even eliminate any "cross-talk" between the input and output. The input transformer is a studio grade device and will not degrade any audio that you feed it. The AD903 is also commonly used for connecting to a video camera CCU where a built-in intercom is provided that is not compatible with Pro Intercom or any of the other 200 Ohm unbalanced intercom systems. Key Features The AD903 is powered by the intercom system and requires no batteries or separate power supply. The AD903 connects to the intercom circuit just as a beltpack does, through a rear panel 3-pin XLR. Access to the input and output are via a rear panel 4-pin XLR. Pins 1 and 2 are input and pins 3 and 4 are output. Both the input and the output are transformer isolated from whatever devices are connected. The wide range of level adjustments will accommodate almost any audio signal. Technical Specifications Power requirement 24 - 30 VDC, 15-25 mA Input -60 to +30 dBm into 10K Ohm nominal, balanced and floating Output -60 to +30 dBm from 200 Ohm nominal source, balanced and floating Sidetone rejection 50 dBA Audio bridging impedance (to the intercom system) 200 Ohm unbalanced Size 3.70 x 4.30 x 2.50 in. (93.98 x 109.22 x 63.5 mm) Weight 14.5 oz (0.411 Kg)