The Model XT-4 4-Channel Stationary Mid-range Transmitter is designed for use in various wireless remote control applications. When triggered with an external switch, the Model XT-4 transmitter will send a 10 watt, 27.255 MHz, digital encoded, FSK modulated, signal to its companion receiver. The receiver will verify the digital code, activate its output, and trigger the remote device. The XT-4 transmitter has full supervision capabilities. If the status option is selected, the XT-4 sends hourly status signals to its receiver. If these signals cease, the receiver will indicate trouble by activating its status output after four hours. Contact supervision allows the receiver's outputs to follow the transmitter's inputs, staying activated as long as each transmitter input is activated. Alternately, an auto-restore option can be selected, causing a momentary receiver output each time any transmitter input is activated. Each input can be configured for either N/O or N/C contacts (switch selectable). Power for the XT-4 transmitter can come from an external regulated 12 VDC power supply (Linear Model T-1224DC) or from a 12-volt battery. A 3-amp fuse protects the unit from reverse power polarity. The XT-4 draws about 15 mA standby, and about two amps during transmissions. If the power supply voltage drops below 10.5 volts, a low battery message will be included with any signal transmitted, causing the receiver's low battery output to activate. Two antennas (sold separately) are available for the XT-4. The Model ANT-1A is an 7-inch rubber duck antenna for short range applications (less than 1 mile). The ANT-1A is supplied with a CON-180A (straight) connector to mate the antenna to the transmitter. For a right angle antenna mounting, use a CON-90A right-angle connector with the CON-180A. The Model ANT-2 is a 3-foot whip antenna for use in long range or difficult installations where more range from the XT-4 is required. A common 9-foot 1/4 wave CB whip antenna can also be used with the XT-4 for maximum range. Two 8-position switches set the unit's system code. This code must be matched in the XT-4's receiver. There are 65,536 different system codes possible. The 4-position option switch selects the receiver's bank (for XR-16 receiver only), and options for status and auto-restore transmissions. The transmitter is housed in a rugged weather-resistant metal enclosure with a sturdy SO-239 antenna connector and a water-tight wiring strain relief bushing. During transmissions, the red operation indicator (visible through a window on the case) lights. If the XT-4's input voltage is low, the indicator will blink during transmissions.