ATV Repeater System Exciter

Posted on Jul 24, 2012

The ATV exciter described here uses a pair of Hamtronics model TA451 2-watt narrow-band FM voice transmitters to develop video and audio carriers on 439.250 MHz and 443.750 MHz. The TA451 is a single board, phase modulated exciter designed for amateur radio and commercial two-way land-mobile radio service. Several circuit modifications were made to each exciter to permit their use in this application. In operation, one TA451 exciter is operated at 439.250 MHz and is amplitude modulated with video information, while the second operates on 443.750 MHz and is frequency modulated to produce a broadcast-standard FM aural subcarrier. The RF output of each exciter is combined in a diplexer and further amplified through several linear power amplifier stages.

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