Some maritime TVRO antennas used a mechanical scan at the feed point. A motor would either rotate an attenuator disk or offset the feed in a circular motion. A resolver kept track of the feed location in relation to received signal strength. The antenna was then slewed in the direction of best signal in both AZ and EL. Sort of a poor mans monopulse system. This works OK for antennas in the microwave region but would not work to well for VHF/UHF low gain arrays. What might work well is to use a pair of antennas with a "doppler scan" circuit that steered the rotor toward the estimated direction of the signal.
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