SCANNER_WITH_SEARCHBACK

Published:2009/7/13 23:03:00 Author:May | From:SeekIC

Combines scanning between two repeater channels with periodic searchback, to prevent scanner from locking on one of channels during long periods of use NE555 timer is added to squelch recognition circuit to provide automatic control of scanner so both frequencies are checked at least every 15 s，If scanner is extended to monitor four channels, none are unguarded for more than 1 min，Article shows how receiver section of transceiver is modified for diode switching by scanner of oscillator crystals for individual channels．-P, Shreve, Two-Channel Scanner for Repeater Monitoring, Ham Radio, Oct，1976, p48－51.



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