30_kHz_MARKERS_FOR_2_METER_FM

Published:2009/7/21 1:47:00 Author:Jessie | From:SeekIC

Crystal is placed in loop of standard TTL MVBR, Circuit is modified so 32-pF parallel-mode unit will work into effective load of 32 pF. Series 220-pF capacitor raises crystal frequency enough to permit accurate frequency adjustment by trimmer. Oscillator output is fed to two decade dividers; output of second decade IC3 is 30-kHz square wave with 20% duty factor, coinciding with standard 2-meter FM channels. Regulated sup-ply is 5 VDC at 110 mA.-G. E. Zook, Channel Marker Generator, CQ, April 1972, p 41-42.



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