KEYER_FOR_AFSK

Published:2009/7/15 1:48:00 Author:Jessie | From:SeekIC

Uses one center-tapped 88-mH toroid tuned to desired RTTY space frequency by suitable value of C1 (0.0628μF for 2295 Hz). When relay is closed, suitable value for C2 (0.0156μF for 2125 Hz) is paralleled with C1 to give desired space frequency. Output is perfect sine wave. Plug output into audio input jack of transmitter. Plug relay coil directly into 150-V 60-mA loop of teleprinter. When loop current is turned on, relay closes and AFSK is on mark. Space frequency occurs when relay is opened by teleprinter keyboard.-J. B. Dillon, Audio-Frequency Shift Keyer, Ham Radio, Sept. 1976, p 45.



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