Morse Code Generator

FE February 1989 MORSE CODE GENERATOR In this circuit, four 74HC series ICs are used to produce either a string of dots, or a string of dashes. The dash has three times the length of a dot. Spacing be- tween characters is equal to one dot. Characters are selected by shorting either of two contacts of a paddle-type key to ground. The generator allows the string of "automatic" dashes to be re- placed by dashes whose length and fre- quency are controlled by the operator, whilst the string of dots remains un- changed. The frequency of the dots ranges between about 130 and 910 per minute. A variable-level sidetone is available at a fixed frequency to enable the operator to hear the characters he is sending. Output from the generator is a normally-open relay contact for con- necting to the CW transmitter. A switch is included to disable the morse relay and so reduce the current consumption while practising. The morse generator is pow- ered by a 9 V battery or by a mains adaptor with an ...