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| The above transmitter was built from the the article in the 2000 ARRL Handbook on page 17.98, "An Experimental 1/2Watt CW Transmitter". It uses a 74HCT240 Integrated Circuit chip for all the functions. This Chip is available from Radio Shack at a very reasonable price. The original article was written for use on 20, 15, and 10 meter bands but I plugged in a minature 7040Khz Crystal and changed the output filter for 40 meters and it seems to work very well. It is built in one of the Minature Altoids cans which are about 1/4 the size of a regular Altoids candy tin. It has a good output waveform, about 420 mw of power and clean keying signal. Since no one seemed fit to name the little feller, I am calling this one "CHIPPY" after the main part of it's innards. It is built "Manhattan Style" on a piece of PC board outside the can and then was shoe horned into it's Altoids home. To give you an Idea of it's size, I have photographed CHIPPY sitting in the lid of my PIXIE which was built with the same techniques. This is the photo that appears below. Using even smaller parts scrounged from newer VCR's this radio could probably be even reduced some more. Hope you all have as much fun building these things as I do. 73.....Dave |
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