Usually this month, I like to provide a column that, while exhibiting some “unknown” phenomenon or unresolved technique, has unique possibilities. This time, however, I would like to bypass that and provide a so-called “Universal AM Modulator” which, while not intended as an attempt to solve an impossible application, nevertheless has all sorts of opportunities for the true experimenter.
Figure 1 is the schematic of the device. You will note that while this is really just a simple basic audio amplifier, it has all sorts of other applications beyond just amplifying an audio signal to drive a speaker. It uses a common LM-386 with a control to adjust the maximum output. Before going any further, however, let me also indicate that the basic applications that follow do not have to…
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CQ Amateur Radio (Digital) - 1 Issue, April 2023