Dan's Radio

CB Radio

New Modulation Kits

  Today we have two new circuit concepts to employ for improving modulation while ridding ourselves of the problem with modulating past the negative peak cutoff point.  The methods include a controlled carrier modulation circuit I have designed for Galaxy radios, as well as a circuit conceived of by John Bartal and designed by David Dowler, known as the Asymmetrical Modulator or Mauldulator.  Both circuit concepts can be used to control the negative peaks and hence reduce spurious in band and out of band products, the Asymmetrical Modulator however is quite ingenious and actually provides the kind of modulation I envision for use on 11 meters which results in the idea that allot of CBer's think they have with suppressed carrier but really do not since in using suppressed carrier they still have this problem with cutoff of the negative peaks.

  Since my designing of a controlled carrier modulator circuit, I have encountered David Dowler who suggest I make a LTSpice model of his circuit and run it to familiarize myself with how it works, and I can verify that it does work just as the videos describe.  David gave me permission to use one of his prior generation circuits to design with as I please.  I however have been sharing my designs with both John and David since then.  Mostly I have added such things as a line level mixer and low pass filter section to the audio input.


  You can encounter John and David in my Facebook group Broadcast Quality CB Radio.

  The Asymmetrical Modulator definitively is one of those ingenious ideas that come along once and awhile and changes everything, and hence what this can change is the future of broadcast radio technologies, and I think the realm of shortwave broadcasting is what will embrace this for the most part.

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