The inventors of the original zapper, Hulda Clark and her engineer son Geoff Clark, wrote only of building your own zapper instruments, and encouraged multiple ways of doing it.
She also wrote that the frequency of the zapper was potentially very wide ranged, from the hand-pat version, maybe one pulse handhold pat each second, 1 Hz, up to the frequencies of parasite bioresonance, in the hundreds of KHz. The 30 KHz utilized in the design shown for building your own zapper in her book, she had found was possibly the best for a single frequency general purpose instrument; but was not identified as the needed frequency for a zapper.
However, some people preferred to have somebody else build a zapper for them, and eventually commercially built zappers appeared on the market. The first commercially built zappers used the identical circuit suggested by Hulda Clark in her book "The Cure for All Diseases" and soon were made with professional quality circuit boards and outer chassis, focusing on enabling the experimenter to just use it in their experiments, without first having to build it.
Increasing specificity: adding frequency zapping and programmed sets of frequenciesEdit
That book by Hulda Clark also described the earlier form of instrument, which she called "frequency zapping," which involved using the specific bioresonant frequency of a particular parasite, instead of the general 30 KHz pulse rate zapper described for construction in that book. The purpose for doing frequency-zapping was to target a particular parasite, which had managed to locate in a place not easily accessed by the usual zapping.
This mode of zapping was utilized by some manufacturers of commercial instruments, such as those sold by drclark.com currently the module-programmable VariZapper and the user-programmable VariGamma instrument http://www.drclark.com/pictures/VariZapper_Gammatext_en.htm . Such instruments are not built in America. The current VariGamma instrument costs about $600, which greatly reduces the customer base, not affordable by many casual hobbiests; it also uses nine-volt batteries up very quickly, one battery consumed for a couple hours of experimentation, and the batteries are expensive, several dollars each.
Yet the program modules for these frequency-zapping instruments, separately available and again only from Europe, invited exploration of specific kinds of problems such as headaches. these were found to be hugely interesting to the experimenters, discovering effectiveness; each plug-in module had up to sixteen separate bioresonant frequencies, primarily including the bioresonant frequencies of parasites Dr Hulda Clark had found in her private research to sometimes be involved in particular symptoms.
The complexities of the circuitry and plug-in modules were beyond what the home-brew experimenter was able to match, and so these commercial instruments were the sole way to explore the wide range of possible applications of the technology by individual experimenters. However, a significant portion of the multi-frequency programability has recently been made available through an instrument that has been devised, built and example testing done, as a build-it-yourself instrument called the "Audio Programmed Zapper" http://www.audioprogrammedzapper.com/ which utilizes control signals the experimenter can record in the form of ordinary mp3 audio signals, and then played back through the Audio Programmed Zapper instrument to generate the desired set of frequencies. This instrument combines the zapper form of waveform with not only the 30KHz zapper pulse rate, but also the wide range of frequencies long explored by Rife-type signal enthusiasts worldwide, such as can be found at http://www.electroherbalism.com/Bioelectronics/FrequenciesandAnecdotes/CAFL.htm Also it enables exploration of another interesting set of frequencies that are not intended to zap parasites and other pathogens, but instead to stimulate and balance various body systems such as found at http://stenulson.net/althealth/stimfreq.htm
All these signal sets can be made available in zapper pulsed-dc form by the Audio Programmed Zapper circuit, which combines the Rife-type frequencies with the Clark-type pulsed single polarity voltage signal found by Hulda Clark to be so effective in helping people stay healthy, and thus the instrument provides a new tool for the experimenter that is quite versatile.
It is anticipated that this instrument will eventually be made available in kit form or as a finished instrument, hopefully at its potentially low cost to the experimenter.