I think I will try to do the same with the zapper. I am thinking of doing up to 4 frequency selector unit. That should put the frequency question to rest. And hopefully more manufactures start making multi-frequency units.
Here is very interesting study on zapping effectiveness on Candida Albicans by a polish doctor:
What is interesting is the description of the most effective device in this study: "In our study, the source of alternative current was the Medikzap device designed by the
Medi-Flowery Company Ltd. (Fig. 1). It generates a square wave current of basic frequency within the 25 - 40kHz range with a rich spectrum of harmonic components above 1MHz. Another generator was also used (Fig. 2) of a much simpler design based on the popular NE 555 integrated circuit. This device generates a square wave current with a frequency characteristic directly resulting from the parameters of the integrated circuit"
They have also tested Dr. Beck device and plain alternating current, and plain always on DC current. Conclusion is that on Albicans the most effective device is pulsed positive offset units.
Beck device is highly effective against strong viruses like HIV, Zapper is highly effective against parasites and molds like Albicans.
Perhaps zapper just needs bit more juice, the limit is 15V on the 555 timer chip, feeding this voltage trough a step up circuit or 2x 9V batteries passed through 15V regulator should accomplish this trick.
The other thing is how to accomplish this "rich spectrum of harmonic components above 1MHz"? This suggests that "the Medikzap" device is using two frequency generators one to create low amplitude harmonics at 1MHz and the other takes that creating 20-40KHz frequency output. I think two 555 chips with two input sources 9V creating 30KHz and 1.5V creating 1MHz should accomplish this, just join the output from these two chips at plus handle. (I'm not sure if this would work as we have to return 10.5V at negative side of both batteries. I never done this so I do not know if it is feasible.)
Perhaps it is best use one V source to run the signal first through 1MHZ timer then through 30KHz timer. Again I'm not sure if that would work.
Any thoughts and contributions are welcomed to the discussion.