Here is an email I received in June, 2010, from an electronics expert in Italy, Giovanni P. It is reproduced here in its entirety as I received it in my email box except that I have corrected 1 spelling mistake and 1 punctuation error.

Dear Mr. Presner,

I received The Ultimate Zapper today, thank you for a very quick delivery. In preparing for using the ultimate zapper by reading carefully the instructions and the FAQ on your site, I came to this paragraph: "The square wave produced by The Ultimate Zapper creates a universal vibration that resonates with the broad spectrum of all pathogens at all frequencies. How does it do this? Frankly, I don't think anyone really knows, not even Dr. Hulda Clark herself. I have never seen an explanation regarding "how" the square wave creates this broad-spectrum effect."

As an audio expert and enthusiast, I thought you would appreciate if I could help you visualize how a square wave creates the broad-spectrum effect. I attach an image of an actual frequency content analysis of two 100Hz square waves with different duty cycles (these are sound waves, but the mathematics is the same). The actual frequency I used (100Hz) is unimportant, I chose it just because it's easy to work with.

wave1  wave2

The Ultimate Zapper                            All Other Zappers

The top [right] graph shows the frequency content of a 'plain' 100Hz square wave with 50% duty cycle (the same kind in use in all zappers I researched before finding yours), sampled at 192000Hz (so to be able to show as many harmonics as possible). The graph shows that the square wave contains all ODD harmonic frequencies starting from 100Hz (100Hz, 300Hz, 500Hz, 700Hz and so on 'ad infinitum'). And the harmonic frequencies get progressively weaker the higher they get. The bottom [left] graph shows the frequency content of a 100Hz square wave with 99.9% duty cycle (so nearly 100%, the same kind in use in The Ultimate Zapper), sampled at 192000Hz as well. This time the graph shows that the square wave contains ALL harmonic frequencies (odd and even) starting from 100Hz (100Hz, 200,Hz, 300Hz, 400Hz and so on 'ad infinitum'). And the harmonic frequencies keep constant all the way up. So, a square wave is actually the SUM of an infinite number of sine waves (single frequencies) of progressively higher frequencies.

The 50% duty cycle square wave contains only the ODD frequencies that are multiple of the fundamental frequency and at progressively diminishing amplitude. The nearly 100% duty cycle square wave contains ALL frequencies that are multiple of the fundamental frequency and all at constant amplitude. Most zappers operate with a 50% duty cycle at 30000Hz. So they generate a broad spectrum containing the odd multiple frequencies: 30000Hz, 90000Hz, 150000Hz, 210000Hz, 270000Hz... and so on. But these frequencies get progressively weaker, so there's a point somewhere soon along the way where they cease to be effective at all. And these frequencies are also very much 'spaced' in my opinion, risking to be ineffective on some kind of pathogens whose resonant frequency happens to lie in between those generated by the square wave...

As the Ultimate Zapper operates with a 100% duty cycle square wave at 2500Hz, it generates a much broader and denser spectrum containing ALL multiple frequencies: 2500Hz, 5000Hz, 7500Hz, 10000Hz, 12500Hz... and so on. Now, these frequencies DON'T get progressively weaker, but they keep constant all the way up. Of course there must be a physical upper limit somewhere, but that applies to ANY kind of zapper and device of this kind. In conclusion: following its specifications, The Ultimate Zapper generates way more frequencies (both in terms of density and upper limit) than any other zapper whose specifications I've checked. And that was one of the reasons for me to pull the trigger and get one.

I hope you found the above interesting and useful.

Giovanni P.


Dr. Mondo S., Ph.D., wanted proof of The Ultimate Zapper's superiority so he took his zapper to Dr. Richard Loyd, a leading researcher who makes electronic devices. The proof was forthcoming.

"I [Dr. S.] took your zapper to Dr. Loyd. I asked him to "scope" it on his test equipment. He was impressed. It was the only zapper with a true square wave and harmonics in both odd and even number frequency range. It was positive 90%, down only 10%. Almost all other zappers [generate] waves only 50-65 or 70% of the time."

Dr. Loyd called The Ultimate Zapper "the best single fixed frequency unit".


From a Naturopathic Dr. & Kinesiologist
-- received on Jan. 7, 2019

Dr. Martin C. The Ultimate Zapper does kill parasites in the GI tract and that is unique to your equipment. It also kills parasites contained with cell nuclei and larva buried within cysts, again, unique to your equipment ... I want to continue to use [The Ultimate Zapper] and recommend it ... you have developed an excellent piece of equipment of which you should be extremely proud and I am thankful you did ... You clearly have designed and manufactured a fabulous product and your knowledge on this subject is extensive and impressive. In fact, I am absolutely dumbfounded that you have been able to produce such an effective product ...

From Dr. Mitchell H.

Hi Ken,

I just wanted to give you an update on our progress.

My wife and I had a microscopic blood analysis before buying your zapper. Between the two of us, our blood showed a very large infiltration of several organism types including toxoplasmosis, yeast, fungus and trichomonas. We could also see a great deal of red blood cell damage and anemia being caused by the infestation. We were considering using the toxic parasite medicines available by prescription.

We only used the zapper around 8 to 10 times total for 7 minutes each session over the course of 3 weeks. After this short time frame, incredibly our new blood test showed the absence of all the parasites and most of the yeast and fungus. We also used some parasite clearing herbs, but the examiner was quite amazed at the incredibly fast result which I believe is directly related to your device. No drugs needed and tremendous results.

We are very happy as you can imagine. Our blood is now utilizing B12 and other nutrients that the parasites were stealing and the free radical damage is reversing very rapidly.

Your device really does work and should be a staple in every household. Thanks for your work and for providing a safe, affordable and non-toxic way for people to get well. We really appreciate it. Feel free to add my testimonial.

Thank you and best regards,

Dr. Mitchell H.
Feb 17, 2011

From Dr. Ben G. in Lusaka, Zambia

Dear Ken, I met Jo some time ago and he was able to kindly lend me your Zapper to use for some people in my house. The results are below:

Person A: Normal to lower body weight. Male. Using of hand holds only. (A) was diagnosed with Malaria. (A) had Anti-bodies against Malaria present. (A) was partially immune to Malaria, that what explains why a good number of people who live in Malaria effected areas don't even get much of a fever even if the Malaria Parasite is highly present and active in the blood.

1. Day: 3 x 5 Minutes, morning and evening

2. Day: 3 x 10 Minutes, morning and evening

3. Day: 3 x 15 Minutes, morning and evening By completion of 3. day all Malaria symptoms had disappeared. (A) mentioned feelings of well being.

4. Day: 3 x 20 Minutes, morning and evening

5. Day: 3 x 20 Minutes, morning and evening

6. Day: 3 x 30 Minutes, morning and evening

After the 6. day (A) completed a lab-test for Malaria which came out "negative".

Person B: Normal to lower body weight. Female. Using of hand holds only. (B) was diagnosed with Malaria. (B) had also Anti-bodies against Malaria present. (B) was partially immune to Malaria.

1. Day: 3 x 5 Minutes, morning and evening

2. Day: 3 x 10 Minutes, morning and evening

3. Day: 3 x 15 Minutes, morning and evening By completion of 3. day all Malaria symptoms had disappeared. (B) mentioned feelings of well being.

4. Day: 3 x 20 Minutes, morning and evening

5. Day: 3 x 20 Minutes, morning and evening

6. Day: 3 x 30 Minutes, morning and evening

After the 6. day (B) completed a lab-test for Malaria which also came out "negative". Both persons, A and B, mentioned after completing the 6 day course, that they feel very good and healthy.

Hope this information is informative and helpful.


Dr. Ben G. (Lusaka, Zambia)
Oct 27, 2008

From Health expert Imran R.

Imran R. is a health expert who is has been contributing to the AllExperts website since 2004. He has endorsed The Ultimate Zapper for various conditions.

Here is his endorsement of The Ultimate Zapper for lipomas posted to AllExperts.

Here is his endorsement of The Ultimate Zapper for ALS (Lou Gherig's disease) posted to AllExperts.

Here is his endorsement of The Ultimate Zapper for brain tumors posted to AllExperts.

Here is the index of all of Imran. R's articles on AllExperts. He endorses The Ultimate Zapper for dozens of conditions.


I am qualified [in the UK] in many modalities. Fully qualified Scenar therapist (Russian taught), Acmos Bioenergitian (trained in Paris), Electro Crystal therapist, Tai Chi Instructor, Hypnotherapist etc. I have cutting edge electro equipment and treat people ... I have used basic zappers, a Hulda Clark frequency generator with inbuilt zapper mode, a Don Croft terminator, Sota Blood Electrifier ... I feel The Ultimate Zapper is the most effective unit I have used -- ever. Strong statement? Yes it is, especially as I have 20,000 worth of equipment that relates to healing. I congratulate you on a simple device that will probably work on all [people] ... Howard G., Oct 3, 2012


Professional dowsers know The Ultimate Zapper works on the spiritual plane and have verified its superiority. At a Vancouver Trade Show a professional dowser said "The Ultimate Zapper increases the human aura by 3 times. It is a very healing instrument." Another said, "Ken, I have tested your zapper and it is the most effective zapper, by far, of all the zappers out there." Yet another said, "I'm a dowser and when I was shopping for a zapper yours is the best."

Here is an unsolicited testimonial I received on September 22, 2010 from a dowser in Texas.

From a Dowser

... I've had parasites for many years, the most nagging is intestinal amoeba, and candida. Just a note - I have used Beck's RSG-1 that I bought in 2005 but it had mechanical problems after about 2 years, so I bought Arthur Doerksen?s device. Can't remember what it's called [Auto-Zap], and it works but not very well. How do I know? Muscle testing. Want to know how I chose the Ultimate Zapper? Pendulum. I am a dowser. Yours won among all the others offered on the net. I hope you find that interesting. I am expecting some good results.

William H.


Lynda Jakiro has been my loyal UK distributor for many years. She wrote: "Ken, my spirit guides directed me to your [zapper]. I am a complementary therapist and healer and I am thinking of becoming a distributor."

Many people have felt the metaphysical healing effect of The Ultimate Zapper after being guided to my site. This is demonstrated by Well-Being in The Archive. This scripture expresses a profound truth that is my guide.

Ask, and it shall be given you;
seek, and ye shall find;
knock, and it shall be opened unto you.
(Matthew 7:7)


Gregor R. is one of many electrical engineers who have emailed me about The Ultimate Zapper's features: "I think you are going in the right direction. Your 12 points [features] are correct."

ENDORSED on CureZone and Cancer Tutor

Those who follow these two alternative medicine websites will be aware of the reputation that The Ultimate Zapper has garnered there.


I received this email about Terminator II from a customer on Aug. 10, 2010.


Thought you might be amused with the email exchange I had with Don Croft, below. [Allison B. attached a series of emails with Don Croft to this message.] I found out about zappers viewing some David Wolfe videos of Longevity Conference presentations with Don Croft and his wife, so Googled them and found their website. I was ready to purchase one of their Terminators, but Don was not at all forthcoming about his product and this gave me plenty of time to do some further searches to learn about zappers - and find your Website. You're right, the Croft's Web pages are not at all substantive ... I have to thank Don for being so hesitant to give me any info, otherwise I would have one of his (less effective!?!) Terminator models, instead of the UZnmSE [The Ultimate Zapper New Model SE] ...

Allison B."

Don Croft and Allison B.

Here is the last email exchange between Don Croft and Allison B.

On Aug. 9, 2010 Allison B. emailed Don Croft:

"... While waiting your response(s) I found the Ultimate Zapper webpages, which answered most, if not all, of my questions which I thought were legit to ask ... I'll be ordering one of those. Too bad that we could not have done business!"

And on Aug. 11, 2010 Allison B. received this reply from Don Croft:

"No problem -- it's a good zapper. -- Don"


Talking in the third person singular, David Etheredge of ParaZapper misrepresents his credentials on his website. He leaves the clear impression that he is electrical engineer. He is not. Click here for his site page with this misrepresentation:

... introduced by David Etheredge, an electronic and biomedical engineer ...

The truth about his credentials is on his resume page that he keeps off-site:

David L. Etheredge

5537 Balboa Ct. Pinson, Al

35126 E-mail: Davideth@david-etheredge.name


1976 - Present

Self taught in electronics and programming. Accomplished in both.

1974 - 1980

University of Alabama in Birmingham

Undergraduate, Biology and Chemistry. Graduate studies in Biomedical Eng.

David Etheredge acknowledges that he did graduate studies in biomedical engineering but does not specify what those studies comprised. Since they overlap the "self taught" notation in his resume one can fairly assume that he is mainly self-taught. I am also self taught -- a fact that he ironically disparages on Curezone since this fact also applies to him.

Ironically, David Etheredge conceded on Curezone that The Ultimate Zapper "may be the most powerful single frequency zapper" in the world but is now trying to undo his endorsement by a dedicated "not so ultimate" page on his site -- complete with the lies he has been making about my zapper, my site and my work for over 10 years. Realizing the damage that his endorsement of The Ultimate Zapper did to his sales he has reversed course by openly trying to trash my zapper on his site. He is now in full self-destruct mode as I point out on the Deceptive Marketing page.

Read about my step-by-step program for detoxification and revitalizing the immune system in My Recovery Protocol.