Mr Lester J Hendershot's magnetic generator.

[GSM]

Guys I have something to share on this thread and am in process myself of a replication from Lester Hendershot archive notes.

Gerry.

Thank you the Gerry link, also for your re-regenetion etc.
Neither for HF, nor for even making thx1138 - The Spin Field Ferrite Sleeve Antenna

Very Best Wishes ..... Graham.

[thx1138]

Radar magnet poles

I received the radar magnetron and disassembled it. The separated magnets like are shown in the L. Hendershot and Aho builds have South poles on both ends and a North pole in the center. Since there is a hole in the center there is also what feels like a neutral zone there.

I'm not sure what this means yet but will look into it further.

[thx1138]

More on radar magnets

The below images show only one side of the magnetron magnet. It is North in the center and South on the ends. The other piece is South in the center and North on the ends.
















If the Hendershot device utilizes the Wesley Gary neutral zone, that zone is not where we were thinking it is.

The magnets are quite powerful. The combined unit before disassembly would affect a compass about 3 1/2 feet away. Using one piece only, as shown in the L. Hendershot and Aho builds, the compass begins to move about 27 inches from the magnet which would project into the board holding the capcoils including the buzzer coils which are right in front of it.

There appears to be a neutral zone about 6 inches from the magnet. At about 4 inches one pole of the compass is strongly attracted to the magnet. At 6 1/4 inches the magnet needle is at 90 degrees. At 9 1/4 inches the opposite pole of the compass points toward the magnet.

You will notice the magnet shown in the above images is different from the Aho build. It is from a Russian radar magnetron which was the only thing I found that had the same physical configuration as the ones shown in the early Hendershot photos.

[thx1138]

I'm looking at this again and saw one correction I need to make: The Ed Skilling schematic showed the three pole magnet but the poles had no polarity markings.

Question for someone who knows 50's television (maybe radar display) circuits: What's special about a vertical oscillator type transformer?

The last page of Mark M. Hendershot's From the Archives of Lester J. Hendershot shows a materials list the transformers are described this way:

5:1 Ratio 24 Volt to 120 Volt Transformers
(Vertical Oscillator Type)
Red, Black, Blue, Green Coded Wires

I was thinking that since Lester used a magnet from a radar magnetron the transformers might also be from a radar display. Or they could be from a regular TV circuit of the 50's.

I've found several types of "vertical transformers" (vertical blocking oscillator transformer, vertical deflection oscillator transformer, and vertical output transformer) but I don't know, nor did I find what, if anything, makes them a special kind of transformer. It just seems to me since they were specified that way that there is something special about them.

I think Graham said in an earlier post that they were built on an E & I frame with a gap between the E & I laminations when assembled. I can see where that would affect saturation but I'm wondering if there are other characteristics that differ from a power transformer. Phase - are the primary and secondary in phase or 180 degrees out? Are the laminations made of a special material that might affect their permittivity? Is there anything else that makes them special?

[morpher44]

Carbon and Aluminium

I've stumbled upon various interesting youtube videos where people show they
can make very effective batteries using carbon and Aluminium.
Now Hendershot's cylinders were Aluminium (and possibly the magnetic kind).
Hendershot was also rumored to have used carbon rods in his design.
We also know he hand-made his capacitor, by dismantling a perfectly good capacitor, removing the oil, cutting the foil a very special way, to specific dimensions with 3-plates rolled up around the cylinder.

Now, it occurs to me that not only do carbon and aluminium produce a very nice galvanic battery, there is also potential here for thermoelectric power generation.

Imagine carbon doped inside a hand-made capacitor.
Now imagine high-voltage ARCs between the plates and thru the carbon, with high-intensity HEAT at the atomic level in this carbon-aluminium mix.

This could explain why Hendershot's hand made capacitors seem to be damaged inside when you open them.

The power from this reaction may not be the entire story, but it might be useful in starting the machine w/o the need or appearance of manufactured batteries.

Anyway, I think this is an interesting area of research to pursue with respect to reverse engineering Hendershot.

[morpher44]

Carbon and Aluminium continued...

https://www.youtube.com/watch?v=k9Zbmwf5uEQ

[thx1138]

Seebeck Effect

The Seebeck Effect is what makes thermocouples work. My first experience with one was the thermocouple on a gas water heater. The end of the thermocouple is positioned in the flame of the pilot light. The main gas valve to the heating burner detects the presence or absence of the electricity from the thermocouple. If the voltage from the thermocouple is present at the valve controller it allows the feed to the main burner to open and thus heat the water. If the voltage is not present the controller keeps the main supply to the burner turned off since there is no pilot light to light it. When the thermocouple fails the main burner will not light because, although there is a pilot light flame, the controller doesn't sense it. That's what happened to me and what got me to look into it.

Thermocouples can be made from any two dissimilar conductors. The water heater thermocouple is made from copper and iron. The key is the separation between the ends where one end is hot and the other is cool. That heat gradient between the ends is what sets up the electric potential. They can be engineered for just about any particular heat range needed depending on the materials used.

I haven't seen any documentation on carbon being used in the Hendershot device. But I guess we could consider the carbon in the metal coffee can to be the source.

I don't see it working that way though because as soon as there is a short in the capacitor part of the capcoil it is no longer a capacitor and therefore no longer a tank circuit. So it would just be a shorted coil.

What would be nice is to find a thermocouple that would work between 70F and 120F. I could then harness the power of the gradient between the attic of my house and the interior. I've never seen anything that would work on that small of a gradient though.

[dragon]

I've stumbled upon various interesting youtube videos where people show they
can make very effective batteries using carbon and Aluminium.
Now Hendershot's cylinders were Aluminium (and possibly the magnetic kind).
Hendershot was also rumored to have used carbon rods in his design.
We also know he hand-made his capacitor, by dismantling a perfectly good capacitor, removing the oil, cutting the foil a very special way, to specific dimensions with 3-plates rolled up around the cylinder.

Now, it occurs to me that not only do carbon and aluminium produce a very nice galvanic battery, there is also potential here for thermoelectric power generation.

Imagine carbon doped inside a hand-made capacitor.
Now imagine high-voltage ARCs between the plates and thru the carbon, with high-intensity HEAT at the atomic level in this carbon-aluminium mix.

This could explain why Hendershot's hand made capacitors seem to be damaged inside when you open them.

The power from this reaction may not be the entire story, but it might be useful in starting the machine w/o the need or appearance of manufactured batteries.

Anyway, I think this is an interesting area of research to pursue with respect to reverse engineering Hendershot.

It does seem to require an "initial charge" to excite the unit into operation which requires a reasonable current flow and would justify your theory of a galvanic structure to initiate a charged state. I've never achieved a self sustaining operation but once the caps are charged the whole thing pulses or vibrates. The best I could achieve on the output was lighting a 40 watt bulb at around 30 hz with a very noticeable pulsing both visually and physically. It would run about 30 seconds as the caps transferred energy back and forth until the energy was depleted.

The only schematic that would function like this was the original Aho circuit. The "buzzer" is arranged as Thx stated where both ends are similar poles. This tends to initiate a very high voltage spike upon break.

Once you understand his original 3 coil oscillator you can see what he was trying to achieve with other units. Dr Stiffler created a similar 3 coil PSEC - both of which take an enormous amount of patience to set up.

A good understanding of early microphones and pick up coils is quite helpful also - particularly the balanced armature units also known as the sound powered systems that are still in use today. You can still find the old sound powered headphones on ebay used by the Navy in ships to assure communications throughout the ship if a power failure was to occur. You'll notice one of the pictures of Hendershot standing by one of his devices used an Ader microphone to communicate signals into the device.

I've since moved on to other projects but I must say it was a fun and very challenging experience working with the mans ideas. Truly a genius of his time !

[David G Dawson]

Hendershot Detail

Dragon, thx1138,
Some good exchanges between you two and most impressed.
Dragon, an excellent build and one which works even if not full time.
Good to see someone else has built the capacitors as my unit is fully completed, not working and need to change the capacitor former to a soft Iron.
Also good that you are using the original Aho schematic.

The twin coil bell ringers, I now have 11 in my collection, are all of 500 ohms each and have been able to induce voltage up to about 3.5v simply by moving a magnet along their length.
The reason for buying these is also for the Dollard 'Cosmic Ray Detector' (CRD) but also for a Tesla Mechanical Oscillator.
Still not able to get the 'resonator' to work as per the Hendershot detail and still working on that.
thx1138 as been most helpful in the realisation that the Magnet is of the 3 pole Radar type.

Not happy with using a laminated power transformer due to frequency limitations for the 5:1 step up and am using two horizontal deflection types out of old Blaupunkts - luckily, I had two.
There is a picture somehwere of these but probably back at the other Forum.
These are of the Ferrite type with many windings and are adjustable with respect to reluctance.
Although, what Lester is using appears to be of the general laminated form but there would be some design feature incorporated that would make it more appealing for the higher frequency used in TV deflection circuits up to 15 Khz.
This may need to be researched in some detail.

Building the Hendershot Generator in itself was a lesson in construction ability and technique in particular with the basketweave coils and home-made capacitor and will not ever regret not building.
Still here waiting for another approach but too time limited as I am into a Steven Mark TPU but of a contractive type and not his expansive.

Dragon,
I should be asking some questions here like what was the final capacitance value of your caps and what did you use as the former?
What did you actually use as the 'resonator' and what voltage were you able to achieve out of the twin coils?
I didn't see a 'resonator' in your picture.
Thanks.

All the best with your builds.

Smokey

[dragon]

Hi Smokey, thanks for the kind words. I used 500 ohm coils also, tried many others that didn't work at all or worked poorly. One thing to point out that I don't think I've ever seen posted is the fact that the coil wires are also connected to the cores. I don't know where the close up picture of the buzzer came from but if you look closely you'll see the wire coming from the coil to the buzzer is connected to the core and coil. Once I saw that I realized they were shorting the coils through the core when the bar was attracted - once shorted it de energized the coils, you get a spike as it's pulled off the core by the magnets.

I don't remember the final capacitance of the wound cap, I could never get them perfectly matched - lots of screwing around with them - as close as I could get them to the stated capacitance. I tried aluminum, thin iron sheet and copper - the aluminum seemed to give the best results but its really hard to say because they all seemed to work to varying degrees - none of which I would consider completely successful.

Like you I've moved on to other projects but maybe someday I pull it from the shelf, dust it off and ponder what I may have missed...

[ProfessorTinkerer]

Greetings. Professor Tinkerer here. New to this forum, but not the Hendershot. Been researching it since the first time I saw Skilling's article in 1985.
thx1138: Can I ask where in the world did you come by that magnetron magnet? Aside from archive photos from across the pond, I haven't had any success in locating a physical one. Would love to know.

I have replicated this device three times thus far, with no success, but I have gained some insight into it's construction. There is a detail left out, which is typically the case in these unknown areas. Upon finding this forum on the net, I recently pulled out the last rendition from the mothballs and checked the cylinder cap values. It has been in storage since 2008. I was surprised to discover that they both measured exactly the same value: 9,340pF. Just a 'for what it's worth' I suppose.

Like to hear about the magnet, though. Signing off.....

[thx1138]

thx1138: Can I ask where in the world did you come by that magnetron magnet? Aside from archive photos from across the pond, I haven't had any success in locating a physical one. Would love to know.

eBay, believe it or not. It was from Poland and said to come out of a Russian radar which matches with the Wikipedia article - 3rd picture exactly matches what I received.
Cavity magnetron - Wikipedia, the free encyclopedia

I asked if he had more but the answer was no. He said he might be able to get more but they would be expensive. You might contact him.
Soviet Radar Tube Magnetron MI 189W MI 189V МИ 189В | eBay

[ProfessorTinkerer]

Very interesting. Obvious next question: Since they are a complementary pair, would you be willing to part with one of them?

[thx1138]

Very interesting. Obvious next question: Since they are a complementary pair, would you be willing to part with one of them?

They have opposite polarities. One side is south pole on the ends and north pole in the center and the other is north pole on the ends and south in the center.

I won't part with one until I have tested with both and maybe not even then. If I can get this device to work with both pieces I'll look into tying the two builds together to see if I can get that will work.

BTW, I'm having problems finding pure 30# Kraft paper for the capacitors in the capcoil. Any suggestions?

[ProfessorTinkerer]

Well, with one build I did, I used the unrolled wrap of AC starter capacitors. Finding the right length (not too short) was iffy, but I finally did find two the same. They weren't as stable as this last pair, which were actually made from sample wraps of photoflash capacitors. I used to be an engineer at a photography flash manufacturer and could obtain sample caps from several vendors. Our main supplier just sent me rolls of paper and foil complete with terminal tabs, so I was able to cut them to size. It still wasn't any fun and took a tremendous amount of planning and effort.

In answer to your question, no not really. I am of the opinion now after years of pursuing this riddle, that some aspects of the design are inconsequential providing the results yield the correct capacitance values. The different variants of the dielectric only seem to alter the overall thickness of the foil/paper wrap and require that the tension applied be altered to achieve this goal. But, I could be wrong. I still have yet to see any results from all the effort.