Mr Lester J Hendershot's magnetic generator.

[mikec_ut]

...
First of all I agree the working of the device is not what it at first seems the most logical explanation. The collector being the main distraction. In my opinion, this small plate does nothing more than shield the underlying components, and may pick up some very small signals to input to coil #006. But that's not the case. After having read other information, it becomes clear that the oscillation starts because of the special arrangements of coil #008 a/b and coil #006. Most likely the oscillation process is positively influenced by coil #004 / soft iron core #003, coils #013 and #015 with soft iron cores #014 and #016 together with resistor #017, and resonator #002.

Wire #005 and collector #001 are - in my opinion - an added distraction. The mystery is around #008 a/b and coil #006. A ring magnet must be added to the build. A big one that fits inside coil #008 a/b (3'' outer diameter, 2.5'' inner diameter, 2-2.5'' thickness, preferably alnico 5, polarization either diametrically or radial). Did you do that mikec_ut or are you planning to?

...

Finally, the coils a/b are part of the mystery to solve here. They must be wounded in a special way, possibly honeycomb, or basket, but I wouldn't be surprised if they are wound using a combination or even a different method.
This is why I'm going to concentrate around this part of the MK1/2 device and am sure to find out some real interesting stuff when I'm finally at the bench, testing.

@pjotterkjen
The ring magnets that I have are 2 3/4" x 1 1/4" x 1/2" not big enough, the ID is a little narrow. The only reason I have not placed a ring magnet inside coil a/b is because I am have a mental problem with the weight of those magnets. The size your suggesting will almost consume the entire space within the coils. I build a/b in a basket weave (not honeycomb) and combined them on the same form (both coils interleaved together) with a 3" dia. it leaves no room for any ring magnet.

However, if coil a/b were 2 separate coils, one inside the other the height would be 1/2 the size and the combined coil could sit on the ring magnet. One of the combinations of coil design was to make the dual coil in a basket weave layer but honeycomb together to overlap the field that could be generated. There are just so many things to try.

I am still not sure about the ring magnet on the MK1. At the air force base where the construction was be made the MK2 was the model. Besides the new coils within coil a/b all the other parts were the same as MK1. We are still missing something. The 3" dia coil a/b that I made is only 2" in height, your ring magnet would be taller than the coil. I don't need to copy the MK1/2 I want to understand and just make something work. If the ring magnet will do the trick I am good with that.

[GSM]

Hi Mike and pjotterkjen,

I recon coils 008a-b won't work with a large metal, field shunting, ring magnet closely inside of them. A lesser diameter might shunt less but would the overall field polarisation be correct ?

However a larger sized axial field polarising ring magnet external to the coils and close to one end - as a unidirectional Earth field substitute - might have been a possibility concealed within Lester's Mk2 model aeroplane.

Also there is no reason why we should not be able to drill apart older type loudspeaker ring magnets, or fabricate our own with iron/steel wire/rings either side of tiny neody magnets circumferentially spaced.

Cheers ............... Graham.

[pjotterkjen]

MK1/2 considerations

The ring magnets that I have are 2 3/4" x 1 1/4" x 1/2" not big enough, the ID is a little narrow. The only reason I have not placed a ring magnet inside coil a/b is because I am have a mental problem with the weight of those magnets. The size your suggesting will almost consume the entire space within the coils. I build a/b in a basket weave (not honeycomb) and combined them on the same form (both coils interleaved together) with a 3" dia. it leaves no room for any ring magnet.

OK, I see your point. The weight would be an issue if you consider that it was built in a model airplane. While you are considering double height, I'm considering a total height of only 2-2.5" here. Let's make it 2" height.

IMO the ID of 2.5" should leave enough room to fit in some small coils, but well I'll have to find out at the bench. We know that Major Lanphier stated the first device he witnessed had a ring magnet smaller than 3", but we don't know that for sure. So the OD may well have been a bit more, say 3.5". Then, an ID of 3" would have more space available of course.

However, if coil a/b were 2 separate coils, one inside the other the height would be 1/2 the size and the combined coil could sit on the ring magnet. One of the combinations of coil design was to make the dual coil in a basket weave layer but honeycomb together to overlap the field that could be generated. There are just so many things to try.

If I remember well your pictures, you built a basket coil where two coils are on top of each other. But in the drawings these two coils a/b are on top of each other. The airplane picture does not indicate much height too.

So in the end we'll only need a ring magnet that's about 2-2.5" high. Still the weight could of course be a problem - if building it as an energy source for a model airplane - but I'm not worried about that for the moment as I'm concentrated on the how to make it oscillate mystery.

I am still not sure about the ring magnet on the MK1. At the air force base where the construction was be made the MK2 was the model. Besides the new coils within coil a/b all the other parts were the same as MK1. We are still missing something. The 3" dia coil a/b that I made is only 2" in height, your ring magnet would be taller than the coil. I don't need to copy the MK1/2 I want to understand and just make something work. If the ring magnet will do the trick I am good with that.

According to what I've read, both the MK1 and MK2 were shown at the Selfridge Field; we also know the ring magnet was at least in one of them and I think that would be the MK2 design, where energy was generated in all (I assume horizontal) directions. Major Lanphier confirms having seen a ring magnet too.

We may still be missing things, yes. But we're also getting closer.

Now pay attention to this. I remember having seen a youtube video from a user Magnetflipper, he shows us what he calls the Magnetic Vortex Spinner. See it here: MAGNETIC VORTEX SPIN its against the LAW built by Magnetflipper Sept. 2011 - YouTube

This rotating effect is exactly what Hendershot must have been exploiting while trying to invent a better compass, and then while testing with devices based on the Earth Inductor Compass, he lliterally stumbled upon the effect that the two windings armature must have started spinning without applying any external energy source... so then he got excited and thus changed plans and started his MK1 device.

Looking at the video again, I was struck by the resemblance of the copper blades when comparing them with the two copper windings inside the Earth Inductor Compass.

The Utility Engines article I referred earlier to, which is a document hard to comprehend and mixes up several devices, refers also to these windings rotation and *short-cut* on each side... this is the same case as in the video!

The same document states that the ring magnet and the two wound coils around it (no on it) were only necessary to 'sensitize' the inner windings and get the thing spinning. So this ring magnet later disappeared when Hendershot invented slowly the MK3 design, but then again I could be mistaken. Whatever he did in between we'll never know.

OK. So to continue, whatever you may try to explain the spinning effect - whether it is a magnetic vortex spin or not - there is a resulting force on each of the four blades that amplify the others, and this results in a spin with considerable speed.

We'll need to take this to the MK1/2 devices somehow. Hendershot found a way to not use the rotating inner two windings and commutator... but used instead a set of coils and cores positioned in such a way that somehow inside coil #008 a/b a spinning magnetic field was generated. In this sense, maybe the collector #001 and wire #005 were still necessary to start the magnetic oscillation (and thus not a distraction). This oscillation having a positive feedback by the other components used.

So I'm convinced having found some basic principle to work from, by looking at specific parts of the device, and trying to reason why those parts are actually in the device.

I'd say let the adventure continue!

[thx1138]

Hi thx1138.

I did not reply to your Double Coil Relay contribution because I was not sure why you had included it, and I was not going to make any assumptions.

Sorry, but I missed this one earlier. Remove the vertical magnet between the coils and what remains is a pivoting armature above two coils wound to have opposite polarities.

These devices actually exist and come from pay phones. The coils are triggered to direct the coin to the hopper or the return tray in the pay phone. So maybe LJH wasn't using ringer coils at all but one of these devices with the central magnet removed.
Antique Telephone History Website

Figure 1 at that page shows a drawing of the entire device and figures 2a, 2b, and 2c show that the magent should be easily removable.

[GSM]

Hi thx1138.

Thank you for your last post - I'll reply shortly.

Before I continue, I wish to first mention something I do not wish to become a part of this thread, and it relates to many YouTube reports in some parts of the United States over the last two days, this being falls of fake (polymer based) snow.
Do Internet searches about it. Kids can buy it. Some versions will chemically take up 500X water to the fundamentally active microscopic white powder particles. It does not "thaw" like real snow either.
Now we've all seen un-naturally spreading jet trails up in the sky along flight paths not always at heights or directions of those having flight controlled commercial pemits.
Well I was found unconcious and hospitalised with a serious "kidney infection" during Nov2013, and coincidentally there was a "snowball" in my closed back garden which took about 10 days to disappear even though temperatures were nowhere near freezing. After examining it and realising it was NOT SNOW I stayed well clear, but at that time I was not aware of the existence of fake snow polymers, nor the directly related possibilities now being observed in the USA.
A parallel aspect relates to our mains tap water, for we have distilled all of our drinking water for more than four years without problems. However in Nov2013, just before I found the polymer type "snowball", I noticed this off-white creamy gunge in the bottom of the distiller. It looked as if a bacterial or fungus like sponge, except this was after the tap water had been boiled off at 100'C !
I complained to the Water Board. They took the gunge away for analysis and promised a phone call to let me know what they found.
No reply = no surprise !
There will not be any follow up from me either because I realise that microscopic polymers raining or snowing out of weather controlled clouds is way beyond anything the water boards can control.
My metabolism has still not yet fully recovered from the truly shocking hit I experienced, and I can now imagine wider polymer related damage to our environment and all life within it (human mental capabilities especially) arising via those "authorities" who give themselves rights to act in totally un-natural ways.
See here what I did not drink !
Got yourselves a water distiller yet ?

[thx1138]

Resonant Ring Cavity

I stumbled upon this this morning and it really grabbed my attention.

This first link is to the original article that got my attention. It is about sound and that interested me because sound is a longitudinal wave. The phrases that stood out were:

"a new physical mechanism to break time-reversal symmetry and subsequently induce nonreciprocal transmission of waves". Non-reciprosity is a key to OU, i.e. don't consume the dipole.

"At the core of the team's sound circulator is a resonant ring cavity" which got me thinking about the Hendershot cap/coils.
To hear without being heard: First nonreciprocal acoustic circulator created

I explored "ring cavity"and "ring resonator" which took me to the following links. Most of what I found was about light and lasers but it may be applicable to magnetic circuits also.
Ring Resonators
Scroll down a bit in that PDF file and the drawings should grab your attention.

For those of you looking at ring magnets, the following animation should get your attention.
Optical Ring Resonator

The other thing that popped up in my mind was Eric Dollard's explanation of the fields of DC transmission lines being between the conductors, i.e. the straight lines outside the ring resonators.

I haven't really figured out how this ties into Hendershot other than the north/south parallel lines of the earth's magnetic field lines could be a clue and the fact that the magnet in the Mk3 being between everything else.

Seems this would have major interest to those working on the Mk1 and 2.

Other chores to do today so I'll come back to it later but thought I should pass this along.

For more info seardh "ring cavity"and "ring resonator". There's a lot of it out there.

[thx1138]

Barkhausen effect

An excellent video to understand the Hendershot Mk3 is at the link below. At about 2:56 the demonstration uses a soft iron rod. Note that the static created by the amplifier is heard both when the magnet is moving toward and away from the coil. It also explains why iron is preferable to steel and shows, while using the steel bolt, the effect of reversing the magnetic field.
The Barkhausen effect - YouTube

Looked at in this light, the rest of the Hendershot device is the amplifier.

[pjotterkjen]

Thanx for your pointers thx1138, will continue my research this weekend, finally hope to have a bit more free time to continue my testing too.

[thx1138]

No neutral zone

I finally got my hard drive magnets and encased them in a resin block. The ones I received were only 45 degree arcs so I had to use four per layer to get a 180 degree arc to simulate the horseshoe magnet. I stacked them four high. I should have had 5 layers from the 20 magnets but broke one getting it off of the backing plate and dropped another one and it broke.

I sanded away the resin around the ends of the arc to expose the ends of the "horseshoe" with a belt sander. The field at the ends was strong before sanding but stronger still after sanding.

I couldn't find a neutral line by trying GSM's experiment with the rod and coil. I can get the compass needle to spin but I'm using a larger compass and the needle is mounted on a wheel showing five degree markings. I think it is more the momentum of the compass wheel carrying the wheel around to the next pole than a neutral zone. I also didn't have and couldn't find a ferrite rod locally so used steel.

So maybe the hard drive magnets won't work. I'm not sure where to go from here. I'll probably try a soft iron rod if I can find it.

[gyula]

I finally got my hard drive magnets ....
...

So maybe the hard drive magnets won't work. ...

Hi,

Hard drive magnets are magnetized in an unusual way with respect to "normal" magnets. They have two unlike poles on one side and also two unlike poles on the other side of their thickness. Here is video to show this:
How To Find The Polarity Of Hardrive Magnets - YouTube

For simple tests to find the neutral zone you could use soft iron like a keeper, no real need for a ferrite rod yet. The latter will be needed when you want to take out power from the coil wound on the keeper (to reduce eddy current which is bound to occur in a soft iron piece unless you use transformer laminations or indeed ferrite rod).

For the neutral zone, you need one pole say S from a rod or disk-like magnet facing one end of the keeper and the other pole say N from another rod or disk magnet while an iron yoke also bridges the other side of these two magnets (as a horse shoe shape does). In case of a hard disk magnet this 'one S - one N pole' facing the keeper cannot be achieved becasue there are always two poles at the edges of such magnets.

Gyula

[thx1138]

Hard drive magnets are magnetized in an unusual way..."

That explains it. I earlier just tested them at the ends, not the faces. I guess I'm done with this project. I'm not willing to spend $500 to build a project that no one even knows how it is supposed to work. With no access to radar magnetron magnets and no info on the magnet pole face size, type of magnet material, or magnetic field strength it is purely a shot in the dark that would cost too much for me to only light a light bulb. If I remember correctly, somone in the first tests said the magnet would need to be replaced after 2000 hours so it wouldn't even provide enough power to pay for itself. The replacement magnet cost would excede any benefit derived from the device. Of course that's not a factor in government sponsored projects like the early air force tests because they have virtually unlimited budgets.

[thx1138]

What's missing?

What is missing from all of the schematics and drawings and the builds that don't work that is in the builds of Lester Hendershot and the Aho build that did work? Look at the attached paste up and see if you can see it.



Then check out the video at the following link from 18:30 to 26:00 paying particular attention to what is said at 25:25.
Primer Fields

[GSM]

What is missing from all of the schematics and drawings and the builds that don't work that is in the builds of Lester Hendershot and the Aho build that did work?

Hi to you thx1138.

I have become very seriously unwell via thus column, but I also trust that you too and otherwise are remaining well.

I also expect remained expressed here, with your own remains similar completely usefull here, and still not yet properly investigated.

Very Best Wishes ..... Graham.

( Then check out the video link from 18:30 to 26:00 paying particular attention to your point out at 25:25. )

[thx1138]

Hi to you thx1138.

I have become very seriously unwell via thus column, but I also trust that you too and otherwise are remaining well.

I also expect remained expressed here, with your own remains similar completely usefull here, and still not yet properly investigated.

Very Best Wishes ..... Graham.

( Then check out the video link from 18:30 to 26:00 paying particular attention to your point out at 25:25. )

Sorry to hear of your problems. I am physically fine but have suffered a few hits with loved ones and finances recently.

Here's what is missing from the non-working builds. The magnets were said to be radar magnets and the ones shown look like what is used to make a radar magnetron. I don't know, however, how radar magnetron magnets are magnetized or what their field would look like. I think assuming the magnet is magnetized like a regular horseshoe magnet may be a mistake.


Note the jets coming out of the hole in the Primer Field videos and keep in mind that the plasma is just demonstrating the shape of the field. He never says, however, how his bowl magnets are magnetized other that saying they a "specially prepared".

Also note the underlined text in the bottom right of the image. Radar magnets are designed to create a magnetic field along the axis of the hole in the magnets which is what leads me to think they are not magnetized like a horseshoe magnet. The bottom, left image is just my guess as to how radar magnets are magnetized.

[smoky]

Mr Hendershots Generator

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

If anyone's looked at parametric oscillation/amplification as in eg https://www.youtube.com/watch?v=ekaeS8AmerY and many others.

It can be seen we need to pump an oscillator circuit at twice it's resonant frequency to maintain free running oscillation.

In a photo of Lester Hendershot beside his machine a normal AM radio can be seen in the picture.
AM band covers from 525KHz to 1605KHz this radio was part of his test equipment.
He did not have or enjoy the ease of test gear we have today so was a pretty smart guy.

I believe he tuned each tank circuit coil for resonance on the low end of above AM band.
The drive excitation to do this comes from the local oscillator itself within the superheterodyne aerial winding inside the radio. By holding the radio's aerial in cabinet close to the basketweave coils he was likely able to tune them both close to identical.
If we label basketweave coil 1 as freq A and basket weave coil 2 as frequency B, by cross coupling them with coil windings we can have frequency A plus frequency B. Since they're just about equal frequencies we can say freq A=B which is same as Freq of 2 times A and two times B.
This is basic requirement for parametric amplification.

Now if you follow me so far these tank coils are not phase locked ...they're free running which means they will wander off frequency over a few hundred cycles so freq A minus freq B can be anywhere from 0 Hz thru to several hundred Hertz. Not a stable setup really.

In old CRT TV sets the vertical frame output frequency was 50Hz, in EUR countries and 60Hz in USA ( not to be confused with TV horizontal scan frequency of 15.625KHz).
So anyhow by using the two low frequency frame output transformers he was able to pick off the difference frequency between basketweave coil A and basket weave coil B. The small A & B difference would still allow parametric amplification to occur because running at 500KHz or so, when we divide the few hundred Hertz difference by the resonant frequency of 500 000 Hz the phase degrees per cycle error isn't very great.

The large electrolytics in series with his vertical output transformer primaries was to cancel the series inductance making them broadly series resonant at the low freq A - B.

The actual power generation I think is done by the magnetic buzzer, this is a threshold device, delicately balanced within a strong differential magnetic field. It was able to also respond at the low audio frequency difference rate between basket weave coils A and B. Once energised broad frequency high energy splatter (or RFI as we'd call it today) is enough to keep both basket weave coils shock excited and power the output circuit.

Basketweave design was for highest Q value he could achieve in the day, by minimising interwinding capacitance without access to todays ferrites.

In a modern design we'd probably use the spin field antenna approach instead eg The Spin Field Ferrite Sleeve Antenna

Hope this helps anyone else considering taking the project on.
Gerry