Hendershot Replications

[thx1138]

Sorry, I just saw this post. You should have PM'd me. I am out of town for a few days, but I will check it out first chance I get. I installed satellites for a while in my younger days, and you many just be right about that.

Dave

No hurry at all. I'm pretty tied up with holiday/family things myself.

[Turion]

Sorry, I just saw this post. You should have PM'd me. I am out of town for a few days, but I will check it out first chance I get. I installed satellites for a while in my younger days, and you many just be right about that.

Dave

[thx1138]

We have this AMAZING warehouse here in San Jose that is full of ancient equipment and old test equipment in wooden boxes. I love to poke around in that place.

Would you mind looking for something for me? I want to try a Hendershot generator armature made of permalloy but can't find anything the size I need online.

I remember some old C-band satellite receivers from the 70's/80's/early 90's that had a medium grey casting that was partitioned into internal compartments and they had circuit boards mounted inside the partitions with an aluminum top cover that was attached with screws into the casting. The assembly then was fitted into a metal and plastic cabinet to make it look better and hold the user controls and meters. At first glance one might think the casting was aluminum but the unit was relatively heavy for its size. I'm thinking that casting might have been permalloy to shield the internal microwave signals from each other and any external EM fields. That's how it was used in aviation magnetic compasses.

Since permalloy is mostly nickel and iron I think the coating might be zinc to prevent corrosion. If you scratch the casting it should be bright silver underneath the coating and it would be highly magnetic if it is permalloy or not magnetic at all if aluminum.

I'm thinking I might be able to cut a 6" X 1 3/4" piece out of one of those to make an armature but haven't found one yet.

Or if anyone remembers a make and model of such a C-band receiver that might help me narrow down the search. I opened up a DirecTV receiver a few years old and they no longer use the casting for shielding in the modern units.

[Turion]

Picked this up on eBay a while back. Thought it might eventually be good for this project or someone here might be looking for something like it.

2J39 MAGNETRON RAYTHEON HORSESHOE MAGNET VINTAGE MILITARY TUBE HIGH FREQUENCY

I don't have the time right now, but if someone else is interested, I paid $49.50 plus $15.19 for shipping.

Photo attached.

I am NOT in the business of buying stuff on eBay to resell, and this is the first time I have offered to sell anything from my collection. We have this AMAZING warehouse here in San Jose that is full of ancient equipment and old test equipment in wooden boxes. I love to poke around in that place. I can always find a coil or a transformer there of any size I can imagine, and I can imagine some pretty BIG coils!!!! So I am always buying stuff there and on eBay that looks like it might be hard to come by.

Dave

[cris]

resonator coil

has anybody used a single resonator on your project

[thx1138]

Build almost complete

The only thing remaining is the capcoil capacitors. I'm still pondering the dielectric paper.

I thought I would do some testing on what I have to determine if my theories are close or completely off the mark.

I did find some vertical oscillator transformers but they are 1:4.14 rather than 1:5. I may need to make some transformers later but thought these would be OK for initial testing.

One of my theories per the mag amp schematic is that the capcoils are the oscillators and the buzzer assembly is the power source. So I connected a line powered (120VAC, 60Hz) transformer to the right side of the Aho schematic setup where the J. G. Gallimore schematic shows the battery powered oscillator. That is the right side buzzer coil to the load connection in the Aho scematic. The transformer has dual taps so I tried it with 12V and got nothing. When I tried it with the 24V tap I get a good buzzing at the buzzer and can definitely feel the vibration in the buzzer coils. The buzzer coils are wired exactly as they came out of the telephone ringer circuit and the permalloy "heel iron" is across the back of the coils and mounted to aluminum angle for adjustment. My magnet side armature is just carbon steel cut to the size of the magnet poles because I haven't yet found a cheap source for permalloy from which to make the armature. If I can get any output at all (see below) I'll probably buy mumetal for the armature.

Interestingly, I get zero volts at the output and it's a solid zero volts. It doesn't vary at all. I've checked all connections and continuity and the circuit is good in that respect. I'm guessing the zero volt output is due to phasing of the two sides of the circuit cancelling each other out. So that's my next step - to get the two sides in phase.

[cris]

God bless us all who where looking for free energy!

[boguslaw]

Wow! You guys are better each day ! Morpher44 , definitely Tesla fountain is antigravity device plan. I believe you can build working replica of Hendershot device very soon.
Can somebody clean picture of the original Hendershot device ?

[thx1138]

A couple of interesting points

My build is coming along slowly. I ran into some information that seems relevant.

The 80/40 capacitors - all or nearly all of today's AC capacitors have an internal bleed resistor built in that discharges them when they aren't in use. That changes the schematics when you put the parallel resistors in them. Typically they are in mega Ohm ranges. I'm not sure when this practice was started but it seems doubtful that Hendershot's original build would have had them. More info and/or thoughts from anyone?

There is a piece of metal on the back of the ringer coils that I bought that ties the coil cores together magnetically. The coil cores appear to be the same material. I found that it is most likely permalloy which has interesting magnetic properties - very high permeability and very low coercivity both of which would be needed for high frequency magnetic fluctuations. The high permeability also allows it to react to weak magnetic fields. An interesting tie in is that it is about the same as mu metal which is used today in aviation magnetic compasses to shield the compass from electrical fields from the engine and other circuits in the instrument panel. I'm wondering if this is the compass tie in to Hendershot's generator. Was the magnetron magnet armature made of permalloy? The armature in the ringer mechanism that actuates the bell clapper is also permalloy.

The capcoils were said to have paraffin poured into them between the capacitor part and the coils. You can see it in the Aho photos. Paraffin has about the same dielectric constant as paper. Since the outer layer of the capacitor wrappings is an aluminum foil that isn't shown to be attached to anything, I'm wondering what the role is here. The magnetic fields from the coils would induce a current in the aluminum foil but with the paraffin separating them I'm not sure what the result would be. Any thoughts?

[dragon]

It's quite possible... I don't have a lot of experience with litz wire other than some basket coils made up for crystal radio projects. I'm not sure how it would react used with a core - possibly making it more efficient, higher Q... Other than the expense of the wire it might be interesting to wind one up and experiment with it.

[Bob Smith]

So lets say we have a coil pointing in the north south direction, in order for that coil to produce a current the magnetic field has to be "cut",disturbed, altered or blocked in some way with just enough time for the field in the core to collapse. At that point we open the gate and allow the natural field to follow its normal path through the core which generates a current in the coil. Any change in the cores state of magnetism produces a current - collapsing or naturalizing. Either collapsing or naturalizing the current always flows in the same direction unless the field is reversed.

So the question might be how to cut that field without an external power source such as wind or a small motor.... if you lay a coil and core in the north south position you could consider it charged - divert the field slightly it will collapse creating a current flow, allow it to naturalize and again a current in the same direction produced... a generator functions on a change in field strength.

Dragon,
Would a multi-stranded (litz) wire coil help in this instance? Would it not essentially provide inductors that can be charged in parallel (by a changing mag field)? If you could alter the magnetic field acting on a litz core and discharge the resultant charge thru a diode into a small cap, followed by a perpendicularly wound coil, you'd have another pulse to get the system ringing. - just a thought, probably more of a TPU question, but maybe there's something they have in common.
Bob

[dragon]

Morpher, they were using the earths magnetic field to produce a detectable signal. The spinning core wasn't a magnet only a magnetic core - iron. The strength of the field then could be measured when rotor was aligned with the 2 coils forming a magnetic path through the coil cores - producing a current flow. When it was off north the signal would be weaker and straight north was strong. Thus the deviation would show up in the meter as a high or low signal indicating how far off north they were.

Basically the induction compass was a wind generator using the earths magnetic field as the "magnets" to generate a measurable current. Most of the early units used wind to propel the rotor and later added a small motor to control the speed and increase accuracy.

If you take a long extension cord and string it east and west, connect the ends together with a uA meter and swing it like a jump rope the meter will rise and fall based on it's position in rotation in regard to north and south( moving toward or away). If you could do the same thing in a vertical position you could determine north by strength of the signal and by it's sine either east west or south.

So lets say we have a coil pointing in the north south direction, in order for that coil to produce a current the magnetic field has to be "cut",disturbed, altered or blocked in some way with just enough time for the field in the core to collapse. At that point we open the gate and allow the natural field to follow its normal path through the core which generates a current in the coil. Any change in the cores state of magnetism produces a current - collapsing or naturalizing. Either collapsing or naturalizing the current always flows in the same direction unless the field is reversed.

So the question might be how to cut that field without an external power source such as wind or a small motor.... if you lay a coil and core in the north south position you could consider it charged - divert the field slightly it will collapse creating a current flow, allow it to naturalize and again a current in the same direction produced... a generator functions on a change in field strength.

[thx1138]

Yes. I recall this picture.
There are a couple of things that bother me about it.
1. It is very poor quality.
2. You cannot work out if the light bulb is actually glowing, or if the device is just on the table with him working on it -- un-powered.
3. There can be a source of light from ABOVE, that spot-lights down onto the board. Certainly if he's inside, he probably needs the lights on to work on the unit.

So although this is an interesting picture, it is not necessarily showing the unit operating.

Even with today's photographic devices it is difficult to take a picture of a lit 60W light bulb. There's no date on the picture but I imagine it was 40's or early 50's and I don't think he would have had the best photographic equipment of that day. Probably part of the problem is also how it was reproduced for inclusion in the paper.

There is definitely another light source off to the right somewhere. Look at the light and shadows on the table (not the mounting board) on the right and left sides of the photo plus the light on his left arm (right side of the photo). Then look at the pool of light below the light bulb and the reflected light off of the capcoils, magnet, capacitors. A spot light directly above wouldn't produce those reflections and shadows and if the bulb were not lit it would cast a shadow from the light source out to the right. I would think that if it were a spot light from above we could see the outline of the light bulb and possibly the components inside it since the light would reflect somewhat from the glass bulb.

Another thing I never noticed before. That METER. At first I thought it might be an ammeter or something. But thinking about Hendershot and his desire to improve the induction compass, I wonder if that meter is actually from an induction compass, and is showing more of a turn-left versus turn-right indication, with no energy being the CENTER point of the meter.
In other words, to work out the "balance" and "tuning" of the system, he might want this device to find the "center" point.
Just an idea -- I have no evidence or anything else to back that up with other than just the idea the Hendershot worked with induction compass technology.

I did notice the meter and researched it somewhat but many kinds of panel meters (volts, amps, decibels, torque, etc.) of the period had that same general construction and layout. So without being able to read the text on the meter it's really not possible to determine what it is.

The text that accompanied the photo said it was a picture of him tuning the device. I think it would have to have been operating for him to tune it.

So I think it is definitely running or it is being powered from a wall socket which is possible since we can't see the bottom left corner where a wire could come into the circuit.

[morpher44]

left and right coils

So again thinking about the induction compass.
We need a left and a right coil, with a curious arrangement where
I think the wiring of each of the two coils are counter-wound --
one clock-wise, the other counter-clockwise.
Place a spinning magnet between them (from wind power),
and you can generate a signal that has a phase relationship
that is affected by the orientation relative to the Earth's Magnetic Field.
This signal will be WEAK at some orientations of your device
and STRONG at other orientations -- very much along the lines of the
story told about how Hendershots toy plane only worked certain
headings of the compass, but not others.
Now traditionally, you need a magnet to be spinning in this thing,
or you need a coil structure spinning within the Earth's field.
So the question is, is there a way to do this w/o spinning "physically" anything?

If our amp circuit was switched around to be an oscillator and went backwards INTO the coils, instead of using the coils for pick up, then a magnetic field between them oscillates and possibly can provide the push-pull with the Earth's field. Move the device around various orientations, and your other "pickup", very much like a Magnetometer, can thus pickup an additional "signal". Magnetometers actually kinda work this way -- a sort of backward hookup of induction compass.

So as to the L1, L2, L3, L4 coils on Hendershot's coil, yeah the bottom ones look like a transfomer, doing the conversion from high-current/low voltage, to high-voltage/low-current. I imagine the high-current side to be the tank-circuit with the hand-made capacitor. I imagine the high-voltage side as the light-bulb side. The other two coils are some sort of "pickup" or "tickler" coil arrangement to provide a feedback and phase-shift function of some sort.

Suppose you had an induction compass, pre-made. You took out the spinning magnet motor thing, and instead were tinkering with just an oscillator and the coils themselves. If you were able to "juice" up the relationships a bit by perhaps doing "more" windings, or a special way so as to reduce "wire" and "resistance", your sensitivity could be improved, and the labor involved reduced. So you might be inspired to read up on amateur radio coil winding techniques -- found in hobby magazines. You would read about basket-weave, honeycomb coils, etc. You would read about the optimum geometries for such coils, and what special wire to buy, etc. Only in Hendershot's case, he's not trying to make a radio. He rather might be taking a radio apart for the special wire, and the materials inside, to deploy in his device. His coils are for picking up this "beat" signal created with the Earth's field. So he's interested in large inductance with the least amount of wire (since wire is expensive).
In physics, you learn that there is a direct relationship between
the magnetic field and current. So that motivates you to keep resistance LOW. Hence, you have the problem of how do I keep current as large as possible, and yet create a very large inductance?
Wrapping a coil around iron is one way.
How about wrapping a coil around a MAGNET?
The B-H curve is known for IRON.
What about the B-H curve for a magnet? Not well understood.
Anyway, Hendershot appears to have taken a ring magnet,
and wrapped a special coil around it in his "special" way, or so the
story goes.

Certainly if this is "flux-gate magnetometer" or similar, then looking at the human art for these magnetometers can give a clue.
I think the key here though is how to boost that signal. How to get the best possible gain from off-the-shelf parts, and to go BIGGER than just a simple sensor.

I have worked out how you can make a compass SPIN using a horseshoe magnet, a bar, and a solenoid. It works and is EASY.
I have videos demonstrating this.
In other words, you can make the static magnetic field of a magnet MOVE using a solenoid. This doesn't take that much power, but the field at your command can be a large one if your magnet is large.
Thus with a small current, you can control a LARGER magnetic field. Doesn't this sound like AMPLIFICATION, since
current and magnetism have a relationship, and yet we have exploited or leveraged a "free" magnetic field already present in a natural magnet.

[morpher44]

watt meter

In this patent:

Patent US2444290 - Earth induction compass - Google Patents

the device uses what they call a WATT meter, to indicate
"the angle between the longitudinal axis of the system of iron cores and the direction of the horizontal component of the earth magnetic field".

Notice how the circuit in this patent has a
spinning "motor" attachment between two symetric coils, call them left and right. These are arranged to feed into a "tube" amplifier, which feeds a transformer, which then goes on to feed the watt meter.
There is a further pick-up coil arrangement near only the "right" coil,
with a phase shifter, providing the other input to the other coil in the meter. Also a "filter" is seen across those leads of the watt meter.

I can almost imagine Henershot thinking it would be fun to put a device like this in his son's toy plane, to demonstrate to his son, "the induction compass". That might have been an original inspiration, but it could have led to his discovery of how to create rotation w/o batteries.
Normally an induction compass would have "wind", as the plane flies', inspiring the rotation near the coils to generate power enough to move the meter. I could imagine he might have substituted a meter in the tiny plane with some hand made things made from coils, magnets, and iron.

When your interested in something like this, you want to show off your knowledge to family members and get them interested too, so working on this is a toy would be a way to do that, with the tiny airplane a sort of model for what he imagines could be productized once he's worked out the kinks.