The homotenna (homopolar motor + antenna).

[broli]

The shielding material will act similar to the braided or woven wire around the dielectric of a coax cable (B in the image below)?  We can use flat pieces of copper wire on top of thin pieces of tin foil which will be split up into regions around the magnet according to the osscilating current, since we won't need the flexibility of a braided wire, and this should offer better shielding performance.

I really like this concept.

GB

Yes, a ring magnet would be easier to shield in segments either by wrapping wire around slices of it or using some kind of coil. The magnet should preferably not have a metallic skin like a the nickel coating on neo mags. Also I didn't mention this but the piece of wire can really be a coil as well.  So you are not limited by driving voltage. The way this is done is by simply using a shielded wire like you showed and removing the insulation/shielding layer around the part that's going to do the actual emmiting. This way you can have arbitrary large currents at modest frequencies.

[gravityblock]

What are your thoughts on using the concepts of a mult-wave oscillator (the magnet being sandwiched between two plates with concentric ring(s) to produce static longitudnal waves)?  It is known that waves of varying length do not interfere with one another as is shown by radio, even though they occupy the same area of space.  The multi-wave may complicate things in regards to the shielding, but we don't have to use mult-waves with this concept. We could always use a single ring in each of the antennas, which would oscillate at only one frequency.

Here's a video of Eric Dollard explaining a multi-wave oscillator:
Part (2 of 5) http://www.youtube.com/watch?v=aiN0kZZ-vrA
Part (3 of 5) http://www.youtube.com/watch?v=XUrzZLVH6ng

GB

[broli]

It's all good as long as you have the asymmetry, namely shielding parts of the magnet. It's indeed pointless to radiate all the energy, with the proper enclosure you can create standing waves which could increase efficiency and power a lot.

[exnihiloest]

I'm not. What you mention is what exactly what should be prevented. The constant field of the magnet can go outside the shield. However the field of the wire cannot go inside the shield and torque the magnet.

You want a constant external field of the magnet. Or else that variation effects the wire and causes it to induce a current and you don't want that.

I find the setup rather obscure. You explain effects but not the principle.
You named your device "homopolar motor + antenna" but it is not homopolar because I is AC. And in a homopolar motor or generator, the current must be perpendicular to the magnetic field in order the Lorentz force to apply.
Then here why should the magnet rotate? What are the forces which exert a torque? Are they acting onto the shield or onto the magnet? Where are they coming from and how?

[broli]

I find the setup rather obscure. You explain effects but not the principle.
You named your device "homopolar motor + antenna" but it is not homopolar because I is AC. And in a homopolar motor or generator, the current must be perpendicular to the magnetic field in order the Lorentz force to apply.
Then here why should the magnet rotate? What are the forces which exert a torque? Are they acting onto the shield or onto the magnet? Where are they coming from and how?

I suggest you re investigate how a homopolar motor really works I've addressed this many times. Unlike what the most popular google searches tell you, it's not the spinning disc that causes the torque but the outside brushing circuit. When the disk is attached to the magnet the forces on both cancel out due to newtons third law. However you still have the force interaction between the magnet and outside brushing wire.

This concept attempts to exploit the fact that you can only use that "outside" circuit without a real return path for current. Current goes forward in the single wire circuit and torques the magnet forward, and when it's about to go back the magnet is shielded from the supposed field of the wire which wants to rotate it back.

Even though Lorentz's force is an incomplete concept you can still show that it holds. Use the famous right hand rule and you'll see that the magnetic field either pushes the wire piece up or down depending on current direction. And what do you think the reaction of this force affects? The answer is the magnet, it will be seen as a torque.