RadioBanter - View Single Post - No antennae radiate all the power fed to them!

[email protected] · November 3rd 14, 05:46 PM posted to rec.radio.amateur.antenna

rickman wrote:
On 11/2/2014 3:58 PM, wrote:
Lostgallifreyan wrote:
wrote in :

Apples and oranges; we already know what will happen if one were to
build an antenna from a superconductor.

Fire up EZNEC and set material loss to zero; done.

Yeah, anyone with a map could say a great deal about the shape of West Africa
based on ocean travel.

Again, apples and oranges as we know EXACTLY and in DETAIL what would happen.

My point isn't so much about antennas, as about
exploring the easy availability of cold environments for superconductors in
space.

Easy availability measured in thousands of dollars an ounce to get
stuff there.

Not having to lug heavy coolers up there might be an offer someone
cannot refuse, and that someone might come back with all kinds of
discoveries, things no models or predictions are going out there to find.

The only thing that makes a superconductor different is the lack of
resistance.

That is far from true. There are all sorts of magnetic effects.

All of which are due to the lack of resistance which results in enormous
eddy currents.

Are you familiar with the eddy current dampers found on some balance
scales consisting of a piece of aluminum between two permanet magnets?

If the scale is see-sawing up and down, the eddy currents induced in the
aluminum generate a small magnetic field in oposition to the motion,
thus damping the motion.

Replace the aluminum with a superconductor and the scale is no longer
damped, it is locked into position because of the huge eddy currents
from even the slightest movement.

--
Jim Pennino