[TenTec] cone Antenna PHOTO of how to wind them which band?

[Tom Rauch]

> It is somewhat unconventional to all of us used to single wire
> antennas. That is why it works better than the Isotron, the EH, or the
> other small antenna ideas that do not contain full resonant lengths of
> conductors.

Antennas radiation is directly tied to ampere-feet of linear 
distance, nothing else. EM radiation occurs because of charge 
acceleration, nothing else. 200 feet of wire in a ten-foot physical 
length cone, spiral, box, square or anything else is a ten foot 
antenna. 

We often don't like that concept, and look for a 200 mpg carburetor 
for our 5000 pound Cadillac's, but it isn't going to happen.

> The ten meter model uses four of these folded monopoles spirally
> around the cone.  This photo shows a ONE folded monopole for ease of
> understanding. Four gets you above 90 per cent efficiency.  One can be
> as good as 60 per cent. A small loop (MFJ) may be only 10 per cent
> efficient.  But with good propagation, 10 per cent can work a lot of

That isn't correct.

On ten meters the MFJ loop antenna **measures** almost 90% efficient 
in actual FS measurements. It calculates to be over 90%, but of 
course falls short of theoretical limits. It is far above 10% even on 
30 meters, the worse band for the 10-30MHz model. Not bad for about 
three feet of linear spatial distance to accelerate charges over.

If we pack any amount of wire we like into a five-foot box, we still 
have a five-foot antenna. We can make it worse than an end-loaded 
antenna with capacitance hats, but never make it better. No matter 
what fancy shapes we use.73, Tom W8JI
W8JI@contesting.com