On 10/22/2014 5:13 AM, gareth wrote:
Try this ...

http://farside.ph.utexas.edu/teachin...es/node94.html

This is one of a series of lectures by a prof at Texas Uni.

In fact, if you go right back to the home page of
http://farside.ph.utexas.edu/teaching,
this leads to a most excellent revision of the necessary EM theories, and,
briefly
glancing thereto, the post grad stuff even exceeds my current interest and
knowledge.

I'm fairly sure now that this area is where I came across the governing
formula that I
alluded to recently in this NG when doing my own revision previously in
2005, although
the URLs and lecture node numbers have changed since then.

Obviously, none of this is new. It states in the article that the short
antenna is inefficient due to the wire (ohmic) resistance swamping the
radiation resistance. Your first post on this subject did not include
wire resistance in your statement that short antennas are inefficient,
which is why people jumped on that statement.

If you include wire resistance, yes, a short dipole is less efficient
that a full-sized dipole (if you can manage to get the power into it,
which is a different problem). Note that a short antenna, properly
constructed with, say, 4-inch copper pipe will be just about as
efficient as one with #12 copper wire.

Try it, please. Make the measurements. Record what you get and let us
know. We are hungry for additional knowledge.