On 3 May, 13:43, Spam Collector wrote:
While reading about antennas, I've been unable to find
answers to what I thought would be basic questions.
Most of what I've read seems to concentrate on narrow-
bandwith antennas, and even at that seems to concentrate
on what happens when lengths become shorter and ignores
the effects of longer lengths (for definitions of 'longer'
meaning 'much longer, as in many wavelengths longer).
The question is how various low-band antenna types
will perform at higher bands. For example, if I were
to run a wire around my property (about 300 x 500 feet),
giving me about 1600' of antenna length, I could run it
as a folded random wire (fed from one end), a loop (fed
from a corner or the middle of one side), or as a dipole
(if fed like the loop but cut on the oposite side).
What are the performance differences between the
three configurations, and is there a upper frequency
limit for practical use of them? For example, would it
work on say 2m or 70cm, where the antenna would be
hundreds of wavelengths long?

Thanks for any insight,
Frank
KE5MJZ

Frank, all of your antennas will work for receiving in one way or
another, the real problem is matching your radio to the antenna
whether it is for receive or transmitting the latter being the most
important. Cofiguration of the antenna determines the matching ability
as well as the directivety. The bottom line is where do you wish to
communicate to and then design accordingly which means determining
first the frequency, then the direction and then attaining a suitable
match between the radio and the antenna. If you are only concerned
with receiving then most of those requirements fall by the wayside in
terms of operational importance. The main excitement that antennas
bring is when you introduce skywave type of deflections of radio
paths, even the simplest of antenna arrangements provides unexpected
surprises that tittilates your imagination such you become more
adventurous about your desires and where you are aware that your
transmitter could easily fail if you did not take protective measures
which requires good matching between the antenna and your radio.
Regards
Art