On Wed, 10 Sep 2003 06:06:45 -0500, "Kim W5TIT"
wrote:
"Dick Carroll;" wrote in message
...
Mike Coslo wrote:
JJ wrote:
Len Over 21 wrote:
Incorrect. The word "dipole" refers to anything with two elements
and a
polarity. [a "monopole" is a single element with no polarity]
A dipole ANTENNA refers to a wire type having two elements of
wires,
balanced-fed from the center with RF voltage in opposition.
The length of this dipole antenna may be ANY length, from
near-infinitesimal
(fractional wavelength) to many wavelengths.
The radiation pattern of the dipole antenna will vary based on
many
factors:
length relative to wavelength, distance above ground or other
imperfect
conductor being the two most affecting patterns.
Len is correct, dipole simply means two separate elements (di means
two). A dipole of a certain length will be a half wavelength at xx
frequency, a quarter wavelength at yy frequency and a full wavelength
at zz frequency and so on.
Sure enough. a dipole can be anything at all as long as it has
those
two separate elements.
But do you think that is what they meant? Is the test going to
ask you
to design a dipole that won't work very well?
If I saw that question on a test,(design a quarter wave dipole)
I would
assume it was a trick question.
That a quarter length dipole can exist is in no doubt. Most of
them are
a quarter length at some frequency. But this was a mistake, and not an
uncommon one. Its okay, people do that once in a while! 8^)
The point is, Why would anyone deliberately construct a 1/4 wave dipole?
A better question would be, why would someone buy one and why would
someone build one for sale?
http://www.aerocomm.com/OEM/antennas.htm
http://www.woken.com.tw/abroad/produ...na/antenna.htm
There are probably about 15,000 more links to 1/4 wave dipoles.
Google shows over 30,000
Since they woiuldn't for obvious reasons, the fact that a dipole designed
for a
certain frequency just happens to be 1/4 wavelength at half that frequency
doesn't
automatically make it a 1/4 wave dipole. An antenna is what it was
designed to be, not
what some wag-troll declares.
For HF, you are right, for UHF, well...what can I say?
Sure, anyone *could* construct a 1/4 wave dipole, if he was that ignorant.
No one does. So
there aren't any around.
See above. When you make incorrect blanket statements like that, it
make you look....well just plain foolish.
Good 'ol DICK and the World of Absolutes.
Kim W5TIT
Dick's killfiled and his sockpuppet may be soon.