Richard Fry wrote:
"Cecil Moore":
Jimmie D wrote:
One such mistake is calling a 4 ft long antenna that has a coil to
make it resonate on the 10M band a "10M loaded 1/4 wavelength antenna".

They should be more careful and specify that they are
talking about electrical lengths, not physical lengths.

They also should point out that, although a radiator
physically/electrically shorter than needed for first self-resonance can
be "loaded" to resonance, this does not mean that loaded and
self-resonant radiators perform equally well in an installed system. In
some applications there can be as much as a 100:1 difference in their
radiated powers, for a given power at the transmitter output connector.

Good point, Richard. An antenna's ability to "load"
is proportional to its electrical length. An antenna's
ability to radiate seems to be proportional to the
physical length of the antenna that is carrying the
highest current. In 75m shootouts, the mobile antennas
with the loading coil furtherest away from the feedpoint
(closest to top-loaded) generally won the shootout.
--
73, Cecil http://www.w5dxp.com

On Feb 2, 11:14 am, Joaquin Tall
wrote:
Hello All,

I have just gotten my tech license and am eager to get my station up and
running. I am starting on a shoestring; currently, I have no equipment
whatsoever and don't know what I should buy just yet. In absence of a
rig, I am now studying to pass my General license exam next month.

I am very interested in building my own HF/VHF/UHF antennas. I've seen
the ARRL books, but I was hoping that you good folks might have some
favorite websites, book titles or magazine issues [old or new] that
you'd be willing to pass along that could get me started.

Many thanks for taking the time to respond!

After you thrash your way through the ARRL Antenna book (which
includes a CD with the entire searchable text.. very handy, as well as
some useful planning programs like HFTA)...

Another book that is quite useful are ON4UN's Low Band DXing... yes,
the focus is on 40m and down, but there's lots of good construction
info, as well as matching networks, etc.

And, finally, I think everyone who's seriously fooling with antennas
should get a copy of J. Kraus, "Antennas". This is a standard
textbook on the subject, and I find it much more accessible than, say,
Balanis, although the theoreticians tend to prefer Balanis, because of
the rigor.

Finally, if you need math stuff for antennas.. Sophocles Orfanidis at
Rutgers has an online electromagnetics and antennas textbook that I
find very handy (because it's online, and you can download the pdfs
and carry it with you on your laptop)... http://www.ece.rutgers.edu/
~orfanidi/ewa/ Orfanidis also has a bunch of very useful Matlab (or
Octave) routines as an appendix to the book.


Jim, W6RMK

"Joaquin Tall" wrote in message
...
Hello All,

I have just gotten my tech license and am eager to get my station up and
running. I am starting on a shoestring; currently, I have no equipment
whatsoever and don't know what I should buy just yet. In absence of a
rig, I am now studying to pass my General license exam next month.

I am very interested in building my own HF/VHF/UHF antennas. I've seen
the ARRL books, but I was hoping that you good folks might have some
favorite websites, book titles or magazine issues [old or new] that
you'd be willing to pass along that could get me started.

I will make my (usual) pitch for the j-pole antenna.

Take a look at http://www.hamuniverse.com/jpole.html and see what can be
done at UHF/VHF with a few pieces of pipe, some solder and a torch. The
j-pole is a good match after a little fiddling, It's durable, requires no
ground plane and can be mounted almost anywhere. I have made about two
dozen of them for myself, for RACES and for friends in the local club. My
first one (early 90's) is on the roof of my house and I used it on 2m
earlier this evening, as I do most evenings.

Search google.com for jpole antenna and see about 40,000 other links.

The "quad antenna" and its cousin the "quagi," a quad/yagi hybrid, are also
possible, but I've never built any of them, myself. The venerable
whip-over-downward-radials is easy but can be tedious to tune for a good
match. (I built one of them onto a construction hardhat as an novelty; got
a good match, too.)

I'm next door to you in Chula Vista, by the way.

KD6VKW
http://members.cox.net/sobars/

On Tue, 6 Feb 2007 20:55:54 -0800, "Sal M. Onella"

Don't ever sell the good ol' Di-Pole short! Besides being CHEAP,
it's easy to set up and take down, and not too annoying to the
neighbors ether.

If you got one set up, you can sling a wire under it and turn it
into a "Cloud Warmer", and that has a whole lot of interesting
possibility right there too.

73's
FFF




wrote:


"Joaquin Tall" wrote in message
.. .
Hello All,

I have just gotten my tech license and am eager to get my station up and
running. I am starting on a shoestring; currently, I have no equipment
whatsoever and don't know what I should buy just yet. In absence of a
rig, I am now studying to pass my General license exam next month.

I am very interested in building my own HF/VHF/UHF antennas. I've seen
the ARRL books, but I was hoping that you good folks might have some
favorite websites, book titles or magazine issues [old or new] that
you'd be willing to pass along that could get me started.

I will make my (usual) pitch for the j-pole antenna.

Take a look at http://www.hamuniverse.com/jpole.html and see what can be
done at UHF/VHF with a few pieces of pipe, some solder and a torch. The
j-pole is a good match after a little fiddling, It's durable, requires no
ground plane and can be mounted almost anywhere. I have made about two
dozen of them for myself, for RACES and for friends in the local club. My
first one (early 90's) is on the roof of my house and I used it on 2m
earlier this evening, as I do most evenings.

Search google.com for jpole antenna and see about 40,000 other links.

The "quad antenna" and its cousin the "quagi," a quad/yagi hybrid, are also
possible, but I've never built any of them, myself. The venerable
whip-over-downward-radials is easy but can be tedious to tune for a good
match. (I built one of them onto a construction hardhat as an novelty; got
a good match, too.)

I'm next door to you in Chula Vista, by the way.

KD6VKW
http://members.cox.net/sobars/