You'll find information on this kind of antenna in many publications.
It's commonly called a "discone".

Roy Lewallen, W7EL

Maarten wrote:
Tnx fer ur ideas OM's, I will surely check the books out.
I might choose a monopole conical antenna for broadband vertical
omnidirectional radiation (if I discover building plans somewhere) (if
you do'n know what a monopole conical antenna is, check out
http://www.antenna.be/vm.html )
I will keep researching this subject, so as before, all ideas and
suggestions are more than welcome.

73

"Maarten" wrote in
oups.com:

Hi,

I seek some help, advise or suggestions on HF antenna's. I've bought a
house with a plot of approx 330 x 80 ft / 100 x 23 mtr available for HF
antenna's.
But when I research HAM HF antenna's, home build or commercially
available, I only find a lot of small, smaller and smallest HF
antenna's (eg. wire antenna's, inverted V, T2DF) that don't take full
advantage of the size of my land available. On the other end of the
spectrum there are plans for very, VERY large antenna's like Rhombic
and Beverage. For this size of antenna's my plot is to small.

Do you have suggestions for HF antenna's I should check out? Let me
know in this forum or pm me. Thanx in advance. 73

You have enough room for a full dipole at 1.8mhz. That's about 260 feet
long and, if you feed it at the center with twinlead or 450 ohm ladder
line or 600 ohm open wire line and run a tuner in the shack, it will also
function as an extended double zepp on 3.5mhz. Fed this way, these
antennas are incredibly frequency tolerant. You will be able to use it
right up through 10 meters, but be aware that it will have an
increasingly crazy pattern the higher you go. For best low-band
performance, you also want it as high as you can get it, depending on
whether your interest is DX or NVIS (near-vertical incidence nearby
contacts on 160 and 80m). If DX is what you're after, you may want to
consider some alternative strategy, depending on how much height you can
achieve. But for NVIS, 85 feet is about optimum and the antenna will
play well all the way down to around 30 feet. Below that you'll see some
ground effects.

If DX is your goal, you may want to consider phasing verticals. On 160m,
spacing them about 130 feet apart can make for a fairly steerable array.
This would still leave you room for full-size radials on two sides of the
antennas. If you use smaller, base-loaded verticals, then you can get
away with even shorter radials. On 80m, you actually have a LOT of room.

I once put two Electrospace HF verticals 65 feet apart (E-W) on a lot
quite a bit smaller than this. The Electrospace verticals played quite
well with just 8 radials each of 32 foot length (about the same as the
verticals' height). I brought equal length feedlines into the shack and
made a delay box with 65 feet ELECTRICAL length of RG8X in it, cut up
into pieces of 1/2, 1/4 and two of 1/8 the total length with dpdt
switches to but them in and out of the loop. Adding one more dpdt switch
for reversing the delay to the other side completed the box. This
antenna was VERY effective on 80m off its ends. On 40m (they were 80-40-
20m verticals), the pattern was more bipolar, but sharper than the more
oval pattern on 80m when the zero-delay setting was selected (for N-S)
pattern. Similarly, it began to be a bit grassy on 20m. Still, the main
lobe of it went the same place on every band for the same settings. And
the thing was efficient and had a low radiation angle. It was easily S9+
in New Zealand and Syria from Halifax, NS on 75m. The only drawback was
that, with short antennas like that, I had to either tune at the rig and
put up with losses on the coax or go out and tune the antennas to cover
the whole 80m band. If I had the real estate today, and the gear I have
now to tune antennas with, I'd probably try something similar, though
maybe in a four-square array for 80. 80 feet is a bit tight for one of
those, but you MIGHT just squeeze it in if you're careful.


--
Dave Oldridge+
ICQ 1800667

"Maarten" wrote in message
oups.com...
Hi,

I seek some help, advise or suggestions on HF antenna's. I've bought a
house with a plot of approx 330 x 80 ft / 100 x 23 mtr available for HF
antenna's.
But when I research HAM HF antenna's, home build or commercially
available, I only find a lot of small, smaller and smallest HF
antenna's (eg. wire antenna's, inverted V, T2DF) that don't take full
advantage of the size of my land available. On the other end of the
spectrum there are plans for very, VERY large antenna's like Rhombic
and Beverage. For this size of antenna's my plot is to small.

Do you have suggestions for HF antenna's I should check out? Let me
know in this forum or pm me. Thanx in advance. 73

Maarten
maartenkoning2002 (at) yahoo.com


Check out -
http://www.bloomington.in.us/~wh2t/ant.htm

I discuss some large antennas.
73, Ace - WH2T

Congratulations Dr. Ace!

You sure know how

to trash a place!

Best regards, Richard Harrison, KB5WZI

"Richard Harrison" wrote in message
...
Congratulations Dr. Ace!

You sure know how

to trash a place!

Best regards, Richard Harrison, KB5WZI


Richard,
Yes, that's a fact.
73, Ace - WH2T