Alan Taylor wrote:


Alan Taylor wrote:
I have some space and some high trees. I already use a 400ft doublet with
atu for several bands and a 30m half square and get good results. I want
to improve my performance on 17m. I am now thinking about a wire
antenna with reasonable performance for 17m only. I have thought about a
full wave loop, even a bobtail. A broadside array would be great but I
am not keen on antennas with reflectors or directors because of the
complexity of support ropes. So, really some kind of antenna supported by
ropes from two trees would be ideal. Any ideas please?

Alan VK6BN

The EDZ is the easiest I suppose. About 5.1 dbi/3dbd if I remember
right.
You could run two half wave dipoles, spaced a half wave apart
with rope. Feed in phase. Also good for about 3dbd. The lazy H
antennas could be run between two trees. Too bad you can't run a
yagi. That what you really need.. Or at least the most bang for it's
size,
and it can be steered. Also, I guess you could run a larger franklin
type
array. IE: 3 or more 1/2 wave elements. BTW, you also can use
"extended"
lazy H type arrays where the elements are EDZ length. Gives more gain
than the usual 1/2 wave lengths.
MK

Alan Taylor wrote:
Roy, ruling out quad loops and multi element antennas what do we have
available? I like the idea of working both LP and SP to the US but if you
have an idea for a wire antenna supported by only two ropes I would consider
that. What would the pattern be like for a bobtail with extra vertical
elements spaced the usual half wave? With the trees I have in mind I could
possibly fit in six vertical elements.

Of course, what I'd recommend is that you model some of these antennas
with a program like EZNEC. The free demo program is adequate for some of
the antennas you're interested in. The demo program is able to model
some more complex arrays with quite an accurate pattern -- what suffers
is the accuracy of the reported feedpoint impedance.

One antenna you might consider is the "Field Day Special"
(http://eznec.com/Amateur/Articles/Fi...y_Special.pdf). It has two
elements, but can be suspended with two ropes by using spreaders made
from PVC pipe or other light weight material. The advantage to this
antenna over some others is that it has a unidirectional pattern which
is easily and instantly reversible. With a unidirectional pattern, you
get a broader beamwidth for a given amount of gain, compared to a
bidirectional array. It also reduces QRM off the back, but of course you
get more to the sides of the broadside direction since the beam is wider.

Roy Lewallen, W7EL

Some good ideas, thanks.
Uni or Bi directional are both OK. I can get about 55ft in height. I just
want to use the space I have as effectively as I can for a 17m antenna. I am
OK for quite a few bands with my existing antennas but cant put up my tower
because of the visual impact! I will look at some of the antennas you have
suggested.

73 Alan

"Alan Taylor" wrote in message
...
I have some space and some high trees. I already use a 400ft doublet with
atu for several bands and a 30m half square and get good results. I want to
improve my performance on 17m. I am now thinking about a wire antenna
with reasonable performance for 17m only. I have thought about a full wave
loop, even a bobtail. A broadside array would be great but I am not keen
on antennas with reflectors or directors because of the complexity of
support ropes. So, really some kind of antenna supported by ropes from two
trees would be ideal. Any ideas please?

Alan VK6BN

Try this
http://www.gopherlink.com/DeltaXray/...rComments.html

Rich
*********************************************NN
"Jim Leder" wrote in message
...
If you can get it high enough, and I assume you can, why not a Delta loop
with the apex at the bottom? I have tried several different 17 meter
antennas, but the Delta loop is the best I found. True, it is only
bi-directional, but mine is NE/SW and works pretty well in those
directions. I use a Sigma 5 vertical dipole for everything else, but the
loop is better that the vertical in it's favored directions by a lot.
I also used a half square on 30 meters, but have since removed it in favor
of a simple inverted vee. I found the half square, while very effective on
transmitting, was noisy on receive. The vee 'heard' things better and
seems just as effective on transmitting. Fortunately, I was able to get
the vee's apex up to 45 feet. Anything lower than that favors the half
square on 30. I mention this because I also tried a half square on 17, but
the loop was MUCH better.

--
Jim Bob Buckeye
AKA
**** Jim Leder****
K8CXM since 1961
IBM retiree since 1999
http://home.fuse.net/k8cxm/


"Alan Taylor" wrote in message
...
I have some space and some high trees. I already use a 400ft doublet with
atu for several bands and a 30m half square and get good results. I want
to improve my performance on 17m. I am now thinking about a wire antenna
with reasonable performance for 17m only. I have thought about a full wave
loop, even a bobtail. A broadside array would be great but I am not keen
on antennas with reflectors or directors because of the complexity of
support ropes. So, really some kind of antenna supported by ropes from two
trees would be ideal. Any ideas please?

Alan VK6BN