Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old January 4th 17, 06:27 AM posted to rec.radio.amateur.moderated,rec.radio.amateur.dx,rec.radio.amateur.equipment
external usenet poster
 
First recorded activity by RadioBanter: Aug 2014
Posts: 422
Default [W2LJ] Portable operations antennas


W2LJ QRP .... Do More With Less

///////////////////////////////////////////
Portable operations antennas

Posted: 03 Jan 2017 07:50 AM PST
http://feedproxy.google.com/~r/feedb...medium=ema il

So with all the NPOTA operating and other portable operating that I've done
over the years, you might think that I've become some sort of expert on
portable antennas, right?

Nope - not even close.

I have become "expert" enough to tell you that there's no "one size fits
all" or all purpose antenna that will work in every situation. That
antenna continues to be the "Holy Grail" or "Golden Fleece" of Amateur
Radio. It is rumored to exist and is still being searched for. Some will
tell you that they possess it, or a reasonable facsimile, thereof.

In my mind, it's a myth, a fairy tale, a legend. I have found that in
every situation, all portable antennas will work well, some better than
others. It all depends on the situation and the circumstances of that
particular day or event.

Do you have trees available? Awesome! I think back on Day One, the Good
Lord knew that someday, radio would be discovered, and that our species of
hobbyists would be spawned. So He created trees. "The World" seems to
think that trees were created for the purpose of shade, food, converting
carbon dioxide to oxygen, as well as a source of wood. We Ham Radio
operators know better - that trees were created to hold our aerials up in
the sky, away from the ground, and that the other services that trees
provide are just side benefits.

If you have trees available at your location, put them to their intended
purpose ....... get wire in them, as high as you can get it. Whether it be
a dipole, doublet, end fed, zepp, or any other kind of wire antenna, get it
up as high as you can. Of course, for portable operations, you want to
keep the antenna as uncomplicated as possible, while still maintaining the
ability to work as many bands as possible. In my experience the W3EDP or an
end fed wire connected to a 9:1 UNUN will give you the most bang for the
buck. These can be used as verticals or slopers. And if you have enough
real estate and feedline, they can even be stretched between two trees, as
high as you can get them. In the five years of the NJQRP Skeeter Hunt, my
best year was accomplished using a W3EDP strung between two trees in a
horizontal configuration, about 40 feet up, or so.

But what if there are no trees; or only one tree? If there's only one
tree, then I would suggest using said arbor as a support for a sloper -
again. getting the end up as high as possible. If there are NO trees, then
you have to become creative and a bit more flexible. If you're at the top
of a mountain, you might try taking an end fed and just allow it to dangle
off the side of the peak. If that's not practical, or you're bothered by
heights like I am, and will go nowhere near the edge of a cliff, then you
have to resort to something else.

That something else might be something like a portable vertical. Portable
verticals can work very, very well. But to work very, very well you need to
lay down a radial field or use a counterpoise. When I used the PAC12
antenna, I used to lay down a set of 8 sixteen foot lengths of wire,
arranged around the antenna in a wagon wheel fashion. It worked well, but
could become a nuisance if the radial wires became entangled. Care had to
be taken during storage to make sure that didn't happen. Also, the radials
will work the best while being elevated, even if that means just an inch or
two off the ground, which means some sort of radial support also becomes
necessary.

If you operate from your car .... if you can operate from your car, the
radial problem becomes much, much easier to deal with. Put your vertical
on a magmount and allow your vehicle to become the ground plane. I was
only so-so pleased with my Buddistick until Bob W3BBO recommended this to
me. After I abandoned using the Buddistick counterpoise wire, and let my
Jeep fulfill that function, my Buddistick literally began to soar! Over
the years, I have worked over 60 countries and just about all 50 States
using 5 Watts or less. Having a huge hunk of metal under that vertical
makes all the difference in the world.

That being said, does it work on ALL bands well?

No.

The Buddistick on the roof seems to work well for me on 20 through 6
Meters. If I want to hop on 40 Meters from the Jeep, I resort to a
Hamstick. The Hamstick, on that same magmount, works exceedingly well. I
suppose I could get the Buddistick to work decently, but I would need to
add extension arms and figure out whip length. It seems easier to just
plop the Hamstick on for 40 Meters and the Buddistick for 20 - 6 Meters. I
have fiddled around with the Buddistick enough to find a tap setting that
will allow me to work 20, 17 and 15 Meters without changing the physical
configuration. The autotuner in my KX3 compensates as needed for each band,
and minimally at that.

So what do you do, if you're away from your vehicle, there are no trees,
and no way to support a wire with a portable mast; and you don't want to
mess with a vertical and radials? This is where a magloop can come into
play. The magloop is the newest antenna in my portable ops arsenal, and I
have to admit that for a long time, I was doubtful of its capabilities.
But (there's always a but) I remained intrigued by the idea of having
something like that and hoped against hope that the stories I had been
reading were not just wishful thinking.

So far, I have found that the claims seem to have some truth to them. From
the limited use I have given my home brewed magloop, I have been quite
pleased as well as surprised. I have easily hopped the Atlantic several
times with 5 Watts as well as crossing the Continental US to the west
coast. What has surprised me about the loop is that the noise floor, while
using one, is so low that you may think you have it tuned wrong. The
incoming radio signals seem to jump out of nowhere and are quite loud. But
using a loop takes some getting used to. You have to teach yourself how to
find the "sweet spot", which means turning the tuning capacitor for loudest
ambient band noise. In an environment where there may be lots of traffic or
people talking, that means resorting to using earbuds or headphones. Once
you carefully tune for that loudest band noise, though, means you are there
- flat SWR. But you have to be careful, though, because the tuning is very
sharp and if you're even a tiny bit off, the SWR can be sky high. If
you're going to be frequency hopping a lot, this is a major pain. Also,
the tuning capacitor works best with some sort of reduction drive. As I've
mentioned before, tuning can be tricky until you're used to it, and without
the reduction drive, it can be difficult to find that noise peak.

The bottom line is that, if you're going to do a lot of portable operating,
you really should have at least three or four options at your disposal.
There is no situation where one antenna where work in all cases, either due
to lack of set up time, real estate, available antenna hanging resources,
etc. Once you've gotten some experience under your belt you will be able
to size up the situation and will be able to determine what option will
work the best for that given day.

Always keep in the back of your mind the equation, "MOE = A + R + T" . That
is, Maximum Operating Enjoyment becomes an art. It is a mixture of Antenna
Efficiency Resources and Set Up Time. The desired outcome for an
enjoyable outing is always using the most efficient antenna you can, using
the resources you have at hand, with the minimal amount of set up and tear
down time. After all, the idea is to be on the air making contacts, not
silently cursing antenna wires or trees under your breath while
simultaneously elevating your blood pressure.

A word of warning, though ..... this will become a lifetime endeavor and
you will be constantly perusing the Internet and Ham publications looking
for that "all purpose, all in one antenna". I doubt that you or I will
ever find it, but as they say, "The fun is in the journey, not the
destination."

Have fun and see you on the air from the Great Outdoors in 2017!

72 de Larry W2LJ
QRP - When you care to send the very least!





Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[W2LJ] Portable operations antennas W2LJ via rec.radio.amateur.moderated Admin Dx 0 January 4th 17 06:27 AM
WANTED: Spilsbury Portable Antennas Norm VE3CZI Boatanchors 0 March 7th 08 09:15 PM
WANTED: Spilsbury Portable Antennas Norm VE3CZI Swap 0 March 7th 08 09:15 PM
FS: Brand New 800 MHz Portable Antennas RGOLD1161 Swap 1 September 20th 03 03:01 PM


All times are GMT +1. The time now is 11:51 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017