(Consolidating replies to a couple of messages here...)
The object of my exercise was not to measure the exact losses in the
loading coil, nor to determine why it made such a poor antenna, but to
determine which antenna would work best for the appropriate bands from a
SOTA summit.
The
If you you are looking for a portable self-supporting antenna that is multi
band and functions well, independent of terrain,
it is really hard to beat a portable magnetic loop like the Alex Loop.
I have used Magnetic Loops for at least the past 10 years (I have an MFJ and an
Alex Loop and I
-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Wes
(N7WS)
Sent: Tuesday, July 21, 2015 11:02 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Miniature self-supporting HF antennas
I was going to say something similar.
Funny thing is though
email: b...@wjschmidt.com
-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Wes
(N7WS)
Sent: Tuesday, July 21, 2015 11:02 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Miniature self-supporting HF antennas
I was going to say something similar
As they say, your callsign alone is probably worth 20db.
;)
Dave AB7E
On 7/21/2015 5:24 PM, Dr. William J. Schmidt, II wrote:
I use a Superantennas YP3 with my own modeled tunings and some refinements
(new set of coils and full sized elements on 12 meters too). 30-160 I just
use dipoles.
That is exactly what I did, with the help of a friend a reasonable
distance away with a reasonable S-meter, repeated antenna swapping, and
a little help from skimmers on the RBN for control. I'm pretty sure the
difference is real. I'd rather carry a lightweight telescopic pole with
the means
Your deep suspicion is probably unjustified.
Certainly, examples can be found of inefficient antennas which suffer some
inefficiency because of the coils but generally, the inefficiency is due to the
need for the coils in the first place.
Any antenna satisfying what I perceive are Wayne's
I was going to say something similar.
Funny thing is though, although I'm a pretty active DXer, I've only worked J68HZ
once. Three years ago on 20M RTTY.
On 7/21/2015 5:54 PM, David Gilbert wrote:
As they say, your callsign alone is probably worth 20db.
;)
Dave AB7E
On 7/21/2015 5:24
, 2015 3:08 PM
Subject: Re: [Elecraft] Miniature self-supporting HF antennas
That is exactly what I did, with the help of a friend a reasonable
distance away with a reasonable S-meter, repeated antenna swapping, and
a little help from skimmers on the RBN for control. I'm pretty sure
Unless I misunderstand (always a possibility) you compared a coil-loaded
vertical to a wire inverted vee. Is this correct?
If so, you are not determining the effects of loading coil loss, you are
determining that a vertical antenna is different from a (nominally) horizontal
antenna. It
I never said anything about base loading. That's where most of the
current is, and therefore the most opportune location to create loss.
There's no current at the end (top), of course, so a loading coil does
no good at all there ... somewhere in between is generally best.
Dave AB7E
On
Yeah, that's a low Q coil on a short antenna ... it's not going to be
very efficient.
Dave AB7E
On 7/20/2015 2:35 PM, Rick M0LEP wrote:
The one I got bitten by was the one reviewed here:
http://www.eham.net/reviews/detail/1378
It isn't too bad for the top end of HF when most of
Exactly, although of course a coil at the very top sees no current so
doesn't do any good there unless there is some capacitive loading above it.
Dave AB7E
On 7/20/2015 2:44 PM, Jim Brown wrote:
On Mon,7/20/2015 1:56 PM, David Gilbert wrote:
It all depends on the rest of the antenna, and
My practical experience is that miniature antennas do not work very well.
You end up with a miniature signal which is not much use with QRP.
I recently operated from Vanuatu as YJ0BJ and I used a Steppir CrankIR
vertical for 10 - 40m. It worked very well indeed and whilst it does not
assemble in
On 19 Jul 2015, at 17:45, Wayne Burdick asked
Is the best antenna for backpacking a very small magnetic loop? A cleverly
designed, center-loaded telescoping whip? A length of #30 wire lofted by a
small helium balloon? (Or, more intriguingly, some combination of these?)
How about a
LOL.
Well, with poor ground conductivity, they become worm cookers. ;)
Dave AB7E
On 7/19/2015 9:59 PM, Phil Wheeler wrote:
Dave,
Re It's not going to radiate any lower than the horizon... -- I'd
swear, based on on-the-air results, that I've had a few antennas which
achieved that
So far, I've found nothing that comes close, and there's nothing more
frustrating than getting to the top and then finding the antenna you
have is doing a poor job. I now regard anything which relies on loading
coils with deep suspicion. That coil's usually doing a fine job of
converting RF to
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Well, I never operated from uncomfortable locations like above the tree
line, but my experience with portable antennas has been the same. Short
loaded antennas are not as good as wires. I prefer a dipole that can be
configured as a sloper, V, etc. I have a 33' collapsible fiberglass
pole that
I suggested this about two years ago as a DXpedition antenna for 160m.
With the right drone, it could hold up enough wire to continuously power
it, and with GPS it would automatically adjust for varying wind. It's
not a backpacking antenna, though ... far too much weight.
Dave AB7E
Yes, I too prefer to get wire in the sky, and an inverted-V dipole works
pretty well. I have one with link breaks in it so that it can quickly be
changed for different bands (using 2mm or 3mm radio-control power
connectors for the breaks because they're very small, light, and make a
good
One of the better sources of information and portable antennas is found
at http://www.dj0ip.de/antennas/ http://www.dj0ip.de/antennas/
Rick has some extensive test results on baluns and portable antennas on
his website. His OFCD antenna is an ideal back packing antenna covering
most all
My favorite all around travelling/hiking KX3 antenna is a 20 mtr endfed
half wave (EFHW) wire fed with an electrical quarter wave of TV
twinlead. See
http://w0vlz.blogspot.com/2012/06/another-portable-antenna.html With the
KX3/KXAT3 it will load up on 40, 30, 20, 17 and 10.
My 20 meter zepp
On Mon,7/20/2015 7:34 AM, Niel Wiegand wrote:
My favorite all around travelling/hiking KX3 antenna is a 20 mtr
endfed half wave (EFHW) wire fed with an electrical quarter wave of TV
twinlead. See
http://w0vlz.blogspot.com/2012/06/another-portable-antenna.html With
the KX3/KXAT3 it will load
The one I got bitten by was the one reviewed here:
http://www.eham.net/reviews/detail/1378
It isn't too bad for the top end of HF when most of the adjusting coil
is not involved, but performance drops off dramatically once more than
about a third of the adjustable coil is exposed. If you've
Terrible spelling, Buddipole, Sorry.
Mel, K6KBE
From: Mel Farrer farrerfo...@yahoo.com
To: David Gilbert xda...@cis-broadband.com; elecraft@mailman.qth.net
elecraft@mailman.qth.net
Sent: Monday, July 20, 2015 2:38 PM
Subject: Re: [Elecraft] Miniature self-supporting HF antennas
On Mon, Jul 20, 2015 at 3:56 PM, David Gilbert xda...@cis-broadband.com
wrote:
...properly built coils aren't nearly as bad as you say
===
True, but even with a high-Q coil a typical base-loaded antenna inevitably
has low efficiency. This is the consequence of the fact that a
A good example is the Biddipole concept.
Mel, K6KBE
From: David Gilbert xda...@cis-broadband.com
To: elecraft@mailman.qth.net
Sent: Monday, July 20, 2015 1:56 PM
Subject: Re: [Elecraft] Miniature self-supporting HF antennas
In general, properly built coils aren't nearly as bad
On Mon,7/20/2015 1:56 PM, David Gilbert wrote:
It all depends on the rest of the antenna, and yes, a very short
antenna with a crummy coil in the wrong place is going to suck. But
some of the best antennas on the market right now use coil loading
very effectively.
There was an excellent
In general, properly built coils aren't nearly as bad as you say they
are. It is possible to build coils with a Q of several hundred, and if
you do the math you'll see that the resulting loss is essentially
trivial. It all depends on the rest of the antenna, and yes, a very
short antenna
Small dimension and weight dictate thin wires, say gauge 26-28. A magnetic
loop is relatively heavy for portable QRP.
Verticals made of piece of wire are great over salt water or when conditions
are great. For support I use 25ft pole collapsible to 2 ft. Away from the
sea, two long wires made
I use two different portable antennas, One is the super antennas yp3 3 element
antenna and the other is the TW 2010 antenna. If i'm going to be portable for a
while Ill put the 3 element antenna up. Its pretty fiddly and changing bands is
a pain. Its one band at a time. The performance is very
On Sun, Jul 19, 2015 at 9:12 PM, Don Wilhelm w3...@embarqmail.com wrote:
Richard,
Two properly spaced and phased radiators
=
I have a terrific wire-beam antenna that rolls up into a package that
weighs only a couple of pounds. However, it requires one rope into a tree
or other
Used to be a fellow that owned and operated motel in a small town in Ne.
He was in a fringe area for tv.. and didn't want to have the guests bothered
with
anything more than just the fringe (noise and snow) reception on all but one tv
channnel.
SO.. his ham antenna was alternatively the 2nd
Usefulness of any 10 meter antenna is declining. :-)
FWIW:
My Buddipole weighed 17 lbs, and I sold it and used the proceeds to get
an AlexLoop. It weighs about 1.6 lbs, less if I take it out of the neat
canvas case, 2 lbs with the lightweight tripod. I like it a lot. I can
set it up in
Richard,
Two properly spaced and phased radiators are all that is necessary for a
2 element beam - two Alexloops, 2 verticals, two dipoles, etc.
While setup in 2 minutes may not be practical at 20 meters, it is
practical at 2 meters, and you may even devise something that looks like
an
I recently used a 20m EFHW to operate from 12,300' Trail Ridge (SOTA
W0C/FR-123) on June 28. I wanted a very quick activation due to
thunderstorm concerns so I took a 15' mast (collapsible to ~18 inches),
mounted it to a cairn of stones with a bungee and attached the far end to a
stone. I made 6
My two cents worth. My favorite antenna for SOTA
turns out to be the 20 meter Endfedz followed by the Alex Loop.
I have done a receive comparison between the Alex loop , Endfedz and a full
size 20 meter vertical with radials. In this sketchy little test the
Verical came out best followed very
My favorite is the bush sloper. To launch it, I use an E-Z Hang
(slingshot / fishing reel).
The scrub on SoCal mountains is usable to support an end-fed wire,
facing downhill. I recommend a counterpoise facing uphill. The
end-fed can be 50 to 200 feet long (145 feet seems best all-around
match
Wayne,
From time to time, my radio club collars me to do a program at one of our
meetings. I usually lecture on antennas targeting the new ham. There are two
points I try to leave the crowd with:
1. There is no such thing as the perfect antenna. Each is a compromise of some
sort.
2. No ham
I’m interested in where this one’s going. Restrictions on my living
accommodations relegate me to an indoor wire. I managed to work coast to coast
with the KX3 and JT65 using its internal tuner. I’d like more ideas.
dale
W5OHM
On Jul 19, 2015, at 11:45 AM, Wayne Burdick n...@elecraft.com
I am not an antenna purist and will use whatever is handy but my favourite
antenna (at the moment) are a 44 foot Center feed zepp with tv twinlead and
a 4:1 balun or if trees are not available I really like my semi homebrew
center loaded vertical using a 12 inch base rod, a Wolf River Silver
Dave,
Re It's not going to radiate any lower than the
horizon... -- I'd swear, based on on-the-air
results, that I've had a few antennas which
achieved that dubious distinction :-)
73, Phil W7OX
On 7/19/15 9:52 PM, David Gilbert wrote:
It's not going to radiate any lower than the
On Sun,7/19/2015 9:52 PM, David Gilbert wrote:
It's not going to radiate any lower than the horizon, and that kind of
low angle is extremely useful for long distances. That can be
appropriate even for QRP, although it might be more propagation
dependent versus making some high angle short
It's not going to radiate any lower than the horizon, and that kind of
low angle is extremely useful for long distances. That can be
appropriate even for QRP, although it might be more propagation
dependent versus making some high angle short skip contacts. If I want
to see how far I can
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