, 2013 6:54 AM
Subject: Re: [Elecraft] cobweb antenna
Hello Bill,
I have no intent to denigrate the design and functionality
of the Cobweb style antenna but.
Several years ago I was inclined to acquire the G3TPW
commercial
Joe Subich, W4TV wrote:
The near field (basically within the range where it follows an inverse
cube law) can be predominantly magnetic or predominantly electric in
nature. Whilst the ratio of electric and magnetic fields in the far
field is constrained to 377 ohms per square, that is not true in
Jim,
Thanks for the links interesting...
This is the Elecraft list so yes my KX3 with internal ATU and another
without and T1 ATU finds a match easily, same for K1 or K2 with this
antenna.
You do not have to buy the antenna at all ... you can build your own
from a few parts as I did. A
Whether the field is predominately magnetic or electric, it must
still couple to the environment around it or the antenna *will not*
radiate. whilst the same folding that is responsible for the low
feed impedance and low efficiency will result in more cancellation
close to the antenna than at
Joe is right...
Maxwell's equations relate time dependant electrical and magnetic fields. If B
is changing with time, E cannot equal zero everywhere in space and if E is
changing with time, B cannot be zero everywhere in space (otherwise you can not
fulfill the two equations for the curl of
Actually, you have confirmed my point by showing that, in the near
field, magnetic loops and electric dipoles interact very differently,
thus may have rather different EMC behaviour. I was not disputing that
the far field component interacts at short distances. I was only saying
that the
I was only saying that the near field component can make the total
interaction significantly different.
That is not the point here ... whether the antenna is an electric or
magnetic radiator, it *will* interact with items in the near field.
*Further* the cobweb is an electric radiator just
a cobwebb will do - a few weeks ago on 17m my
KX3 (no atu) and I had a 10w SSB qso from here to WA (W7 land). Our report
was 53 with the cobwebb at 25ft.
73
Geoff
G3UCK
-Original Message-
From: Bill Blomgren
Sent: Friday, May 31, 2013 3:27 AM
Subject: [Elecraft] cobweb antenna
I came
For the rather rare times I operate on the DX bands, I use a Cushcraft
R5 (five bands 10-20). Much smaller foot print than a cobweb style
antenna. Has been up for over twenty years and is still going.
Bill W2BLC
__
Elecraft mailing
- Original Message -
From: Bill Blomgren billb...@nc.rr.com
To: Elecraft@mailman.qth.net
Sent: Thursday, May 30, 2013 10:27:22 PM
Subject: [Elecraft] cobweb antenna
I'm still in the pre-purchase stage.. but I'm sort of thinking that the K3
is where I'm going to end up.. Possibly
On 5/30/2013 7:27 PM, Bill Blomgren wrote:
Has anyone tried one of these critters, and if so, is the Elecraft
happy with it?
Why BUY an antenna when you can very easily build one for a lot less
money that will likely work better? Here are some articles by hams who
have done a lot with
Jim Brown j...@audiosystemsgroup.com wrote:
Here are some articles by hams who have done a lot with only a little bit of
space. The first is by AC0C, who built a complete antenna system in the attic
of his apartment!
A fun read, Jim. Thanks. I've also had good success with attic antennas in
Having once owned an R-5, and having opened the matching network box
to see what's inside it, I'd take the cobweb antenna over the R-5 for
performance any day.
Dave AB7E
On 5/31/2013 3:35 AM, Bill wrote:
For the rather rare times I operate on the DX bands, I use a
Cushcraft R5 (five
as important as functionality
when deciding which products to acquire. Just my opinion...
Rich K2CPE
K2 #1102
- Original Message -
From: Bill Blomgren billb...@nc.rr.com
To: Elecraft@mailman.qth.net
Sent: Thursday, May 30, 2013 10:27:22 PM
Subject: [Elecraft] cobweb
, May 31, 2013 12:25 PM
Subject: Re: [Elecraft] cobweb antenna
Having once owned an R-5, and having opened the matching network box
to see what's inside it, I'd take the cobweb antenna over the R-5 for
performance any day.
Dave AB7E
On 5/31/2013 3:35 AM, Bill wrote:
For the rather rare
Theoretically, performance should be similar to a dipole, although with a
near-omnidirectional pattern (and of course reduced bandwidth). It might be perfect for
certain antenna-restricted circumstances.
There is a statement on the G3PTW website which is interesting, and I would like to hear
Different strokes for different folks but the R5 along with an 80/40
trap inverted V at 40 feet allowed me to make Honor Roll both Mixed
and CW over the past 10 year (100W maximum power) after being off the
air for most of the previous 20 years.
The R6000 (current incarnation of the R5) and the
Does this sound reasonable?
No. If the field is not able to couple to nearby objects, it is not
able to radiate (couple to) distant receivers. The statement flies
completely in the face of physics.
73,
... Joe, W4TV
On 5/31/2013 2:59 PM, Vic K2VCO wrote:
Theoretically, performance
On 5/31/2013 12:05 PM, Joe Subich, W4TV wrote:
Does this sound reasonable?
No. If the field is not able to couple to nearby objects, it is not
able to radiate (couple to) distant receivers. The statement flies
completely in the face of physics.
Agreed.
Jim K9YC
Maybe a quick email to Balun Designs could produce a better quality
matching network for the R5? This crossed my mind earlier today and I
wonder if this is a reasonable way to make the R5 a decent antenna for the
higher bands.
On Fri, May 31, 2013 at 11:25 AM, David Gilbert
That is not a reasonable statement at all.
It may be that bringing the ends of the dipole close together will allow
it to be placed close to those objects without the normal de-tuning
effects, but to state that those objects will not absorb radiated power
is a real stretch of the imagination.
The R5/R6000 does not need a better quality matching network.
If you want to replace the capacitors with something a bit beefier
that's fine. Otherwise, an external common mode choke might offer
marginally better feedline decoupling than the common mode choke
already included in the R5/6000/7/8
#1102
--
From: Bill Blomgren billb...@nc.rr.com
To: Elecraft@mailman.qth.net
Sent: Thursday, May 30, 2013 10:27:22 PM
Subject: [Elecraft] cobweb antenna
I'm still in the pre-purchase stage.. but I'm
: Elecraft@mailman.qth.net
Sent: Friday, May 31, 2013 6:54 AM
Subject: Re: [Elecraft] cobweb antenna
Hello Bill,
I have no intent to denigrate the design and functionality of the Cobweb
style antenna but.
Several years ago I was inclined to acquire the G3TPW commercial
HTC on the Now Network from Sprint!
- Reply message -
From: Don Wilhelm w3...@embarqmail.com
Date: Fri, May 31, 2013 5:14 pm
Subject: [Elecraft] cobweb antenna
To: elecraft@mailman.qth.net
That is not a reasonable statement at all.
It may be that bringing the ends of the dipole close
Hi Chris,
The M0ZIM website clearly says , PLEASE NOTE UK SALES ONLY NO EXPORT . I'm
guessing export sales from UK may entail too much red tape to bother
with...which seems a shame as I am an anglophile...
Regards,
Rich K2CPE
K2 #1102
- Original Message -
...@comcast.net
Sent: Friday, May 31, 2013 5:47 PM
To: G5VZ Chris
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] cobweb antenna
Hi Chris,
The M0ZIM website clearly says , PLEASE NOTE UK SALES ONLY NO EXPORT . I'm
guessing export sales from UK may entail too much red tape to bother
: [Elecraft] cobweb antenna
Hello Bill,
I have no intent to denigrate the design and functionality of the
Cobweb style antenna but.
Several years ago I was inclined to acquire the G3TPW commercial
version of the CobWebb antenna, I found the website ( www.g3tpw.co.u
I'm still in the pre-purchase stage.. but I'm sort of thinking that the K3
is where I'm going to end up.. Possibly with the preamp...and then there is
the big problem: what to make it to the air with.
The idea of starting off with the buddipole system is out there - and very
possible...
I had never heard of the 'Cobweb' but when I googled it...it looked
interesting but a tad on the large side for what you call 'apartment
life'. I myself live in an apartment and find my best luck simply
using a piece of 14 gauge electric fence line I had on a spoolcut
for 20
On Thu, May 30, 2013 at 9:47 PM, Lee Stephens
b2rie...@cincinnaticomm.comwrote:
never heard of the 'Cobweb' but
===
Well, it's really the same thing as a halo, which in turn is the same thing
as a dipole that's been bent into a circle (or in this case a square) and
trimmed so
I built one for a disabled friend of mine and it worked 'right out of the
box' as you might say. It required very little tweeking to get it centred
on the phone bands that he required. I know several people who have them
and they stay up and stay tuned even in what we call windy conditions.
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