I personally reckon, the Kaeferlein loops are the best on the market!
The one from Italy I believe uses a Gamma Match for feeding the antenna
and that might be not the best solution for a mag loop. I know Matthias
personally, a very nice guy and he worked with Kaeferlein as a teenager,
to earn some pocket money, so he is well aware of the technics and
mechanics. But apart from that, the crucial thing is to build them
proper. I would make them out of one piece and round! But that is only
my opinion. As I said, I have very good experience with mag loops and
for someone with no space, they are perfect. Yes, shipping is a big
problem, but I guess, if you can spend 1200 -1500 Euros on an antenna,
the extra 200 Euros shipping wouldn't be a problem. I got my 2 loops
shipped to Australia in a crate, but there was of course other stuff in
it as well. And for sure, I will never sell them, even though I have
people asking me about them, you never know what happens in the future
and I have to move in to an appartment or retirement village and then I
can use them again ;-)!
Btw, you find ama antennas quite often cheap for sale in cqdl, I got
mine for a swap of a Gap Challenger and never regretted it.
Enough of that.
73's
Richard
On 27/04/14 16:07, Rick - DJ0IP / NJ0IP wrote:
Richard's advice is sound.
Kaeferlein "made" good loops.
However he's gone.
His successor is Matthias Beese (DH6MM) and he still makes and sells the
same quality of good loops.
The commercial loop I tested and then used for many years was the Kaeferlein
AMA-8.
However as I said, it was actually too large to use indoors.
I couldn't get it to work on 80m until moving it outdoors.
NOW THE PROBLEM: Shipping cost to the states is probably about $200 or more
for even the smallest loop.
There is also an Italian company making great loops.
They are made by I3VHF.
See: http://www.ciromazzoni.com/English/Loop%20Antenna.htm
These will handle more power than the Kaeferlein loops. Cost more too!
BUT AGAIN, shipping cost is huge on these.
DOWNLOAD: (English language) his 48-page document on these antennas and see
for yourself.
The guy in my club I spoke of earlier with the 80m loop is running the
"MIDI" loop from this company. Great product if you don't mind spending
$1700 on an antenna.
I am unaware of a source for good loops like these in the states.
Business opportunity? (hi)
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Richard
Tschur
Sent: Sunday, April 27, 2014 1:57 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] New Jupiter on its Way _ A Few Questions
Hi all,
a really good quality magnetic loop is available from Kaeferlein in Germany!
I have one with 80cm in diameter and it can handle up to 500Watts and it
performs really well. They are not cheap, but they do perform. I bought mine
used years ago for like 300 german Marks (good old times;-)), and i had
great contacts on it. For example, the antenna was mounted about 50 cm above
ground between the houses and i had a contact from Melbourne VK to Italy
with 100 watts. But the important thing is, from what I've been told, no
joins, one loop out of aluminium with at least 33mm diameter. This
Kaeferlein guy is sort of a pioneer with loops, he made them for decades.
Just my take on them, so if you have no space, go for a good quality loop,
you can put them nearly everywhere, in the garage, in the basement, height
is not really critical, from what I have experienced. Just my take on it.
Here is the link to Kaeferleins web side www.ama-antennen.de Unfortunately
only in german, but I think pretty much self explaining.
I forgot to mention: the loop I have covers 13.5 to 30 MHz. I have another
one from DJ0HV, he makes sort of homebrew semi comercial, this one is 2 m in
diameter and covers 80 to 20 m and can handle up to 1 kw.
The aluminium pipe is 60mm in diameter. Both of them are fully remote
controllable! The only disadvantage in my opinion is, you have to retune
every like 15 to 30 KHz, if you transmit, but you get a very selective and
quiet antenna and in comparison with a dipol, it is maybe half to an s point
lower! An that, you can compensate with a bit of juice behind the antenna
;-)!
Regards and greetings from Down here
Richard VK3KVK / DK3KVK
On 27/04/14 06:49, Rockinghorse Winner (Terry) wrote:
K8JHR wrote:
I have used the Wellbrook ALA-100M receiving loop for over a decade
with good results at two locations. It is a "medium or large
aperture" loop, because you supply whatever size wire loop you want.
I used mine outside, but you could do it inside, but of course it
tends to be more RF quiet the farther you get away from your
dwelling. Wellbrook also makes a model that uses a 1 meter alum
loop, which works well indoors. The loop does not have to be round or
symmetrical, and you can use very light litz wire which is nearly
invisible outside. They can also be used indoors, as in an attic,
but you don't want to be listening on it when you are transmitting on
it, if you cannot locate it at least 1/4 to 1/2 wavelength away from
the transmitter antenna (which applies to all receive only antennas I
suppose.) These work on the magnetic portion of the electromagnetic
waves we work with, as does Rick's project.
See The Wellbrook products here:
http://www.wellbrook.uk.com/antennashop/
I have also used a DX-Engineering active whip with good results. I
have mine in the front yard, away from the transmitting antennas in
the back yard, and it has a very low profile. These work on the
electrical portion of the electromagnetic waves we work with. They
have a single vertical whip model, and a dipole model, and you can
see them here:
single vertical model:
http://www.dxengineering.com/parts/dxe-arav3-1p
dipole model:
http://www.dxengineering.com/parts/dxe-arah3-1p
I have used both the Wellbrook loop and the DX-E active whip with
good results as receive only HF antenna on my small suburban lot,
although they are substantially more expensive than Rick's home brew
project. I know several SWL's who have built similar loops to Rick's
project, with good results. It is a classic.
I went to the Wellbrook site. But the antenna you cited was 60" in
diameter, too large for my room. Did you say they had some smaller
loops? In any case, I'm going to try to build a receive mag loop
according to the instructions Rick provided. It seems like a straight
forward project that should take a few hours at most.
Happy trails.
---------------------- K8JHR -----------------------
On 4/25/2014 6:05 PM, Jim Allen wrote:
You might also consider the helically loaded loops that K8NDS has
been developing.
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