On Sun, Apr 27, 2014 at 09:56:36AM +1000, Richard Tschur wrote:
> 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
>
Good cite. Here in the U.S., Pixel makes them with all the bells and
whistles for about 500., but I'm not interested in them for that reason. I
want a receiving antenna that can null out or reject all the QRN in my area.
For this, the mag loop is perfect, and doesn't need the heavy duty treatment
of a transmitting loop.
>
>
> 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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