In article
,
" wrote:

On Jun 28, 6:17*pm, Telamon
wrote:
In article
,

" wrote:
On Jun 25, 5:29*pm, "Justtis" wrote:
Anyone know of a good site offering build plans. *Prefer plans from
someone
who has built and used same.
I need a quiet antenna like this and Wellbrook is just too
expensive!http://www.wellbrook.uk.com/index.html

I use the ALA100 with home brew loops. Damn good, but you are right
that it is expensive. The ALA100 is the cheapest of the Wellbrook
products. They have some variants of it now. You need a good radio to
use an untuned loop since it delivers a huge amount of RF.

SNIP

So stop whining about the cost and build a low cost passive loop. It if
works well but you still need further improvement it will at least tide
you over.

All the amplification does for you is allow the loop to be smaller,
which may mostly be a convenience depending on the environment.

Be sure to build a balanced loop that only responds to the magnetic
field.


I saw your other post on the subject. Feeding a loop to a 50 ohm input
of a radio will not work well since once side of the loop will be at
ground.

It works very well. I have several loop antennas.

This is where the wideband transformer comes into play. You
can float the loop above ground if you have the transformer. It is
possible to do the same with a differential amp, but good transformer
would be lower noise.

The transformer is not necessary for a connection to the coax or a
balanced amplifier input.

You could clamp a few ferrite cores around the coax lead-in to the radio
at the antenna connection to block noise coming from the radio if you
don't already have the radio plugged into a EMI noise suppression power
strip.

--
Telamon
Ventura, California