In article vCsnf.20308$7r6.11890@trnddc07,
"Dale Parfitt" wrote:

"Telamon" wrote in message
...
In article Fnrnf.16004$hB6.15653@trnddc05,
"Dale Parfitt" wrote:

"Telamon" wrote in message
.
..
In article ,
"Robert11" wrote:

Hello:

Lots of good info on loops from posts. Thanks all.

Just want to be sure re this:

When you talk about a Horiz Loop, you mean a true loop where
the end is connected back to the beginning.

Right ?

(not just a folded random length config with a free end)

Any possible advantages in not connecting it back ? (Interested
in broadband, omni coverage)

The answer to the first question is no. If you connect the ends
together you short the loop. The loop is a circular, triangular
or square shape with one opening in it. At this opening in the
loop you can directly connect coax cable lead-in to the radio so
the coax is connected across the loop gap.

The answer to the second question is no. If you do not connect
the other end to something then the loop is open and will behave
as a random length of wire or a wire antenna. This will pick up
signals and a lot of local noise. The loop connected across the
coax will have lower signal levels and in general will pick up
less local noise.

The loop wire routed horizontally will be fairly
omnidirectional.


As in my above post, an omni horizontal loop is a rarity and
occurs only over a very narrow BW. Don't confuse the fact that the
wire runs in 4 directions with making an omni. The resultant far
field pattern is a function of the vector currents in each wire-
they add and cancel resulting in patterns with a number of lobes
and a number of nulls, but not omni.

If the loop is electrically small then it will receive in the plane
of the loop, which in this case is horizontal and so will receive
omnidirectional.


The discussion I see is about running a wire loop with further
questions about whether the far end is connected or left open-direct
coax feed. Maybe I missed something- these would appear to be simple
wire loops- not electrically small loops I would associate with a
capacity tuned loop and/or loop preamps. Electrically small loops are
traditionally mounted vertically so the user can take advantage of
the nulling properties to reduce a local noise source.

I guesstimated an inside loop around the ceiling of a 10 foot square
room for example. This would be electrically small on the lower bands.
I've done the same with fairly good results.

--
Telamon
Ventura, California