In article ,
(Mark Keith) wrote:

(RHF) wrote in message
. com...
YODAR,

The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas {RHF}
http://groups.yahoo.com/group/Shortw...a/message/1626

I too tried to build a Coax Cable [Shielded] Loop Antenna
that was made of "TV type Coax" that had a 'Shield' made
of Foil and about 33% Braid. The Results were very poor.

Hummm... It *should* have worked just fine. Besides being lousy to
solder to, there is nothing wrong with a foil shield. Thats solid
coverage, and better than strands of wire. The coax shield for a SW or
MW loop should be fairly non critical. The only purpose is to ensure
balance. MK

"The Results were very poor" is not very much information to go on to
any conclusion or solution.

Maybe he was expecting more output from the loop than he got. A shielded
loop that is not very large is not going to have a big output. Maybe he
screwed up and did not have a shield gap.

--
Telamon
Ventura, California

= = = Telamon wrote in message
= = = ...
In article ,
(Mark Keith) wrote:

(RHF) wrote in message
. com...
YODAR,

The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas {RHF}
http://groups.yahoo.com/group/Shortw...a/message/1626

I too tried to build a Coax Cable [Shielded] Loop Antenna
that was made of "TV type Coax" that had a 'Shield' made
of Foil and about 33% Braid. The Results were very poor.

Hummm... It *should* have worked just fine. Besides being lousy to
solder to, there is nothing wrong with a foil shield. Thats solid
coverage, and better than strands of wire. The coax shield for a SW or
MW loop should be fairly non critical. The only purpose is to ensure
balance. MK

"The Results were very poor" is not very much information to go on to
any conclusion or solution.

Maybe he was expecting more output from the loop than he got. A shielded
loop that is not very large is not going to have a big output. Maybe he
screwed up and did not have a shield gap.


MK & TELAMON,

My reason for stating that the performance was 'poor' had to do with
may small problems:

* Learning Curve - It was my first Coax Cable [Shielded] Loop
Antenna.

* Questionable 'quality' of the old RG-59 Coax Cable being used.
[ Learned to use 'new' better quality Coax Cable. ]

* Trouble getting a good 'connection' at the Bottom-Joint between
the Aluminum Braid.
[ Learned to use more exposed Braid to make 3-4 complete Wraps
around the other section of Exposed Braid at the Bottom-Joint. ]

IDEA: Got the Idea for the LOOP-HUB using a 'modified' TV
type Two-Way Splitter.

* The "F" Connector' End had a Center Wire that was 'short' and
resulted in an intermittent connection when moved.
[ Learned to make sure that the Center Wire was Long Enough
and that I did NOT Bend them and Short-them-Out when installing
them. ]


The basic design of the "GreerTech" Coax Cable [Shielded] Loop
Antenna is good and very practical.
LOOP= http://www.greertech.com/hfloop/mymagloop.html


My 'second' Coax Cable [Shielded] Loop Antenna was made from
Thirteen Feet (13 Ft) of standard size RG-8 Coax Cable.

* Big and difficult to work with.

* Easy to get a good 'connection' at the Bottom-Joint.


The most recent Coax Cable [Shielded] Loop Antenna was made from
a standard 'pre-made' Twelve Feet (12 Ft) of RG-6 'Quad Shield'
Coax Cable.

* RG-6 is 'easy' to work with.

* Pre-Made Lengths with "F" Connectors already attached.

* Just 'cut' the One Inch "Gap" at the Center of the Length.

* Easy to get a good 'connection' at the Bottom-Joint using the
LOOP-HUB made from a TV type Two Way Splitter.

RESULTS: Very Good Performance. (Equal to the 13 Ft RG-8 Loop.)

NOTE: Lessons Learned.


iane ~ RHF
..
Some Say: On A Clear Day You Can See Forever.
http://groups.yahoo.com/group/Shortw...na/message/502
I BELIEVE: On A Clear Night . . .
You Can Hear Forever and Beyond - The Beyond !
..
..

(RHF) wrote in message


MK & TELAMON,

My reason for stating that the performance was 'poor' had to do with
may small problems:

* Learning Curve - It was my first Coax Cable [Shielded] Loop
Antenna.

* Questionable 'quality' of the old RG-59 Coax Cable being used.
[ Learned to use 'new' better quality Coax Cable. ]

The coax shouldn't matter much at all...

* Trouble getting a good 'connection' at the Bottom-Joint between
the Aluminum Braid.
[ Learned to use more exposed Braid to make 3-4 complete Wraps
around the other section of Exposed Braid at the Bottom-Joint. ]

That could cause a problem...

IDEA: Got the Idea for the LOOP-HUB using a 'modified' TV
type Two-Way Splitter.

* The "F" Connector' End had a Center Wire that was 'short' and
resulted in an intermittent connection when moved.
[ Learned to make sure that the Center Wire was Long Enough
and that I did NOT Bend them and Short-them-Out when installing
them. ]


The basic design of the "GreerTech" Coax Cable [Shielded] Loop
Antenna is good and very practical.
LOOP= http://www.greertech.com/hfloop/mymagloop.html

I notice he likes PVC...I do also...About the easiest frame you can
build for a loop...Here is one design I have used...
http://web.wt.net/~nm5k/loop5.jpg



My 'second' Coax Cable [Shielded] Loop Antenna was made from
Thirteen Feet (13 Ft) of standard size RG-8 Coax Cable.

Kinda heavy....:/

* Big and difficult to work with.

Yep...

* Easy to get a good 'connection' at the Bottom-Joint.


The most recent Coax Cable [Shielded] Loop Antenna was made from
a standard 'pre-made' Twelve Feet (12 Ft) of RG-6 'Quad Shield'
Coax Cable.

* RG-6 is 'easy' to work with.

* Pre-Made Lengths with "F" Connectors already attached.

* Just 'cut' the One Inch "Gap" at the Center of the Length.

* Easy to get a good 'connection' at the Bottom-Joint using the
LOOP-HUB made from a TV type Two Way Splitter.

RESULTS: Very Good Performance. (Equal to the 13 Ft RG-8 Loop.)

NOTE: Lessons Learned.

I've tried a few coax loops, and I guess they are ok, but in general,
I prefer the normal solenoid windings using plain wire... Much
lighter, and the performance *if properly balanced* , is the same. I
only use variable caps to tune the loop. My present loop that I use
the most is a diamond, appx 44 inches per side, and has 5 turns. "The
PVC frame is about 6 ft tall, counting the mast below the loop
winding, and the cross arm is 5 ft across" I use a multi gang
variable for tuning, and it has a switch to change to a small value
gang for upper freq range use. Also have some fixed caps to tack on if
I want to listen to LF. With all the cap variations, the tuning range
is about 250kc to about 2500 kc or so. But it's usually used on MW and
160m. It's indoors on a stand thats next to me on the floor and
rotates...MK