BpnJ,

If the Loop were free standing in open Air; then yes what you say
would be generally true. However, the Wire Antenna Element is
usually laying against the surface of the House's Interior Walls
and therefore may not be as theoretical as expected.

TIP - Try the Loop Antenna with both Antenna Inputs the LO-Z 50
Ohms and the HI-Z 500 Ohms on Several Shortwave Bands :
120M - 90M - 75M - 60M - 49M - 41M - 31M - 25M - 22M
- 19M - 16M - 13M - 11M

YMMV - On some the LO-Z may be the best connection and
on others the HI-Z may be the best connection.

BALUN - As you stated a simple Matching Transformer may
provide the necessary Broad Banded 'match' to be able to use
a single In-Door Loop Antenna Input for All Bands.

TWIN LEAD DOUBLE LOOP - Another 'Trick' is to make the
Loop a Double Loop using 300 Ohm TV type Twin Lead wired
in Series with a piece of the same 300 Ohm TV type Twin Lead
from the Ceiling Loop to the Radio/Receiver. In this instance
the HI-Z 500 Ohm Terminals usually work the best and it goes
without saying that the Double Loop is Twice as Long as a
Single Loop ) This does not seem to work as well with
the narrower and closer together common Speaker Wire.

FWIW - Some Claim that the Double Ceiling Loop Antenna
provides more signal and less noise then a Single Ceiling
Loop Antenna. I have yet to do a side-by-side of the One
or the Two around the same Ceiling at the same time.
Note - I would thing that it would take at least 6" or may
be closer to a Foot between the Single and Double Loops
to give each one a reasonable independent test in the same
room.

Some Food-for-Thought and an Invitation to Experiment
with In-Door Horizontal [Flat] Ceiling Loop Antennas.
[ Surprise Yourself :]


iane ~ RHF

Sanjaya,

Wire Wire Everywhere . . . Pick a Wire - Any Wire !

Ninty Feet (90-Ft.) of 22 AWG Stranded Hook-Up Wire
RadioShack Catalog # 278-1218
http://www.radioshack.com/product/in...ductId=2036275

Fifty-Five Feet (55-Ft.) of 18 AWG Stranded Hook-Up Wire
RadioShack Catalog # 278-1220
http://www.radioshack.com/product/in...ductId=2049741

Fifty-Five Feet (55-Ft.) of 18 AWG Stranded Hook-Up Wire
RadioShack Catalog # 278-1220
http://www.radioshack.com/product/in...ductId=2049741

Fifty Feet (50-Ft.) of 24 AWG Clear Insulation Stranded Speaker Wire
RadioShack Catalog # 278-1301
http://www.radioshack.com/product/in...ductId=2102499
[ For That "Instant" Dipole Antenna ]
- In-Door In-the-Attic In-the-Room -

For that "No-See-Um" [Hidden] Ceiling Loop Antenna . . .
http://groups.google.com/group/rec.r...a4ff8558eb78c8

Fifty Feet (50-Ft.) of White 30 AWG Single Strand
Kynar Insulated Wire Wraping Wire
RadioShack Catalog # 278-502
http://www.radioshack.com/product/in...ductId=2062641

I'm with Tom...

One should NEVER use the metal screw or electrical conduit for an earth
ground. Not only is this contrary to the NEC code but it allows ground loop
currents to exist along the single ground path due to inconsistent bonding
between conduit, flanges, flange screws and...eventually...the ground rod.
Lightning will follow the path of least resistance. You will often see a
coil (even a single turn) of taped of professional communications atenna
systems at the point of entry into the building. This is to provide, however
slight, a small impedance to discourage lightning current from taking THAT
path and, instead chosing a separate direct ground path.
Do this little experiment: Install a good ground at the entry to your house
and run a wire to it for your shortwave receiver. Once done, take an
ohmmeter and measure the resistance between that ground wire and the screw
on your wall outlet. I have often been surprised at how much resistance
exists between the wall outlet and a "real ground." Well, that resistance is
probably more than enough to divert a lightning current to a shorter path to
your receiver such as through its antenna. Good luck.


Vern Weiss W9STB


"w_tom" wrote in message
...
Protecting the antenna means providing lightning with an
alternative path to earth. Your building does that just fine.
But be better advised to earth using a lightning rod located
above the roof.

Safety ground system and earthing system share many
components. Different systems for different purposes with
some common parts. AC wall receptacle is not an earth
ground. An antenna is earthed so that lightning will not take
a more destructive path via the receiver. Ac receptacle
ground means lightning would spread out inside the building to
damage other electronics.

Connect things to the wall receptacle grounded screw to
protect human life. This is not same as earthing lightning.
To earth lightning, install Ben Franklin's well proven
solution above the roof. Earth incoming transients on utility
wires using either 'whole house' protector or a ground block -
all connected to a common earth ground that remains outside
the building.

Steve Rabinowitz wrote:
I guess the old way of attaching a wire to the screw that holds
the face plate of the electric outlet won't be any good then. I
could have swore my father years ago used that for grounding.

Hi,

Question re the "loop"

Would you connect the end of the loop to the beginning, thus making a "true
loop" up there, or just leave it
open at the end ? Why ?

What is the effect of the vertical run down to the receiver ?
Would you suggest coax for this vertical section, or usually not necessary ?

Bob

--------------------------

"RHF" wrote in message
oups.com...
SR,

Vice using the questionable the Ground {Green Wire} of your
Household AC Power System.

Why not consider a simple Around-the-Room {Ceiling Level}
Horizontal [Flat] Loop Antenna. The Loop Antenna is consider
a 'blanced' Antenna that does not require a Ground and is
Horizontally Polarized so it generally pick-up less man made noise.

The "In-Door" Horizontal [Flat] Loop Antenna is easy to build;
usually is relatively long 40-60 Feet for an In-Door Antenna;
and relatively lower noise pick-up to an in-door vertical antenna
or long wire antenna.

The Radio or Receiver can be run off of AC with an AC Ground
connection via the AC Power Plug or DC without any Ground
connection at all.

something to consider - iane ~ RHF
.
.
. .
.

Robert 11,

THE LOOP ANTENNA ELEMENT :
The Loop being a Square/Rectangular Shaped Loop completes the
Circling of the Room around the Four Walls. Both Ends of the Loop
come together at some point on the Wall or at a Corner of the Walls
near the Ceiling and are connected to a Pair {Two} Parallel Wire
Feed-in-Line that goes down to the Radio's Antenna Input.

THE FEED-IN-LINE :
The short vertical Feed-in-Line for this type of In-Door {In-the-Room}
Loop Antenna is usually a Pair {Two} Parallel Wires.
* 300 Ohm TV type Twin Lead works well as a Feed-in-Line
for this type of Loop Antenna.
* Speaker Wire also can be used; either flat or twisted will work.
* The basic wire used to make the Wire Loop Antenna Element
can be continued as a single piece from the Radio up the Wall;
around the Four Walls; and down back to the Radio. If this is
done then it is recommended that the short vertical parallel run
has the two Wires Twisted together.
* A piece of Audio Coax Cable can also be used; especially if
the Radio uses an 1/8" Mono Jack for the External Antenna Input.


WANT A BIGGER LOOP ANTENNA - PUT IT IN THE ATTIC :
[ When an Out-Side / Out-Doors Antenna is NOT Permitted. ]

KISAP: I recommend using TV type Antenna Parts for most
"In-the-Attic" Antenna installations.

* 75 Ohm Coax Cable for the Feed-in-Line for Household
'man-made' Noise RFI/EMF Reduction.

* TV 75 Ohm to 300 Ohm Matching Transformer (Balun) for
Noise RFI/EMF Reduction and AM/MW Band Signal Reduction.

* TV 300 Ohm Twin Lead for the Wire Antenna Element
50-100 Feet -or- 90 Feet of Insulated Hook-Up Wire.

* "F" Jack to 1/8" Plug (1/8" Mono-Jack Adapter)
RadioShack Catalog # 278-257

READ - For Shortwave Listening (SWL) here is a "Simpler" Horizontal
Loop Antenna in the Attic using common TV type Parts.
http://groups.yahoo.com/group/Shortw...a/message/6656
http://groups.google.com/group/rec.r...59a36c32f5ecd7


READ - Shortwave Listeners (SWL) Horizontal Loop Antenna
built with common and cheap TV Parts
http://groups.yahoo.com/group/Shortw...a/message/6135
http://groups.google.com/group/rec.r...8323867b8b44a3



ADDITIONAL READING LIST - Here are several Messages
to Read about In-the-Attic Antennas:

* Things-to-Think-about: Using Attic Antenna with the your
'portable' AM/FM/Shortwave Radio.
http://groups.yahoo.com/group/Shortw...a/message/1658

* A Compilation of "In-the-ATTIC" Antennas
http://groups.yahoo.com/group/Shortw...na/message/426

* Low Cost SWL Antenna (Made From TV Parts)
http://groups.yahoo.com/group/Shortw...nna/message/17

* ATTIC - Receiving Antenna Question - Think Loop made from TV Parts
http://groups.yahoo.com/group/Shortw...a/message/1635

* Ground Required At Balun ? {Getting "Grounded" in your Attic}
http://groups.yahoo.com/group/Shortw...na/message/287

* Snake-in-the-Attic SWL Antenna {Simplest Low Noise Attic Antenna}
http://groups.yahoo.com/group/Shortw...na/message/313
http://groups.yahoo.com/group/Shortw...na/message/317

* AM/MW Band Signal Reduction using TV Type Coax Cable Parts
for better Shortwave Listener Antenna
http://groups.yahoo.com/group/Shortw...na/message/930

* Simple SW Antenna = Improved Random Wire Antenna
using TV Antenna Parts
http://groups.yahoo.com/group/Shortw...na/message/740
..
..
hope this helps - iane ~ RHF

Vern Weiss [W9STB],

Do the same simple experiment in a 50+ Year Old House
and you may be 'shocked' at the results ;-) ~ RHF

In article ,
"Smokey" wrote:

I'm with Tom...

Snip

Then you would be the "thunder" to the nut case lightning Troll.

In any event into the kill file with you.

Plonk

--
Telamon
Ventura, California

In article . com,
"RHF" wrote:

M... - " The loop will be unbalanced if you don't use a balun. "

Please Educate me as to Why the Loop Antenna
would be Un-Balance without using a Balun ?

i want to know - cause -iane ~ RHF

Any time you connect a transmission line directly to a antenna the coax
shield can affect the antenna unless you decouple it.

You can:
1. Run the coax at a right angle from the antenna elements.
2. Use a choke of some type on the coax.

Otherwise the coax shield become part of the antenna.

--
Telamon
Ventura, California

M...,

My assumtions were that he said he was getting ready for a Table Top
Receiver; and that it would have both a LO-Z 50 Ohm {SO-239 Jack}
and HI-Z 500 Ohm {Pair of Terminals} as the External Antenna Inputs.

But in re-reading the original post; I see that it is a RadioShack
DX-394 which only has the one SO-239 Jack as it's External
Antenna Input.

My general preference with a Ceiling Loop Antenna is to use 300 Ohm
Twin Lead as the Feed-in-Line from the Wire Loop Element to the
Receiver's HI-Z 500 Ohm {Pair of Terminals} for the External Antenna
Input. The exception being if the Radio uses an 1/8" Mono-Jack as
the External Antenna Input. Then a short piece of simple Audio Coax
Cable with an 1/8" Mono-Plug can be the better choice for a
Feed-in-Line from the Loop Antenna to the Radio.

Note - Horizontal Wire Loop Antenna Element directly connected to a
Vertical Feed-in-Line.

iane ~ RHF

In article .com,
"RHF" wrote:

M...,

My assumtions were that he said he was getting ready for a Table Top
Receiver; and that it would have both a LO-Z 50 Ohm {SO-239 Jack}
and HI-Z 500 Ohm {Pair of Terminals} as the External Antenna Inputs.

But in re-reading the original post; I see that it is a RadioShack
DX-394 which only has the one SO-239 Jack as it's External
Antenna Input.

My general preference with a Ceiling Loop Antenna is to use 300 Ohm
Twin Lead as the Feed-in-Line from the Wire Loop Element to the
Receiver's HI-Z 500 Ohm {Pair of Terminals} for the External Antenna
Input. The exception being if the Radio uses an 1/8" Mono-Jack as
the External Antenna Input. Then a short piece of simple Audio Coax
Cable with an 1/8" Mono-Plug can be the better choice for a
Feed-in-Line from the Loop Antenna to the Radio.

Note - Horizontal Wire Loop Antenna Element directly connected to a
Vertical Feed-in-Line.

You would be better off using 50 ohm coax for the loop antenna and also
the lead-in using the radios low Z input.

If you are in a low noise area then use an unbalanced coax loop for more
pickup. If local noise is a problem then use a voltage balanced loop.

--
Telamon
Ventura, California