Three-in-Plain-View Clothesline [Hidden] Shortwave Listening (SWL) Antennas
 

For One and All,

Three-in-Plain-View Clothesline [Hidden] Antennas for the
Shortwave Listener (SWL).
http://groups.yahoo.com/group/Shortw...a/message/9071

A good old fashion Coated Wire-Core Clothesline that has a Pulley
on each end can be an effective External {Out-Side} Antenna for
Shortwave Listening (SWL) for those who must 'hide' their Antenna
from the Neighbors.


FIRST - THE BASIC CLOTHESLINE [HIDDEN] ANTENNA :
{ Basic Longwire Antenna Design }
1. Wire Core {Metal} Clothesline
2. Two 5"-6" Pulleys one for each end of the Clothesline.
3. Three Strong 2"-4" Ceramic Insulators are required :
* One (2) between each of the Pulleys and their Supports.
* The Third one (1) between the two ends of the Clothesline
to hold the Ends Secure and Separated to form an 'open-loop'
Wire Antenna Element. Double Wrap the Clothesline Wire
Through the Ceramic Insulator's Holes and Remove the Outer
Insulation and Expose the Inner Wire. Use Metal Clothesline
Fasteners to Lock the Clothesline-in-place and ensure that
they have good Metal-to-Metal contact with the Inner Wire
of the Clothesline. {Electrical Continuity}
NOTE - Locate the Ceramic Insulator on the Bottom {Out}
Wire; and NOT the Top {Back} Wire of the Clothesline.
This makes the Metal (Wire) Clothesline into a
Folded {Bent} Random Wire Antenna Element.
4. Rig the Pulleys and Insulators
5. Rig the Clothesline with about a 2"-3" Drop in every
20 Feet when unloaded. (no clothes hanging on it)
6. Connect an Alligator Clip to the End of an Insulated Wire
that is used as the feed-in-line from the Clothesline Antenna
to the Radio when the Antenna is in use.
7. Connect the other-end of the Insulated Wire
feed-in-line to the HI-Z (500 Ohms) Antenna Input
of the Radio.
8. Attach the Alligator Clip to the Metal Clothesline
Fastener and ensure that they have good Metal-to-Metal
contact with the Inner Wire of the Clothesline.
{Electrical Continuity}
NOTE - Please Disconnect the Alligator Clip feed-in-line
when the Clothesline is being used to Hang Clothes :o)


SECOND - THE IMPROVED CLOTHESLINE [HIDDEN] ANTENNA :
An improved version of this Clothesline [Hidden]
{Folded or Bent} Random Wire Antenna starts with
a Ground Rod . . .
1. Install Ground Rod at the Base of the End of the
Clothesline that is being used as the Feed-Point for
the Antenna.
2. Run a Vertical Ground Wire from the Ground Rod
directly up to a location near the Clothesline Pulley.
3. Mount a 9:1 Matching Transformer at this location.
* One End of the Antenna (9) Side of the Matching
Transformer is attached to the Ground Wire.
* One End of the Antenna (9) Side of the Matching
Transformer is attached to a short wire with an Alligator
Clip on it to attach to the Metal Clothesline Fastener
when the Antenna is in-use and to the Ground Wire
when the Clothesline is being used to Hang Clothes.
* The Two Ends of the Coax Cable (1) Side of the
Matching Transformer are attached to a SO-239
Connector - One to the Center-Pin and the other to
the Outer Threaded Fitting.
4. Connect a Coax Cable between the Matching Transformer
and the Radio / Receiver.


THIRD - THE ALTERNATIVE CLOTHESLINE [HIDDEN] ANTENNA :
Use Ladder-Line or 300 Ohm TV type Twin Lead as the
twin-feed-in-lines for the Wire Clothesline Antenna Element.
1. Attach an Alligator Clip (2) to each of the Wires on the
Antenna End of the feed-in-line.
2. Attach the Alligator Clips (One each) to the Two Ends
of the Clothesline (the Metal Clothesline Fasteners) where
they are held separated by the Third Ceramic Insulator.
3. Reel the Clothesline out to it's Center-Span-Mid-Point
to us it as a Fold Dipole Antenna. -or- Reel the Clothesline
out to it's Off-Center-Span-38%-Point to use it as a Folded
"Windom" Antenna. My preference is the Off-Center
Folded Windom Antenna.
DOING-THE_MATH :
For a Off-Center Folded Windom Antenna
Pulley-to-Pulley = Pulley-to-Off-Center
- - - Length - - - - - - - 38%-Point - - -
20 Feet = 7.6 Feet {Double this for 40 Feet}
25 Feet = 9.5 Feet {Double this for 50 Feet}
30 Feet = 11.4 Feet {Double this for 60 Feet}
35 Feet = 13.3 Feet {Double this for 70 Feet}
45 Feet = 17.1 Feet {Double this for 90 Feet}

One other point . . .
Watch Out ! - Keep The Clothesline Wires High-in-the-Air :
You Don't Want To Be Clotheslined By Your Own Antenna ;-)


as always - iane ~ RHF