Vangellis,

Here is the KISAP {Keep It Simple And Practical} Evaluation
of the Watson-Miller Shortwave {Listener} (SWL) Receiving
{Only} Antenna

Watson-Miller Shortwave {Listener} Receiving {Only Antenna
1.8 - 30MHz (Small Vertical Passive SW Antenna)
WM SWL ANTENNA - http://tinyurl.com/2g2hqx

NOTE - Watson Miller makes several Antennas for Scanners
and VHF and UHF usage
http://www.wsplc.com/acatalog/Watson..._Antennas.html
http://www.wsplc.com/acatalog/Watson..._Antennas.html
http://www.wsplc.com/acatalog/Watson..._Antennas.html
+ Plus Watson does make some HF Wire Antennas
http://www.wsplc.com/acatalog/WATSON..._Antennas.html
Mostly for the Amateur Radio Bands -but-
SWL-DXDL Watson Long Wire + MLB Antenna Kit
SWL-DX1 Watson SWL Long Wire Antenna Kit
WA-103 Broadband T2FD Antenna 7-30 MHz
WDP-30 Watson 1~30 MHz Receiving Dipole including Coax Feeder
Watson-Miller SW Receiving Antenna 1.8 - 30MHz (Passive)

Evaluation of the Watson-Miller Shortwave {Listener} (SWL) Receiving
{Only} Antenna : Visual Examination and Review
of the Written Description.

Start by taking a look at the Photos and Reading the Info
presented : Here is what I 'think' can be reasonably said
about the Watson-Miller Shortwave {Listener} (SWL)
Receiving {Only} Antenna.
WM SWL ANT - http://www.wsplc.com/pages/pdf/miller.pdf

1 - Designed to be Broad-Banded for the Shortwave Bands
Frequency Coverage 1.8 MHz to 30 MHz.

2 - Passive Antenna Element 'appears' to be Made of Bent
Aluminum Tubing. Estimate 3/8 Inch Diameter and
Approximately 12 Feet Long with 3 Inches of separation
between the parallel tubes.

NOTE - Bent to resemble an Off-Center Folded Dipole
{Skinny Loop "Balance"} Antenna -but- IT IS NOT.
-why- Claims to use "End Loading System"
http://www.wsplc.com/pages/pdf/miller.pdf

3 - I believe that the Black Tube part is simply a PVC Pipe
Stiffener to Secure and Hold the Two Ends in Place.

3 - Uses a Balun to 'match' the Bent Antenna Element to an
SO-239 Socket for connection to a 50 Ohm Coax Cable
feed-in-line.

NOTE - Most likely using the word "Balun" cause it sells
when what they have is a Matching Transformer (UnUn).
"with Built-in Magnetic Long Wire Balun"
"the very latest High Quality Magnetic Long Wire Balun"
http://www.wsplc.com/pages/pdf/miller.pdf

4 - Height = Two Metres (2m) ~ 6 Feet 6 3/4 Inches
[ ~ 78.74 Inches ]

DO-THE-MATH : Double the 78.74 Inches to 157.5 Inches
and Subtract 13.5 Inches = 144 Inches = 12 Feet of Aluminum
3/8 Inch Tubing.

5 - Length of the Antenna Element : 12 Feet

WHAT YOU "GET" PRACTICALLY SPEAKING :
[Shortwave Radio Bands 60m ~ 19m : 5 MHz ~ 15 MHz]

1 - Start with a normal size Whip Antenna found on most
'portable' AM/FM Shortwave Radios : The Whip Antenna
is about 36 Inches long {3 Feet} with a 1/4" Base Diameter
and an 1/8" End Diameter having an Average Diameter
of 3/16".

The Watson-Miller Shortwave {Listener} (SWL) Receiving
{Only} Antenna [WM SWL Antenna] is 12 Feet with an
Average Diameter of 3/8"
Result : The Antenna Element is Four Times [12 to 3] as
Long and Twice the Diameter [ 3/8" to 3/16"] with an
RF Signal Area of 170" to 21" which is Eight Times
as large as the Whip Antenna.
Improvement Equals = 4X + 2X + 8X

2 - The Signal Capture Area of the Whip Antenna can
crudely be estimated at 36" x 1" for 36 Square Inches.
WM SWL Antenna's Signal Capture Area can be estimated
at 72" x 3" for 216 Square Inches.
Result : The Signal Capture Area improves by Six Times
[216 to 36].
Improvement Equals = 6X

3 - The Whip Antenna is located on the Radio and inside the House/
Building where the RF Signal is often much weaker
and the Man-Made Environment is saturated with the RFI
and EMF that is there.
WM SWL Antenna is located outside the House/Building
where the RF Signal is often much Stronger and away from
the Man-Made Environment inside the structure; so it is
not saturated with the RFI and EMF.
Result : The Antenna Element receives at lest Two Times
[2 to 1] the RF Signal and Half the RFI and EMF [1 to 2]
giving at least a 4 to 1 Improvement in the relative
Signal-to-Noise Ratio coming into the Radio.
Improvement Equals = 4X

4 - The Radio's Whip Antenna is an e-Probe type of Antenna
Electrically Short and smaller that a Tenth (1/10) of a
Wave-Length for the Shortwave Radio Bands.
* Most Radio's Whip Antennas are 'passive' but some are Active.
* Most Radio's Whip Antennas are 'un-tuned' but some are Tuned {Pre-
Selected}.
WM SWL Antenna is a Passive and Un-Tuned e-Probe also
-but- It is Matched to the Antenna Feed-in-Line with an UnUn
type of Matching Transformer; which also helps to de-couple
the Antenna Element from the Feed-in-Line and the Man-Made Noise from
within the Structure.
Result : The Improved Performance with the WM SWL Antenna.
Improvement Equals = 1X

SUMMARY : Adding Up the "X"s
4X + 2X + +8X 6X + 4X +1X = 25X
Then Divide-by-Ten for a 2.5 S-Unit Improvement in the
relative 'Merit' of the Watson-Miller Shortwave {Listener}
(SWL) Receiving {Only} Antenna over the normal Radio's
Whip Antenna.

COMPARISON TO AN INVERTED "L" ANTENNA :
The previously mentioned Radio's Whip Antenna to a Par
EF-SWL Antenna configured as an Inverted "L" Antenna
located outside with a 15 Foot Vertical-Up-Leg and a
30 Foot Horizontal-Out-Arm.
http://www.parelectronics.com/swl_end.htm
http://www.grove-ent.com/ANT8.html
http://www.universal-radio.com/catalog/sw_ant/2205.html
PAR EFL-SWL Antenna, and Inverted-L Antenna Questions
http://groups.google.com/group/rec.r...11c0ac4f084b87
http://groups.google.com/group/rec.r...2ff595de9fea91

1 - Wire Antenna Element is 45 Feet Long by 1/8" Diameter
with an RF Signal Area of 212" to 21" which is Ten Times
as large as the Whip Antenna.
Improvement Equals = 15X - 1.5X + 10X
2 - The Signal Capture Area of the Wire Antenna Element
can crudely be estimated at 540" x 1" for 540 Square Inches.
Improvement Equals = 15X
3 - Wire Antenna Element is Outside versus Inside
Improvement Equals = 4X
4 - Par EF-SWL Antenna is a Passive and Un-Tuned Random
Wire Antenna Element -but- It is Matched to the Antenna
Feed-in-Line with an UnUn type of Matching Transformer;
which also helps to de-couple the Antenna Element from
the Feed-in-Line and the Man-Made Noise from within
the Structure. Plus It is 'configured as an Inverted "L"
Antenna with a Ground Rod at the Base.
Improvement Equals = 2X

SUMMARY : Adding Up the "X"s
15X -1.5X + 10X +15X + 4X +2X = 44.5X
Then Divide-by-Ten for a 4.45 S-Unit Improvement in the
relative 'Merit' of the Par EF-SWL Antenna over the normal
Radio's Whip Antenna.

COMPARISON : Comparing the Par EF-SWL Antenna
to the Watson-Miller Shortwave {Listener} (SWL)
Receiving {Only} Antenna would show on average of a
Two (2) S-Unit Improvement in the relative 'Merit'.


and that is the way i 'see' and 'read' it - iane ~ RHF {pomkia}