N9NEO,

MY IDEAS ON AN IN-THE-ATTIC T2FD ANTENNA :
Old Idea - Terminated 'Tilted' Folded Dipole (T2FD)
[ Twisted -Not- Tilted ]
New Idea - Terminated "Twisted" Folded Dipole (T2FD)
[ Twisted / Flat-not-Tilted / In-the-Attic ]

First Build the Terminated Tilted Folded Dipole (T2FD)
as Big as you Can to get down to your "Lowest Desired
Operating Frequency" per the design Formulas.

Second the In-the-Attic T2FD is after all In-the-Attic and so . . .
It Ain't Gone-Ah-Be Tilted - It's Gone-Ah-Be FLAT [.]

QUESTION - What Did the Tilting Do For the T2FD ?
1 - Added to the Broadbanded Frequency Characteristics
of the T2FD Antenna.
2. Added to the Omni-Directional (All-Around 360 Degrees)
Characteristics of the T2FD Antenna.
Note - The TILT of the T2FD Antenna was usually about
30 Degrees and that would mean that the Height of the
Antenna "Vertical Dimension" was 50% of the Length of
the T2FD Antenna plus the Elevation at the Lower Base
(Bottom) Support.

Doing the Math - Your 45 Foot Long T2FD Antenna would
have to have a "Vertical Dimension" Drop of 22.5 Feet and
to keep the Wires overhead a minimum Lower Support
Height of 7.5 Feet for a Top Mounting Support Height of
at least 30 Feet. All sort of hard-to-do in most Attics.

ALTERATIVE - Omni-Directional Antenna Trick :
Build a T2FD Antenna In-the-Attic with a TWIST
Terminated "Twisted" Folded Dipole (T2FD)
- - - Instead of a Tilt )

The Ends would both have "Vertical" Spacers / Spreaders
and the Center Spacer / Spreader would be "Horizontal".

The Left-Top-Wire would become the Center-Near-Wire
and then the Right-Bottom-Wire -while- The Right-Top-Wire
would become the Center-Far-Wire and then become the
Left-Bottom-Wire.

If additional Mid-Point Spacers / Spreaders were used
then they would be set at 45*/225* and 135*/315* to
maintain the distance between the two Wires.

When building a T2FD Antenna In-the-Attic :
Think - Twisted -not- Tilted :
Terminated "Twisted" Folded Dipole (T2FD)


MORE GENERAL INFO ABOUT THE T2FD ANTENNA :

B&W makes two general statements about the
Terminated Tilted Folded Dipole (T2FD) Antenna :

* For example, an {T2FD} Antenna for the lower portion of
Shortwave (3 - 18 MHz) will be roughly 33m (110 feet) long,
with conductors spaced 1m (3.3 feet).
[With a Top End mounted about 60 Feet High at 30 Degrees.]

* In order to cover the higher portion of Shortwave (5 - 30 MHz),
this {T2FD} Antenna will be roughly 20m (66 feet) long,
with a spacing of 60 cm (24 inches).
[With a Top End mounted about 40 Feet High at 30 Degrees.]

Build one size or the other = No Formula Required.

READ : Terminated Tilted Folded Dipole (T2FD)
Antenna - WOW ! ! ! {One SWL's Experiance}
http://groups.yahoo.com/group/Shortw...na/message/293

Hard Core DX - "T2FD Antenna" - Info and Design Links
GoTo= http://www.hard-core-dx.com/nordicdx...ire/index.html
- - - The Terminated Tilted Folded Dipole (T2FD)
- - - The "T2FD" is a Broad All Band Antenna for SWL.
http://www.hard-core-dx.com/nordicdx...wire/t2fd.html
http://www.hard-core-dx.com/nordicdx.../t2design.html
http://www.hard-core-dx.com/nordicdx.../t2fdfeed.html
http://www.hard-core-dx.com/nordicdx.../t2fdcomp.html
http://www.hard-core-dx.com/nordicdx...re/t2fd_1.html

More About the Terminated Tilted Folded Dipole (T2FD)
* How To Build the TTFD : A Broadband Antenna for
Shortwave Reception - by Arnie Coro [RHC] Dxers Unlimited
http://www.radiohc.org/Distributions/Dxers/ttfd2.html
* Modeling the T2FD - by L.B. Cebik [W4RNL]
http://www.cebik.com/wire/t2fd.html

The Formulas for Calculating Terminated Tilted Folded
Dipole (T2FD) Dimensions are found at :
http://www.hard-core-dx.com/nordicdx.../t2design.html

TIP - Take a look at the Wellbrook Universal Magnetic Balun
UMB T2FD is a Receiving Antenna Balun designed to
simplify the construction of the Terminated Tilted
Folded Dipole (T2FD) Antenna.
http://www.wellbrook.uk.com/images/umbt2fd.gif
http://www.wellbrook.uk.com/images/umbt2fdc.gif
http://www.wellbrook.uk.com/images/umbt2fde.gif
(o: Construction Hints )

RF Systems - Terminated Tilted Folded Dipole (T2FD)
Receive Antenna - Coverage : 3 - 35 MHz
http://www.universal-radio.com/catalog/sw_ant/0562.html


hope this helps in a twisted sort of way - iane ~ RHF