3 Element Direct Feed 17 Meter Yagi
by Danny R. Goodrum N5DRG
Centered at 18.118 Mhz 
Efficiency of 99.50%


17 Meter Yagi in the air

Overall diagram and layout. Note driven element insulator.
Driven element MUST be insulated from boom. See photo closeup below:


Driven Element runs left to right under the boom. Center insulator in center of photo.

Element Length, Diameters, spacing and specifications

Element	Position from Ref.	Position from Ref. Inches (ft)	Length Inches	Length Feet	Element Dia/ Taper	Material	Gain dBi	F/B Ratio	SWR
Reflector	0	0"	325.95	27'-1-15/16"	1.0 > 7/8 > 3/4	Al	7.08	16.01	1.1:1
Driven	1	62.78" (5'-2-3/4")	320.18	26'-8-3/16"	1.25 > 1.0 > 7/8	Al
Director	2	118.11" (9'-10-1/8")	298.33	24'-10-5/16"	1.0 > 7/8 > 3/4	Al

A PDF file of plots, charts etc is available for this project. See end of article.

A 2" x 11' foot boom was used.
The Driven Element is isolated from the boom, the Reflector and Director are direct connection with boom.

On Air Testing: 17 meter Yagi vs W5GI Mystery Antenna

I have two 17 meter setups, one is a multiband dipole. (W5GI's Mystery Antenna) Fed through a MFJ tuner.
The other is my NEW 3 Element Beam in this project.

The difference on the dipole vs. the beam is… well like night and day.
Stations I can just hear on the dipole are S-9 on the beam.
One station in Hawaii was calling me when I was on the beam, yet when I switched back to the dipole, I could not ever detect his signal at all.

Resources:
I would like to thank Paul Mcmahon VK3DIP, for the use of his YagiCAD6 6.0 in the development of this antenna.
I used his program, along with dimensions that I have come up with using standard formulas for antenna building, that are published in the ARRL Hand Book, and various other sources.
Paul Mcmahon VK3DIP, Software can be found at:
www.yagicad.com/YagiCAD/YagiCAD.htm