Grounded Loop Antenna
My grounded loop antenna (non-resonant, unbalanced), works well on the HF Bands and is relatively quiet. On 160m it acts much like a vertical with a counterpose. On higher bands it seems to radiate like a vertical and somewhat less like a traditional vertical loop. It is oriented in the east to west plain.
Various and sundry radials provide for an extended counterpose on the ground side of the loop. I will be experimenting with different configurations of radials. All the radials and return wires are mostly 0' to 4' above actual earth. Three buried 8' ground rods provide for a direct earth connection. Static charges are grounded out with this antenna design.
Inspired by:
The
Novice Antenna Notebook by Doug DeMaw, W1FB
ARRL 1988
First Edition pg 87 – 88.
Grounded
Loop webpage by G4NSJ
The Half-Delta Loop, A Critical Analysis and Practical Deployment by John S. Belrose, VE2CV and Doug DeMaw, W1FB. ARRL: QST Sept 1982 p28-32
ARRL’s Wire Antenna Classics. The Tilted Half-rombic Antenna by AA2PE, Ch 5 p 5-10.
Efficient Ground
Systems for Vertical Antennas, by Archibald C. Doty, jr.,
K8CFU, John A. Frey W3ESU and Harry J. Mills, K4HU. ARRL: QST Feb
1982 pg 20 – 25
AM
Elevated Radial Systems Radio
Guide Aug. 06
The
antenna is supported by large fir trees native to the area. A
system of pulleys and weights provide tension relief for the thin
steel cable wire as the trees sway in the wind.
Basic
configuration.
I am making
counterpoise
modifications
based on EZNEC results.
AA7OK's
Station:
Locator:
CN87wp
Rig: Yaesu FT-950
Interface: SignaLink USB
Software:
HRD/DM780
Winkeyer WKUSB by K1EL
Iambic Key by
www.K8RA.com
TransMatch:
MFJ
Feed: Short/ High Quality Coax
This illustration draws the comparison between a ground mounted vertical (Marconi) and the ground mounted loop. In both cases the "earth image" of the above ground vertical elements, complete the antenna electrically. The grounded loop is a ground image antenna. It is always a half loop with the other half an Earth Image. The term grounded half loop would be an accurate descriptor.
This antenna is inherently unbalanced. Like a ground mounted vertical or an elevated vertical with a counterpoise.
The loop is referenced to ground at any and all frequencies. This has an effect on the angle of radiation from the antenna at any given frequency. We are forcing the position of waves created on the loop (at the feed point) to be maximized for current. This antenna radiates like a vertical.
Buddy
is one of the world's greatest dogs and is my friend.
The
RF seems to be good for my garden.
I have a large city garden.
I
work at one of the high schools in this city and help run the
radio station. I've been in public education for many years and
in many roles.
KB6AEC
(8/23/83), KG7EN (5/29/90), AA7OK (9-21-03)
Member: SEIU, SBE, E.T.A., ARRL, NAEOP,
Certifications: Extra Class, FCC
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