Angier,

Let me start by saying I don't have any experience with the AirWhip antenna.
I am an electronics engineer (retired) and Ham. If I read the AirWhip description correctly it appears to be a network that
end-feeds an antenna element that is the length of a dipole, eliminating the
need for a ground plane. I have no doubts that it does that, and the
impedance match is good. That said, I see some issues.

1) The antenna needs to be oriented to match the polarization of the signal
it is attempting to receive or transmit. For VHF voice that is vertical
polarization, and for VORs that is horizontal polarization. 2) The antenna length need to be 1/2 wavelength long to get the best gain.
That’s about 54 inches for the bottom of the Nav band and 50 inches for the
bottom of the Comm band. 3) The antenna element needs to be close to straight to achieve maximum
gain, so it shouldn't be wrapped inside the empennage (for instance). While
composite planes can usually find a 55 inch horz location of an antenna
(wing, belly, etc.), and vertical location is more challenging. That's why
the Archer dipole antenna is usually bonded inside the vertical stabilizer.
It's the only location that supports the physics of the situation.

On the positive side, the connection appears much more substantial than the
center feed for the Archer dipoles, and from that standpoint it could be an
improvement. The site doesn't say what type of coax pigtail extends from the AirWhip. If
it's just RG-58, or some other single shield coax, the pigtail should be
shortened, a new BNC installed, and the remainder of the run done using
RG-400, or some other high quality 50-ohm double shielded cable.

Hope this helps

Paul Bricker
N63PB

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of
Greenbacks, UnLtd.
Sent: Saturday, March 22, 2008 6:40 PM
To: lml@lancaironline.net
Subject: [LML] Re: Miracle Antenna/AirWhip

Is there anyone on the list with knowledge of, or experience with this  product?
Looks interesting...

http://www.miracleantenna.com/AirWhip.htm

Angier Ames
N4ZQ


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