[Antennas] Loop vs Dipole

Wed, 1 Oct 2003 20:42:57 -0400

Ron, I have to agree with George, feed it with ladder line and a balun at the tuner, also, I am assuming your feeding the system at the top and not at the bottom corners, should do better feeding it at the top, dont really know the physics why that it but that has been my experience... good luck... I love loops and Bi-Squares...73  Tim K8WBL
> 
> From: "Ron & Madhavi" <[email protected]>
> Date: 2003/09/30 Tue PM 01:13:41 EDT
> To: <[email protected]>
> Subject: [Antennas] Loop vs Dipole
> 
> Here's a tough one....or is it?!
> 
> I live in a townhouse in Kingston - the backyard is no more than 32' long
> and 10' wide, with a concrete parapet wall at the back.
> 
> I have a 25' tall aluminum pole clamped to the wall and ran an inverted vee
> on 20m (25' at the apex). Results were fair and with my 850S, I worked into
> Asia and more consistently into Europe.
> 
> Wanting to improve on it, I replaced the vee with a full wave loop and
> expected it to outperform the inverted vee. The loop has perfect resonance
> (a nice 1.1 SWR). The matching is done with a  1/4 75 ohm transformer.
> HOWEVER, even though I have tried to move the feed to a corner, 1/4 from a
> corner, center, apex etc., nothing seems to make it outperform the inverted
> vee. I know that this does not confirm theory -- as the loop is larger, has
> a lower take off angle (at least so they say!) and better SWR etc.
> Adddmitedly, the base of the delta is a FEW feet lower off the ground than
> the ends of the vee, but I expected the claimed superiority of a full wave
> loop to offset that.
> 
> Used many 40/80m lops in the past, but never compared them to dipoles and
> vees at the same height! The results however were quite pleasing. First time
> I am running comparisons on  loops and dipoles on  20m . Is the superiority
> of the loop greatly exaggerated or am I missing something here?  I have
> written articles encouraging people to use lops instead of dipoles and now
> wonder if I lead them astray!!!!
> 
> Again...perfect resonance (checked witha  RF1 at the feed point, end of a
> half wave section of coax and after matching with the 1/4 transformer too! I
> can't see I have made any mistakes here! If its the height......how come the
> inverted vee works MUCH better?
> 
> Any thoughts. comments, advise?
> 
> 73,
> Ron, 6Y5/4S7RO
> 
> 
> 
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