[Lowfer] loop performance

Wed, 28 Jan 2004 04:26:28 -0800

Hi Bill and all,

The square loop has 200 feet of conductor, while a circular one of the
same area has only about 177 feet.  So, in free space and with an ideal
resonating capacitor, I would expect circular Q to be 12.8% higher.  In
the real world, perhaps coupling and capacitor losses are roughly equal to
the conductor loss (do you have any figures on this?); it would still
leave about a 6% Q improvement.

But that's only about a quarter of a dB more ERP; only a fanatic would
invest the additional effort in construction and support for such a small
gain :) 

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Bill Ashlock
Sent: Wednesday, January 28, 2004 12:34 AM
To: [email protected]
Subject: RE: [Lowfer] loop performance

>Have you seen any difference in performance of loops with equal wire
>length but of varying shape?  Specifically, can you tell a difference
when
>your loop is "perfectly" round as opposed to being something closer to a
>square, with essentially horizontal runs near top, bottom, and/or sides?

Eric, there's not much difference in the performance of 2500sq ft loops of

varying shapes as long as the lower horizontal portion isn't much longer 
than 50 ft. My measurements indicate loops, having the same area, that are

much wider than they are tall have excessive ground losses, but I haven't 
put a number on this loss, yet. I also have a hunch that circular loops
have 
a higher Q than square loops of the same area but I haven't proven this
yet 
either ....and textbook articles all say there is no difference. Of course

most authors claim the TX loop has no practical value at LF, so what do I 
know!

Bill

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