Al, W1AEL, is very correct on this one. Thus the reason one finds
commercial Ladder line having a spacing of about 1" and Window line having a
space of about 1". As the spacing becomes a larger part of a wavelength,
i.e. at higher frequencies, radiation can start to be a problem. The
homebrew line is usually easier to build if the spacing is 2" to 3" and use
larger conductors such as #14 or #12.
73
Bob, K4TAX
----- Original Message -----
From: "Allan H Kaplan" <w1ael@mindspring.com>
To: <tentec@contesting.com>
Sent: Sunday, February 05, 2006 9:11 AM
Subject: Re: [TenTec] Open-Wire Feeders
Catfish wrote: ..."the wider the space the better",
but I urge a more moderate approach. Getting the lines more than a few
electrical degrees apart will allow them to radiate some of the power we
would like to transmit to the antenna. Art Collins held his
engineering staff to a very demanding tolerance of one electrical
degree -- about an inch at 30 MHz.. I believe that a 3 to 6 inch
spacing is reasonable. I use line supplied by W7FG, spaced at about 4
inches. It has held up well in the hills of east Tennessee. 73, Allan
W1AEL.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|