[Antennas] spencer dipole from Mccoy's book

[Charles Greene]

At 11:17 PM 1/2/2002 +0000, Gary Lee wrote:

Gary,

I used a somewhat similar situation for several years.  It was a classical 
OCF antenna, 135 ft long fed at 45 feet from the end.  I fed it with two 
lengths of RG8, with shields open at the antenna and connected at the 
antenna tuner.  I got the design from an old issue of 73 magazine.  For an 
OCF antenna, and any dipole antenna, the radiation resistance depends on 
its height, so using a 50 ohm or 75 ohm coax is a choice depending its the 
height.  In my case, the RG8 worked fine and the antenna and feed line 
performed well.  I didn't see any advantages to the RG8 and ladder line is 
cheaper, so I replaced it with a 4:1 balun at the antenna and a single 
length of RG8 the next time I put it up.  You can also use 300 or 450 ohm 
open wire line and place the balun at the ground level, or just route the 
open wire line to an antenna tuner.  It depends what you have to work 
with.  Try what you have before going out and buying something.  My 
preference is ladder line to the ground, a 4:1 balun to the antenna tuner 
but I make my own baluns so they are cheap.  GL

>I am considering this antenna for several reasons, not the least of which
>is shielded balanced feedline.  If I understand Lou Mccoy's description
>correctly, this is a dipole 139 ft long, fed at the 82 ft point with the
>center conductors of two pieces of rg-11 72-ohm coax.  Grounds are tied
>together at the tuner, and left open at the antenna feedpoint.
>
>I am totally blind, so got the book on tape, unfortunately with not much
>description of pictures.
>
>Am I correct?
>
>Also, anyone out there with experience with this setup?
>
>Thanks for any help.



73, Chas, W1CG