[TenTec] The problem with directly end fed wires

[JAMES HANLON]

Bob wrote:


>
> I still stand on the position that a center fed wire of any length, fed 
> with
> a balanced feed from a tuner will perform best as an all band 
> configuration.
> If it is reasonably well balanced, no RF in the shack will exist, with or
> without a ground.
>

For more than 40 of the 51 years I've been licensed, my antenna has been a 
"Center-Fed Zepp" ala what Bob described.  For about 20 of those years I 
lived on a city-sized lot in Columbus, Ohio, and the longest flat-top I was 
able to get up was only 67 feet.  I center fed it with open wire line, long 
enough to reach from the antenna to the shack in the basement - no magic 
length - and it loaded and worked well on all bands including 80 and 75 
meters.  As Bob says, I have never had a problem with RF in the shack using 
this type of antenna.  My current antenna is a half-wave on 160, thanks to 
four acres of land here in NM, and it works well on all bands.

For several years when I lived in Emmaus, Pennsylvania, I had an end-fed 
version of this antenna up, 134 foot flat-top end fed with open wire line. 
That also worked very well.

By the way, while I was in PA I happened to talk to G. H. Brown, VP of RCA 
Labs in Princeton, NJ.  Dr. Brown was the inventor of the turnstile antenna 
used by TV broadcasters among many other antenna types.  He chided me as a 
ham because we amateurs, according to him, hang a lot of matching networks 
out in the middle of our antennas where they are subject to deterioration 
due to weather and where they are very hard to get to for adjustment.  He 
mentioned a satellite antenna that he had designed that had a vswr of 6 on a 
very short run of coax.  He figured that he got less loss by putting his 
matching network "inside" rather than out on the antenna.

In case you have a copy of Terman's Radio Engineers' Handbook, look up G. H. 
Brown in the Author Index (page 997 in my 1943 edition).  He has 19 
citations, second only to F. E. Terman who has 43.  But then Terman wrote 
the book!

73,

Jim, W8KGI