[Elecraft] Balun suggestions

Bob McGraw K4TAX rmcgraw at blomand.net
Thu Feb 4 18:10:39 EST 2016


As one that has personally used a balanced fed antennas for years, I 
suggest you review the info on this site.
  http://www.dj0ip.de/balun-stuff/ <http://www.dj0ip.de/balun-stuff/>

Good stuff on evaluating or building a proper balun.

And for open wire fed antennas:
http://www.dj0ip.de/open-wire-fed-ant/

To answer your question, a high power 1:1 current balun is likely best.  
Of course you could built a balanced tuner as I did.  Problem solved.  
That's another story.

Keep in mind that balun power ratings are for "matched" conditions. 
Which in fact is never the case with a center fed wire and open wire or 
a  balanced feed line.  At a mighty 5 watts it would not be of concern.

If at all possible, run the balanced feed line from the antenna feed 
point all the way to the operating position.  Keep the coax run between 
the tuner output and balun input as short as practical. After all, the 
reason to use balanced feed line is to take advantage of the low loss 
properties.

Never fear, the use of balanced feed line is not near as critical or 
fussy as the "masses" will so tout.  Many hams express fear in using 
balanced feed systems, largely because of what they have heard. Mostly 
because it frankly isn't fact.  Mine feeds a 256 ft center fed wire and 
comes down the tower supported on home made 9" PVC stand-offs, through 
the attic eve vent, across the roof rafters, and drops down through the 
ceiling to the tuner on the shelf above the desk.  Not bad for a 160M - 
10M antenna.    {see my pix on QRZ.COM that shows a bit of the line 
going up the wall.}

73
Bob, K4TAX

<http://www.dj0ip.de/open-wire-fed-ant/>

On 2/4/2016 2:55 PM, Jim Allen wrote:
> K2/100 and KAT100 here.
>
> I am changing around my modest antenna configuration now.  I have been using the K2/100 with my AH-4, and now wish to use the KAT100 with balanced feedline antennas.
>
> What balun, homebrew or commercial, if any, should I use?  I almost always run 5 watts, all CW.
>
> 73 de W6OGC Jim Allen
>
> Sent from my iPad
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