[Elecraft] Tuner/Balun Question

Don ehrlich at olypen.com
Mon Oct 3 00:34:34 EDT 2005


The output of a conventional tuner is not balanced and is intended to be 
connected to an unbalanced load like coax.  However, it certainly is 
possible to connect it to a balanced feedline and it *may* find a match when 
so connected.  However, the "balanced" feedline will not be balanced when 
that is done because one side is connected to ground.  The result is that 
power may be delivered to the antenna but the feedline will be radiating and 
the pattern from the antenna is unknown.

That's the short answer ... I await the many antenna experts on the list to 
embellish it.

Don  K7FJ

>I just read the Aerials article by Krusty Kurt in the October issue of 
>World
> Radio.  Near the end of the article, Kurt is describing a well known 
> method
> of running parallel coax through the wall to connect ladder line to the
> antenna tuner.  His method ties the shields together at both ends to get 
> 100
> ohm feedline, while I've always left the braids near the ladder line
> floating.  What really caught my attention, however, is his comment that 
> you
> can run the parallel coax lines straight to the tuner without a balun. 
> I've
> always used a balun in this setup; either 4:1 or 1:1.  I recall emails to
> this reflector in the past describing connection of ladder line straight 
> to
> an Elecraft tuner with no problems.  I'm now wondering if I could ditch 
> the
> baluns in my installation.  Any thoughts/experience with this?  Is the
> output from a tuner balanced at the coax connector up until such time that
> it's connected to an unbalanced load like a single coaxial line?



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