[Elecraft] Baluns and 450 ohm line

[kc4kgu@ENTERZONE.NET]

> On Tue, 4 Jun 2002 N2EY@aol.com wrote:
> 
> > >  No.  No balun.  The two center conductors are used for the feedline and
> > >  the shield floats at the antenna and is grounded at the shack.
> > 
> > What happens to the two center conductors at the shack end?
> 
> They're connected to the balanced feedline connector of the transmatch
> unit.
> 
> > That means the impedance at the shack end of the coaxes (as measured between 
> > the center conductors) will be a pretty close replica of the impedance at the 
> > feedpoint. But as you QSY from the freq where the coaxes are exactly an 
> > electrical  halfwave long, all sorts of things will happen to the apparent 
> > impedance and SWR because the line will act as a transformer unless the 
> > feedpoint Z is exactly 100 ohms.
> > 
> > 73 de Jim, N2EY 
> 
> Nothing different than would happen when feeding it with 50ohm coax or
> open-wire or ladderline.  I expect that to happen, as should any
> amateur.  You tune and test the antenna system on the desired center
> frequency though.  Since I rarely stray very far from 3.875 on 75m, that
> is where I design/tune the antenna for. Am I missing something?
> 
> 73 de John - KC4KGU
> K2/100 #2490