[AMRadio] Re: Link coupling

[A.R.S. - WA5AM]

On 9/5/07, D. Chester <k4kyv at charter.net> wrote:
>
> > This brings up a thought I've had about link coupled tuners, of which I
> > use.
> >
> > Of course I feed the 50 ohm coax to the link.  The center to one side
> > of the link and the shield (ground) to the other.  What effect does
> > the "link position" have on a tuner?  I suspect the link position
> > (mine is rotatable) would affect the matching impedance to the coax?
> >
> > 73
> > Brian / wa5am
>  If you have a variable link on the antenna tuner coil, there will be one
> and only one critical degree of coupling that will give a perfect matching
> impedance to the coax (assuming that impedance match is within the range of
> the tuner).  Increasing the coupling will make the coax  see  too  low an
> impedance, and decreasing the coupling will make the load impedance too
> high.
>

Thanks Don, that's what I thought, and have indeed observed.

73, Brian