Frank wrote:
2 elements required? What does that mean?

In most cases an inductor, and capacitor, is required to match
a complex impedance, as follows:

Shunt C, Series L;
Shunt L, Series C;
Series L, Shunt C, or;
Series C, Shunt L.

Only rarely can a single component provide a match.

Other combinations can be used, for example, adjusting a transmission
line stub length and position, or a transformer in conjunction with a
reactance. The point is that an impedance has two values, commonly
expressed as R and X or as a magnitude and phase angle, so to achieve a
specific impedance requires two "degrees of freedom" -- that is, two
things which you can adjust and which, in simple terms, don't adjust
exactly the same thing. With only one adjustable element, you can get a
specific R, say, or X, but not both.

Roy Lewallen, W7EL

Roy Lewallen wrote:
With only one adjustable element, you can get a
specific R, say, or X, but not both.

With only one adjustable element, i.e. ladder-line length,
I get X=0 and 35 R 85 ohms which is close enough to
50 ohms for most of us non-perfectionists.

http://www.w5dxp.com/notuner.htm
--
73, Cecil http://www.w5dxp.com