Someone sed:

"So, the 300/75/50 ohm term, characteristic impedance, is the square root of
L/C"
==================

Not always!

73 de Jack, K9CUN

To a first approximation ... YES. In the context of providing a simple
explanation, an introductory level explanation, as in the context of the
original question ... YES.

In the interest of more advanced analysis:

Zo = SQRT[[R + jwL]/[G + jwC]]

In a lossless line that converges to SQRT [L/C].

DD

JDer8745 wrote:

Someone sed:

"So, the 300/75/50 ohm term, characteristic impedance, is the square root of
L/C"
==================

Not always!

73 de Jack, K9CUN

"In a lossless line that converges to SQRT [L/C]."

There is no such thing as a lossless line. The formula becomes SQRT(L/C) as
the frequency increases, but the losses don't go away. In fact losses of TLs
increase as frequency increases. Nice graphs of this in the Handbook.

73 de jack, K9CUN