Actually, not.
1. the line is mismatched at both ends, 450 balanced to 50 ohm singelended.
If you put in or assume transformers for the balanced to unbalanced 450 to
50 ohm conversion at both ends, then it is matched (still assuming that Tx
and Ant are 50 ohm resistive.) I have an equation that calculates the loss
from a text book. (if the section is mismatched it is not conjugally
matched)

2. If I have a 50 ohm load at each end, and a line of impedance Z, 1/2
wavelength long, what does Z have to be for max power transfer? Nothing
constrains Z to be a value. Z at 50 is great, Z at 500 is not bad (have to
do some matching)
This problem the way it is stated 50 1/2 line 50 is implying that any type
of line will do as long as it is 1/2 long, then Z can be 0.01 and Z=20,000

So as long as the matching transformers are in,(assuming the right ones) it
is matched max power too.
The Tx out 50 ohm unbalanced is matched to the 450 balanced line 1/2
wavelength long and another transformer back down to 50.

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"JDer8745" wrote in message
...
"Isn't a 50 ohm transmitter conjugately matched to a 50 ohm load
when fed through 1/2 wavelength of 450 ohm ladder-line?"

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Heck yes, I'm assuming u mean 50 + j 0 Ohms.

73 de Jack, K9CUN