On Sep 24, 9:24*pm, Tim Shoppa wrote:
On Sep 23, 11:03*pm, "justme" wrote:

I GET DIFFERENT RESULTS WHEN COMPARING TO A GRAPH.

Exact impedance of ladder line is usually unimportant. It is so low-
loss, that even large impedance mismatches do not result in any
appreciable transmission line losses.

Another thing, base 10 log and natural log often are confused.

Tim N3QE

Not so!

For example in this month's QST magazine there's an article on using a
40m full-wave loop on 80m. The designer uses a series quarter-wave
section of 450 ohm ladderline to make the impedance "more manageable".
He quotes 300+j8000 at the antenna end of the ladderline. Now plug
those values into Owen's calculator, using something like Wireman 551
for the line, and you'll get 7dB of feedline loss.

73,
Steve G3TXQ