On Mon, 05 Apr 2010 20:33:47 GMT, Owen Duffy wrote:

Bob wrote in
:

The more I look at it, the odd 1/8 wavelengths is probably the way I
will go, connecting to my tuner's 4:1 balun. There will be a 130 foot
flat-top, and the 450-ohm feedline length can be somewhere between 50
to 100 feet or so. Tnx for the input!

I guess then that you didn't look at the article I quoted.

Actually, I did look at the article.

It mentioned the voltage maximum problems, the current maximum
problems, and then said, "Is there a better option?" And I don't
understand the few sentences that follow that query. In other words, I
don't understand the solution -- i.e. "line lengths around 135
degrees longer than voltage maximum" :-)

Bob
k5qwg


Typical T match ATU's are lossier on capacitive loads than on inductive
loads.

The odd eighth wave rule of thumb is a popular one. But, alternate odd
eight waves (on a resonant load) assures the highest ATU losses for the
given SWR.

These rules of thumb, and there are plenty that are conflicting, are
usually given without explanation of why they work. We are a gullible
lot!

The same occurs with 4:1 voltage tuner baluns which anecdotal evidence
suggests assist match of a wider range of loads. There is good reason to
think that the mechanism behind this is that their own loss assists, and
it is an inefficient work-around for another problem.

Owen