[Towertalk] Trap dipole fed with ladder line?

[Jeff Burns]

Is there an advantage to using a trap dipole over a simple doublet if they
are both fed with ladder line?

Until just recently I could not figure any good way to get ladder line
anyplace close to my radio. Thinking I would have to use coax I sent for
information on W9INN antennas. I was surprised to see he recommends using
ladder line with his multi-resonate antennas. If ladder line is being used
why not just use a simple doublet antenna? These are the reasons I thought
of:

1. To maintain a typical dipole radiation pattern on the upper bands rather
than breaking up into multiple lobes.

2. To raise the impedance on bands were the antenna is very short.

One more idea is to keep the impedance in a narrower rang. But the idea is
not valid because with changes in the length of the feed line the impedance
changes dramatically.

Now I have found a way to get open wire almost all the way to the radio so I
can consider using a simple doublet. In my case I can put up a wire up to
about 100-ft long. At one end it will be about 35 to 40 ft off the ground.
At the other end it will be 15 to 25 ft off the ground. The broad side of
the wire would be pointing at Europe.

Would there be any advantage to putting up one of W9INN's antennas over a
simple wire? I may be able to put up a second antenna, but it would just be
a vertical or perhaps a short dipole at 90 to the first. Any point in adding
a vertical? I have a K2 with KAT2.

Jeff Burns
AD9T