Hi Jack,

I usually lurk here quietly, but thought
I'd stick my neck out.

I just did a quick analysis on EZNEC.
Imagine a wire that is 50 feet up, 70
feet across the top, hanging down 40
feet on each end for a total of 150 feet.
Feed it in the center of the top with
75 feet of 450 ohm line.

The impedance seen at the end of 75
feet of 450 ohm feedline looked pretty
workable on both 2182 and 4125 kHz.
(Yes, you need an antenna tuner, but
it could be very simple for just two
frequencies.) An NVIS antenna like
this is great for short range (a few
hundred miles).

Download the demo version of EZNEC
from www.eznec.com . It'll take you a
couple of hours to get familiar with it,
but then you can play "what if" with
a lot of simple antennas like this.

73, John - K6QQ

Thank you very much John. I admit not giving two hours of learning time to
my EZNEC demo, but I wrote it off as too complicated to assimilate in the
time I could spend on it. That's an interesting finding on a "short" dipole
tuning up on 2182. I had not considered what ladderline to a dipole might
allow...

Jack

"John Moriarity" wrote

Hi Jack,

I usually lurk here quietly, but thought
I'd stick my neck out.

I just did a quick analysis on EZNEC.
Imagine a wire that is 50 feet up, 70
feet across the top, hanging down 40
feet on each end for a total of 150 feet.
Feed it in the center of the top with
75 feet of 450 ohm line.

The impedance seen at the end of 75
feet of 450 ohm feedline looked pretty
workable on both 2182 and 4125 kHz.
(Yes, you need an antenna tuner, but
it could be very simple for just two
frequencies.) An NVIS antenna like
this is great for short range (a few
hundred miles).

Download the demo version of EZNEC
from www.eznec.com . It'll take you a
couple of hours to get familiar with it,
but then you can play "what if" with
a lot of simple antennas like this.

73, John - K6QQ