Richard Fry wrote:
"Cecil Moore"
Approximately a foot and a half of 75m Texas Bugcatcher
stock will be self-resonant at 4 MHz. That's 90 degrees of
antenna stuffed into about a foot and a half of coil.

But that self-resonant coil is not the electrical equivalent of a
90-degree linear antenna. A coil by itself is not a very efficient
producer of EM radiation, whether self-resonant or not.

I'm not saying anything about radiation efficiency
just commenting on the phase relationship between
the forward wave and reflected wave.

At the first self-resonant frequency, the feedpoint
impedance is purely resistive indicating that the coil
is indeed electrically 90 degrees long.
--
73, Cecil http://www.w5dxp.com