Total posts : 45366
[quote:17214a266c]I see a bunch of insulated wires laying on the ground around your antenna. Are they the radials? [/quote:17214a266c]
Yes, they are 4 radials of 10 ft suspended about 1 inch above the soil.
[quote:17214a266c]Does your coil have taps?[/quote:17214a266c]
No. The main reason is that i am not planning to change the frequency for broadcasting.
[quote:17214a266c]I don’t see a way to adjust your antenna pipe height[/quote:17214a266c]
My antenna is 3-meter fixed height. So i can’t “retract” antenna like a TV antenna.
[quote:17214a266c]A tapped coil will get you in the ballpark, but you must have a way to fine-tune the antenna capacitance (adjust the height) to get absolute resonant peak. [/quote:17214a266c]
It exists an application (DOS version) which calculates the loading coil inductance based on the frequency, the height and the diameter of vertical antenna which is called [b:17214a266c]BOTLOAD2[/b:17214a266c]. You can download this application at this following link:
The application will also gives the number of turns on coil based from the coil former diameter and length.