Total posts : 45366
Yves-Roy et les autres,
I remember reading an article in the ARRL magazine “QST” back around 1972 or 1973 on shortened antennas. I remember ’cause I remember going to the Dayton Hamvention that year and sitting in the crowd as the author of the article gave a talk about how tuning up shortened antennas worked.
So somewhere in the QST archive for 1972 or 1973 there’s that article. I suspect that you’d find a lot of good info (and technical stuff) about how shortened antennas work &c.
I do know from experience that any change to any antenna feed point (adding radials, adding the neighbor’s dog’s leish &c) changes the feedpoint impedence & makes for an interesting dance back and forth between radio & antenna. And you get to say lots of bad words very loudly so as to scare your family out of the house while you go legally insane for a while.
Every time I get started on one of these radio projects, I keep hoping that someone will give some intervention. But no. I get to go crazy doing simple things.