Move the cursor down over Antennas' height buttons and you can see antennas' characteristics behavior in a vertical plane with changing of the height.
Quad, 4 elements, 28.400 MHz
Yagi, 4 elements, 28.400 MHz
Antennas' height buttons
Quad 4 elements
Yagi 4 elements
It is visible here that at lower heights the quad has a lower angle than the yagi antenna.
Then at the height of 1 wave length and higher angles almost coinsedening.
And some extrapower going out into high beam which appear earlier than with a quad.
Maybe this is the reason that a quad antenna outperform a bit an yagi one.
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