drooping 1/4 wave radials

While building a VHF-HI quarter wave antenna, I observed the radials in various sales brochures and online, of the horizontal radials at both the 90 degree position, in relation to the vertical element, and other models, with the radials "drooping" below that 90 degree position. What, Where, When, and Why? For the different positions of the radials. THANKS

A 1/4 wave vertical with 1/4 wave radials 90 degrees from the vertical element has an impedance of around 30 ohms.
When the radials are 45 degrees below horizontal the impedance increases to around 50 ohms.
When the radials are straight down forming a sleeve dipole the impedance increases to around 72 ohms.

Thanks so much. Understand fully.

nd5y said:

A 1/4 wave vertical with 1/4 wave radials 90 degrees from the vertical element has an impedance of around 30 ohms.
When the radials are 45 degrees below horizontal the impedance increases to around 50 ohms.
When the radials are straight down forming a sleeve dipole the impedance increases to around 72 ohms.

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Right on Tom, that is what we found on the antenna range. 50 degrees below horizontal is what we used on the commercial VHF groundplane design. That was a long time ago. Using one of them I found abandoned on the roof of a hospital we were installing a new 2m / 440 ham station at a couple of years ago.

The groundplane in action..