Topband: Upside down Vertical Antenna

[Y.G.Yu]

Recently I moved to new apartment house.

It is 15th floor and we have void space in front of the building.

Because the height of my room would be more than 40 meters,

it would be possible to install a little sloped 1/4 wave length wire 

vertical antenna. To reduce the length of coaxial feed line, I am 

thinking about the "Upside down vertical antenna".

 

Do anyone have experience for this kind of configuration?  I have no

idea how to install the radials.

 

73! 

Yu HL5BPL