Topband: 160 meters vertical. HELP

[salvatore farina]

Hi,

I would like to try during next 160 m. SSB contest operations
an 18 meters high (60 ft.) aluminium radiator.
I would like to use a top loaded way to achieve resonance.
I may add 2 or 3 wires from the top in sloping configuration.
Any suggestion about their lenght?
I made same calculations with 2 wires and results was 2 wires
23 meters (76 feet) long.
Any suggested length with 3 wires?
Any experience?
Otherwise I can try also with an inverted L, lenght should be around 32 
meters (105 ft.)
Radial system is buried (16 radials x 25 meters each)
What configuration is better for DX?
Will also use a K9AY loop receiving antenna.
Thanks in advance.
73
Salvatore Farina, IK8UND