Topband: Advise for improving TX antenna

[Riccardo Negro]

Hi all,
this was my first season on 160 and had a lot of fun: 70 dxcc, CW only,
with 100 w and a 12m high monoband inverted vee (very quiet location in the
mountain at 1000m altitude). Current rigs are: IC740 full filtered (very
quiet), TS480 full filtered plus a TR7A and TS930.

I am now improving the station: just bought an IC2KL (500 W), a 18m
spiderbeam pole and I am setting up 3 remote switchable BOGs (soon to
become standard terminated bevs).

Now the critical questions for improving TX antenna.

1) I am planning to increase height of the monoband 160 vee from 12 to 18m
(on a higher tree) while adding wires for 40 and 80 in a fan configuration.
1a) Is adding 40 and 80 going to adversely affect performance of the vee on
160 (bandwidht/takeoff angle) ? Should I leave the vee in monoband
configuration ?

2) I am also planning to add an inverted L using the spiderbeam 18m pole.
2a) Which is a safe distance from the inverted vee in order to avoid
interactions ?
2b) I could also add 40 and 80 1/4 wl radiators to the same spiderbeam
pole: is this addition detrimental to 160 performance ?

Many thanks in advance for your kind help.
73 de Rik, IK2CAW