[TowerTalk] Tower resonant frequency

[cqtestk4xs at aol.com]

Plans are VERY slowly progressing for my new station in Belize.  Plans are for a 106 foot tower with lots of goodies on it.
Here's what is planned:106 ft of Rohn 55 guyed with Phillystran.  Three swing armed  Skyhawks at 32, 64 and 96.  Two A3WS WARCs at around 76 and 42 ft.  I plan on running four ropes to hold a wire 4 square surrounding the tower.  This is similar to what I had in KH6 and the 4 square worked well although the F/B was down to around 10-12 dB.  
My question is this:  I know the tower will have some effect on the 4 square surrounding it.  Obviously I don't want the tower to be anywhere near resonant on 80.  My guess is the top loading of the tower will lower the resonant frequency quite a bit, and the effective height will be around 145-150 ft, but I am not sure.  Obviously if it is in the range of around 130 it would be a big issue.
There is not enough room to put up a 4 square by itself so I'm stuck with this set up.  I do have some fiberglass poles that I could attach to the tower vertically to give it another 13 feet or so by running a wire up the pole and attaching it to the tower, but I really don't want to do that if I don't have to.
Thoughts on this?
73  Bill K4XS/KH7XS