I used elevated guy posts because of area problems as well. my tower
installation is on a rohn 25g at a total height of 60 ft.? i use 3 sets of guys
@ 20'
40' and the top at 60'......i know that is overly cautious but i was unable
to spread guys to 60% of the height....my antennas are:
cushcraft 13b3???????? 1.8sq/ft??????? ?????? 68'??
cushcraft 6176b??????? 4.8sq/ft??????? ?????? 60'
cushcraft 719b???????? 1.2sq/ft??????? ?????? 65'
2-2m big wheel??????????? 1.0sq/ft (apx)??????55'
2-6m loop?????? ?????? 1.0sq/ft (apx)?????? 55'????????
2-70cm loops?????????? 0.4sq/ft (apx)???????55'
10m sloping dipole??????0.2sq/ft (est)?????? ?50'
40-20-15-10m dipole????0.5sq/ft (est) ?????? 50'????????
80m inverted vee?????????0.8sq/ft (est)????????55'????????
discone scanner ant????0.5sq/ft (est)????? ??45'
???????????? ?????? ????? 12.2sq/ft apx
1-7/8" hardline
2-1/2" hardline???
3-RG-213????
1-RG-8X
1-remote coax switch @55'
my 235lb fat butt (sometimes)
Rohn gives 10.2sq/ft at the 60' level with 2 sets of guys at 55' and 28'
levels and allows 1 5/8" feed line on each leg for 90mph wind velocity and no
ice.
if i assume the maximum, then i have exceeded the design, however, i expect
the dipoles to fail with 1/2" ice and therefore reduce the total top load to
10.7sq/ft.? still puts me 0.5sq/ft over the allowable max top antenna load but
there is? 2.4sq/ft at the 55' level and 0.5sq/ft at the 45' level......I am
pretty sure i am in the ball park area of having a safe tower installation.
de kd5qwo, david howard
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|