[TowerTalk] Looking for a sanity check on a tower install

Wood, Marlon Marlon_Wood at kindermorgan.com
Fri Mar 16 15:43:52 PDT 2012


Hard to imagine it wouldn't be easier to just put a 10ft tripod on the roof top, but I realize that wasn't the question.

Not sure why you need the tilt base. Once up and tied off, a single person, a lever & fulcrum could lift the tower up enough for someone on the ground to bolt it to a fixed base.  On my roof anchored 25G, I pounded 3 four foot pipes in the ground and set the tower base legs in them.  Didn't even bolt it; where's it gonna go?  After years it hasn't moved, though gotta make sure there is proper drainage.  I've seen similar installs where the legs rot out.

Tying ropes at the 50ft or 60ft top rather than at 25ft will make it easier to pull up for sure, as would a pully attached to the roof.  It won't flex that much.

I agree that a better ground would be the rebar in the concrete, if it has rebar, or use both ground rods and rebar (that's what I am specifying on my current semi-ufer tower project)  Wouldn't worry about the air gap.  I would worry about tying that ground system in with the building's ground system and doing it well.  If you have a separate ground from other things in the building and they are at all in contact (for instance, through a radio power cord or data cable) then the potential between grounds will be related to the resistance of the earth between them, and the lowest resistance path might just be your wall outlet or radio electronics or something you are holding in your hand inside the building.  

Lets say you have 5Kamps, with soil resistivity of 1 ohm per meter and just 1 meter between grounds... that's enough to scare me!   

Marlon Wood



More information about the TowerTalk mailing list