[TowerTalk] TX-489 MDPL and mounting on another contrete

[K7LXC at aol.com]

>  I was curious if one ever installed one of these on  another concrete 
base. 
 
        Yes - people do it  every day. It just takes a rotary hammer with a 
concrete boring bit and then  installing the new anchor bolts with 
industrial epoxy.
 
>  I have a 4x5x5 that currently has rohn 25 sticking out of  it but does 
NOT have any rebar installed within. Can one drill holes in the  concrete and 
mount the tower base?
 
        Maybe. Your existing  base has 3.7 cubic yards; the factory 
brochure calls for 4.1 cubic yards. While  the amount of concrete is pretty close, 
the configuration for the crank-up is  different - it's 7 feet deep. 
 
        The purpose of the rebar is  to keep the concrete from cracking. 
Over time, that might be a fatal problem  with the lack of rebar - especially 
with a free standing tower and that 72-foot  lever arm. With a guyed tower, 
that isn't a problem. 
 
        BTW  your Strafford County windspeed rating is 85 MPH. It'd be 
difficult -  if not impossible - to get a permit for a crank-up for this much 
windspeed. 
 
>   The specs page talks about J bolts but those would  not be feasible. 
The benefit of this base is that working on the antennas are  facilitated by 
roof access.
 
        You just cut off the  J-part of the bolts. They are for when you 
pour the bolts in the concrete.  Actually these days UST welds 2 bolts to the 
bottom of the bolts for that  purpose. 
 
>  My second thought is sucking it up and making a base for  it but I have 
this beautiful pile of concrete that could be re-purposed. 
 
        True. See comments above. 
 
Cheers,
Steve      K7LXC
TOWER TECH -
Professional tower services for amateurs
and
UST factory authorized installer