I plan to put up a motorized HG-70 HD, with a 4 element SteppIR and a 7 element M2 6M beam. Hy-Gain says 1 week for foundation curing, UST says 4 weeks. What's realistic? My current guyed tower has a
It's a good tower. No limit switch. Gravity not positive pull down. Cure for 30 days and don't ground your rebar. For antenna mounts fabricate a cross arm and mount above second section. Works great.
Mike, I I disagree with a previous assessment of this tower. principally " gravity-no pull down" Picture self trying to lower the tower durin g a strong wind. ( you may not have been home before the
Mike, FYI, newly poured concrete for foundations reaches 70% of its maximum compressive strength in 7 days. It is considered fully cured in 28 days. Bob K6UJ concrete is for building foundations , fl
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sat, 30 Nov 2013 15:52:22 -0500
I'll try again... Comparing the new base (yours) to the old base (mine), I'm wondering how different they are. The old rebar cage is a simple affair consisting of a bunch of straight pieces tied toge
Mike, The Portland Cement Association says that standard mixes cure to 90% of their final strength in 28 days. There is no magic number for 100% cure. Strength asymptotically approaches its final val
Mike Talk to your local concrete supplier about the mix. If you add more bags of Portland cement, it will increase the final compressive strength. So you'll reach a higher strength after the first 7
Contrary to other advice, do ground the tower anchor bolts to the rebar. Then you have a great Ufer ground, considering the area of the concrete in contact with the earth. The rebar should be tied pe
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sat, 30 Nov 2013 20:26:30 -0500
Recent, commercial rebar cages ordered with the towers have come through welded instead of tied. I have the wire, but it's a whale of a lot easier to weld it. If it's good enough for the manufacturer
Interesting, welding is clearly better as it won't loosen in shipping or handling. There is a weldable grade of rebar which should be used. For small tack welds, maybe not so important. One PE told m
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Sun, 01 Dec 2013 00:23:45 -0500
On 11/30/2013 11:32 PM, Grant Saviers wrote: Interesting, welding is clearly better as it won't loosen in shipping or handling. There is a weldable grade of rebar which should be used. For small tack
Thanks, Patrick. The manual for the tower calls for "minimum 28 day strength of 2000 psi and no more than 7 1/2 gal. of water per sack of cement". Mike NF4L __________________________________________
Thanks Grant. I'm buying the base/cage from the mfg. I think it's all fastened together. Hy-Gain calls for 2000 psi/28 days and a max of 7 1/2 gls. of water per sack. I'll talk to the concrete guy ab
Mike, Be careful. Don't let anyone add excessive water to make the mix easier to work with or self leveling or whatever. That lowers the strength irrespective of what the strength would have been (ho
I am curious. All this talk about concrete strength, rebar, etc. Is anyone aware of a tower base failure due to strength of the concrete or lack of rebar? (Except for damage from a lightning strike.)
Do you think maybe that attention to concrete base details may be one reason failures occur elsewhere? Sure, tower companies are risk adverse and may go a tad HD to avoid legal problems but careful d
On 12/1/13 7:55 AM, Ken wrote: I am curious. All this talk about concrete strength, rebar, etc. Is anyone aware of a tower base failure due to strength of the concrete or lack of rebar? (Except for d