[TowerTalk] EHS cable and torque bars

[Mike H]

At the suggestion of WV4P, I spoke with a Rohn engineer about the 
incompatibility of their TB45B torque bars and 1/4 in EHS cable. See here:

https://www.3starinc.com/manuals/ROHN_Torque_Bar.pdf

All Rohn 45G tower designs require 1/4 in EHS on at least one of the 
guys. My 50 ft install uses a single 1/4 in EHS guy, presumably 
precluding the use of torque bars.  He was not certain, but suspected 
the issue was simply that the shackle required for 1/4 in EHS would not 
clear the hole in the bar. I also have this guy bracket:

https://static.dxengineering.com/global/images/chartsguides/r/roh-ga45gd.pdf

except that mine has $1000+ worth (!) of torque bars in place of the 
ringfills and eyelets. I asked about ordering those to replace the 
torque bars and he said it would be cheaper to just buy the entire 
bracket assembly. He also said to investigate getting substitute eyelet 
hardware from another vendor.

I'm open to suggestions.

Mike WB2FKO

On 6/9/23 21:27, Ron WV4P wrote:
> When the Catenary weight of 1/4" EHS changes the angle of the torque bar to
> destroying the bracket VS resisting twist it all makes sense... Adding
> larger shackles compounds the issue.
>
> Likely not an issue with your short tower but worth a call to Rohn.
>
> Ron, WV4P
>
> On Fri, Jun 9, 2023 at 8:21 PM Steve Maki <lists at oakcom.org> wrote:
>
>> That's idiotic, or at least short sighted.
>>
>> Use the biggest pin shackle that will fit in the torque arm, and 1/4"
>> big grips (preforms) with thimble in the shackle. This makes it easy to
>> remove a guy wire temporarily whenever needed.
>>
>> As has been pointed out often, the torque arms don't do much for
>> rotational resistance, but if you have them, use them. It makes a nice
>> install.
>>
>> -Steve K8LX
>>
>> On 2023-06-09 8:34 PM, Mike H wrote:
>>> I acquired some used Rohn 45G in very good shape and will be going up
>>> 50 ft. Antenna will be stacked 2 x 9-el for 2m. I'm following the Rohn
>>> engineering guidance very closely: base is a new R-SB45G buried in the
>>> prescribed concrete block along with GAR30 guy anchors, also in
>>> concrete. I have the older style guy bracket for 45G that has (very
>>> expensive!) TB45D torque bars
>>> <
>> https://www.3starinc.com/rohn_45g_torque_bars_for_use_with_guy_bracket_r-tb45d.html>
>>
>>> along with several hundred feet of brand-new 1/4 in EHS for the guys.
>>> According to the Rohn instructions, however, I can't use EHS cable
>>> that's greater than 3/16 in:
>>>
>>> https://www.3starinc.com/manuals/ROHN_Torque_Bar.pdf
>>>
>>> This means I'd have to buy either smaller EHS cable or their newer guy
>>> bracket that doesn't use torque bars. I'll do this if I have to, but
>>> I'd sure like to understand why 1/4 in EHS is a deal-breaker for the
>>> torque bars. QTH is north Florida so I want to make the setup as
>>> storm-proof as practical. Any insight appreciated.
>>>
>>> Mike WB2FKO
>>> _______________________________________________
>>>