[TowerTalk] Wire Antenna Supports

[Lux, Jim]

On 2/16/21 5:03 PM, Jack Brindle wrote:
> Jim;
>
> It appears that Mike is in North Texas, where lightning is a factor (unlike here in Silicon Valley). Would well-grounded metal supports be a better option to fend off that problem?
>
> My question isn’t just academic - I’ll be having the same problem not too long from now in southwest Louisiana.
>
> 73!
> Jack, W6FB

If lightning hits the fishing pole, it's gonna die. I guess you could 
run a AWG 10 wire up the side of it and it would probably survive.

You could also just couple a 20 foot pieces of steel pipe (fence top 
rail) or aluminum pipe (all manner of sizes available) . The problem 
isn't the mast, it's the base support.


If you can dig a hole, you might be able to get away with the "removable 
tetherball post" approach - sink a piece of pipe that has an ID just 
larger than the OD of your mast, and fill around with concrete. But 
you're back to the "will it lever out?" question, which is sort of a 
combination of mass and physical area (pushing against the surrounding 
soil).

The other approach is a sort of teepee - 3 40 foot masts with the bases 
set fairly far apart (5 or 6 feet) and joined at the top. That turns the 
overturning moment into a down force on some legs and an upforce on the 
others, but something that is potentially manageable with a plate and 
some tent stakes, or a screw in earth anchor.

Or guys - I guess the OP didn't say "no guys" so that is a great way to 
get it to stand up.  N6RK has some fairly large masts that are guyed, 
made of irrigation pipe.





>
>> On Feb 16, 2021, at 4:54 PM, Lux, Jim <jim at luxfamily.com> wrote:
>>
>> On 2/16/21 4:18 PM, Michael Poteet wrote:
>>> This is a request for opinions.  I am thinking about putting up a wire
>>> antenna.  At my age (81) I have no interest in climbing towers, trees or the
>>> roof.  Nor I am I interested in installing any support that requires a
>>> concrete base or that weighs over 100 pounds.
>>>
>>> I've noted there are at least a couple of telescoping masts (up to 50 feet)
>>> that could be used to support simple wire antennas (when guyed
>>> appropriately).  One is carbon fiber, the other is aluminum.  Is there any
>>> advantage of one of these over the other for "permanent" antenna support?
>>> Initial cost is not a factor.
>>
>>
>> I have one of the 40-ish foot carbon fiber collapsible poles. It's fairly sturdy and easy to put up, but the top part *does* bend (it's pretty small, think fishing rod tip).
>>
>> The challenge is coming up with a way to support the bottom so it stands vertically.
>>
>> You don't want a big concrete base, which makes supporting a challenge, to resist the overturning moment from wind loads and the wire. With a 40 foot lever arm it doesn't take much force at the top to have impressive forces at the bottom.
>>
>> I've tried things like driving a 8 foot T-post about 5 feet in, leaving 3 feet sticking up, and lashing a vertical to that.  Aside from the spectacular "trip hazard" of the T post, even with a tennis ball on the top, it *will* bend or shift if the antenna is loaded.  And that's a fair amount of work to drive (my shoulders and back felt it for days).
>>
>> What kind of surface are you putting this mast up over? Grass? dirt?
>>
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