[TowerTalk] Fwd: Fwd: Temporary tower/antenna question

[Gene Fuller]

Making the gross assumption that you can drive a substantial three or four 
foot stake a foot or so into the ground or find a suitable fence post or 
railing to tie the base of one of the collapsible masts to, why all the fuss 
re guy anchors. I've always found that my 40 foot collapsible fiberglass 
mast with a center fed vertical dipole taped to it was quite capable of 
standing up on it's own in winds up to what I would guess to be at least 
20-30 MPH. If guys should be necessary just put a hose clamp on the mast at 
half to three quarters of the way up, to keep the guys from sliding down, 
take a good guess at the length needed to run a guy at about 45 degrees, and 
cut three pieces of the 1/8 inch light rope you brought along for just such 
a case. No need to make a big engineering project out of it. The guys can be 
tied off to anything available or to the simple tent stakes you also just 
happened to bring along.  Even with the wire and fifty feet of 450 ohm 
ladder line, your transceiver and power supply will all fit in a small box 
or suitcase, can be deployed in less than a half hour and will let you have 
lots of fun on the air with your own little expedition.

Gene / W2LU


----- Original Message ----- 
From: "Jim Lux" <jimlux at earthlink.net>
To: <towertalk at contesting.com>
Sent: Saturday, February 02, 2013 2:57 PM
Subject: Re: [TowerTalk] Fwd: Fwd: Temporary tower/antenna question


> On 2/2/13 11:39 AM, Brian Alsop wrote:
>> I guess the rest of the earth is flat.  With the uneven terrain around
>> here no way pre-cut guys would work.  Also there is a likelihood that
>> where you try to screw in an anchor, you can't because of rocks, roots
>> or whatever.
>
> Sandbags or lead shotbags are your friend. You get it close, hoist away, 
> then move them in or out as needed.
>
> yeah, they drag on the surface, but it's a temporary install.
>
> A back of the envelope shows that a 40 foot mast 2" in diameter would have 
> a wind loading of about 16 lb in a 30 mi/hr wind. Using my guy anchor at 
> half the height scheme, the "dragging force" is only about 8lb (half the 
> force is on the base of the antenna, half at the top), although the 
> lifting force is twice that. You need a pretty heavy anchor to hold it in 
> place, so it's gonna slide. (you need at least 24 lb to hold, if friction 
> coeff is one).  My sandbags are about 10 lb.
>
> To stabilize things, I've piled rocks on the sandbag, for instance. I 
> think a 5 gallon water jug might work well, but you need to carry water 
> then (or be able to fill it on site, which takes time).
>
> And I'm not real interested in carrying 100 lb of sandbags or lead shot 
> around.
>
>
> But in a 15 mi/hr wind, the load is about half the load at 30 mi/hr.. so 
> that's getting more reasonable, and to be honest, 15 mi/hr is fairly 
> windy.  If it falls over in a Santa Ana... oh well.. it's not so heavy 
> that anyone will get hurt.
>
>
>
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