[SCCC] Retracting towers in high winds

[Dio]

It's a great idea providing a fail-safe is provided to prevent rotating 
the antenna while nested.

Living in Pine, Colorado(elevation 8800') , I found the surrounding 
trees gave me a lot of shelter from the wind. I also found, when the 
antenna was cranked up enough to 'wiggle in the breeze', it would not 
accumulate much snow or ice. Granted, we don't have the big ice-storm 
problems.

I also found turning the antenna so the boom was broadside to the wind 
kept things from rattling too much.

--joe
KR6NA


Michael Tope wrote:
> Wayne,
>
> I mentioned this to NT6AA recently. Has anyone ever thought
> of using cradles for the element tips on a nested antenna?
> Let me explain. The ideal situation would be to lower a big
> antenna like the MonsterIR to the ground in high winds, 
> but since most cranks don't drop much below 20 - 25', the
> alternative is to bring the ground up to the elements. One way
> to do this is with a series of telephone poles or short Rohn
> 25 stubs. Each stub would have a wide V block that would
> except the element tip (actually you'd probably want to grab
> it ~30% back from the tip). You would rotate the antenna
> to a pretermined azimuth and then drop the tower until the
> elements were nested in the V-blocks. This scheme would
> cut the stresses on iced up elements in the wind to a fraction
> of what the elements would see if they were hanging free in 
> the wind. 
>
> 73, Mike W4EF......................................
>
>
> ----- Original Message ----- 
> From: "Wayne Overbeck" <overbeck6 at yahoo.com>
> To: <sccc at contesting.com>
> Sent: Wednesday, December 06, 2006 1:21 AM
> Subject: [SCCC] Retracting towers in high winds
>
>
>   
>> It makes a lot of sense to have a way to retract 
>> a tower to prevent a catastrophic failure of the 
>> TOWER during high winds.
>>
>> However, that may not prevent the antenna itself from 
>> being destroyed by high winds.  In a wind-exposed 
>> place, the winds can be nearly as ferocious 25 feet 
>> above the ground as they are at 70 or 80 feet.
>>
>> At one time or another, I've lost antennas made by 
>> Cushcraft, Force 12, Hy-Gain, KLM and by me--when they
>>
>> were on a fully retracted tower.  The HF antennas that
>>
>> survived the longest at my Tehachapi mountain site 
>> were homebrew ones built using construction techniques
>>
>> described in Dave Leeson's book, "The Physical Design 
>> of Yagi Antennas."
>>
>> Wayne, N6NB
>>     
>
>
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