[SCCC] Retracting towers in high winds

[Michael Tope]

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