[TowerTalk] Request for Advice - Rohn 25 vs TRI-EX HZN 471

K8RI K8RI-on-TowerTalk at tm.net
Sun Feb 19 17:47:32 PST 2012


On 2/19/2012 7:46 PM, Eric - VE3GSI wrote:
> Bruce,
> You noted:
>> The tower site is covered in 60' plus trees and there is a similar
>> height hill with similar height trees between my tower and the far end.
>> I need to get above the trees plus above the fresnel zone so I want to
>> go as high as I can.
> I won't try an sort out the mechanics of you project, but I will assure you
> trees grow.  So what ever antenna you put up will dwarf the tower, most
> likely sooner than you think.  When I lived in town, my first tower at only
> 56 foot was taller than the near by trees, eventually the trees got somewhat
> taller than the tower.  My second tower was at 72 foot and you guessed it,
> the tower shrunk the trees did not.
Here I have *mature* trees pretty much around me. Those are not going to 
get taller, so it depends on whether they are young or mature trees.
At 100 feet I have been well above the trees ever since I put the tower 
up and except for some trees in yards none have grown. Those are 
approaching maturity.
Likely in town those trees are going to grow and trees are pretty much 
opaque to 1.4 Gig.

My first tower "in town" was only 30 feet with a tribander on it with no 
attempt to get above the trees. Actually the tower was just 30 feet of 
pipe telescoped and pinned. The pipe was mounted on the fence between us 
and the neighbors to the North.  We got along well so mounting the thing 
on the fence was no problem.  Not exactly the ideal DX location, but it 
did work and sun spot cycle peaks were much higher than they are now.

73

Roger (K8RI)




More information about the TowerTalk mailing list