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RE: Vultures



>  > Does anyone have any previously used solution to bird perching?
>>  And does anyone know if the white material is bad for aluminum?
>>  I found a manufacturer of plastic spike strip to deter the birds.
>>  Anyone have experience with it.
>  > Tnx Kevin N6CWF Phoenix Az
>
>The final answer.  Termination with extreme prejudice.  A
>sudden case of high-velocity lead poisoning.  14.4 grains of
>lead at about 850 feet per second.  I am a high-power rifle
>competitor.  They asked me to pick out a pellet rifle, they
>paid for it, and once a week I remove the critters from the
>work area.  At first there were too many, I got too tired
>pumping the air rifle.  Now there are one or two a week.
>They are the stupid ones, the smart ones moved to the
>horse track.

I've used an air rifle for this very purpose, although it wasn't an 
antenna I was trying to remove the birds from.  Try not to hit parts 
of your antenna though -- a BB driven at maximum muzzle velocity will 
a) punch a hole clean through any aluminum elements it hits, which 
will mess up your SWR as sure as shooting, and b) ricochet off any 
steel parts (like the tower) in dangerously random directions. 
Pellets are a little less likely to ricochet, but they also don't 
have the penetrating power a BB does, and on my rifle at least, 
cycling the "bolt" will reload while it arms the pump mechanism, so I 
can fire them a lot faster than pellets ..

Seriously, though, the plastic spikes may keep the birds off, but if 
they are attached directly to the element they will add both lumped 
and distributed capacitance to it (they are, after all, made of 
dielectric) and this will require you to retune the antenna with the 
bird guards in place.  They will also drastically increase the wind 
cross section and you may have wind/rotator problems with the bird 
guards on the antenna.  An air rifle is probably by far the simplest 
solution ..

-- 
<BGB>
                  --... ...--  -.. .  -. ..... ...- -...
              Bruce Bostwick  N5VB  Austin, TX  Grid EM10DH
ARRL / UT ARC / Austin ARC / Travis Co. ARES / ARRL+W5YI Vol. Examiner
    http://ccwf.cc.utexas.edu/~lihan/  mailto:lihan@ccwf.cc.utexas.edu
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