[TowerTalk] Tall towers & ERP

Michael Keane K1MK k1mk at alum.mit.edu
Mon Dec 11 10:31:28 EST 2006

At 01:59 AM 12/11/06, you wrote:

>This thread seems to be setting in early, this year.  Usually it's
>much closer to Dayton time.  heh.

Well, at least the current round is event driven, not the annual 
reappearance of a yet another TowerTalk urban legend.

The FCC does have an NPRM that is open for public comment at present.

>To which I will append....how is it that nobody addresses the multi-megawatt
>ERP's at SHF frequencies?  It's well known that there are regular bird
>deaths from exposure to TV emissions on the Empire State 
>Building.  Or, at least
>there used to be, the summer I was a transmitter tech.

Gee, there's broadcast TV at SHF? ;-)

Tall, lighted buildings are "well know" to kill migrating birds all 
by themselves, TV transmitters not required. And tall buildings are 
also up there on the environmentalist's agenda. 

But there are many more buildings than towers, with much more 
invested in then, and they aren't all regulated by a single federal 
agency. Towers are the easier target even if they kill fewer birds.

>I must say that Bob's indication that the estimated losses are 40-50Million
>annually, makes more sense, as compared with the reported NFWS 4-50M.  The
>latter must be a typo.

Nope, not a typo. To quote the NPRM:

"The agency [FWS] estimates that collisions with communications 
towers are responsible for at least 4 to 5 million bird deaths per 
year, and that if a proper cumulative impact study were conducted it 
might indicate the number to be closer to 50 million per year."

>On the other hand, I think there's a lot of extrapolation going on.

Oh yeah.... a whole lot

>I repeat my personal observation, echoed by cell phone techs who are
>hams:  I have not seen piles of birds around cell sites.

Typically, cell towers are "short" towers, unlit and without guys.

It's the multi-hundred foot, illuminated and guyed towers that are 
being accused by the FWS and others of killing all those birds.

Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu

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