[amsat-bb] Re: FW: ARLB013 ARRL aiding effort to mitigate repeaterinterference to military radars

Lee McLamb ku4os at cfl.rr.com
Tue Apr 24 16:51:21 PDT 2007

On Tuesday 24 April 2007 13:20:24 Nate Duehr wrote:
> Some more information from another Amateur -- he phrased it all better
> than I can:
> "First of all, let me point you to the FCC document (47 CFR 2.106
> Footnote US7) that spells out the 50 watt limit and the map showing
> the areas affected:
> http://www.fcc.gov/oet/info/maps/us7/

Thank you for posting that link.  As a resident of Florida I know there are a 
lot of locals who are unaware of that limitation.  I'm sure the situation is 
similar in other parts of the country.

> This particular map shows areas that are under this particular ruling.
> Not all of these are PAVE-PAWS sites. There are three major PAVE-PAWS
> sites in the US. One at Cape Cod at Otis AFB, One at Beale AFB in
> California and one in Alaska. They are a part of the ITW/AA or
> Integrated Attack Warning/ Attack Assessment system that is controlled
> by NORAD at CMC ( Cheyenne Mtn.) now to be moved to Schreiver AFB.
> These other areas on the map may or may not be part of the ITW/AA
> system described here but have some strategic gear that may have the
> potential for UHF radio interference."

There are multiple government systems operating in that band, not all of them 

> My comments:
> The map is interesting.  For example, the ENTIRE state of Arizona is
> under this rule.  Did you Arizona hams out there know this?  Same with
> Florida.  Any repeaters higher than 50W in either place?  Any hams
> using more than 50W to hit birds from either place?  Sure.

The 50w limit is transmitter power output. Which should be more than enough to 
work any satellite given the resulting EIRP with even a modest gain antenna.

There is a provision where hams in the affected areas can operate with higher 
power by coordinating their use with the local government frequency 
coordinator's offices.  I know of several systems here in Florida which are 
legally operating at greater than 50w output after going through the process.  
At least here it is not really more involved than what they need to provide 
to the local repeater coordinating council anyway.  Same info, just provided 
to another group.


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