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

Nate Duehr nate at natetech.com
Tue Apr 24 10:20:24 PDT 2007

On 4/24/07, Edward Cole <kl7uw at acsalaska.net> wrote:
> Tony, Roger, etal:
> A "slice" will not be a solution to PAVE PAWS  which is broadband
> covering the whole spectrum (420-450 MHz).  There already exists
> restricted use of 70cm within range of selected military
> installations in FCC regs.  Those unlucky to live within the affected
> areas cited will have no recourse but to restrict operations (however
> that takes effect).  Voluntary negotiations may lead to some time
> slots of permission.  Otherwise, we get "regulated" off the band.

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:


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."

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.

Proof positive that a reasonable solution can probably be found.

The Amateur allocation in the UHF band is a Primary allocation of the
US Military in the US, with the specific wording in the NTIA
documentation stating the military is to "treat Amateurs as Primary".

Since Amateurs are licensed by the FCC, the FCC has final say on what
and where we can operate in these bands that are mixed-use.

Right now, the politics are afoot... the AF, NTIA, and FCC are
probably all having a ball discussing what the next move is, with ARRL
right in the middle of it offering "technical assistance".

> So now its use it AND lose it...can't win!
> good luck to us?

Could be.  Maybe not.  Quite a few "interested parties" involved on all sides.

It will be interesting to see how professional and courteous all sides
can be in the negotiations.  Panic and conjecture don't really help
anyone involved in the process, I'm sure.

Locally, an agreeable solution to problems arising from a different
military system (EPLRS) was found here in Colorado a number of years
ago.  The system was hammering the inputs to all of the high-mountain
UHF repeaters in the area with pulse modulation type noise.
(Generically, EPLRS is a spread-spectrum data system.)

The folks in charge of the system talked with other reasonable folks,
and the operational frequency characteristics of the system were
modified to avoid the repeater inputs... so it wouldn't be "heard" as
much... it was still in use and on-air, but didn't continue to be a
daily problem for repeater owners/operators.

Only through the anonymous and patient help of some volunteers in the
right organizations did the problems get mitigated.

Hopefully in this new scenario, the "right" people are once again
quietly engaging in conversation/thought, and are sending appropriate
feedback to the people making the decisions.

Nate WY0X

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