==> ARRL, DoD, FCC TRY TO COME TO TERMS WITH PAVE PAWS

The ARRL has sent out more than 100 letters to repeater owners/trustees
who have repeaters affected by the "Pave Paws" radars (PPR). Citing an
increasing number of interference complaints, the US Air Force has asked
the FCC to order dozens of repeater systems to either mitigate
interference to the Pave Paws radars or shut down. The ARRL is working
with the US Department of Defense (DoD) to develop a plan to mitigate
alleged interference from 70 cm ham radio repeaters to this military
radar system on both coasts.

The situation affects 15 repeaters within less than 100 miles of Otis
Air Force Base on Cape Cod, Massachusetts, and more than 100 repeaters
within some 140 miles of Beale Air Force Base near Sacramento,
California.

ARRL Regulatory Information Specialist Dan Henderson, N1ND, stresses
that the Defense Department acknowledges Amateur Radio's value in
disasters and emergencies and is being extremely cooperative -- and a
wholesale shutdown of US 70 cm Amateur Radio activity is not on the
table.

The Amateur Radio Service is a secondary user in the 420-450 MHz band,
both by the Table of Frequency Allocations and the FCC Part 97
regulations. As such, Amateur Radio licensees, jointly and individually,
bear the responsibility of mitigating or eliminating any harmful
interference to the primary user, which in this case is the Government
Radiolocation Service that includes the DoD Pave Paws systems.

The letters sent to affected repeater owners/trustees give them an
up-to-date briefing on the ongoing negotiations with the US Air Force,
as well as outlines the DoD's plan. The DoD has indicated a willingness
to try a mitigation proposal, but they have also indicated their need is
for these issues to be resolved sooner rather than later. With that
expediency in mind, the proposed mitigation strategy is as follows:

* All repeaters on the DoD list in the affected areas will immediately
reduce power to 5 W transmitter power output (TPO). Each repeater
licensee/trustee should contact Henderson to confirm this once this has
been done for their system. Confirmation of this being done is needed
from each repeater owner by Friday, June 15, 2007.

* The ARRL will provide the Longley-Rice calculations for each repeater
to the DoD by June 15, 2007. The DoD will provide engineering data to
the ARRL and FCC by June 15, 2007. These studies will be reviewed by the
DoD, the ARRL Lab and the FCC to determine the amount of mitigation
necessary for each repeater. Based on this review by the DoD, additional
mitigation proposals for individual repeaters (including further power
reductions, lowering of antenna heights, use of more directive antennas
and other possible mitigation techniques) will be provided by the ARRL
as needed to individual repeater owners. If there is a disagreement on
the conclusions, a conference call will be held to resolve any
outstanding issues.

* All interference must be resolved no later than August 1, 2007.

* Beginning in August 2007 (and continuing on a periodic basis), the DoD
will have a follow-up engineers study at each PPR site to ensure
corrective actions have been taken and the interference and to ensure
that successful mitigation continues.

According to the DoD, the in-band interference from Amateur Radio fixed
FM voice repeaters has increased to an unacceptable level. Pave Paws
radars are used for national security functions, including early
detection of water-launched missiles. They are critical to our national
defense and are in use 24 hours per day, seven days per week.

The goal of the ARRL has been to develop and implement a plan that would
mitigate the interference, and at the same time to permit the repeaters
to continue operation and to operate on as liberal a basis as possible.
To do so, the League has offered to work closely with the two involved
repeater coordinating groups, as well as the individual repeater owners,
sharing information and dealing with this issue on a coordinated basis
with all stakeholders.

The League has also been in contact with representatives of the FCC.
They have the ultimate responsibility for enforcing any mitigation plan,
up to and including ordering specific repeaters to shut down operations.
The FCC is aware of the complex nature of this problem and the
mitigation strategy being proposed by the DoD.

Since Amateur Radio operators are secondary users on the band, the ARRL
has few options, and all options involve cooperation with the DoD. It is
hoped the Longley-Rice calculations from the ARRL and the DoD's
engineering studies will provide enough data to allow as many of the
repeaters in the affected areas as possible to remain on the air at
reasonable power levels.

It is entirely probable that even with extreme mitigation techniques,
some repeaters in close proximity to the PPR sites may have to be shut
down permanently. If that happens, official notice would come from the
FCC. It is also possible that some repeaters might be required to
operate permanently at a lower power level in the areas near these Air
Force bases. In those cases, the League will be in contact with the
individual repeater owners with that information and the FCC will be
notified.

Henderson requests that all repeater owners/trustees affected by this
issue immediately implement the 5 W TPO for your repeater/s; please
contact his office by June 15 indicating if you have implemented the
power reduction. This will allow the ARRL to have voluntary compliance
on hand that can be used to show the cooperation of the amateur
community.

Henderson stresses that it is to each repeater's long-term advantage to
implement the power reduction as soon as possible. The DoD indicated
they will be collecting engineering data during June. This presents the
opportunity to assess a repeater's actual impact at the lower power
level and a more honest determination of its continued potential for
harmful interference to the PPR sites. If any repeaters are running at
higher power levels, then the determinations can only be based on
assumptions rather than on actual data.

Tags: ARRL, DoD, FCC, Repeaters