FW: ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
Hi All, Should this ARRL msg. cause us to worry about the future of mode B operations? 73, Tony, N2UN
[Original Message] From: ARRL Web site memberlist@www.arrl.org To: tjjapha@earthlink.net Cc: <Subscribed ARRL Members:> Date: 4/24/2007 12:06:01 AM Subject: ARLB013 ARRL aiding effort to mitigate repeater interference to
military radars
SB QST @ ARL $ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
ZCZC AG13 QST de W1AW ARRL Bulletin 13 ARLB013 From ARRL Headquarters Newington CT April 23, 2007 To all radio amateurs
SB QST ARL ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
The ARRL has been working with the US Department of Defense to develop a plan to mitigate alleged interference from 70 cm ham radio repeaters to military radar systems on both coasts. 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 in Massachusetts and California or shut down. Amateur Radio is secondary to government users from 420 to 450 MHz and must not interfere with primary users. The Commission has not yet responded. 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 in the offing.
''The ARRL Lab is working up calculations on each repeater system the Air Force has identified to determine where interference-mitigation techniques offer a reasonable chance of keeping the repeater on the air,'' Henderson says.
The situation affects 15 repeaters in the vicinity 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.
A US Air Force contractor identified the problematic repeater systems last summer, but the situation didn't become critical until the Air Force contacted the FCC a month ago. ARRL officials met with Defense Department representatives in late March to discuss alleged interference to the PAVE PAWS radar sites. Henderson has contacted Amateur Radio frequency coordinators in both affected areas.
PAVE PAWS is a missile and satellite detection and tracking system, and its facilities occupy essentially the entire 70 cm band -- one factor that makes mitigation difficult. As a ''first step,'' however, the ARRL is recommending that all affected repeater owners reduce power -- possibly to as little as 5 W effective radiated power (ERP).
''We understand the difficulty this may cause to owners and users,'' Henderson said, ''but the alternative to operating with a smaller coverage area may be not operating at all.''
Henderson says the League is still seeking further information on the problem. ''Until the Defense Department accepts a mitigation plan, repeater owners should exercise patience,'' he cautioned.
Contact Dan Henderson, N1ND, n1nd@arrl.org, or 860-594-0236, with specific questions or issues associated with this situation. NNNN /EX
Tony wondered:
"Should this ARRL msg. cause us to worry..."
Yes... The key is that in the US we are secondary users in the 420 - 450 mHz band and while there are only 2 PAVE PAWS sites active, another interesting "land grab" can be found by googling wind shear radar and 449.000 mHz.
We are at the whim of the government with no primary allocation, for example there is this "grab" -- "Tire Pressure Monitoring System with Frequency Range of 433.92MHz."
An effort for Amateur primary allocation of even a "slice" would be prudent.
Roger WA1KAT
----- Original Message ----- From: tjjapha@earthlink.net To: amsat-bb@amsat.org Sent: Tuesday, April 24, 2007 9:30 AM Subject: [amsat-bb] FW: ARLB013 ARRL aiding effort to mitigate repeaterinterference to military radars
Hi All, Should this ARRL msg. cause us to worry about the future of mode B operations? 73, Tony, N2UN
[Original Message] From: ARRL Web site memberlist@www.arrl.org To: tjjapha@earthlink.net Cc: <Subscribed ARRL Members:> Date: 4/24/2007 12:06:01 AM Subject: ARLB013 ARRL aiding effort to mitigate repeater interference to
military radars
SB QST @ ARL $ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
ZCZC AG13 QST de W1AW ARRL Bulletin 13 ARLB013 From ARRL Headquarters Newington CT April 23, 2007 To all radio amateurs
SB QST ARL ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
The ARRL has been working with the US Department of Defense to develop a plan to mitigate alleged interference from 70 cm ham radio repeaters to military radar systems on both coasts. 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 in Massachusetts and California or shut down. Amateur Radio is secondary to government users from 420 to 450 MHz and must not interfere with primary users. The Commission has not yet responded. 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 in the offing.
''The ARRL Lab is working up calculations on each repeater system the Air Force has identified to determine where interference-mitigation techniques offer a reasonable chance of keeping the repeater on the air,'' Henderson says.
The situation affects 15 repeaters in the vicinity 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.
A US Air Force contractor identified the problematic repeater systems last summer, but the situation didn't become critical until the Air Force contacted the FCC a month ago. ARRL officials met with Defense Department representatives in late March to discuss alleged interference to the PAVE PAWS radar sites. Henderson has contacted Amateur Radio frequency coordinators in both affected areas.
PAVE PAWS is a missile and satellite detection and tracking system, and its facilities occupy essentially the entire 70 cm band -- one factor that makes mitigation difficult. As a ''first step,'' however, the ARRL is recommending that all affected repeater owners reduce power -- possibly to as little as 5 W effective radiated power (ERP).
''We understand the difficulty this may cause to owners and users,'' Henderson said, ''but the alternative to operating with a smaller coverage area may be not operating at all.''
Henderson says the League is still seeking further information on the problem. ''Until the Defense Department accepts a mitigation plan, repeater owners should exercise patience,'' he cautioned.
Contact Dan Henderson, N1ND, n1nd@arrl.org, or 860-594-0236, with specific questions or issues associated with this situation. NNNN /EX
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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.
Build satellites that require no more than 5w EIRP from the ground station may be the only answer. OR move to another uplink band. That's a possibility that may be the "hard news".
UN-Licensed users are more the long-term problem facing ham radio, than the military user...in my opinion. Ham radio has a long history of sharing allocations with the military. The short history of "part-15" and their "ilk" is not pretty.
So now its use it AND lose it...can't win! good luck to us?
73 Ed - KL7UW
At 05:23 AM 4/24/2007, Roger Kolakowski wrote:
Tony wondered:
"Should this ARRL msg. cause us to worry..."
Yes... The key is that in the US we are secondary users in the 420 - 450 mHz band and while there are only 2 PAVE PAWS sites active, another interesting "land grab" can be found by googling wind shear radar and 449.000 mHz.
We are at the whim of the government with no primary allocation, for example there is this "grab" -- "Tire Pressure Monitoring System with Frequency Range of 433.92MHz."
An effort for Amateur primary allocation of even a "slice" would be prudent.
Roger WA1KAT
----- Original Message ----- From: tjjapha@earthlink.net To: amsat-bb@amsat.org Sent: Tuesday, April 24, 2007 9:30 AM Subject: [amsat-bb] FW: ARLB013 ARRL aiding effort to mitigate repeaterinterference to military radars
Hi All, Should this ARRL msg. cause us to worry about the future of mode B operations? 73, Tony, N2UN
[Original Message] From: ARRL Web site memberlist@www.arrl.org To: tjjapha@earthlink.net Cc: <Subscribed ARRL Members:> Date: 4/24/2007 12:06:01 AM Subject: ARLB013 ARRL aiding effort to mitigate repeater interference to
military radars
SB QST @ ARL $ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
ZCZC AG13 QST de W1AW ARRL Bulletin 13 ARLB013 From ARRL Headquarters Newington CT April 23, 2007 To all radio amateurs
SB QST ARL ARLB013 ARLB013 ARRL aiding effort to mitigate repeater interference to military radars
The ARRL has been working with the US Department of Defense to develop a plan to mitigate alleged interference from 70 cm ham radio repeaters to military radar systems on both coasts. 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 in Massachusetts and California or shut down. Amateur Radio is secondary to government users from 420 to 450 MHz and must not interfere with primary users. The Commission has not yet responded. 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 in the offing.
''The ARRL Lab is working up calculations on each repeater system the Air Force has identified to determine where interference-mitigation techniques offer a reasonable chance of keeping the repeater on the air,'' Henderson says.
The situation affects 15 repeaters in the vicinity 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.
A US Air Force contractor identified the problematic repeater systems last summer, but the situation didn't become critical until the Air Force contacted the FCC a month ago. ARRL officials met with Defense Department representatives in late March to discuss alleged interference to the PAVE PAWS radar sites. Henderson has contacted Amateur Radio frequency coordinators in both affected areas.
PAVE PAWS is a missile and satellite detection and tracking system, and its facilities occupy essentially the entire 70 cm band -- one factor that makes mitigation difficult. As a ''first step,'' however, the ARRL is recommending that all affected repeater owners reduce power -- possibly to as little as 5 W effective radiated power (ERP).
''We understand the difficulty this may cause to owners and users,'' Henderson said, ''but the alternative to operating with a smaller coverage area may be not operating at all.''
Henderson says the League is still seeking further information on the problem. ''Until the Defense Department accepts a mitigation plan, repeater owners should exercise patience,'' he cautioned.
Contact Dan Henderson, N1ND, n1nd@arrl.org, or 860-594-0236, with specific questions or issues associated with this situation. NNNN /EX
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
On 4/24/07, Edward Cole kl7uw@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:
http://www.fcc.gov/oet/info/maps/us7/
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
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:
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 military.
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.
73, Lee-KU4OS
On Apr 24, 2007, at 11:20 AM, Nate Duehr wrote:
"For example, the ENTIRE state of Arizona is under this rule. Did you Arizona hams out there know this?"
Actually the map is out of date and the area with teh 50 Watt limitation has increased so that the entire state of New Mexico and the southern portion of Colorado is included. Yes we know about this, our SCM and Division Director sent out a reminder when the change went into effect and does so every year or so.
We don't like it, but like I said, with shared allocations what can you do? - Dr. Megacycle Kk6MC/5 -- James Duffey KK6MC/5 Cedar Crest NM 87008 DM65
Those unlucky to live within the affected areas cited will have no recourse but to restrict operations (however that takes effect).
Yes, in New Mexico we are limited to 50 Watts. That used to be only near the White Sands Missile Range, but now it it is the entire state. It pretty much curtails any serious weak signal work, but satellites can still be worked at that level. Much lower, though and even that will be a problem. This is the dual edged sword of shared allocations. It is nice that we have the band, but the restrictions can be difficult to live with. Sort of like a 16 year old with the family car. :^)+ - Dr. Megacycle KK6MC
-- James Duffey KK6MC/5 Cedar Crest NM 87008 DM65
participants (6)
-
Edward Cole -
James Duffey -
Lee McLamb -
Nate Duehr -
Roger Kolakowski -
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