Interference between two agencies - how to get it resolved

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RadioGuy7268

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FCC public notice just released today.

http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-09-2589A1.pdf

by January 1, 2013, Industrial/Business and Public Safety Radio Pool licensees must
- operate on 12.5 kHz (11.25 kHz occupied bandwidth) or narrower channels, or
- employ a technology that achieves the narrowband equivalent of one channel per 12.5
kHz of channel bandwidth (voice) or 4800 bits per second per 6.25 kHz (data).
 
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N_Jay

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. . The DIS tech told the entire AR Hospital Ass'n, State EMS admin, and all others monitoring the date was moved to 2020 on air as well as at the meeting. So if he was mistaken, then there are a lot of folks that are in for surprises if this country is still in one piece in 2013. . . .

Yes! A lot of people are mistaken.

There is no date set for 6.25 kHz operation, and most systems (public safety, at least) will be "6.25 e", with actual channels being 12.5 kHz and using 2 slot TDMA (P25 Phase 2).
 

902

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Yes! A lot of people are mistaken.

There is no date set for 6.25 kHz operation, and most systems (public safety, at least) will be "6.25 e", with actual channels being 12.5 kHz and using 2 slot TDMA (P25 Phase 2).
NXDN is an alternative technology and has a 4K00 FDMA emission. This would fit comfortably within the 7.5 kHz channelization mess of VHF. Regardless of NXDN or MotoTRBO, or P25 phase II (whatever that may become), VHF will continue to be a mess due to a long legacy of randomness.
 
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N_Jay

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NXDN is an alternative technology and has a 4K00 FDMA emission. This would fit comfortably within the 7.5 kHz channelization mess of VHF.
Yes, but that is not the issue.

There is no (zero, zip, zilch, nada) requirement to move to 6.25 kHz.

Regardless of NXDN or MotoTRBO, or P25 phase II (whatever that may become), VHF will continue to be a mess due to a long legacy of randomness.
Also very true.

Point being that P25 Phase 2 (and MotoTRBO) will meet a 6.25 kHz efficiency requirement on 12.5 kHz channels.
 

902

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There isn't a 6.25 kHz migration date yet, but eventually. Probably even for 800 MHz at some point. I don't think we'll ever get any more spectrum, so we'll need to keep sawing what we have in half until we learn to manage our resources better (or radio just becomes an app on a computer...). Let's see if the FCC changes the 700 MHz date from 2017 to 10 years after the DTV transition.

My point wasn't that everyone needs to go to it more than an 11.25 kHz emission on 7.5 kHz channelcenters is still going to spill over into adjacent channels. Narrowbanding did not really achieve any channel gain because the service contours of the incumbent users still have to be protected, and because 7.5 kHz adjacents still have to be treated as though they are co-channel users. The only somewhat acceptable adjacent channel arrangement is P25 phase 1 to P25 phase 1, but there is still some overlap.

Coulda, woulda, shoulda, the FCC probably should have followed through with "refarming" rather than "narrowbanding," particularly on VHF. Then they could have done some radical things, like continued the NTIA 6.25 kHz channelization from 136 - 174 (minus 2 meters), standardized inputs and outputs, reduced excessive HAAT and ERP to NPSPAC-like service contour containment (37 dBu service contour falls within 5 miles of a community's border, and 40 km radii are disallowed unless you really have a 40 km operational area). Eh, I'm daydreaming. There are bigger issues on the land mobile horizon.

Oh - and 19.2 kbps data also meets throughput efficiency for a 25 kHz channel, so that won't need to be narrowbanded. Other than that, VHF's an absolute horror show.

Someone needs to check to see if that interfered-with agency ever wrote the interferor a letter of concurrence.
 

902

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We have a problem...

Gentlemen,

We have a problem.

Yalobusha County is properly licensed.

When I go into ULS for WNYZ545 (Grenada, MS), 159.1500 does not appear on the license. If this is in fact what they're using, it's no wonder they are getting interference. They apparently are not supposed to be there.

Someone may have keyed in the wrong frequency into RR or recorded what they thought they heard, after all, it's only as good as what people enter. So, that may be at issue and the problem not Yalobusha County, but someone else. Or, the problem could be some shop just set them up on a channel and thought it would go unnoticed (this is exactly what happens when someone does that).

At the end of the day, the many words of advice about minding one's own business might be sage advice, particularly as this ball of yarn starts to unwind. N Jay's right about an outsider peering into a living room window. As a listener, you are not a party to the interference. If you KNOW something is a hazard (and this isn't an "I think," but an "I've confirmed"), you might be able to go to the police chief, the FOP, or the mayor, and pass it along, but your obligation stops there. And, again, you may be walking into a domestic with people possibly attacking you for making an observation (especially if you picked up that someone set them up for something they don't have a license for).

Good luck with that!
 

TomServo

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Well, this has been an educational thread. I'm back to being glad I asked. ;)

I'm not a scanner user and not up on a lot of the radio news, so all this stuff has been educational. My only way to listen these days is with a dual band ham radio (I'm licensed but inactive.) So I only get VHF-high and UHF, no trunking or low band stuff. My apologies if I came across as a meddler or anything, I was just thinking there might be some coordinator I could talk to about the problem, keeping me from saying anything to any agency involved.

If I did talk to the mayor or chief of police, I wouldn't mention right off that I listen, just that I'm aware that there is at least an occasional interference problem and if they are aware of a way to solve that problem, then steer them in the right direction if I could.

902, thanks for confirming what I was thinking, that 159.1500 is not licensed to Grenada. I'm inclined to believe that there is some ignorance of how the radio system here is set up. (Ignorance seems to be a common theme in many different aspects here, I'm afraid to say.)
 

radiofan1

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I'm confused. I don't even see 159.150 on RR's database...? Are you sure that's what they're using for an input?


FCC Callsign: WNYZ545 (GRENADA, CITY OF)
Licensee Name: GRENADA, CITY OF
License: WNYZ545
Status: Active (2003-03-28)
County: GRENADA
State: MS
Radio Service: PW: Public Safety Pool, Conventional
Loc # Frequency Emission Class Mob Pag Pwr Lat Long City County State
1 155.43000000 20K0F3E FB2 1 0 45.000 33.77511 -89.77147 GRENADA GRENADA MS
1 155.68500000 20K0F3E FB2 1 0 45.000 33.77511 -89.77147 GRENADA GRENADA MS
2 155.43000000 20K0F3E FB 1 0 45.000 33.76622 -89.80758 GRENADA GRENADA MS
2 155.49000000 20K0F3E FB 1 0 45.000 33.76622 -89.80758 GRENADA GRENADA MS
2 155.68500000 20K0F3E FB 1 0 45.000 33.76622 -89.80758 GRENADA GRENADA MS
3 158.91000000 20K0F3E FX1 1 0 45.000 MS
3 159.03000000 20K0F3E FX1 1 0 45.000 MS
4 155.43000000 20K0F3E MO 75 0 45.000
4 155.49000000 20K0F3E MO 75 0 45.000
4 155.68500000 20K0F3E MO 75 0 45.000
4 155.73000000 20K0F3E MO 50 0 45.000
4 158.91000000 20K0F3E MO 50 0 45.000
4 159.03000000 20K0F3E MO 50 0 45.000
 

TomServo

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I'm confused. I don't even see 159.150 on RR's database...? Are you sure that's what they're using for an input?

Yup, that seems to be where it is centered. My radio only goes down to 0.005 MHz resolution though so it might be 159.145 but I doubt it.
 

902

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Well, this has been an educational thread. I'm back to being glad I asked. ;)

I'm not a scanner user and not up on a lot of the radio news, so all this stuff has been educational. My only way to listen these days is with a dual band ham radio (I'm licensed but inactive.) So I only get VHF-high and UHF, no trunking or low band stuff. My apologies if I came across as a meddler or anything, I was just thinking there might be some coordinator I could talk to about the problem, keeping me from saying anything to any agency involved.

If I did talk to the mayor or chief of police, I wouldn't mention right off that I listen, just that I'm aware that there is at least an occasional interference problem and if they are aware of a way to solve that problem, then steer them in the right direction if I could.

902, thanks for confirming what I was thinking, that 159.1500 is not licensed to Grenada. I'm inclined to believe that there is some ignorance of how the radio system here is set up. (Ignorance seems to be a common theme in many different aspects here, I'm afraid to say.)
Tom,

I don't think anyone here thinks you're a meddler, but just be careful. You never know what the back-stage dynamics are in some places, and nobody here wants to see you get jammed up because you walked into something.

Many places have 'inconsistencies.' I've caught a few with repeater inputs and outputs reversed, but never updating their license. When the band opened, one would kill the input to one of the repeater channels I was responsible for. When I spoke to the communications center director there, "director to director," he told me that he knew, that the vendor set him up like that (makes you wonder about some in the business), and that it was too expensive and there were several hundred radios on it now, so he wasn't going to change it. I offered to buy the software, drive out and change it myself, and he told me it was too complicated, that there were all sorts of other agencies, etc. sharing the channel and he didn't want it taken down. Then I called a contact at the FCC, who looked into it, and as far as I know, it's still like that. So, on VHF you never quite know what you're going to come across. I suppose in a sick, dysfunctional way that puts some sport into the hobby?

Everyone here has been more or less correct about coordination and those 7.5 kHz coordinations are denied every day because the stations are too close, let alone a repeater output being 7.5 kHz away from a repeater input in the next county. Sometimes a friend calls a friend and gets a letter of concurrence to use a particular channel. Then all the engineering studies are off and the adventure of 90.173(b) begin. Below 512, it's ALL shared use, and the FCC will tell everyone so! (Unless the other station is protected as an FB8, but that's another big can of worms.) It's like daddy telling the kids to go play nice and work out stuff amongst themselves.

Good listening!
 

nbruark

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Again I must state the deadline has been switched. The old 2013 date has been moved to January 2020 for ALL agencies nationwide to switch to radios capable of narrowband operations and capable of digital operation. This includes ALL Public Safety, as well as Railroads. The FCC made this change about a month ago. I can't say for sure if the Federal deadline has been pushed back also, but the non fed systems must be operational in narrowband and capable of digital by 2020. The old deadlines were phase I narrowband by 2013, phase II narrowband by 2017. The Phase II (6.25 Khz) of course will require digital operation. At this time about half of the state of MS has already complied with the Phase I requirements in order to be ready by 2013, the OLD deadline. The following reasons are why this deadline was changed- 1: Not all radios on the market are fully compliant for both phases yet, though all the newest production models are Phase I compliant. 2: There are still MANY agencies nationwide that have not been able to afford to change out all their gear. Another little bit of information... This one is obvious- Bye Bye VHF Lo Band as of 2020.

Most current production scanners are fully narrowband capable for Phase I, and the newest can do Phase II narrowband. So you should not have any issues in that respect. The only thing that current scanners can't do is APCO P-25 Phase II digital. This may change by the time 2017-2020 rolls around and the mandate for switching to P-25 Phase II takes place.

Sorry, sir, but the information you heard is inaccurate. The VHF/UHF Part 90 LMR narrowbanding date REMAINS 01/01/2013. Furthermore, NO DATE for 6.25 KHz migration has been set by the Commission as of today. The ONLY exception to this applies to 700 MHz licensees who must narrowband by 2017. Perhaps you (and those who mis-informed you) should visit Business Industrial Utility Municipal Government Public Safety Narrowbanding Updates Information for FCC Part 90 VHF UHF LMR Licensees for more accurate information.
 

SCPD

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Gentlemen,

We have a problem.

Yalobusha County is properly licensed.

When I go into ULS for WNYZ545 (Grenada, MS), 159.1500 does not appear on the license. If this is in fact what they're using, it's no wonder they are getting interference. They apparently are not supposed to be there.

Someone may have keyed in the wrong frequency into RR or recorded what they thought they heard, after all, it's only as good as what people enter. So, that may be at issue and the problem not Yalobusha County, but someone else. Or, the problem could be some shop just set them up on a channel and thought it would go unnoticed (this is exactly what happens when someone does that).

At the end of the day, the many words of advice about minding one's own business might be sage advice, particularly as this ball of yarn starts to unwind. N Jay's right about an outsider peering into a living room window. As a listener, you are not a party to the interference. If you KNOW something is a hazard (and this isn't an "I think," but an "I've confirmed"), you might be able to go to the police chief, the FOP, or the mayor, and pass it along, but your obligation stops there. And, again, you may be walking into a domestic with people possibly attacking you for making an observation (especially if you picked up that someone set them up for something they don't have a license for).

Good luck with that!

Basically if you are NOt a legit( licensed user of the frequencies involved . It's none of your business.. plain & simple.
 
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