Two repeaters on the same frequency and tones, 20 miles apart. What to do?

[Suburbazine]

So what's the correct way to address a repeater conflict? Where I'm at seems to have 2 active repeaters on 550 141.3 and any transmits are coming back heavily stepped on in the region between. Is there an official way to contact both owners that isn't going to offend them? WRJZ925 and WRFL895

 

EDIT: WRFL seems to have noticed my comment and deconflicted.

PS: It seems like this would be a great chance for MyGMRS to do something really cool and check their database automatically for conflicts when new repeaters are listed. Don't know how complicated checking estimated range overlap would be, though.

[BoxCar]

That's really the responsibility of the repeater owners as part of the rules do state "not cause interference and accept all interference." As the service does not require coordination, it is the responsibility of the repeater owners to do the oft times laborious task of checking for other stations that may be affected or they may affect with their installation. (It's also the main reason I always tell new licensees 'No, you don't need a repeater.'

[kidphc]

We have multiple repeaters in this area that are on different tones. The repeater owners do a good job self coordinating, there are problems sometimes.

For the local area users, this sounds great. Till they learn they have to change their behaviors. You can either run no pl on receive, you get to hear all the landscapers and kids on simplex. Me I just run "monitor" for a more than a few moments before transmit. To make sure the carrier signal is not occupied by the other repeater.

Why? Doesn't matter what the pl is if the carrier is taken. You will get collisions If both repeaters transmit at the same time.

There is a benefit now though. Cross repeater talk. Both parties on both repeaters use no pl or monitor. One party transmits, second party waits till both repeater tails drop then they the second person transmits. Woot, you effectively have linked repeaters legally, and now have one huge repeater where the coverage effectively overlaps.

Sent from my SM-S901U using Tapatalk

[WRUE951]

6 hours ago, Suburbazine said:

So what's the correct way to address a repeater conflict? Where I'm at seems to have 2 active repeaters on 550 141.3 and any transmits are coming back heavily stepped on in the region between. Is there an official way to contact both owners that isn't going to offend them? WRJZ925 and WRFL895

 

EDIT: WRFL seems to have noticed my comment and deconflicted.

PS: It seems like this would be a great chance for MyGMRS to do something really cool and check their database automatically for conflicts when new repeaters are listed. Don't know how complicated checking estimated range overlap would be, though.

Where??   New York, New Jersey??     if so, understandable  

[WRYZ926]

This is going to happen since there are only a handful of repeater channels available for GMRS. And you can't always go by the mygmrs repeater map or repeaterbook.com either. Not everyone lists on either website or they don't keep things updated.

We looked here and on repeaterbook.com when our club first looked into setting up a GMRS repeater. Repeaterbook.com was outdated and the two closest repeaters to us were not listed on mygmrs.com. Several of us listened to all the repeater channels for a while before deciding what channel to use for our repeater.

We did talk to the owner of the two closest GMRS repeaters to let him know that we were setting up a GMRS repeater. He then updated the map here to show his to repeaters. Missouri is pretty rural outside of the 5-6 big metro areas so we don't have too much conflict with GMRS repeaters. I know that the Kansas City area has more repeaters than the St Louis area and there aren't any problems.

And it doesn't help that people don't bother to check either website before setting up their own repeaters.

There is the repeater counsel for amateur radio repeaters that takes care of keeping repeaters from operating on the same frequencies if they are too close and/or in the same state. This doesn't always help though. There is a 2m repeater right across the river from St Louis in Illinois that uses the same frequency tones as our 2m repeater. Normally there isn't any issues but sometimes  we do have issues when propagation is just right.

[MaxHeadroom]

This is a good moment to discuss a sad reality about GMRS:

This is why linking has been an issue. Too many people think about their repeater footprint and that's it - but forget that RF still travels outside the circle on their map just not in a way that would be considered reliable or even usable. Because of that, Part 90 services not only look at the height/power of the transmitter but plots it for a known service area and then adds a "protection zone" further around the coverage footprint to avoid interference when a frequency is reused too close to another transmitter location. 

VHF is terrible for this because of atmospheric phenomena, but UHF is not exempt from it either. This is why sites like this are critical for the GMRS community, because frequencies/locations should be listed somewhere unified BUT there is no current rule/procedure to prevent adjacent reuse of channels outside of "don't be a bad neighbor". Add linking and super-wide-area systems that are motivated to build out to recoup capital expense, and this turns into a cesspool quickly. GMRS never had these issues until the last several years because there was a higher barrier to entry that gets removed with each generation of rule change to the point that we are trying to talk about coordinating a community/family service in a way that won't devolve into CB radio.

Hopefully this provides some insight because there's "some influencers" in this forum that do nothing to discuss these issues civilly, offer input, or do anything except widen the divide between people that just want to talk and the ones that want to protect their investment in the service for their use. Time for everyone to swallow some ego and talk like adults.

[Suburbazine]

5 hours ago, WRUE951 said:

Where??   New York, New Jersey??     if so, understandable  

Basically Sevierville, TN. Decent repeater coverage but somehow two very powerful repeaters on line of sight mountaintops got shared tones and frequencies. One of them has strong audio and near instantaneous propagation, the other has weak audio (strong signal) and a slight delay on propagation. This lead to very garbled transmissions when they both picked up a signal and rebroadcast it. It actually took me 2 days to figure out what was wrong as prior commenters had also mentioned garbled audio. Pulled out the trusty SDRs and a couple of antennas and went hunting for interference. Only after I found an unexpected second repeater did I cross-reference MyGMRS and found it, updated 2 days ago.

I found some other interesting things that I wasn't expecting, like someone running a Pirate DMR in apparently simplex (encrypted, no less!) on 467.725 in the nearby area.

[WRUE951]

1 hour ago, Suburbazine said:

Basically Sevierville, TN. Decent repeater coverage but somehow two very powerful repeaters on line of sight mountaintops got shared tones and frequencies. One of them has strong audio and near instantaneous propagation, the other has weak audio (strong signal) and a slight delay on propagation. This lead to very garbled transmissions when they both picked up a signal and rebroadcast it. It actually took me 2 days to figure out what was wrong as prior commenters had also mentioned garbled audio. Pulled out the trusty SDRs and a couple of antennas and went hunting for interference. Only after I found an unexpected second repeater did I cross-reference MyGMRS and found it, updated 2 days ago.

I found some other interesting things that I wasn't expecting, like someone running a Pirate DMR in apparently simplex (encrypted, no less!) on 467.725 in the nearby area.

[WRUE951]

Four listed nearby you (4=11 miles.  One appears to be offline 

[MarkInTampa]

2 hours ago, Suburbazine said:

Basically Sevierville, TN. Decent repeater coverage but somehow two very powerful repeaters on line of sight mountaintops got shared tones and frequencies. One of them has strong audio and near instantaneous propagation, the other has weak audio (strong signal) and a slight delay on propagation. This lead to very garbled transmissions when they both picked up a signal and rebroadcast it. It actually took me 2 days to figure out what was wrong as prior commenters had also mentioned garbled audio. Pulled out the trusty SDRs and a couple of antennas and went hunting for interference. Only after I found an unexpected second repeater did I cross-reference MyGMRS and found it, updated 2 days ago.

I found some other interesting things that I wasn't expecting, like someone running a Pirate DMR in apparently simplex (encrypted, no less!) on 467.725 in the nearby area.

I sit between two repeaters on the same tone and frequency. 35 miles from repeater A, 25 miles from repeater B and the repeaters are around 60 miles from each other. Repeater A is up 400ft and hits me full scale. Repeater B is up around 50ft and is fully readable but just above the noise floor and is networked with far more (but very little local) traffic. They are far enough from each other that most of the time there is no issue except when you get folks trying to use one or the other when operating between them (like myself) or there is even a slight band opening. I do get a bit of heterodyning most of the time on repeater A on receive if repeater B is transmitting but not to bad. I have to bring up the system status page of repeater B on the web and drop my power to 5 watts to verify that I'm not keying it at the same time, 50 watts and I will. If there is a REALLY strong band opening I have talked on up 4 repeaters on the same frequency and tone with one being 160 miles away as long as nobody is using the other 3. Gotta love 141.3 and 4 squelch tails!

There is somebody local out here that is running a encrypted DMR repeater on 462.700. It's driven at least 3 GMRS repeaters off that frequency because of interference. Its been reported by quite a few folks to the FCC but nothing has been done in the 1.5+ years its been on the air. Oh well, just subtract one frequency from being used, not much you can do about it.

The City of Tampa also has a grandfathered GMRS repeater on 462.625 that ID's every 10 minutes but in two years I've yet to hear anybody actually use it. Its CTCSS decoder has been screwed up for years, it will repeat on the wrong tone (or any tone) one or two times (mostly at the beginning of a transmission) and then behave by not repeating on the wrong tone. It's also driven a few local repeaters from using that frequency. Subtract another frequency from being used.

[TrikeRadio]

2 hours ago, MarkInTampa said:

I sit between two repeaters on the same tone and frequency....

And I suppose neither repeater owner is willing to just change their tones? Seems like they would want to so it was not messing up people between the two.

[MarkInTampa]

49 minutes ago, TrikeRadio said:

And I suppose neither repeater owner is willing to just change their tones? Seems like they would want to so it was not messing up people between the two.

You would think so... Repeater A has been around for 5+ years and is the dominate repeater in its area. Repeater B popped up about a year ago and almost instantly I notified the owner about the issue (within a day or two of it going up) and asked if could change the tone and he never responded. I tried to be a good trooper but if I accidently hit his repeater (and the repeaters networked to it) when using repeater A there isn't much I can do about it. I sent a link to the repeater A owner of repeater B's linked status page so if there is interference on their repeater they can at least see if it's a user of repeater B doing it.

It doesn't happen often, the band has to be open just a bit then it becomes a bit of a problem or confusion to users on both repeaters. Folks on one of the repeaters or the other are hearing just one side of the conversation and wondering what's going on and from where I sit I hear both.

[JLeikhim]

5 hours ago, Suburbazine said:

Basically Sevierville, TN. Decent repeater coverage but somehow two very powerful repeaters on line of sight mountaintops got shared tones and frequencies. One of them has strong audio and near instantaneous propagation, the other has weak audio (strong signal) and a slight delay on propagation. This lead to very garbled transmissions when they both picked up a signal and rebroadcast it. It actually took me 2 days to figure out what was wrong as prior commenters had also mentioned garbled audio. Pulled out the trusty SDRs and a couple of antennas and went hunting for interference. Only after I found an unexpected second repeater did I cross-reference MyGMRS and found it, updated 2 days ago.

I found some other interesting things that I wasn't expecting, like someone running a Pirate DMR in apparently simplex (encrypted, no less!) on 467.725 in the nearby area.

It could very well be that the owners of those two repeaters are unaware of each other. When you are in a mountainous area in Tennessee, the signals can go quite far and since you happen to hear them, I assume you are in a good location to hear both repeaters. That does not mean 90% of the actual users of each repeater are experiencing a problem 90% of the time. But if you hear a lot of regular traffic hitting both repeaters, than yes it may be a problem needing attention. The custodians of those two repeaters could coordinate a change of tones between them. That is a normal thing.

Looks like they may have discovered a legal method of linking!

[MaxHeadroom]

17 hours ago, MarkInTampa said:

You would think so... Repeater A has been around for 5+ years and is the dominate repeater in its area. Repeater B popped up about a year ago and almost instantly I notified the owner about the issue (within a day or two of it going up) and asked if could change the tone and he never responded. I tried to be a good trooper but if I accidently hit his repeater (and the repeaters networked to it) when using repeater A there isn't much I can do about it. I sent a link to the repeater A owner of repeater B's linked status page so if there is interference on their repeater they can at least see if it's a user of repeater B doing it.

It doesn't happen often, the band has to be open just a bit then it becomes a bit of a problem or confusion to users on both repeaters. Folks on one of the repeaters or the other are hearing just one side of the conversation and wondering what's going on and from where I sit I hear both.

Isn't there a cargo ship or such that pulls into port regularly in the area using a grandfathered GMRS license that mucks with one of the systems to the point they need to use an "alternate input" during those times?

Its stuff like that which always gives me a reason to scratch my head when talking about how GMRS can be better suited "for public benefit" when there's still so many issues to resolve service-wide.

[MarkInTampa]

1 hour ago, MaxHeadroom said:

Isn't there a cargo ship or such that pulls into port regularly in the area using a grandfathered GMRS license that mucks with one of the systems to the point they need to use an "alternate input" during those times?

Its stuff like that which always gives me a reason to scratch my head when talking about how GMRS can be better suited "for public benefit" when there's still so many issues to resolve service-wide.

There is ship traffic that causes occasional interference on the Tampa 575 repeater. It has a alternate input of 467.725 as well as the primary input of 467.575. The primary input (467.575) is part of the ITU standard for UHF vessel communications and the repeater overlooks the port of Tampa. The ship traffic doesn't key the repeater but does mix in with normal GMRS traffic so they shut down the primary input if it becomes a problem.

FYI - ITU UHF standards for vessel communication coexists with two GMRS repeater inputs, 467.550 and 467.575 as well as GMRS channel 8 (467.5625)

 

[SteveShannon]

40 minutes ago, MarkInTampa said:

There is ship traffic that causes occasional interference on the Tampa 575 repeater. It has an alternate input of 467.725 as well as the primary input of 467.575. The primary input (467.575) is part of the ITU standard for UHF vessel communications and the repeater overlooks the port of Tampa.

I’m curious, why doesn’t the 575 repeater simply change both TX and RX to 725 permanently instead of having occasional interference? That way off-the-shelf GMRS radios with their 5.000 MHz offsets would continue working.

[MarkInTampa]

16 minutes ago, SteveShannon said:

I’m curious, why doesn’t the 575 repeater simply change both TX and RX to 725 permanently instead of having occasional interference? That way off-the-shelf GMRS radios with their 5.000 MHz offsets would continue working.

If I had to guess there is a really strong repeater around 40 miles away already on 725 with excellent coverage up 400ft that can be accessed from the 575 repeater location with a good radio. Far enough away that occasional local traffic on a different tone on the input of 725 won't really effect it but close enough that you wouldn't want them on the same output. Both are by far the strongest repeaters in the area.

[MaxHeadroom]

3 hours ago, MarkInTampa said:

There is ship traffic that causes occasional interference on the Tampa 575 repeater. It has a alternate input of 467.725 as well as the primary input of 467.575. The primary input (467.575) is part of the ITU standard for UHF vessel communications and the repeater overlooks the port of Tampa. The ship traffic doesn't key the repeater but does mix in with normal GMRS traffic so they shut down the primary input if it becomes a problem.

FYI - ITU UHF standards for vessel communication coexists with two GMRS repeater inputs, 467.550 and 467.575 as well as GMRS channel 8 (467.5625)

 

That’s what I was thinking about! I know some of the folks for the Tampa 575 repeater and the system layout to make up for that issue. 
 

it’s just another one of those things that goes to show how congested the spectrum is already, that it would be a hell of a fight to get “more”. 

[WRKC935]

Yeah, that's a good case for getting in an argument with one repeater owner making sure that the other repeater owner hears it and you are getting into both repeaters equally.  I know it's causing 'harmful interference doing it on purpose,,, but no more so than having two repeater owners on the same frequency and PL acting like they don't know the other one is there. 

People do things to be difficult.  This is one of those times.  My stance is when you have two people doing crap like that, you become equally difficult.  Of course my version if difficult is a base station antenna at 120 feet sitting on the highest hill in the whole county running a solid 50 watts.  Or to REALLY add fuel to the fire.  Add a third repeater right in between them on the same frequency and PL.  Only that goes at the top of the tower.  So 240 feet AGL and 1560 above sea level. 

That will spool them both up equally.

 

[MaxHeadroom]

13 hours ago, WRKC935 said:

Yeah, that's a good case for getting in an argument with one repeater owner making sure that the other repeater owner hears it and you are getting into both repeaters equally.  I know it's causing 'harmful interference doing it on purpose,,, but no more so than having two repeater owners on the same frequency and PL acting like they don't know the other one is there. 

People do things to be difficult.  This is one of those times.  My stance is when you have two people doing crap like that, you become equally difficult.  Of course my version if difficult is a base station antenna at 120 feet sitting on the highest hill in the whole county running a solid 50 watts.  Or to REALLY add fuel to the fire.  Add a third repeater right in between them on the same frequency and PL.  Only that goes at the top of the tower.  So 240 feet AGL and 1560 above sea level. 

That will spool them both up equally.

 

That is a lot of what I mean when I say one of the principles of GMRS and even amateur radio is "be a good neighbor". In these hobbies/services its very much like a conquest and first to "plant their flag" has squatter's rights to that location/frequency. FCC directly manages all Part 90 with third party coordinators working on their behalf, and amateur radio has volunteer coordinating bodies in regions to try and do the same. The only problem now is that amateur radio has issues with this stuff as well (frequency pairs being squatted on for decades with no equipment running on it and corruption within organizations) - and GMRS is lacking any sort of structure like that at all.

This site/forum in my mind is meant to be that coordinating place - if people would stop attacking each other and their ideals in a way to actually benefit the service instead of their own egos.

[AdmiralCochrane]

5 hours ago, MaxHeadroom said:

 

This site/forum in my mind is meant to be that coordinating place - if people would stop attacking each other and their ideals in a way to actually benefit the service instead of their own egos.

How many GMRS licenses and how many active members here?  This site is a microscopic fraction of the GMRS world

[WRKC935]

6 hours ago, MaxHeadroom said:

That is a lot of what I mean when I say one of the principles of GMRS and even amateur radio is "be a good neighbor". In these hobbies/services its very much like a conquest and first to "plant their flag" has squatter's rights to that location/frequency. FCC directly manages all Part 90 with third party coordinators working on their behalf, and amateur radio has volunteer coordinating bodies in regions to try and do the same. The only problem now is that amateur radio has issues with this stuff as well (frequency pairs being squatted on for decades with no equipment running on it and corruption within organizations) - and GMRS is lacking any sort of structure like that at all.

This site/forum in my mind is meant to be that coordinating place - if people would stop attacking each other and their ideals in a way to actually benefit the service instead of their own egos.

Yeah, I would REALLY like to agree with you on this.  The problem is you're right about the whole plant your flag statement, and people's ego's.

Is my fix a "my dicks bigger"  or I'm a bigger dick fix?  Yep, 100%.  But the situation he faces is untenable, and it would seem that there is little logic, reason, or courtesy being applied here by the two repeater owners.  

We dealt with folks like this back in the CB radio days where guys with big base stations and amplifiers would chase people form channel to channel being difficult with a wonderful little circuit, 9 feet of thin green wire and a 9 volt battery. The circuit was a wideband oscillator that created whines, howls and other noise across about 10 Mhz rather effectively.  They were painted green and brown to hide in tree's and had several fish hooks on them so they would get caught in a tree.  Pop on a battery,  hop out of the car, and toss in the guys tree in his front yard or a nearby tree.  They weren't super powerful.  Only worked well for a few hundred feet.  But if you were that close, you couldn't hear anything.  Battery would last about a week.  Some of the more difficult clowns took multiple applications for them to see the light.  But a week of listening to what one guy described as a cat and a racoon humping was about the most correct description.  

I don't like to resort to crap like that.  I would rather that people got along, were cordial and courteous to each other and saw the light of cooperation when it comes to stuff like this. But if clown number one on mountain top A and clown number two on mountain top B can't seem to get that concept,,,, more direct measures should be employed.  And since BOTH of them are on the same PL tone and frequency.  Putting up a third repeater with one of those annoying hammie VOICE IDers seems the correct route to take.   You know as opposed to a CW id with no tone present at 20 WPM... I would think alternating a recording of a CW ID performed with voice over of a 3 year old doing it from a Morse code chart and a recorded voice with something like "this is the WRKC  ahhh oh WRKC 9 3 5 repeater on a frequency of 462 DOT 6 2 5 Mega Hurtz , it's megashurtz right?,, not kilohurtz.  YEa Yea,,, four hundred and sixty ... two million,,, six hundred and twenty five thousand hurtz. So 462.625 Megahurtz. With a P L of ...... you get the point.

Back to the PL being the same.  Those clowns are gonna hear that, every 14 minutes.  Alternating.  Because they are setup to hear THAT PL.  One or both will vacate the PL, possibly the frequency in less than a week.  And how do you word your complaint to the FCC in that instance?  Well me and this other guy were warring with each other on the frequency and PL and a third guy came in and put up ANOTHER repeater on that frequency and PL too.  Because we were interfering with each other.  He decided to do it as well.   And his IDer is really obnoxious.  I am sure the FCC will be laughing at the clowns as they hang up the phone. 

 

 

[MaxHeadroom]

5 hours ago, AdmiralCochrane said:

How many GMRS licenses and how many active members here?  This site is a microscopic fraction of the GMRS world

I don’t think it’s “microscopic” but it has something very unique - activity. The main page is also one of the only (and most comprehensive) databases of repeaters/sites/systems and contacts to them. That’s more than what I can say about GMRS several years back. Not much of a stretch to run with that and propose a “regulatory body” for GMRS repeater coordination like hams do or FCC already mandates as a prerequisite to coordinated licensing. 

[MaxHeadroom]

4 hours ago, WRKC935 said:

Back to the PL being the same.  Those clowns are gonna hear that, every 14 minutes.  Alternating.  Because they are setup to hear THAT PL.  One or both will vacate the PL, possibly the frequency in less than a week.  And how do you word your complaint to the FCC in that instance?  Well me and this other guy were warring with each other on the frequency and PL and a third guy came in and put up ANOTHER repeater on that frequency and PL too.  Because we were interfering with each other.  He decided to do it as well.   And his IDer is really obnoxious.  I am sure the FCC will be laughing at the clowns as they hang up the phone. 

 

 

That’s worked before - sometimes enough to get the annoying party off the air for good. Like I mentioned about hams and squatting on pairs - funnily enough in my area they were also hams that thought PL was “new tech” so everything ran CSQ. Put up a repeater with every ID/weather/widget voice ID controller option checked and even if no one uses the repeater the squatter will usually vacate pretty quick! 

[WRKC935]

1 hour ago, MaxHeadroom said:

That’s worked before - sometimes enough to get the annoying party off the air for good. Like I mentioned about hams and squatting on pairs - funnily enough in my area they were also hams that thought PL was “new tech” so everything ran CSQ. Put up a repeater with every ID/weather/widget voice ID controller option checked and even if no one uses the repeater the squatter will usually vacate pretty quick! 

Yeah, we have a local ham repeater that is like that all the time.  The trustee thought it had to be open squelch so it was.  It has two different IDer's on it.  It's actually fun to play with. Top and bottom of the hour it will ID.  Actually ID's every 9 minutes without use.  But top and bottom the hour, Let it ID.  Then key up and ask "WHAT REPEATER"  It will ID AGAIN.  THen ask what did it say.  It will ID a third time.  All this in a course of 30 seconds. 

And it ID's overtop of who ever is using it too.  It's so bad it ran off all the local users because of that BS.  I had to pull the thing out of the logging recorder because it was filling up the hard drive.  Had 30 resources in the thing.  That was always top of the list for record time

 

[WSFJ980]

Here is a hypothetical.... Let's put repeaters along the interstate highway system spaced at some distance apart that would pretty much assure continuous coverage as someone drives.  All the repeaters would be on the same channel with the same tone, but they would NOT be linked in any way.  What kind of interference do you think there would be?  I'm thinking that one user could not activate more than two repeaters at the same time depending on output power, and the repeaters could not activate each other since the input and output frequencies are different.  However, two repeaters could possibly be transmitting the same message at the same time, which could cause degradation of the message heard by users.  Would it be that bad as to be unusable or unpractical?  Could the interference be mitigated somewhat by changing the distance between repeaters?  I would appreciate any feedback.