Repeater Ops Interfering W/ Simplex Ops

[marcspaz]

 

I experienced something a few days ago, that I had not experienced before.  Around my home, we have several repeaters that have 80%-90% reliability for 35+ miles and 70%-75% reliability out to 45-50 miles. We're talking over 7,800 square miles of coverage. 

 

With that kind of footprint, I have always suspected that repeater use could cause interference to simplex users, without the repeater users even realizing it.  I can't hear a simplex conversation between mobiles when those parties are 60 miles away from me.  So, what can you do as a repeater user to reduce that interference?  Is it on you to be sure that doesn't occur?  Is it up to the simplex users to try to use tone or digital squelch techniques.  Or is it up to the simplex users to find a free channel?

 

I got on a repeater the other day and started calling out for my son, and without realizing it, I was interfering with a simplex conversation.  One of the other operators got on the repeater to let me know I was wiping out there local traffic.  Thankfully the owners of the stations with the local traffic are friends of mine, so one of them came on to the repeater to chat.  Everything was friendly, which they are both good guys and I would expect them to be friendly about it, even with a stranger.  One of them simply came up and let me know I was stepping on them and I stopped using the repeater for awhile.

 

Since we're all sharing radio space, it just seemed like a normal situation with a good and expected outcome.  But, what would have happened if those people were not my friends?  What if it was a group who doesn't know the person causing interference?  What if the simplex operators don't have repeater access and the repeater owner or operator simply is unaware of the simplex conversation.  Where does the onus lay to take action, and what is the proper action.

 

I know we have discussed how unlikely it is to get GMRS expanded, but would it be worth trying to petition the government to expand GMRS to included dedicated repeater frequencies so we can avoid situations like this? 

 

I don't know the right answer, but I figure it could be fun to discuss.

 

 

[kidphc]

It is only going to get worse. With more repeaters coming online, more licenses and a limited set of repeater pairs.

I don't see any easy solutions. With mobile radios ( most cant go below 15w) not being able to use lower channels. It is all compounding to be worse.

I told Roland many moons ago, that gmrs will in time become uhf cb radio sadly.

Kinda of why I preach, open the squelch, or use monitor to disable pl tones. To listen before transmitting. That still doesn't help if your station has poor ears. Best operating procedures are the only way to help clear up the clutter.

I mean come on even in the Ham world people trample on each other tuning up, just because that can't hear the other station.

No quick solution, if I think of anything, I will chime back in.


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[WRQC527]

25 minutes ago, marcspaz said:

expand GMRS to included dedicated repeater frequencies

I think the mistake was made early on that there are not already frequencies that are exclusive to repeaters. The amateur radio band plans contain repeater frequencies and offsets, which are already built into radios and attempt to minimize interference between simplex and repeater users. The idea that simplex frequencies overlap GMRS repeater frequencies in seems odd. Just my two cents, which adjusted for inflation works out to not much.

[WRUU653]

This is a great question. I think if you are in an area where you have simplex frequencies open to use and you can use the lower power successfully for your contact it makes sense to do so.  It reduces your own exposure to interference.  Use what you need to get the job done and not more. 

While some inadvertent interference is inevitable having a separate set of repeater frequencies would certainly help eliminate a lot of it. This is where I think linked repeaters is also an issue. You may be stepping on people you don't hear who are on simplex.  I don't know how successful you would be getting this done but separate repeater frequencies is the best reason I have heard for expanding GMRS frequencies  

[AdmiralCochrane]

On the other hand, isn't this a case of simplex users not expecting repeater operation even though they were on the simplex/repeater frequency? 

kidphc is correct, proper understanding of best operating procedures calls for listening FIRST, but GMRS is a no test, buy your license and transmit service. 

 

In this case, all the parties knew 10 times more than the average GMRS licensee; consider that EVERYONE on this forum is probably 5 times more knowledgable than the average GMRS licensee, even those who have come here and asked only a single question.  Separating the repeater frequencies would be the only solution but I don't know if that would even be possible since GMRS is already democracized, there would be older repeater operators that would never switch to the new frequencies. 

[axorlov]

462.xxx5 (channels 1-7) are repeater-free. Perfectly adequate for local traffic between HTs or between HT and mobile. Local traffic between mobiles on 462.xxx0 at full power has a good chance to overpower repeater interference. The opposite happens only when mobiles are far and repeater is close. In this case use reserve frequency, according to your communication plan.

[SteveShannon]

@marcspaz

Assuming the repeater had been established for some time, folks using a channel that’s known to be in use by a repeater is a bit like fly fishing directly beneath a dam.  Sooner or later the dam will spill. 

 

[nokones]

I wish the FCC would mandate that GMRS operate on narrowband for both the main 462 and 467 channels and the interstitial 462 channel to minimize any potential co-channel use contention problems. The interstitial 462 channels would be perfect for simplex operation.

[Raybestos]

8 hours ago, Sshannon said:

@marcspaz

Assuming the repeater had been established for some time, folks using a channel that’s known to be in use by a repeater is a bit like fly fishing directly beneath a dam.  Sooner or later the dam will spill. 

 

Agreed!  Once again, in a perfect GMRS world, with no linked or "networked" repeaters, this should be a minimal problem.  Absent garbage being constantly piped in from across the state or across the nation, most repeaters I have ever heard, have little traffic.  If you regularly operate on one repeater output for 50W simplex, and a repeater becomes active, you could switch to another 50W output and probably find it vacant.  Without linking, the chances that all eight are in use via an overpowering repeater in your area are kinda slim.  With so much linking, well, that can be a problem in some areas, especially when all eight 50W channels are blasting the same conversation out at the same time.

[ULTRA2]

Hi 

I have a different issue here. We have simplex station using GMRS22 and here the problem is that we have our CERT net every Tuesday night on 462.725 and during the net on several occasions I thought heard other signal comes in with the operator trying to check in. I found out later that the other signal is coming from a station on the simplex side of the channel, but if you have an emergency and keeps getting interfered with by the simplex station isn't that a violation? Just curious what you guys think and oh by the way the station in question is using illegal power cause when they key up they cover all the stations on the repeater side.

Edited September 29, 2023 by ULTRA2
Additional information

[SteveShannon]

6 minutes ago, ULTRA2 said:

Hi 

I have a different issue here. We have simplex station using GMRS22 and here the problem is that we have our CERT net every Tuesday night on 462.725 and during the net on several occasions I thought heard other signal comes in with the operator trying to check in. I found out later that the other signal is coming from a station on the simplex side of the channel, but if you have an emergency and keeps getting interfered with by the simplex station isn't that a violation? Just curious what you guys think 

Was there an emergency?

If there was, 95.1731(a) says:

(a) Emergency communications. Any GMRS channel may be used for emergency communications or for traveler assistance. Operators of GMRS stations must, at all times and on all channels, give priority to emergency communications. 

[ULTRA2]

8 minutes ago, Sshannon said:

Was there an emergency?

Thanks goodness that there weren't any emergency at that time, but thanks for quoting me the rules so now I know.

[OffRoaderX]

You should come to L.A..  Its a shitshow and its every man for himself.

[Blaise]

If only we could get all manufacturers to put the same default CTCSS tone on all simplex channels...

[BoxCar]

1 hour ago, ULTRA2 said:

I found out later that the other signal is coming from a station on the simplex side of the channel,.

If the simplex channel is trying to check into the net, why not go back to that person on simplex and give them the correct channel they should be using? They think they are on duplex and using the power allowed for a repeater channel.

[SteveShannon]

Or were the parties on simplex simply using their radios, oblivious to the presence of a net taking place. 

[marcspaz]

4 hours ago, Sshannon said:

Or were the parties on simplex simply using their radios, oblivious to the presence of a net taking place. 

 

This is where my money is.

[WRUU653]

1 minute ago, marcspaz said:

 

This is where my money is.

I’ll second that. 

[SteveShannon]

14 hours ago, ULTRA2 said:

during the net on several occasions I thought heard other signal comes in with the operator trying to check in.

So, your CERT Net was going on and while it was going on when someone checked in you could occasionally hear someone else on the receive frequency.  In other words, when your receiver broke squelch because the repeater transmitted a tone, you could hear the folks in the background who were trying to talk on the simplex receive frequency, is that right?

Could anyone else on the CERT Net hear them, or were they local to you only?

Before you started the Net, did anyone listen with squelch off to hear if the channel was in use?

When you did hear them, did you transmit on 462.675 MHz and announce, politely, that the frequency was in use?

They could have been on GMRS or FRS.  Except during an emergency, they have as much right to be on the channel as your CERT Net.  We share the repeater receive frequencies with simplex users of both GMRS and FRS radios and while it would be ideal for each of us to listen with squelch turned off to hear if a frequency is in use before transmitting, there is no GMRS training that covers that.

It sounds like folks were just using their radios and it happened at the same time as the Net.  If they were using a different tone from you they might not have even heard you.

As far as it being “a violation”, no, it wasn’t, at least in my opinion.  No more than the Net operators were in violation for transmitting on a channel that was in use already by a couple of folks with their radios.

And since you liked seeing the actual regulation regarding emergency use, here’s the one that requires shared use:

§ 95.359 Sharing of channels.

Unless otherwise provided in the subparts governing the individual services, all channels designated for use in the Personal Radio Services are available for use on a shared basis, and are not assigned by the FCC for the exclusive use of any person or station. Operators of Personal Radio Service stations must cooperate in the selection and use of channels in order to avoid interference and make efficient use of these shared channels. 

 

 

[ULTRA2]

6 hours ago, Sshannon said:

did you transmit on 462.675

It was on 725 but I see your point.

 

[SteveShannon]

14 minutes ago, ULTRA2 said:

It was on 725 but I see your point.

 

Sorry, you’re right. 
 

[axorlov]

9 hours ago, Sshannon said:

They could have been on GMRS or FRS.  Except during an emergency, they have as much right to be on the channel as your CERT Net.  We share the repeater receive frequencies with simplex users of both GMRS and FRS radios and while it would be ideal for each of us to listen with squelch turned off to hear if a frequency is in use before transmitting, there is no GMRS training that covers that.

Repeater users rarely can hear local traffic on simplex. Only when simplex stations are close to the said repeater user. That kind of interference from the repeater is a fact of life and unavoidable. Move to another freq if you are on simplex.

[ULTRA2]

On 9/30/2023 at 1:13 PM, axorlov said:

Move to another freq if you are on simplex.

I would like to change channel however all traffic I do is on the repeater side and when I try to explain to the simplex user to give me a few minutes to check in then I will leave you alone, but no you do have smart a***s think they own the channel and that's when I get mad. 

[marcspaz]

24 minutes ago, ULTRA2 said:

I would like to change channel however all traffic I do is on the repeater side and when I try to explain to the simplex user to give me a few minutes to check in then I will leave you alone, but no you do have smart a***s think they own the channel and that's when I get mad. 

 

I might be missing something... but if the Net is going on, no one else on the net can hear them, they obviously can't hear the Net (evident by them talking simplex during the net), then why not just talk over them?  You transmitting into the repeater isn't going to interfere with them, and it sounds like you can hear the repeater just fine, since your words were you " thought" you heard other signal.

 

Obviously, I don't condone someone else being a jerk.  If they are intentionally getting on the air at times that they know the Net is occurring, then they are the ones who have the obligation to resolve the issue. 

 

That said, Tone Squelching (PL Tones) were created so multiple conversations can be had on a single frequency without uninterested parties hearing each other (conversations between conversations).  I would squelch them out and forget about it.

[axorlov]

3 hours ago, ULTRA2 said:

but no you do have smart a***s think they own the channel and that's when I get mad

Don't get mad, life is too short for a petty things like that. Other than that, marcspaz covered the issue, it seems^^^^^