WRKC935

Get over yourself dude. Never said I blocked you specifically. Hell I'm Batman and your the Joker. We need each other. It's a love hate relationship. Where on a rare occasion when the stars align, we might actually agree on something. But we do have a symbiotic relationship where one of us is the host and the other is the parasite. We just can't agree on who is who. But that's all right. You'll keep making my butt itch and I will keep giving you headaches. It's all good.

Well, news flash, YOU have been lied to. There are indeed dumbass ham operators that believe this crap and a number of GMRS guys that fall into this as well. The biggest believer in this BS about SWR by far is CB operators. I have also come across the ones that think that any amount of cable loss that's not an absolute necessity is sinking an installation and the radio system will never talk without more than X dB of cable loss. And these moron's will die on that hill as well with their beliefs. There was a time that being a ham operator actually meant that you had some level of technical ability and knowledge. In fact it was a requirement to prove that knowledge during testing for a ham license. That's not been the case in years. Once the FOIA became a thing and the question pool for the tests were made into study guides for passing the test, there was no longer a need to have specific knowledge of radio, you just had to be able to memorize enough of the questions and answers to pass the test. And these folks that get licensed now did just that and then through a total lack of any real knowledge, listen to wives tails of Whoa when it comes to cable loss and SWR and treat those lies as gospel and preach them to all that will listen. And the reason they believe? Because the dolt that is preaching the good word of SWR has been licensed for 6 weeks longer than they have. I don't understand the 'importance' of the length of time that someone has walked around with a ham license in their pocket. Old people have had drivers licenses for far longer in some instances, it doesn't mean that grandma should still be driving when she has run over 12 curbs, 4 dogs and a shrub or two in the front yard. Does it mean that you are some how a master of bating when you have been playing with yourself for 30 years? No, it just means your old and lonely. And not much different mentally than most teenage boys. Other than they might get some at some point down the road. The guys that had to actually construct a radio at the testing office to get their ham license (yes it was a thing once) are about 3 days older than the dirt that they will be buried in any day now, if they haven't been already. I will have been a ham operator for 30 years in April or 24. And that don't mean crap. Other than I got a ham license long ago. It doesn't prove anything past my ability to fill out a forum every 10 years and send some money to the FCC with that forum and renew my license. It's the same method used to renew a GMRS license, a commercial radio license or many other certificates that someone might have. What does prove out that I know something about radio and electronics? Two years of electronics in high school with a state certificate of completion. Three years of college with a degree in electronic repair and a degree in industrial electronics. Fourteen years as a communications field technician designing, installing and repairing public safety communications system and 911 phone systems. That would be a good starting point. But, any skill that you are being paid to use, and have been paid to use for more than 2 years typically means you must know something about it, because most employers would have fired you in that time frame if you weren't any good at what you are being paid to do. Again, just my personal opinion.

The way to do this right is two radios. One radio that was a 1 to 25 watt radio set at the lowest possible power in each position for inner vehicle communications. These would only be for the operators of the 'train'. A second radio on a different channel for escort and spotter operations. These could be 1 to 25 watt versions as well but turned up to 10 or so watts to communicate with the escort vehicles and the train vehicles. There are two equally important sources of radio traffic when running a setup like this. First of course is from the other operators on the connected vehicle. The second being from spotter / escort ops that are running all around the vehicle. And a front lead vehicle may be a 1/2 mile or more in front of the load vehicle to spot traffic, road conditions or other issues that will effect the navigation of the load vehicle. Being able to hear BOTH is important, to the point two radios are all but a requirement. Licenses can be simple itinerant nationwide frequencies but multiple channels are also a must if you would happen to run into another license holder that would cause interference. If that happens everyone switches to a different channel and the issue is averted. And escort / spotters are NOT on the same channel as the vehicle operations for the same reason. Something as simple as changing speed is a group effort here. All power units have to be doing the same thing at the same time. And that 'team effort' for lack of a better description is why NO ONE else is on their channel. CB radios and other 'distractions' shouldn't be present in the load vehicles either. If CB or other radio monitoring is needed, that needs to be a function of the escort / spotter team. They can then relay important information to the load vehicles across the spotter radios. At least that's the proper way to do it in my mind.

So the first issue that they may be having is the fact the radios they have are in the Part 90 allocation. And do you know what frequency they are on? Could be VHF. could be UHF. Hard to say. All this has to do with the noise floor of the area around the facility. Rural area noise floors are typically going to be lower than urban areas. The type of license they have is also a consideration. If they are saddled with an itinerant license, their neighbors across the street may have the same frequencies as they do further limiting their ability to talk. Lastly, the squelch level of the radios they have, which is programmable only and not user adjustable may have a hand in the lack luster coverage they are experiencing. GMRS and HAM UHF frequencies are typically fairly quiet and the noise floor there is very low typically. Much lower than the noise floor in the part 90 allocated frequencies. But what I can tell you is this. There are a number of different radio services out there that are for different applications and users. FRS radios that are sold in a big box store in bubble packs are meant by the service they are attached to to NOT be used for commercial / government entity applications. Just because you can buy them across the counter doesn't mean they are for every application you can imagine. FRS specifically stands for FAMILY radio service. Meaning they are for family use in a similar way that a child's walkie-talkie is meant for that application and NOT as a radio system for public safety. Could you use kids walkie-talkies in a public safety situation? Sure, if the range was limited, and the interference was minimal, police could use them to communicate. But that's not what they are for, and if a police department was to use them for law enforcement activities and the FCC caught wind of it there would be some fall out over it. Same goes for FRS radios being used for school communications. It's not what that service was intended for. And improper use of a radio service is technically against the regulations. Now, mind you seeing any sort of enforcement with this is pretty far fetched, BUT if the FCC were to get wind of it and decide to levy fines to the schools for using the FRS service as their communications system, those fines could reach over 10K in short order. So messing about with things of this nature, not being aware of the regulations could get them in hot water. And while the FCC can't really come for you for violations, the school could seek to create a civil case against you for sending them that direction.

Correct, the payload is the only ting typically encrypted, but the 'repeaters' in a conventional system are also transparent to the data stream. They look at the signal to see that it's P25 and nothing else. If it's a 'system' then the data stream is further processed to see that the talkgroup ID and radio ID are encrypted before allowing the traffic to pass. But if you stand up a stand alone Quantar repeater in P25, and run encryption on the subscribers, the repeater doesn't care or even have the ability to look at the data stream. Now the headers which carry the ID are NOT encrypted typically. This becomes apparent when you have a radio that isn't encrypted listening to the secure traffic. The transmitting radio ID will be displayed, but the audio is muted since there is no way for the receiving radio that's not encrypted or doesn't have the proper key in it to decrypt the radio traffic. As mentioned, to have 'wireline' control of the repeater, it requires a DIU with encryption in the DIU to communicate via wireline encrypted. The repeater isn't encrypting the traffic, that is done by the DIU and the encrypted data stream is fed directly to the repeater and it puts that stream on the air.

You might have heard that someone had to 'buy back' an entire system over the issues with the interference that it was causing and getting from surrounding agencies. I have first hand knowledge of that system. Those issues were also why the APX line of radios never received the ability to do DMR. That family of radios were built for public safety in mind of course. And Motorola didn't want to even go down that road for interoperability. I know of a Motorola shop owner that did setup a TRBO system after all the mess happened. He told me that M said if it didn't work, they would pull his dealership from him. He was a very accomplished RF engineer, and his system did work without issue. But it was not a case of just taking out the analog repeaters and dropping in DMR on the same frequencies and power levels. Some of the original frequencies were reused, but some couldn't be. And the whole thing was re-engineered. Different antenna's at different heights, and power levels were all significantly reduced. But DMR requires a different mentality and effort than old school analog radio where you run as much power as allowed as high on the tower as you can. This is another concern that I, to this point, have been reluctant to bring up with DMR on GMRS. GMRS users typically do subscribe to the 'height is might' mentality with strong reliance on power. We hear guys complaining that there 50 watt radio only does 48 watts on their meter (coax loss in the test jumper is the typical cause) and wanting those extra 2 watts. With that line of thinking, dumping DMR into GMRS in a suburban or urban environment WILL cause interference problems of course. And getting the max power thought process out of peoples heads isn't going to be possible. So there is yet another reason to steer clear of the whole idea of DMR on GMRS.

yeah, i made a list finally

A sort of limited explanation of ERP vs power. Where the power or watts measured from a power meter, which is where the 50 watts thing comes in. There is something called ERP or effective radiated power. This has to do with antenna gain. Gain is typically figured off of an Isotropic radiator, which is really a theoretical antenna that radiates power in all directions evenly. All directions meaning up, down and every degree of a circle around the radiator at all angles evenly. It's not an antenna that really exists except on paper as a reference. To achieve gain in an antenna, the elements are configured in such a way that the power that is radiated up and down is redirected more toward a flat plane horizontal to the center of the vertical radiator (vertical antenna). Since even basic quarter wave antenna's have some amount of gain over the reference, it's better to consider those as a reference point when trying to figure out performance gain. But it works like this. 3dB of gain, either from some type of amplifier or an antenna is going to effectively be a doubling of power. If you consider the 3 dB of gain against the reference antenna, the antenna in question will perform at a level as if the reference antenna had double the power feeding it. So an antenna with 0dB of gain will talk as far with 100 watts as an antenna with 3dB of gain will talk with 50 watts, as long as you are considering the antenna radiation pattern. Meaning since the antenna is taking radiation away from the higher and lower angles off the horizontal plane across the center of the antenna, it will talk farther across that plane, but you LOOSE coverage in the higher and lower angles of radiation. Yes, this is a difficult topic to really understand. And not having radiation pattern diagrams posted here make sit harder to see. All that being said. There is no 'limit' to antenna gain in GMRS. Part 90 licenses do have a maximum TX power and a maximum ERP. We luckily are not saddled with a max ERP. So we can run right up to the 50 watts of maximum power, and if we so desire to get totally crazy, we can legally put up a 20 foot dish and feed that dish with 30 dB of gain with our 50 watts of limited power and have 5000 watts of ERP. Now there are some safety issues that need addressed with that sort of ERP, and of course, a dish is gonna be pretty tight with the radiation pattern, but it's still technically legal to do it. As a side note to that. We are NOT allowed to operate with those antenna gain levels on the 467 interstitial frequencies and I don't believe we can do it on the 462 ones either. So bear that in mind when getting crazy with an antenna system.

Actually, one book, or set of books, that I would possibly recommend is the ARRL Handbook. Yes, there is FAR more information in that book than needed for a primer, but if someone with previous experience was to read through, all of the major parts of 'radio' would be there and you could figure out a list of chapters and pages to suggest to a new license holder to get them up and going. I would put the following chapters as must reads, in no specific order. SAFETY VHF/UHF antennas COAX Signal propagation in UHF FM radio 'technology' VHF/UHF equipment There is a LOT in the ARRL handbook. In fact, there is enough in the Handbook that my college electronics instructor used the ARRL Handbook as the textbook for the class. For those that aren't familiar, the book is probably the best compilation of electronics technology, communications theory and RF methodology in existence. It covers everything from the most basic explanation of AC and DC circuits, Ohms Law all the way to digital microprocessors. It covers RF techniques from 'DC to Daylight' starting with VLF at 136Khz clear through to Microwave technologies and wave guide design for 40Ghz. There is information on any and every sort of digital modulation method and of course AM/FM/SSB is covered in depth. Sure, it's WAY more than an entry level person would want to try to absorb all at once, but again, if someone were to put together a list of the specific materials to read, it then becomes a reference for furthering the persons knowledge going forward. This set of books and the ARRL Antenna Book are my goto reference for all things radio.

Gee, couldn't get anywhere finding someone dumb enough to petition the FCC for DMR or some other digital modulation format on GMRS , so you decide to bring up the question of the actual existence of the FCC. DO you actually work for a living or are you stuck in your house, just sitting there figuring out new ways to post stuff on the web to wind up the masses and cause trouble? I said this before, if YOU don't like the service, find a different one. Or go entertain yourself with freeband, pirating on commercial frequencies, or just put Zello on your cell phone and use that. It's become clear that you are not here to have a reasonable conversation about any topic that resembles reality and instead just post things that will stir up the best result. Welcome to the ignore list. You have joined a rare bunch that up to now only included OffroaderX. May the two of you find happiness in limbo.

Still didn't answer the question about why YOU don't bother to go petition the FCC about making a rule change allowing DMR on GMRS. And again, as myself and others have said in this thread. This is a dead horse being beaten again. This has been rehashed over and over again. No one is going to petition the FCC for the rule change, including members here who have actually successfully petitioned the FCC for rule changes. And the reason is simple. DMR on GMRS will cause nothing but problems for the current users. It's about as dumb as when the FCC decided to change CB radio from 23 channels to 40 channels making everyone's equipment obsolete when the change took effect. The actual part 95 radios that are in service will be unable to operate with DMR. Same issue exists for adding channels to GMRS or making GMRS narrow band. If you want to petition the FCC for a rule change, and get it to the point that it's open for public comment, we will certainly comment on the change. Until then, be happy with what you have, and if it doesn't suit your purposes use a different service. Because while your numbers are correct, they apply to DMR being effected by Analog signals. Not the effects of DMR on the ANALOG signals of the multitude of users out there currently using the service within the rules as they are now.

There is an 8 page discussion on this topic elsewhere on the board. It's the same dead horse with a different bridal. Here's a thought. Why don't YOU petition the FCC for a rule change allowing digital modulation on GMRS? And I have NO idea where you got the idea that DMR is somehow better suited to deal with analog signals than other analog signals. Any type of signal getting into a DMR receiver will raise the BER and cause artifacting and digitization of the audio. That's if it comes through at all. Public Safety is discouraged by the FCC from using any sort of DMR because of the issues with it not playing well with analog signals and the fact that the public safety frequencies were issued multiple times in an area, sometimes within the same county and the end users would just run different PL's to filter out the other users traffic. There is a requirement under part 90 that a user much first monitor the frequency in use to be sure that there isn't another user on it. That is what the MONITOR button is for, and why there is a 'Hub defeat's PL' that turns off the PL requirement on a mobile radio when you take the mike from the hanger. Now I don't believe that GMRS has such a requirement. It's also why there is a channel free and color code free setting in DMR radios. When using a DMR programmed channel it's suppose to be set for channel free if there is another user close enough that their licensed coverage area overlaps your coverage area. GMRS doesn't have 'licensed coverage area's. We are power limited but that's it, as long as your transmitter is 50 watt's or less, the sky's the limit on antenna height and antenna gain. Yes, if your tower is over 200 feet you have to have it registered and have obstruction lighting, but that's not a height limit, it's an additional requirement by the FAA not the FCC for towers exceeding a certain height. You ant DMR, go get a part 90 license, go get a ham license. DMR is prevalent in both of those services. It's not allowed on GMRS currently and I really don't see that ever changing.

Well, you need to explain 'other networks' Are you talking about networks other than the one associated with this site or are you referring to regional groups within this site / system? With the configuration of the software for connectivity to a specific system, only that system can be accessed with a specific configuration. The system (AllStarLink) that is used for linking requires the configuration to point to a specific set of servers that are for the system. User names, passwords, node numbers and other related stuff only has one entry. So connecting to 'multiple systems' while it MAY be possible, is not a supported configuration with this system that I am aware of. Explain what you are wanting to do, what specific issue you are having and you will be assisted if it's for THIS system. For configuration information to other systems, and you need to define 'systems'. We define systems as a group of NODES (individual repeaters) that are connected together either directly or via a State level HUB or possibly to one of the regional HUBS that are part of the overall system. Are you defining a system as a single or possibly a single group of repeaters, such as the MidWest group, or are you referring to a system level difference such as MYGMRS.com or USGMRS which is a different SYSTEM?

Yeah, If you take your mouse and hover over his name a box will pop up. Bottom right is a button 'ignore'. Just click that as many others have. It's a pretty common practice. He seems to be the self appointed court jester or something. It seems he likes to keep his post count higher than anyone else around here by nitpicking every little thing he can find. Other than that, he's a legend in his own mind with all things GMRS and even has a YouTube Channel to pass on his wicked smartness about hobby radio. Oh, and for some reason no one understands, and by his own admission, he is NOT a river in Italy that Romans can freely cross. Never really understood that one. But he openly states that in his YouTube persona. Welcome to the board.

Is there something else going on here?? Read the copied part of the post again. G R M S ???? really thought it was GMRS but the copied stuff keeps referring to it as GRMS. Not that you can link a part 90 freq to part 97 or any other service, but it just strikes me as odd that the incorrect(?) GRMS moniker shows up multiple times. As if the guy is trying to setup his own radio service.

That is a HUGE decision if you are going to any significant height. And the biggest issue is cost. Putting up a tower over 100 feet can easily exceed $50K in cost. And that could double depending on property value. Any sort of 'group effort' tower should be placed on a neutral site, and not at any one members location. Reason for this is simple. Legally it's THEIR tower. No matter how hard you lawyer that effort, it's on their property and locks it into them. And there is the need to figure out income if a tower of any significance is erected and a prospective tenant approaches the group / land owner for access. The land owner WILL want in on the income stream if a tower on his land is all of a sudden making 2 grand or more a month. And yes, depending on location and other factors is a reasonable number. BUT, do not expect a tenant on your tower as a method to pay for it. Another requirement is cost going forward. Tower sites have maintenance costs, taxes, utility costs and anything else a piece of real estate would have. And additional costs like obstruction lighting maintenance and registration that no other piece of real estate has. But, renting space from one of the large vertical real estate companies has it's own set of issues. Mainly that you would be hard pressed to get into an agreement of less than 5 years with them. And their contracts are iron clad. If you enter a contract with them, it doesn't matter if you are there 5 months, or 5 years. You are going to be on the hook for the 5 year term of the contract. The only plus to renting is you do have some way out at the point of the term of the contract ending. Keep in mind that this is hobby radio. Folks loose interest and ultimately there may come a time that no one is interested any more. With a rented space, you can hire a tower climber to remove your antenna's and such from a rented site and not extend the lease for another term. With an owned site, it is real property and would need to be transferred to another or razed (tower and building torn down) and the property sold. Which again, creates issues with the original group that funded the build. The way that the ownership was worked out will have repercussions on how the money from the sale of the real estate gets distributed. And those things need to be worked out prior to building a tower site that will be for a group. I understand this rat hole pretty well and can give you information on what needs to be done and how to do it, within reason.

I got mine in Dayton as well. Charger, used battery, antenna and the radio for $420. One of the guys with the local group had a couple of them and a couple different mission plans to stick in it. I found the Bluetooth programming function to be great as I don't yet have a programming cable. I also need to track down a KVL adapter as some of my personal radio stuff is encrypted. I did have one issue with dropping a mission plan in it that wasn't right. Radio wouldn't boot correctly. The three finger salute reset the radio and restoration of a known good mission plan got the radio running again. Being a Motorola guy, I was on the hunt for an APX for seemingly no good reason other than the desire to own one. I ended up with a 7000 that was VHF/ UHF-R1. Which is the most desirable option to get for frequency bands. I was never a big supporter of NAS on a carried radio and I have a legit system ID and radio for work (radio service tech) with direct access to a full system key so I can build any codeplug I want for 'scanning' and when ask what I am doing with a system radio I have a reason to have it. I mess with the Harris a bit, but I have found the accessories are stupid expensive. And taking into account I have access to second hand accessories at the office, it's sort of a no brainer to prefer the APX. I have one RSM for the Harris. I have at least a dozen RSM's including the 'commander' type with display and channel knob for the APX. Have the green XE RSM's, have a Pelitor headset and interface for the APX that is noise canceling. The noise canceling feature on the Pelitor is good enough I can have a phone conversation on the Bluetooth model I have connected to my phone from the gun range I am a member of while I am shooting. Of course batteries are not at all an issue as I go through the recycle bin and get out of date batteries. Some that have only been charged a few times and are fine, but out of date. Fire service doen't use out of date batteries. This is due to the safety rating for the batteries while in combustible environments and in fires. My radios are not used in life and death situations on a regular basis, so I am not effected by these things. I will say that the 'mission plan' design with the ability for the radio to have multiple 'code plugs' that are user accessible is a really handy feature for building travel configurations when you are out of area but not needing to have endless radio zones in a codeplug. Sure you can have multiple codeplugs saved in a laptop for the APX and program the radio as needed with them. But being able to store them in the radio, and switch them on the fly is much handier in my opinion. I will also say the programming software is a bit hard to navigate if you are accustom to other programming software. And in truth it's just a pain all around. But once you figure it out, it does it's job. Congrats on getting the radio, welcome to the Harris owners family and if you really like it a lot, there is a mobile version called the XG-100M. Basically the same radio in a mobile configuration with some added features. Might be something to look into.

FAA went nuts on any drone over .55 pounds. So basically anything past the little Walmart drones requires registration. Fines are crazy if you get caught unregistered. I don't know what happened that brought all this about, but they all but killed that hobby, and basically anything related to RC model flying.

And this is the reason the HAM radio repeaters are quiet. GMRS has in a way turned into HAM radio, going beyond what it was intended for. The original intent was for situations that you needed communications, but didn't want to go the full route of a commercial license on Itinerant frequencies or MURS. GMRS is a nationwide license (commercial frequencies outside SOME itinerant licenses are NOT nationwide) you can use with family, and other license holders. We of course have transitioned beyond that to rag chew when it's not being used for the original intent. Repeater linking is a lot of what makes that possible. I have 3 repeaters on the tower. One is the tower owners (725). It is open but all users are requested to use my unlinked repeater (675) for local comms unless the repeater is busy. Then there is the 600 that is linked. It gets a bunch of traffic. Some of it is local traffic for the link but much of it is from other repeaters on the system. The 675 see's maybe 3 hours of use a week and the 725 see's less than that. So area of coverage has a lot to do with how busy a repeater system will be. Stand alone repeaters in medium to low population densities are not going to have much traffic outside the system owners. Large multistate systems that cover multiple high density population centers (Chicago, Indy, Columbus, Milwaukee, and most of the state of Indiana and Illinois) will obviously be busy because there are more people in the coverage area so you have a higher possibility of people being licensed in the coverage area. You mentioned pre-arranged comm's. That's a NET in ham radio. And we do see traffic during nets on ham. But very little normal conversation. And in truth, everyone has a cell phone. Your wife, the kids, the neighbor down the street. So when you tell Jr to take a portable radio you get met with "Dad, I have a phone, I don't NEED this stupid thing" or better yet, try putting an antenna on the wives car. "That ugly shit is NOT going on MY car." Figure out how to get past that and you are getting somewhere. Otherwise, be happy that you have a hobby that you enjoy and hope it doesn't go away in your lifetime.

I just realized that the repeaters on the map site don't actually show the call sign of the repeater. I went looking for a repeater I am hearing from the tower but there is no way to search by call sign or even review by call sign looking at each repeater in Ohio. I was sort of surprised by this.

Oh I know about not being active any more with HAM. I was very active until I got a job doing commercial radio and it seemed I had all these ham friends that I had never met come out of the woodwork wanting to know about old equipment and what was done with it. Wanting me to look at their broken radios (for free) and all sorts of other stuff. Then I ran into the issues of offering to assist with building and maintaining infrastructure (ham repeater) and being told they were different and what I knew about commercial radio didn't apply to ham repeaters (while they were using Motorola repeaters that I serviced daily). That pushed me away from the service for a long time. I am slowly getting back to it and doing my own thing. The problem it created, is I now ONLY do my own thing. I help some folks, but those groups I had issue with are shut out. I refuse to do anything for them. The one group I even offered tower space and a backup repeater to. Completely free, their call sign and all on the machine and would only require a phone call to get it activated if their stuff failed. They balked about it, Said they would need access 24/7 to the site. ( There are two people having access like that, me and the site owner) when I said they would need to schedule, but their access was not needed as I would host it on my gear as a backup and they didn't need keys to the site they again balked and said no. So the tower their repeater is on will be coming down soon. They have no where to put their repeaters and have zero options to stay on the air once the tower is down. I see it as being NOT MY PROBLEM.

Yeah, there is this as well. And even if some GMRS Karen were to call the FCC, if you are on a shared GMRS / FRS frequency, and actually got a response from the call with the FCC inquiring what happened. You just tell them that the minor's all had FRS radios. At that point the situation goes away. I don't believe there is any age limitation on FRS since it's a FAMILY RADIO SERVICE by name. ANd of course no license is available. We as GMRS users can communicate with FRS users so you are good on all levels. And what radios the kids are actually carrying isn't going to be known by the FCC since they aren't going to be tracking through the woods looking for kids carrying APX8000 radios, I am thinking you are pretty safe. Truth is as you sit and look at it, the FCC sort of screwed up with putting FRS and GMRS on the same frequencies with regards to ID enforcement. If you are on a GMRS repeater, then it's pretty cut and dried. You are operating within the capacity of your GMRS license. Outside of that. Since there is no specific text in the regulations that state once you have a license that you are always operating within the scope of that license. That would apply as long as you were not operating any sort of base station at a higher power with an external antenna. FRS radios of course have no ability to have an external antenna, so be mindful of that. So the way the regulations read. If you are in possession of FRS radios and GMRS radios, no one has any idea what radio you were using when you were talking unless directly observed. So what did you use? Only for you to know and there are other laws on the books that apply to requirements of self incrimination. So there is that too. Further, and yeah, I am splitting hairs, but I don't know if there is a requirement for a specific radio to ID or if there is just a general requirement for an ID when it comes to family use. Meaning, can YOU ID for both stations during a conversation so that it's aired? I don't know, but it's completely possible, you would need to ask the FCC for clarification.

I agree with the expensive statement if he were to use off the shelf SCADA gear. It's not even cheap on ebay used. But, since you know the stuff well, you know that it's data packets that are almost spreadsheet simple. It's a 'sensor X value Y' sort of thing. And could be easily written into a combination Raspberry Pi / Arduino setup with both digital and analog I/O being monitored by the Arduino and fed to the Raspberry Pi via serial or USB then converted to the data packets via a conversion app and broadcast. The Pi could then also be programmed to receive packets off air and react to certain values or I/O inputs from the remotes. Including launching status messages via MDC. I did something sort of similar once with a CDM radio and some base logic. A CDM can be commanded to change channels via the rear accessory pins. It's 4 input pins and can select 16 channels. If you build a logic output to control those pins. Programming the radio channels to send individual MDC1200 status packets for each channel then changing the channels and keying the radio it lets you send 16 different messages. The commercial LMR license wouldn't be a requirement on this either. GMRS allows for some basic 'digital' signalling on the service. I don't know how much SCADA type data he would need to be moving around. But if he's writing the software to do this, it would be easier to use a known working solution and copy that instead of reinventing the wheel by writing his own system from scratch.

Went back and read the original post again. What you are also talking about beyond alerting is SCADA (google this) SCADA is a common radio system that is used in utility and industrial systems for monitoring and control of water, sewer, electric and a host of other applications. It's a bi-directional system that uses short data bursts to pass control information and data to and from remote sites and operates on established standards. It could be implemented along side the alerting that was discussed before with the correct squelch setting in a radio so that the datagrams were NOT audible in the subscriber radio unless the alert tones were sent opening the radio up. There are adjustments for the delay and duration of the datagrams being sent so it wasn't constantly busying the channel up with packets. This would certainly require your own repeater and the rules pertaining to using it on GMRS might need to be researched to verify it is legal. But if you are wanting to go this route, spending the money on your own LMR frequency (commercial frequency) wouldn't be a bad idea.

If the application is to do alerting to the radio, there are a couple methods to doing this that are straight forward and commonly used in public safety communications. First being Quick Call 2 in Motorola speak or two tone alerting. This is a method that two tones are transmitted over the air that the radios are pecifically looking for and can be programmed to react to. Think old school fire paging. Low tone, high tone, tweedle tweedle tweedle, and then some voice announcement. The radio when programmed correctly for this sort of alerting can remain silent until the tone group is received or be actively monitoring a channel and alert to the incoming message. The voice announcement would be computer generated, either through a text to speech engine where the alert notification is stripped of the pertinent information and run through the speech engine or conversely could be canned messages, pre-recorded WAV or MP3 files that are played over the air. Their selection of the message would be a function of the alerting engine. Issues with this are simple. The frequency of the tones are specific. They must be generated within about 2 Hz of the programmed values in the radios. And QCII tones are delineated to the tenth (0.X) of a hertz. So accuracy is a must. Interfaces can be constructed with a simple CM108 based sound card that will handle the audio generation and PTT function as well. Search CM108 All Star interface for more information. DTMF codes are also a possibility but may cause issues on repeaters that are owned by others since DTMF signalling can be used for repeater controller function changes over the air. If your DTMF tones turn off their repeater, they may well ban you from their machine all together. But Motorola and other commercial two way radios that are typically used for public safety will also recognize this type of alerting. MDC1200. MDC1200 is of course used for radio unit IDing, but it can also be used for Status messaging. The status programming in all radios that are receiving the messages must all match. Then once you have the status messages figured out you put them in radios that have displays. The display on the radio will show the preprogrammed text message on the screen. This method does NOT send texts. It has a set of 10 or so status messages that are set by the 10 or so MDC1200 data packets. You would need to program your software application to create those MDC1200 datagrams and feed them into the radio for transmission. Remember that you HAVE to identify your transmissions. So in addition to any voice or datagram announcement you have to have the transmitter ID. This can be done via a recording being played, a speech engine or Morse Code at 20 WPM. And remember that if toy are doing this across someone else's repeater, you need to get their permission. Don't simply do it and expect them to be happy with it. I have a local repeater that mirrors the coverage of my linked repeater. It's for local traffic only and I PERSONALLY wouldn't take issue with this on my machine, but if you're not in the Central Ohio area on my repeater, you need to seek out the owner of your local repeater and get their blessing. Moreover, I would offer them the programming information if they would like it so they can set their equipment to receive the alerts as well. Any of this is going to require radios that support the signalling methods talked about here. Your cheap import radios and standard part95 stuff will not work with any of this other than the straight voice announcement. Bear that in mind. CDM1250 and CDM1500 mobiles support these functions. THe 1250 and 1550 HT series portables do are well. The XPR series that are FULL DISPLAY support these functions will also work. If you want to spend more money the XTL radios do this as well.