WRKC935

There is nothing out there that is going to be GMRS and any other band or radio service. I understand what you are asking, but it's not something we can openly answer due to the fact that amateur radios are NOT type accepted to be used on GMRS. There are a number of satellite radios out there, new and used, that have all the bells and whistles needed for satellite work. But I will say this. Sat radios are set to be operated in the lower part of the UHF ham band. So you are looking at the radio being designed for 420-430 Mhz operating range. Sure it's worked to 449.9 but possibly not as well. GMRS repeater inputs are at 467Mhz. That would be 30 plus Mhz away. Not to mention that antenna's for satellite work are all high gain stuff that are also tuned for 420 to 440 Mhz range. The issue here is this, when you build an antenna with gain, vertical or a yagi, the available bandwidth of the antenna drops because the elements are interacting with one another and are designed to do so at a specific frequency range. You try pumping 467 Mhz through a yagi designed for 430 Mhz and you are going to have little to no gain, and your SWR is going to be through the roof. Your best bet is get the satellite radio that you have had your eye on and NOT worry about modding it to operate on GMRS and then get a GMRS specific or commercial radio and program it for GMRS operations and have two. That way you can monitor one while operating on the other. And the better satellite radios are going to have window filters in them that will block RF outside their designed operating bandwidth to boot to give them better performance on the range they are designed for. So there is that too.

And I can promise you that no amount of detailed explanation and math will convince them otherwise. The manufacture says it's 10 watts or whatever and they wouldn't lie. And the reason they get away with it is the same reason that lawnmower engines no longer have a horsepower rating. The lies finally caught up with them and they were required to calculate horsepower the standard way it's done and not any other way. So they took the HP ratings off the motor's and now just tell you what CC they are. That way it conveys the idea it's as powerful as a motorcycle of the same displacement. If a 400 CC motor will propel a motorcycle to 100MPH, then if you took a 400CC motor off a lawn mower and put it on a motorcycle, they infer that the motorcycle would still go 100MPH. Of course that's not the case, but it's inferred and never stated. RF power of 12 watts pertaining to a handheld is the power draw from the battery during transmit, or some other odd thing that isn't specific, but no one is requiring them to rate the radio's based on a standard watt meter into a 50 ohm dummy load. It could be their antenna has 6dB of gain no antenna, or a dummy load or some other standard that would never be accepted if came to light where the numbers came from. But a 3 watt radio with a 6db gain antenna would technically have 12 watts of ERP or effective radiated power. But again, what are they basing the power reading on. GMRS power is legally regulated at 50 watts as measured at the back of a transmitter with a standard watt meter. So there is no 'interpretation' of the rule or how the measurement is to be done. If an FCC agent comes and checks your power output, that is how it will be done. Calibrated meter with a cable jumper of a known amount of loss for the frequency being tested with. If you read in here enough, you will see people that will claim they are sending their' faulty' radio back because it doesn't do the full 50 watts it's advertised at. It's only doing 46 or 48 watts on their meter. They are not taking into account that cable loss between the meter and the radio. And yes, it's that much.

Well, I can explain why that's not true if you are willing to listen to the reason. If there is a grounded and an ungrounded object in the same area at roughly the same height, or even shorter in the case of the ungrounded object, that object will take the hit over the object that is grounded every time. Reason. electricity will always take the path of least resistance. That's pretty well established. But it applies to more than a good conductor VS a poor conductor. Meaning the electric will flow through a wire instead of a nylon rope every time. BUT. the path of least resistance is ALSO going to be through something that already has some induced voltage on it instead of something that has NO voltage on it with reference to ground. People continue to get in their head that a ground wire to a tower, antenna or whatever is there to take a full hit of a lightning strike and shunt it to ground. And that's just not the case. Grounding and bonding is done to dissipate static charges from objects and shunt those charges to ground. If you look on the roof of a tall building, you will see a grounding grid. It's connected to everything on the roof that's metal. That is then attached to the building steel and the steel is grounded to a ground ring in the ground outside the building. During a storm, from wind, there is static built up on different metal objects. If you are a mason jar guy and ran the StarDuster CB antenna's that were notorious for building up static, you would hear the charge flash over in the jar and possibly see the small arc when it would do it. That was because the center conductor on those antenna's was a floating element with no DC ground by design. The distance between the radials and the angle of the radials made those antenna's a giant high voltage capacitor. It would charge up in the wind, without a thunderstorm even, and then you would hear it discharge once the air gap could no longer offer enough resistance to the flow of voltage (voltage got too high) and the air would break down and there would be an arc. Static electricity, pure and simple. When your ungrounded tower is standing there in the wind, it is building a charge. IF that charge is a couple thousand volts, it's a more direct path because there is less voltage difference than there is directly to ground.

Grounding is the most argues topic I can think of for hobby radio. The discussion ranges from folks that are commercial radio guys that would see a HALO around the tower and building with ground rods every 10 feet and thousands of dollars in wire being buried in the ground to the glass jar guys that don't think any of that stuff is needed. And while I am a commercial radio guy and the commercial / public safety towers I work with have all that, I am a realist about what a guy is goig to be willing to spend and how much effort they are willing to put towards a grounding system. And the safety / electrical ground system is NOT an RF ground. It might be resonant on some RF frequencies, but certainly not all. And the halo's and legs are not ever cut to any resonant length on purpose. BUT, an RF grounding system for HF and a safety grounding system does need to be bonded together so that the voltage potential on both stay the same in all situations. But discussing the 'proper' way to ground, and all that typically turns into a mess. I offer what I know of it and leave it at that. Now, there was also a question of height and antenna's. And here's the low down on that. The numbers used for reference for calculating the 'realized gain' of the height of an antenna are a 6dB increase in signal for every time you double the antenna height. Now, That goes both ways. And applies ONLY when it's a doubling of height. So if your antenna is at 40 feet, and you move it to 50 feet, the change is not real noticeable. If your antenna is at 10 feet and you go to 40 feet, which would double the height TWICE 10 to 20 and 20 to 40, then it's gonna have a pronounced effect. When the FCC does calculations for radio station ERP, height is taken into account this way. ANd if you don't thing that's the case, let me remind you there are UHF repeaters that have a 2700 square mile footprint that are running 2 watts. Of course they are in low earth orbit attached to satellites, but those are 2 watt transmitters. Back to the increasing antenna height. If you are 15 feet in the air, and are above the roof tops, unless you can go to 60 feet, it's probably not worth bothering with because it's simply NOT gonna have that much effect on your signal level overall. There are some calculations for what your horizon is as well. That has to do with the fact the earth is curved, and RF at UHF goes in a straight line. As you increase your height, you increase the distance to the horizon. Sailors can tell you all about that. I just know it exists and I have run those numbers a couple times dealing with Microwave shots, but I don't remember how many feet it is UP to increase the horizon by 1 mile.

I use radio primarily as a carrier. I am a field service tech for a Motorola Service Shop. But that is NOT what I use GMRS for. I am also a ham radio license holder and operator, that's the 'secondary' hobby radio use as of late. For GMRS it's communications with others and right now the research and application of different linking and dispatch consoles to the radios. But I will say that I use GMRS and ham radio as a test bed for many parts of the technology that I work with professionally. Outside of that I use GMRS for communications for tower operations and site work, communications with family and for emergency situations. Due to hosting public safety radio at the tower site, everything at the site has that level of redundancy. So it will work when other less redundand systems will fail.

Been down there and noticed it wouldn't take much to have most of that area covered with a modest repeater antenna height. It's pretty flat of course being right there at the ocean. Are you a local sown there or are you vacationing? I was done last year for vacation and found it to be rather relaxing. But back to the radio thing. If someone could secure a spot on one of the light towers out on one of the piers at about 50 to 100 feet, and installed a DB-404 or 408 on it and then put a small cabinet on the pole at a height that was above reach unless someone had a ladder it would serve that area well. With a proper mount, the antenna would stay on the pole to the point the pole would need to fail to bring it down. But even a 50 foot antenna height would cover much of the OBX area. Now that would be the more populous area of OBX mind you. Once you get way down south, it's gonna need another repeater to extend the coverage down there. I seriously doubt the lighthouse would allow an antenna on the structure, but if something with a similar height could be located and an agreement secured, I am sure the repeater would be busy much of the time with licensed travelers. I certainly would use it. Hell, if someone was able to secure the space and take care of the ongoing cost I might be willing to provide some gear to get the project together. I would want an Internet connection for it so it could be linked.

Oh, I don't disagree. And even with ham, you can have a private repeater. I don't have issue with private repeaters at all. I have issue with a-holes getting on their private repeater and getting animated (cussing and such) when someone happens to get on said repeater without permission. If the owner gets on and explains that it's a private repeater, and he uses it for whatever, or it's a club / group machine for his buddies and him or whatever, I take no issue with that sort of thing. When the guy keys up and acts like a jerk, starts cussing and gets red about it, then yeah, he gets the treatment. But, when you are putting up a repeater, and find this sort of thing you tell the polite owner that you are putting up or have put up a repeater on another pair and direct the folks that accidentally get on his private repeater to just switch over to your repeater because it's open and tell him it's open to him too if he wants to.

Oh yeah, that's one for someone else to park a repeater with a coverage footprint that completely covers his coverage right on that frequency and leave it with a public PL and open access to all. And advertise it everywhere. Hell I would be almost motivated to hand out 'loaner' radios to anyone that had a license so they could use it. But I am like that.

Well is it 3.5dBi vs 5dBi or 3.5dBi vs 5Dbd or something else? The dBi gain number is based off an isotropic radiator. Which is an antenna that only exists in theory. It's a 'paper antenna' based on a radiation pattern that is a sphere. Equal signal radiation in all directions. Even a standard dipole will have gain over an isotropic radiator which is the dBd gain number. So in short they could be the same, or the 5dB antenna could actually be worse depending on what the gain number is based on. Now with that being said, Larsen typically has reasonable numbers attached to their products. And they are based on actual testing in a RF free chamber so the numbers are reasonably accurate. Some of the other 'no name' brands could be basing their gain on anything including a dummy load to pump up their gain numbers. One thing to understand here is what GAIN actually is. And what it's not. Amplifiers have active gain. You put 1 watt in and get 10 watts out. That's a 10dB gain number. See that there was no i, d or anything else after the dB. And dB is a measurement of CHANGE or difference between two things. In this case signal. Now power can be measured in watts, which is what everyone typically see's. But it can also be measured in dBm which is based on a 0dBm or 1milliwatt. So 30dBm is 1 watt, and 40dBm is 10 watts, which is a 10dB increase in signal.

It's funny you posted this as I was typing out the same thing. Great minds...

repost

I am in 100% agreement with you. But the OP is new to radio in general and I wasn't gonna go into all that. You certainly can do coverage mapping with a $40K service monitor and calibrated antenna for talk out. The service monitor I have will do it and put the plots on a map if you choose to put a map in it and setup the scale for it. The monitor does it with GPS location even. And then you can park the monitor at the receive site and do talk in testing. I did say that you would need the antenna you were going to use for the repeater at it's expected installed height. But we are talking about GMRS here. Not everyone is gonna do it at our level. There are a few of us on here, you included, that do all this stuff at public safety levels of design, install and support. We run battery plants or systems on our gear and the sites have generators, or other means of long term backup. And while i would like to see every repeater on a 200 foot tower, with miles of coverage, it's not a realistic idea. Some guys are gonna park an antenna on the eve of their roof and strap two mobiles together with a cheap eBay duplexer and run with it. And in some cases that is gonna be enough. But the guy putting a repeater on a shelf in his garage and supporting his antenna with an old TV tower or pipe mast isn't gonna have that luxury. This sort of testing can give him some idea how it will work and where it will work. Certainly NOT a high tech test. And using a cheap radio on the mobile / portable end is going to give a more realistic test as Joe Average isn't gonna go grab an APX 8000 off eBay to use to chat it up on a community repeater.

Testing 'repeater' coverage can be done with nothing more than a radio with a similar output level to the repeater you would be using and the antenna you would be using at it's installed height. Output signal is output signal. Doesn't matter if it's from a mobile, base or if low power a handheld. It's all RF and will work the same no matter what. So you could up up an antenna and do testing with a second person with a portable and /or a mobile to verify the expected coverage area. Have them drive to the furthest area you are wanting to communicate with and have them do air tests with you from both a portable and a mobile. Once you do a first run test, look at the distance and draw a circle with the radius being the distance from the center to the edge. Draw that circle on the map and then pick spots to test in that circle and continue to air test. Once you have that info, draw a bigger circle and test that. If it's all good increase the circle until it's not good. You will have two different radius circles that with indicate portable coverage and mobile coverage. That's how to test it without a bunch of other math, software and more technical stuff involved. Green dots for good test points, red dots for bad test points. Simple as that

Update to your request. I am ACTIVELY working on getting a shell script together that will run on an instance of Debian with ASL loaded on it to convert it to the mygmrs system and get the web management and all the rest working. Once this is done, it will be a simple as loading Debian, then loading ASL and copying the script to the machine and executing the script. I will have detailed instructions for doing this. Now there will still be some other configuration that you would need to complete. Things like setting the correct drivers to be loaded for the repeater / radio interface would need to be figured out by you. But I will say this is all based on AllStarLink that Hams have been using for years. There is a TON of online information on getting ASL setup and running, but there of course are several things that need to be done to make it work with GMRS.

Well, there are two types of interference. The first being interference FROM the vehicle / device / whatever that would interfere with the operation of a radio in close proximity to the device. This would typically be noise generated from the device / vehicle that would either show up in the receive of the radio or in come cases show up on the transmitted audio of the radio being used. Second type is the radio transmissions getting into the electronics of the device / vehicle and causing erratic operation or even damage to the electronic control systems of the device. Both are a possibility, but only one can possibly be harmful or expensive to deal with. That of course being the device reacting to the RF field generated by the radio. At handheld power levels, this is going to be very rare as the electronics on something like a mobility scooter would need to be tested for certain levels of RF exposure to be allowed to be sold as having those issues when going past a police car, fire truck, semi truck with a legal radio system or even a radio station could NOT put the user in danger of the loss of control of the scooter. The type of modulation used in the radio transmission can also effect the reaction of the equipment in question. FM signals typically present the lowest probability of causing issues due to the nature of the continuous signal level during a transmission. Other modes of transmission like DMR, CW, SSB and possibly AM could have effects on sensitive equipment that FM wouldn't bother. There is a LOT to all this, but I will say that since a mobility scooter is a 'medical device' the testing requirements on it are typically going to be rather high. A kids power scooter / E-bike / whatever may or may not have the same level of ability to deal with RF being near it.

Yes, I am running a Pi. Yes, there are 'pinch points' with doing so, and there are additional pinch points depending on the audio interface that you choose to use. Your best option, unless you are a heavy Linux user and have a very strong understanding of AllStarLink / HamVoIP then you are FAR better off to just use the image provided here on the forum and run that image on a Raspberry Pi. Will the software run on another platform? Short answer is yes. But you need to know the modifications for taking the ASL software and getting it talking to the right servers. And I will tell you this now. There is ZERO support for doing it from members and administration of this board / forum. NONE. There are a few of us that have attempted it and failed, and a few more than are doing it that don't talk about it. So either you are gonna KNOW how to do it, and make it happen or you are going to pull your hair out trying. And just because the image for a Pi is available that it's all just gonna load and run. I can tell you from experience in the last week that's NOT the case. I just reloaded the image on a Pi for the third or fourth time tonight attempting to get it running correctly. MODIFICATIONS First mod to the Pi image is putting in your node number and password into the correct places in the files on the image. These are the rpt.conf file and the iax.conf file. And for some reason I can't figure out the image is not pulling the updated rpt_extnodes_gmrs file from the main servers. Now this file is the list of all the nodes that is used as a sort of DNS 'hosts' file and a list of available nodes you can connect to. So that file does two things. BOTH are extremely important for getting things to work. If you don't have that file, and it's not updating every 10 minutes, then the software doesn't have any info on what nodes are out there for you to connect to. Second issue is the port configuration in your firewall. This too is sort of important if you are going to use the website to manage your node. It is where you can go and easily connect your node to the other nodes. Then there is the configuration of the audio interface for connecting your repeater to the software so you can actually get your repeater connected. This is another issue I am fighting. If you get the little repeater that is on the webstore, and the interface for it, and buy the image written to the memory card, then it's all configured for you. If you go any other route, you are on your own to figure it out. And while I did get the CM108 interface working correctly on the Pi, I had to refer to other documentation from teh ham radio world in order to get that going. And keep in mind that I am a professional commercial radio tech and have been for about 15 years. Prior to that I was in IT for 14 years and I fought the thing getting it up and running. So, if you don't know Linux and don't have experience with ASL / HAMVoIP it's going to be a serious learning curve unless you can find someone that is versed in these things.

YOu are going to want to put an antenna as high as possible for best performance. Since you have an HOA and I am going to assume that you have approached them for a variance on their by-laws and failed, the next and most reasonable option is an antenna inside the attic space. This will work reasonably well if you don't have a metal roof. Obviously a metal roof will significantly limit your ability to get RF through it. Another option is a small dish for TV. But be warned that you will need to research the federal regulations allowing for a small dish or off air antenna for folks that are in an HOA and their by-laws 'limit' that. Due to it being a path for emergency communications, the FCC has mandated small dish and off air antenna's be allowed in all instances. But you are going to need to get copies of those federal regulations in hand and present them to the HOA for review before doing anything else. They will no doubt what to verify it before making a ruling. And depending on the caliber of people running your HOA, they may or may NOT take well to being forced by anyone including the federal government to grant a variance. At the point you basically role up the rules like a newspaper and slap them in the face with it. They WILL crawl up your hind parts and file for a new address in there. They will watch you like a hawk, making sure to enforce EVERY other regulation and by-law they have on the books. And of course fine you as often as is possible until you sell out and move. But it's an option, so I figured I would mention it. After all the HOA isn't going to know what antenna is for what. But, first option is filing for a variance with them and seeing if you can put up something on an eve of the roof on a small mount.

But with regard to the bright lights from the gas station on the hill. If that lighting is creating a hazard to motorists, then you are looking at your state DOT or possibly NTSB for regulation and enforcement traffic issues.

Not even certain if you are actually asking if the FCC has enforcement over visible light, or if they can enforce a non-licensed RF user. It's all sort of gray here. Far as record of them going after non-licensed operators using RF spectrum, yep, they are called pirate radio station operators. They come up from time to time in the FM and AM broadcast band. The FCC does go after them, there is a history of this, and it continues to be the case. Now, specifically, lasers and aircraft. I think you have the wrong agency. I would be looking for the FAA not the FCC to be involved here. It's a danger to flight operations. You mentioned a tower or something that is generating output in the 400 to 700nm range. Well that's the 'visible light' spectrum. What sort of radiation is present? Is it a danger to flight operations? Is there a standing NOTAM for this area? Outdoor concert venue's are sometimes marked as no-fly zones at night due to visible light lasers being used during a performance. And there are other instances where they can't use lasers in outdoor venues, or they have a combination of NOTAM's and regulation for the maximum angle the lasers can be with regard to the horizon. Again, nothing to do with the FCC. All that is done through the FAA. There is a bit of crossover with the FCC and the FAA however. And that comes from tower obstruction lighting. The FAA sets the requirements for when a tower is required to be lit. First regulation is a structure above 199 feet in height. There are a very few instances where this requirement is waved, like being in the presence of other towers that are lit and taller than your structure, but for the vast majority, if you are 200 foot or higher, you have lights. There are pages of additional regulations involving obstruction lighting, but since this mostly effects radio towers, the FCC is the registration arm for those regulations. They issue the ASR numbers for the towers. So, if you could explain your issue, link to something posted you read about or give a better explanation of what it is you are talking about, that would help to figure out what's going on here.

as long as it works it's a good setup

Nevermind Couldn't delete

The easier way, depending on your repeater is to directly use batteries to power the repeater. Most repeaters are going to have a 12 or 24 volt power supply and many of them have a specific battery input for backup power. Since I don't know what specific repeater you are running, I can't give a specific answer to this. With a high power (100 watt) MTR2000 the power input is 24 volts and it's a connector right on the back of the repeater. It does require an external battery charger to keep the batteries up, typically these are an ARGUS charger. The low power (25 watt) version of the MTR is 12 volts, also requires an ARGUS charger for 12 volt power. If you have either of those I have chargers and power cords for them. Many kenwood repeaters have a battery hookup that will charge the backup batteries. Refer to the manual for your model. For those units that have neither, there is still hope. There are external modules that connect to a power supply, an battery and the load or repeater. These modules will power the repeater off the power supply and also allow the power supply to charge the batteries. When a power failure happens the load side just reverts to the input with power available, so there is no 'switchover' the unit just keeps going until power returns or the battery voltage drops below a certain value and then the unit drops the load to protect the batteries from being discharged too far. Yes, that's a thing. I have worked with this stuff a LOT. To the point my 5 ham and GMRS repeaters, the network routers and switches, and microwave links I use for Internet connectivity are all running off a large bank of batteries and NOT directly off 110 utility power. The utility comes into the battery charger that in these types of systems is called a rectifier. It powers the 48 volt distribution system and charges the batteries. This rectifier is rated for 260 amps. The batteries consist of 4 parallel strings of 105 amp hour 12 volt AGM batteries. The 48 volt power comes out of the distribution panels and goes to the equipment that requires 48 volts for operation. It also feeds a 48 volt to 24 volt converter that runs to a distribution panel and out to the repeaters and other 24 volt equipment. I am currently working on a 48 volt to 12 volt converter and distribution panel to replace the 75 amp supply and string of six 75 amp hour batteries that power the 12 volt equipment and base radios. I can currently go over 24 hours on battery before I need to get the generator going. But of course it's on a transfer switch and auto starts as soon as the power fails. SO I don't go to battery, except during the transition from utility to generator. I will then fail to battery once the generator fuel supply is expended. So I can go with no power for 72 hours before I need to fuel the generator. It's diesel and I have 8 cans sitting to go get fuel if I need to.

Well if you are looking to 'do your own thing' I will say this. It's not as hard as you might think, but there is some knowledge required. Since no one wants to reinvent the wheel so to speak, it's really going to be easier to use what others have done and adapt it to your own use. All that is being done with mygmrs and gmrslive linking is a 'rebranding' and repurposing of something called All Star Link or HAMVoIP. The basis of that entire system is a open source IP PBX called Asterisk. This is a office type phone system that someone wrote to replace his ageing PBX in his office and then decided to put the source code out in the open for others to use. Another gentleman wrote the 'rpt' part add on for Asterisk that created a manner to connect radios and repeaters into the PBX in what could be defined as a conference call. So when you link two repeaters or radio's together, it's like two phones, with one calling the other. THere is a bit more to it but that's the really basic way it can be described. When you connect a number of radios and repeaters together it's treated as a conference call at that point. The limitation is the amount of bandwidth available for the traffic being shipped from place to place and the processing power of the computer it's running on to process and ship the audio and telemetry (PTT and COR) from site to site to site. Now that's established. ASL or All Star Link is open source. You can go download the servers, hubs and all the manuals and set about modifying it to do what YOU want it to do. There are a couple things that you need to know. First is that the typical downloads are setup for non-computer people to use. So they are preconfigured for the databases of the HAM nodes out there and the info for them to connect together. All that needs to be removed or modified to make it work in YOUR specific application. And although there is no specific requirement for Internet access, linking sites together must be done with IP for this to work. Now you can use microwave links between towers that have LOS or Line Of Site between them and forego the Internet all together. But that might not be what you are desiring to do. But it's going to require someone with significant ASL and Asterisk experience to get this all going. It's not a plug and play solution. USING ANOTHER SYSTEM There is the possibility of using a preexisting system to do the linking where you just create nodes on the system for each repeater and then connect the nodes together. You do NOT want to create loops while doing this. So the easiest way is select one node to be the 'hub' and connect all your other repeaters to that node. Then you are allowing others to do the 'heavy lifting' on the back end so to speak and riding their system. SO this is a possibility. Now, I will say this. There is a way to go into the rpt config files and ONLY allow certain nodes to connect to your node. So it you want to like 5 repeaters together, with node numbers of 1 thru 5 and node 3 is the 'hub' you set repeaters 1,2,4 and 5 to only allow connection from node 3 and node 3 you limit to the other 4 node ID's. Then if I get to playing around with my node that's numbered 10 and I attempt to connect, I will get rejected because I am not in your allowed node list. By default, most systems update their node lists every 10 minutes, so that would need turned off or a different node list would need created that was static (not updated) and the rpt.conf file location would need modified to point to that list and and not the master list for the system. And there are other ways to go about that as well. If' it's a few repeaters, you can just set the system up to not connect to anything and then go back and individually allow the specific nodes you want in to have access. So there are a couple options that are out there and are NOT crazy expensive. If you want to look at third party hardware, I would advise you to look at the nx2-u units from JPS. I THINK that those can be configured for point to multipoint connectivity. which would fit into what you are talking about for a small system but those ain't cheap.

Motorola does have RAC for analog, but it's can be scanned. A better option is to spend the money and get a part 90 license then you have better options. First is you can run DMR (MOTOTRBO) and run a digital RAC and run basic encryption. It would also allow you TWO talk paths on the same frequency. Something that's no possible with analog radio. And the other thing with a part 90 commercial license is if others come in, outside of your family unit, they can use the license under your authority. You can 't grant a non-family member access if they don't have a GMRS license.. so day workers and laborers that are not family can't use the radios. The basic encryption will also keep your radio traffic semi-private. The 6 digit numeric RAC code will keep all but the most determined off the repeater. And it really sounds like it would be a better option for your specific application. The issue is that you are so limited with analog radio. And there is a greater limitation with the lack of encryption due to the regulations of GMRS. I know that someone brought up using a trunking controller that would look at radio ID's to grant or deny access to the system, but there again, I don't know the regulations specifically for GMRS would allow that. Would it work, sort of, until someone with a scanner that could display the LTR data was used to pick apart the information and then it's going to be screwed with if you are really expecting issues with others trying to gain access. I wouldn't typically go to these length's but you seem adamant in you post about it to the point you foresee issues before you even have equipment on the air. And in truth, if you haven't bought any equipment for this yet, now is the time to look at other options that better match your listed requirements. Personally, I am a P25 and AES encryption guy all the way. That will always work and NO ONE gets to listen in. But none of that fits within the rules governing GMRS.

I am thinking that the national HUB's are just what's established. That being said. For a statewide hub, or group hub, you have a couple options. First is to just use one of your NODES as the 'hub'. Link all the other repeaters in the group to that NODE and run it that way. Second option is to build out a Pi without the audio interface and attached repeater. You will need to register it as a repeater on the site and then assign it a node number once it's created. This could also act as a NODE, but I will warn you that you will get people requesting access to it thinking it's a repeater. I took mine 'down' off the site becasue of that. I kept getting requests for access since it displays as a repeater. People will not bother to read the listing first and verify what they are requesting access to. Now, if you are a Linux guru and a ASL guru, you can in theory download the image, and load it up on a Pi and then look at the changes to ASL and see what's been done to it and mimic those changes on a Debian instance with ASL loaded on it in a x64 platform. I have had no luck with that but I am not even versed on either Linux or ASL. So your mileage may vary. If you are knowledgeable on both, and get it working I would LOVE to know what the steps are to making that happen.