WRKC935

yeah, nevermind. Getting in line to kick the dead horse.

What are you asking for here? Full duplex operation where you can hear what YOU are saying on the repeater, or something else? I don't think you are gonna find an ANALOG UHF radio that will operate in full duplex. I know there were 800 radios that would do it, but the frequency split at 800 Mhz if 45Mhz. Not the 5Mhz we have on UHF. If you are meaning something else please clarify so we can better answer the question.

Not really. Couple reasons. First is it would have to be YOUR hub. And the MYGMRS, and midwest groups (mygmrs is the parent group) require a node to be connected to a repeater with reasonable coverage. Now, you said HUB and not NODE. a HUB is a master NODE that a number of other NODES connect to and then that hub is connected to other hubs. So with midwest as an example. Indiana has a HUB, Illinois has a HUB and several other states have a state wide HUB sometimes called Master Nodes, then those hubs are connected (or not) to the Midwest HUB (ID 169). So you what you are asking needs to be worded correctly as well. I can assure you that you will NOT be connecting into a MYGMRS HUB directly from your computer. Unless you establish your own group and stand up a hub, after getting permission from the system admin. So back to doing it with a NODE and not a HUB. Again, would need to be YOUR NODE, and NODES require a repeater be connected to them. So there is the issue of being allowed to do it. I can't speak to would you be allowed. My GUESS is no. But that is a guess. There are only a couple people on here that can grant that permission and I am NOT one of those people. We get questions like this a LOT and the answer I have is always the same. If you have coverage from another LINKED repeater in your area then use that provided access and don't worry about it. If you DON'T have access in your area, then figure out what sort of antenna you can get in the air and how much coverage footprint you could provide. If you don't know how to do that, ask us and we will help you figure it out. If no access exists, there are options. You can purchase a repeater and the needed equipment to fill the void. If you have a spot that will provide significant coverage to a large number of people someone in the group my assist with equipment to get an install done to serve the area. But we can't assist if you aren't asking for the help and giving us information on what you are wanting to do and what you can bring to the table.

It's all going to depend on how you are looking at it. As you mentioned 5 watts to 8 watts seems like a big increase. It is 30% more in fact. BUT, if you look at it in dBm or field strength at the receive site, then the story is told about how much it's NOT an increase. Since dB is logarithmic, and that's the easiest way by far to do the actual math (you ever figure path loss from watts to microvolts?) or adding antenna gain and coax loss in volts, watts or whatever before converting to dBm. And I know the 6dB rule for S-units. Yes, I quote it since many GMRS guys are EX-CBer's. But I also know what we use in the commercial field. And that is dBm for 12dB Sinad measurements, desense testing, receiver full quieting testing and repeater drop out and squelch opening tests. And the differences for those tests are all in either a dBm level, or a dB difference. Now that's established. Lets discuss a new XPR 5700 repeater. These are the current offering from Motorola for a midpower (50 watt) repeater. The standard point in analog wide band squelch opening for these is about -122dBm. Some are a bit hotter, but that's about the norm. And that is JUST opening the squelch. 12dB Sinad, which is about a 70 percent signal to noise ratio. Meaning a 1Kc tone imposed on the carrier with be 70% of the total received signal but STILL 30% noise, is going to occur at about -118dBm or so. Full quieting isn't there (no noise) until -105 to -95dBm. So the increase of LESS than 3dB is NOT going to improve a received signal to a great extent. And even a 6dB increase will not take a signal that is in the noise and bring it to the point it has full capture of the receiver and is full quieting. Once you are applying dB and dBm as a specific power level, things come more into focus. Especially when you are testing receiver performance. Oh, and so you have a reference 5 watts is equal to 36.9897dBm And 8 watts is equal to 39.0309dBm. And for further reference 50 watts is 46.9897dBm.

Purely a guess here. But it would make sense that occupational use would be limited to work activity for 8 or less hours a day, with a small percentage of actual transmit time in that 8 hour period. The difference being with 'hobby use' is the guy that in 10 minutes will time out the repeater 2 times and will be well on his way to doing it a third time as the ten minute time passes. You know, the gas bags that will get on the local ham repeater and seem to never shut up. And again, speculating, that the SAR numbers for the radio's rated wattage over time allows it to be used SPARINGLY throughout the work day, but being a gabtastic hammie would possibly exceed the SAR numbers for that power level and exceed the total exposure limit over time. OF course the sticker is there same as the sticker on your lawn mower to NOT put your fingers under the deck while the mower is running. And not to use a push mower as a hedge trimmer, and all the rest of the dumb stuff we have warning labels for. To LIMIT liability. And while the 'don't be a dumbass' stickers are not gonna keep you from getting sued, they do show some level of effort to inform the user that a danger COULD exist if the product is used in a way that doesn't conform with the design of the product.

The only repeater I have with one is the linked repeater. And it's a three tone setup. One tone is for Linked RX, second is for local receiver RX and the third tone is only heard when the repeater is NOT linked to another node or hub. I do this to inform users that they are both local if that's the case so they can switch to the local repeater and not tie up the system. The third tone I use to verify the system is linked up. I can key and ID and know if things are working right or not.

Actually this is one of the times that MDC is actually a really good thing. If you hear the MDC burst, then you know they unkeyed letting you key up and talk and POSSIBLY not be talking on someone else in the process. Yes, I too run my busy channel lockout on SOME repeaters. Unfortunately, I can't run it on the MIDWEST link due to the fact that when a discussion gets going the repeater may be transmitting for 5 or 10 minutes without a break. But my local repeaters that aren't linked, I do use it.

The SPECIFIC equipment that you need to check a duplexer is a tracking generator and spectrum analyzer. And the knowledge on how to run it. You can also use a VNA including those cheap little ones but they are not going to be as accurate as a better quality piece of equipment. Now there are other ways of doing it that don't involve as much expensive gear. A GOOD watt meter can get you close on the pass. You would place the watt meter in the line BEFORE the duplexer and then connect a dummy load (not an antenna) to the antenna port on the duplexer. Transmit and check your forward and reflected power. If you have more than 1 or 2 watts of reflect, the duplexer is probably not working or tuned right. Then place the watt meter between the duplexer and dummy load. You are looking for LESS than 2 dB of loss. So if the radio is doing 10 watts, expect 7 to 8 watts out. If you are getting 6 or less, then again there is an issue. Now for the RECEIVE side. Program the radio to transmit on the INPUT frequency of the repeater. Connect it to the HIGH side of the duplexer and do the same test. Again you are looking for 2dB or less of loss. At NO POINT should you try transmitting the wrong frequency through the duplexer. The reflect from doing so is higher than having an open coax and WILL blow the finals in the radio you are using to test. And you are also advised to turn the power down on the radio to 10 watts if your watt meter has a setting that it's close to full deflection at that power level. But the lowest setting creating the greatest deflection on the meter is the way to go with this. DON'T try tuning the duplexer with this test method. Doing it wrong will tune the notch across the transmit frequency and again, blow the radio.

JB-weld a mag mount to the top of the vehicle

Well, if there is 'FCC WORK REQUIRED' forget it. And DMR or NXDN is gonna tear up the analog guys. P25 will as well but not to the degree. If you are 'issued' area's of operation, then very little to any of the lower power, limited coverage stuff applies, unless it's in place and running all the time and used as needed. If you can't get the users to license for ham, that's a training / group requirement thing that needs enforced. You set down rules for training and other certifications and REQUIRE it to be a member. It they don't comply, let them be someone else's problem to deal with. Using the MONITOR button. No, program the radios to check for activity on the frequency BEFORE they transmit. Most radios will monitor for a carrier on the repeater output and bonk the user when they attempt to transmit. Second, the monitor button, that is a TRAINING ISSUE. You train for first aid and other skills to certify and then participate in group functions and activation. Train on radio operation. If they don't want to train, again, make them someone else's problem. I am gonna be as honest and frank as I can be right now. YOU HAVE ZERO OPTIONS There is NO OPTION to get others to operate in a proper manner. There is NO OPTION to get a system built that will support what you are trying to do. There is NO OPTION to get cooperation from the other groups to get this ironed out. And there is NO FUNDING to do it right if you can't even get people to take a damn ham test. Of course they will not want to train for anything else either, so why bother with them to begin with. SO, here is what YOU and YOUR group does. Follow what others have said here. Forget GMRS all together for communications during an activation and get an LMR pair and figure out a portable repeater on that pair. AND screw the rest of the clowns that don't want to fall in line and work together to get a communications plan together so these problems go away.

Not a rant. This is the solid truth and thank you for saying it. I have moved repeater pairs due to a pair being occupied I was not aware of when I put the gear on the air. And I put stuff up that covers several COUNTIES. Not just cities or townships. But I am willing to work with people and resolve interference issues. I am also very open about people using my repeaters because they DO cover several counties. Hell, I an in process of setting up meetings with 6 ARES (ham radio) groups to setup an MOU with all of them so they have reliable communications from county to county on ham because my coverage footprint is that big. But coordination of those frequencies is KEY to not causing interference with other repeater owners using those frequencies.

OK, I agree that for PERSONAL use, and non-public safety use it CAN be relied upon for life safety. Hell my repeaters are as stable and redundant as the public safety rack two rows over in the same building and they aren't on the battery plant right now since the rest of their system isn't either. So my stuff is actually better covered then theirs. But that being said. If you are a actual public safety organization with access to real public safety exclusive use repeater pairs and you are instead using GMRS AND having interference issues due to the number of repeaters on the air in your operational area, shame on you. Spend the money and do it right. And here's the real truth. License for GMRS is 35 bucks. EVERYTHING else being equal. If you have 20 members, that's 700 bucks in GMRS licenses. Which would pay for the coordination and license fee's for LMR. Or at least get REAL close. Pool the money, and again, do it right. Then put the thing on the air, in a BIG way and charge access to the other groups putting MOU's in place for how access gets handled, or just do your own thing on your own pair, away from everyone else. A UHF repeater is just that.. Programed for GMRS, or programmed for a Public safety freq or LMR freq. All the same stuff. And all the same cost. And again, if you are running some GMRS portables in a plastic box repeater for life safety level crap. Well we covered that. And here's the issue with GMRS. It's shared spectrum. Meaning everyone can be there with a license. And YOUR emergency traffic is no less important than their emergency traffic. But if you are interfering with each other then NO ONE's traffic gets passed. But for personal use.... yes, it can be more than good enough

I forgot to mention something. And this WILL draw the attention of the FCC and get new rules put into place. Long abut the time that a situation does occur that puts these guys in harms way and the repeaters are overloaded and a group can't communicate out on their repeater because of the others the FCC will step in. Not to help, but to create a ruling that bans the use of GMRS for these types of groups. It's gonna require a group getting up on a mountain somewhere and someone getting killed for it to happen but it will happen. GMRS is NOT for public safety and is NOT to be relied on for life and death communications. It's a shared resource that we are provided by the government for personal and family communications. Go read the rules and see where it says anything different. Using the service for SAR is stretching it and using it for fire fighting or other life safety activities is certainly not what it's for. Those activities are clearly meent for the public safety bands of the LMR allocations. And if the groups are accredited and registered, I am not sure that there is even a licensing fee for them to get frequencies. But there again, these are most likely self appointed groups that aren't serving any specific agency or jurisdiction.

Well, I am NOT going for the short answer. And this reminds me of something said about ham radio operators. I there were 2 ham operators in a city, that city would have 3 ham clubs so each of them belonged to a club that the other one didn't. That being said. I fully agree with what has already been said. Problem is that these groups are the self appointed types that have little to no outside support and do little to support government entities. Reason I say that is simple, if they were working FOR some agency, the agency would provide them the ability to communicate. If they have setup shop on GMRS, then they are one step removed from ham radio and wanted to go their own way and not deal with hams either. Which brings about the second possible cure that will never work due to mentality. And that is SHARED resources. One big repeater that multiple groups use for communications. And if you run a community repeater controller that is multi-PL enabled, then they don't even hear each other talking. We did this for YEARS in the LMR business. Put a few high profile repeaters up that were setup as community repeaters and sold air time on those repeaters. Not real common any more but it was effective. But we are back to the problem of getting people to SHARE. And that is where you are gonna get stuck. The third way to begin to deal with it is system design with limits on coverage area in mind. Directional antenna systems, down tilt, decreased power (which ALWAYS pisses people off when you mention it) and getting the system owners and users to spend money for real radio people to design and install their systems. Problem here is again money. Ham radio is by far the cheapiest way to communicate for SAR and similar groups. You are using repeaters that are typically owned by others, the license are cheap and the radios are just as cheap. But unless it's YOUR ham repeater, you can't have exclusive use of it. GMRS does get you a bit closer, has no test to pass and can be a cheap. But again, if it's not YOUR repeater, no exclusive use. So they spend as little as possible to put up as much repeater as they can so they have exclusive use of it. And I know that's how they treat it because if they were sharing use with other groups, we wouldn't be having this discussion. Actual designed and implemented systems that are tailored to cover a specific area are expensive. Not so much the hardware as the design of it. That requires knowledge that a typical GMRS operator frankly doesn't posses. And that's not a dig on GMRS operators,,, it's just a fact. So by the time you pay for all the design and increased cost for the antenna system you could have dropped 500 bucks and gotten a LMR license and been done with it. Then you have exclusive use of your own repeater pair and can do what ever you want. But they are too cheap to pony up the 500 bucks for coordination and a license fee. You are NOT gonna get more frequencies for GMRS. And license holders have equal access to the allocated frequencies. And contrary to popular belief, putting up a repeater with a different PL or DPL on the same frequency is NOT purposeful interference. By putting a different PL on it, you have shown effort to mitigate interference and you have just as much right to use that repeater pair as the other guy does. Now this of course requires that the other repeater is closed access. But at that point, you are left with no other choice. So letters to the FCC are pointless.

I actually know of at least one system that does this. Down in Tampa there is a GMRS repeater that The input frequency happens to be the same channel that some cruise ship uses for in dock operations and when they come in it tears up the repeater access since the tower is right on the water near the port. That repeater has two Input frequencies. The owner switches between the two receivers as needed to keep the simplex radio operations off the repeater when the ship is in port. Not sure if it's FRS or GMRS being used but I know it causes him problems and that is how it was dealt with.

OK, here's what is being misunderstood here. There was a time the the FCC issued repeater pairs to new GMRS license applicants. These were from the 8 repeater pairs laiid out in the rules pertaining to the service. You typically would get two pairs to use and this was to more or less act as 'coordination' for frequency use. That was stopped and all license holders had unrestricted access to ALL 8 pairs to be put into use or to be used to access other repeaters. Repeaters back then were more 'private use' that what we are doing now with the service where a few put up big repeater systems that the rest enjoy the coverage of. Some charge for that access and others don't. But the bigger point is that we all can use ALL the repeater pairs and WE as license holders are now responsible to do our own frequency coordination. Now that isn't a bad thing as long as both parties involved are willing to work with each other. At the point one or both parties decide to not be flexible, then it turns into a mess that the FCC will NOT get involved in unless the regulations on the books are broken. At that point the pull the license of the problem individual or individuals and the problem is again solved. Guessing this is the basis of what you are understanding with the statement you made. It's partly correct but not close to the truth. No big deal. We all are learning every day. And hope to keep learning.

Height helps always. However, realized gain due to height in dense urban area's is lower than it would be in a rural environment.

Yeah, it's sort of hard to run a 20 foot mast on a vehicle ANYWHERE. Trees, bridges, power and telephone lines that run across the road would all create problems. I have seen some masts that could be deployed at a camp site, but not moving down the road or through the woods. And this perceived gain would also apply more to suburban and rural locations more than urban or city locations. Reason being is the buildings and the attenuation they cause. A residential structure typically will be a 10dB attenuation of the signal both directions (TX and RX). Commercial structures depending on the building materials typically range from 20 to 30 plus dB of attenuation. The worst being metal and E-glass materials for blocking RF. And those numbers are from inside the building. If you are on the far side of it, and talking through the whole structure, it can be twice that. Height increase is not as effective in city and urban situations for this reason. There are a couple reasons for this, but that's a whole page of explanation I am not gonna get into at 7 AM

As a rough rule of thumb it is often said that doubling the height of an antenna will give a 6 dB increase in gain. Although this will depend upon the actual situation and a host of caveats, etc, studies have shown that it is generally not too far from the truth. This kind of goes hand in hand with what Marc is saying here. But of course there is a point of diminished return on investment. To go from 10 to 20 feet or 20 to 40 feet would be a good investment in getting your signal out there, but if you are at 300 feet, the cost alone to double that is going to be too high for the perceived gain you get from doing it. There are other factors in play here of course such as topography of the land around you, so consider this to be pretty close to correct over flat ground, but in hills and valleys your mileage will vary. But, as mentioned before by both Marc and myself, height is king when it comes to antenna's. And it will have a more dramatic effect on your signal than doubling your power.

Well, like I was saying. I was THINKING. which of course means I wasn't sure. So not sure where you came up with it being an ABSOLUTE STATEMENT. Only a thought. Speaking of thoughts, you should try it some time. I know getting in here, taking the words of others, twisting them in your mind to mean something different and then attempting to ridicule them based on your interpretation or what you THINK was said keeps you fairly busy. And it's ok,,, I know it takes a good amount of creativity or bad drugs to get your mind to twist that far. But what ever floats your boat man. As I have said before, if you are pointing this nonsense at me, and not someone else that might take it to heart, then I am fine with it. It keeps them from being bothered by the nonsense. I just go back and see what I actually said. Question WTF is he (you) on, and point out your continued failure to get anything out of me that could be truly seen as negative. So keep smiling, it's a beautiful day.

what, you were asking about Dayton Linked repeaters. If you are in Columbus, you should be able to hit the Johnstown600 fairly easy

Connersville 650 is the closest repeater to Dayton that's a linked machine. I don't believe that you can reach the Johnstown 600 but you are welcome to try. I know I can hear it on and off near Springfield from a mobile. If you have the height and the antenna get it a try. PL is listed on here. Next closest is Indy though. Not sure if you can make that or not. Be mindful of the PL in use on both repeaters. If you want to experiment try the Johnstown 675 repeater. It's not linked but has the same coverage footprint. If you can make that you will make the 600. I don't know what the PL is for Indy. Hoping it's not the same as mine. If you have a decent location for a repeater, let me know and we can look at getting a linked repeater in your area. Minimum of 100 foot of antenna height, Internet access. Little or no cost for access.

I don't think ANYONE was actually talking about repeaters on MURS. Michael needs something to comment on in every post he see's. If he can't find it he will try to make something up. We were discussing a different topic all together. Yes, we hijacked the thread. Talked about commercial radio stuff, not MURS. My advice Michael, go down to the Home Depot, Lowes or whatever home improvement center you prefer, get some lumber, hammer and nails. Drag it all home, and build a bridge, so you can GET OVER IT. If that is too much to handle. Go to the toy store, find Lincoln Logs. There were plans for a fine bridge in there. Knock yourself out. You can feel some level of accomplishment that you created something worthwhile.

That makes more sense. We just issue a request for frequencies for the site, go monitor what the coordinator gives us back as possibles and pick one. But we RARELY are building systems like that anymore. 95% of what we are doing is public safety on a state wide system, the other parts are repeater systems for small and medium business typically warehouses for coverage inside the fence, malls and stuff like that. I guess having a state wide system for public safety has made us lazy.

It's interesting to go back through a thread and see what you missed. Mark, you are charging 3K for licensing fees BEFORE the 500 for the coordinator. I guess we need to be charging WAY more for that. We just charge the 500 plus markup. Malls with 70 watts ERP. That is a failure of the vendor pure and simple. The ERP on the license is a NOT TO EXCEED amount of power. If they NEED to be running 70 ERP, then you configure the system to do that. If they only need 10 watts ERP then the vendor should be turning down the power to that level and doing range checks to see that the coverage meets the customer requirements and doesn't go any further. If you aren't doing that, you really should be. I come across a BUNCH of that chasing interference issues. Of course the problems arise when you attempt to talk to a frequency owner that is causing interference by running more than their legal ERP (happens a BUNCH) or they are excceding their needed coverage area. The first one is simple enough to deal with. If you can prove out the excessive power with a field strength vs distance calculation it all gets submitted to the FCC and they put a letter in the mail to the license holder of record. Vendors RARELY take into account the true ERP when they put up an antenna system. They will park a DB-420 in the air with 9 dBi of gain and have 40 feet of feed line feeding it with a 100 watt radio. Figuring for cable loss and duplexer loss they are at 70 watts to the base of the antenna and their ERP is actually 560 watts. Not taking into account HAAT gain. Which outside of broadcasting, NO ONE does and is NOT required due to antenna height being on the license. Antenna's Rarely are above the listed max height the license, but that does happen at times as well. The other thing no one mentioned here is the radio enthusiasts that have 110 watt radios that they wanted to fill with frequencies. And the MURS, FRS, GMRS, and Itinerant frequencies ALL go in them at full power. Can't tel you the number of high power Spectra and Astro Spectra radio's I have seen that had that stuff in them programmed at 100 watts. Connected to a high gain HAM antenna in their vehicles. I don't see much of that from vendors, it's typically ham's and other radio guys that are doing it. And really don't understand they can't or don't care. They will print off a frequency chart of Itinerant and license-less frequencies and go to town with putting them in their radios.