WRKC935

Be aware that the 'coverage map' on the mygmrs.com web site is NOT a generated heat map like the one displayed above. It's a simple circle around the TX site that gives an average expected coverage based on path loss across flat ground. Meaning, if you look at the map for Johnstown675 on here, it ain't right, or even close, depending on the direction you are from the repeater. The map of my repeater (WRKC935 / Johnstown675) shows coverage in Pataskala, Newark, downtown Columbus, and several other area's that I have no coverage in. Those coverage holes are caused by the topography of the area. Case in point is the Granville ridge. I have good coverage on 161 / St Rt16 going east right up to the point you cross where Granville is and St Rt 16 comes in from Pataskala. After that the coverage stops for a time and then picks back up closer to Newark and continues out to St Rd 146 and further. Same thing happens going West, Works great until Little Turtle exit off 161. Then falls off getting on the 270 outer belt. But if you continue west on 161 it's good most of the way to St Rt 23 (High Street) in Worthington. Then it falls off until you get west of Columbus and then picks up until you are out to St Rt56 on I-70. I have talked from the Honda plant Northwest of Marysville, From Mechanicsburg, and from London (42 / I-70 ) from a portable. So my point is that you should NOT have an expectation that all area's in the green circle are going to work based on the mygmrs.com maps. And you are further limited due to using a handheld radio. The power is lower and the antenna's do not have the gain that a mobile or a base station would have. I say all this based on the programming that you have in your radio you posted the codeplug of. If you have the Pataskala repeater programmed, I know that machine has limited coverage in that area due to antenna height. If you are in the Pataskala area, and are having coverage issues getting into the Johnstown repeater, that's why you are having issues. I can't talk to it from Pataskala with a 50 watt mobile. The coverage just isn't there.

First thing is NOT giving them what they want, which is to be recognized and acknowledged for what they are doing. If at all possible, when the show up and there is a conversation going on, continue the conversation without commenting on the problem. Keep right on talking. If one of you gets covered up by the guy, DO NOT directly say that. Claim it's noise, or something else. If possible have a conversation going on a different channel so that it seems transparent. But DON'T say anything that gives them recognition. That is what they want. If you clear the frequency, again the person 'wins' by default. Don't let that happen. If needs be, get several other people into the conversation. Get a conference call going on telephones so everyone knows whats being said. And just keep talking like the person isn't even there. This will frustrate them the most. If they aren't having any effect, they will go find someone else to screw with. Make sure when they get on initially, ask them to REPEAT their call sign. Act like it's just another conversation. Act like they are having sign issues if you do this. Tell them they aren't making the repeater very well and advise them to try again when they get closer. Mention that they might want a better antenna. This is regardless of how good their signal is. Full quieting or not. THey are weak and barely making the repeater. But address them the same as you would anyone else that had a poor signal and them tell them to give you a call once they get closer. Throw your call and wait. That typically will confuse them and again cause them to be frustrated. I can't explain the mentality of folks that do this. And I use to do it all the time to certain individuals on CB because they had it coming. But to take time out of your day to just be an asshole. I don't follow that thought process, and I even identify as an offensive asshole, so I speak from some level of experience here. But DON'T give them ANY level of satisfaction if you can help it. If you aren't showing any level of frustration with them, they will be more frustrated than you are. They are looking for a captive audience. Don't be one.

While I disagree with it needing to be done by 'someone with proper knowledge and equipment' the nano VNA is fine for a NOTCH duplexer, in my opinion, that's the opinion of a guy that's been donig this for 15 years professionally and over 20 years in general. The little flatpack notch setups aren't going to be tight enough that if they are only close they will not be close enough. And there are tests that can be done to ensure they are at least that close. I have tuned them with nothing more than a radio, attenuator, RF signal meter and a bit of know how. And when I put them on a regular VNA they were dead on. Biggest concern is does the VNA output the frequency it says on the display. Easy test is put a frequency in it that you have a receiver for and verify it can be heard in the receiver. If you can hear it as a carrier, then it's on frequency enough to tune a flatpack. If you decide to take it on yourself, you need to know a few things. First is the open port on the fatpack needs to be connected to a dummy load. If it's not terminated, ti's not going to tune up right. Second is how you actually move the notch. Guys without any experience will just start cranking on whatever cavity they feel the need to and NOT move a little at a time. Once you move one cavity off far enough the notch in that cavity will disappear. Once that happens, it's a PITA to figure out. So make your changes up or down about a half turn at a time and do ALL three cavities with each step move. You will want to set your VNA with a wide frequency range to start. Once you are close, then you drop the bandwidth down to 1 Mhz and finally 500Khz to walk it in all the way. Remember that you are notching the TX out of the high side (receive side) and the RX out of the low side (transmit side). They should be marked high and low. So follow that and you will be fine. DO NOT however attempt to tune one the way I talked about before with just using a radio, attenuator and RF meter. I have tuned hurdreds of duplexers, built up combiner networks from parts, learned all the math and crap that goes with doing that. It's not stuff for a beginner to attempt.

So are they using an MDC control list, or a RAC (repeater access code) to open the repeater? Moto did support those on some of their repeaters. I am not so much interested in locking people out of my repeater at present, but If I could figure out an MDC switch that would turn on such a filter switching the repeater to 'private use' when needed that might be something.

No idea, But figuring that you are reading the labels of the crap you have in your medicine cabinet for daily consumption, you would be far better equip and experienced to answer those questions. But from Googling the names of the medications, and the fact you brought them up. Well it does explain a few things. Guess you subscribe to a statement a friend once made to me. Better living tomorrow through the pharmacological discoveries of today. So just remember to stay on your meds and we will all be just fine.

Hit a repeater at 25 miles with .1 watt? Yeah, it's not hard. Several ways to do it. First is vertical height, if you get the radio in the air far enough it's not hard. Aircraft will do it in any situation. Beyond that, two tall hills over a valley would work as well. Issue is to have unobstructed line of site. Second is antenna gain. Lots of it. Toss up a 12 foot dish that you can pull close to 30dB of forward gain. Same way I do it with 23dBm (200 milliwatts) for 23 miles at 4.9Ghz. Of course path loss at 4.9 is WAY higher at that distance than 460 Mhz. At 460 the path loss is 117dB. At 4.9Ghz it's 137dB. SO 20 dB more. You have to remember that a repeater, or at least one with reasonable coverage is going to have vertical height already. Repeaters with antenna's at 50 or 100 feet don't talk 25 miles period. The curvature of the earth makes the line of site horizon 14 miles for a 100 foot high antenna. Beyond that you need to increase height to maintain LOS.

Count for what?

Set your Repeater tuning steps to 25 as well.

GRID DOWN!!!!!! GRID DOWN!!!!!

How about I prove you RIGHT. The FCC has clearly said several places in CFR 47 that you can NOT operate a radio on multiple services. So no radio an legally operate on GMRS and HAM, MURS and HAM, GMRS and MURS or part 90 and any other service. So yeah, they don't exist. BUT, both MURS and GMRS are cut out of the part 90 frequency allocation. So an antenna like this can and does exist for dual band commercial radios like those offered by Motorola, Harris and Kenwood. But, and I have said this here before, those manufactures spend a good deal of money designing their radios and accessories, including the antenna's to have the greatest performance possible. Taking the factory antenna off a 10 thousand dollar radio, and replacing it with one of these may or may NOT give you a performance increase.

No, and there is a reason for that. The GMRS service is not meant to be used for that type of business communications. If you are a 501c then you are a business. A non-profit, but a business anyway. And while it gets used all the time, FRS is the same way. Not for business use. It's right there in the name FAMILY radio service. Not crane operator plumber electrician and church radio service. No one seems to pay attention to that, they just go buy some WalMart radios and use it for whatever they want. I would venture to say that there are more illegal FRS radio operations out there than guys with CB amps, even in the hey day of CB. MURS is what was created for business use with a cheap license. Of course, no one bothers with that either. But those radios cost more so they just keep buying FRS radios and using them. If you are a business, you need a business radio license and the proper equipment for that license. Not trying to misuse another radio service that is clearly NOT for non-family businesses. IF you were all family, and have a business, then it's legal, as long as only family members are on the radio. Outside of that, you need a part 90 license and part 90 radios.

Well, the first two apply to GMRS. THe third one is for HF (2 to 30 Mhz) operations and not suitable for GMRS work. So we will start with the 'roll up antenna kit' This is the same design as the Ed Fong, and other similar antenna's. If you search around on Google, looking for 'twinlead J-pole antenna' they will pop up all over the place. There is nothing special about them really. And they are a KIT. Meaning that you get to solder them together. If you are comfortable with that, they are a usable antenna and will work well in the right conditions. THe one from DX Engineering. They tend to never sell junk. If they carry it, it's usable. No idea on actual performance, but certainly better than the stock antenna's that came with your radio if it's a cheap import. If you are running around with a Motorola radio, I don't know what you might gain. Mot puts a lot of effort in to their stuff, and so do the other 'big name' commercial radio companies. And in truth, if there was something better for their radios, they would be selling them too.

OK, been meaning to explain this and this is a good time. The commercial guys here will all tell you there are three tests that we perform when installing a new repeater system out in the field. First test is 12dB sinad with the service monitor connected to the duplexer wit no antenna. Second test is for something called isolation. We drop the input signal down to where the repeater squelches, or stops transmitting and then increase the signal slowly until the receiver just opens back up. What we then look for is the repeater to drop again when the transmitter comes up and then drop back out. If the duplexer isn't tuned correctly, the repeater will 'ping pong' up and down because the TX frequency is getting into the receiver and deafening it to some degree. If it does start to ping pong, we increase the signal level in in TENTH's of a dBm until it stops. At that point, we usually stop the testing, touch up the duplexer tuning and run through all the tests again. The last test is antenna desense. An isolation Tee is connected to the duplexer antenna port and a dummy load is then connected to the output. The tap port has signal injected on it to the point the receiver opens and the signal level is noted. Then the signal is removed, and the dummy load is unhooked and the antenna is connected. The signal is injected again on the tap and increased to the point that the receiver opens again. The difference in the required signal level is the antenna desense for that antenna and repeater system at that site. Now, here's how that applies to what YOU are seeing. With the 12dB Sinad test, you need to understand what that measurement is. That being a ratio of signal to noise in the receiver. Here's a good explanation. https://en.wikipedia.org/wiki/SINAD But it's NOT the minimum signal level that the repeater can hear and open up. That is actually the LAST test (antenna desense) where the signal level is just above the noise floor enough for the receiver to recognize it and hear the PL /DPL. On a repeater running CSQ, the level is going to be lower, because it doesn't need to hear the tone above the noise, just the RF. These readings are gonna be 6 to 12 dB different in their levels. And the basis of where I make the statements about needing to be able to increase signal level a BUNCH to get a noisy signal to be full quieting. It's not a watt or two, unless you are only running 1 watt or less to begin with. That's based on using dB and specifically dBm numbers for power output in place of watts. An example is 30dBm is 1 watt, 33 dBm is 2 watts, 36dBm is 4 watts. on the upper end, 50dbm is 100 watts and 53dBm is 200 watts. So when you look at it that way, and start realizing that to go from just opening a repeater receiver at -119dBm to 12 dB SINAD at -110dBm or so, that 9dB signal level change is HUGE in the percentage of power change when you convert it back to watts. And the best part is you can calculate all this if you have the information about the equipment in play. You need the antenna model (so you know the gain) the coax type and length (to calculate the cable loss) the number and type of jumpers (again cable loss) the duplexer model (insertion loss). Then you need YOUR power level in watts (converted to dBm) and your antenna system numbers as well. The last part is the distance between the antenna's to calculate something called PATH LOSS. With all that you can calculate what the actual signal is at the repeater input from your radio transmitter from miles away. And yes, I have tested this and found that it's accurate within a dB or two. The difference is from signals that bounce off other things and arrive out of phase to the antenna and cancel put part of the signal. This is called Rayleigh effect. (Again, go look it up, NOT typing it all out) but that also explains sitting in traffic and the repeater fading out. Moving 2 feet and the repeater signal coming back.

Welcome to the confusing task of programming Motorola Radios

I have used other 'stubby' antenna's. Mostly for Motorola radios, but the antenna really don't care what radio it's attached to. Stubby's are fine if they will put out enough signal and receive enough signal to function in the application you are trying to use them for. If you are using a repeater that you are already noisy into with a standard antenna, you aren't gonna have much luck with a stubby. If you have a good signal, the repeater is close, or the other radio you are talking to simplex is close, then again, not an issue. You're not going to bounce signals off the moon with a stubby antenna. But you aren't gonna carry around a 20 foot dish to talk simplex with that would bounce signals off the moon when powered with an HT either.