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Showing content with the highest reputation on 06/05/21 in all areas

  1. Coverage maps are hard because GMRS is a line-of-sight communications service. There will be spots where you can be less than 5 miles away from a hilltop repeater and not be able to open its squelch, and there are spots where you're scratchy into a repeater that's 100 miles away. Coverage maps can be very reliable tools if both the mobile station and repeater's powers, losses, and thresholds are properly entered; the correct antenna patterns and heights are used; proper statistical losses are taken into account; and an effort is taken to ensure the topography in the mapping software matches real topography. In my experience, none or very few of these tasks are done when generating a coverage map. Real coverage tends to be much less than the modeled coverage, typically because statistical loss has a huge effect (mobile coverage requires staying above the signal threshold more than n% of the time (I usually model at 70% or 87% depending on band), while spot coverage (often used by default) assumes you're standing still in the peak of a fluttery signal), your antenna (especially if portable) probably has less net gain than whatever mobile station the map-maker simulated coverage with, site noise is a very real thing that will reduce repeater sensitivity, repeater owners may not realize that they are using a directional antenna or tower mounting position, and not many repeater owners are willing to admit that it's possible to have 4 dB of loss between the transmitter and the antenna. Repeater owners and users also like to see good coverage come out of the simulations, regardless of actual coverage, so there's even incentive for misleading coverage maps. So, there's a lot of ways to alter the coverage depicted on a coverage map, and there's so much room for variation (about 25 dB worth) that it's not possible to make repeater-to-repeater comparisons unless the same person made all the maps with correct information. And unfortunately, it isn't possible for MyGMRS to generate the coverage maps accurately, as there's a lot of room for variation with repeater hardware (dinky little solar power repeater running 5W into a counterfeit Nagoya antenna duct-taped to a chain-link fence, vs. someone running 50 watts into a solid duplexer with preamplified receive and a 10 dBd gain antenna) and repeater locations on the map are not always accurate for various reasons. So, we just generalize coverage into a circle around the repeater's map position. It's easier for a repeater owner to estimate how far their repeater can cover towards population centers than for the owner to generate coverage maps that are correctly parameterized. It's easier for MyGMRS to handle circular coverage patterns than the rasterized geo-referenced images outputted by coverage mapping software. Radio coverage in general should be taken with a heaping handful of salt due to the wide degrees of variability that are out there, and instead test your actual coverage with a second radio or a friend. And if you know or learn mapping software such as Radio Mobile, you can even make your own coverage maps for estimation if there's enough information about a repeater's location in its MyGMRS listing.
    2 points
  2. I have discovered Chick fil A in my town uses FRS handhelds with their drive thru coordination. I have been sitting in line before listening to them say who goes where. Might try giving myself a shortcut and a free frosted coffee next time
    2 points
  3. Yeah, and it’d be relatively simple if they were simplex only. They could make it even easier if they used those DTR 900 MHz units if they want no license for simplex only, I’m sure any number of dealers would be willing to sell a pallet of those to them. Lots of good options out there really
    1 point
  4. I know... A major university with way deeper pockets then most. They could justify and spend $50,000 on a system of their own and no one would bat an eye..
    1 point
  5. Personally (and I emphasize that) I’d call their IT director and tell them to man up and apply for a Part 90 license but that’s just me
    1 point
  6. I bought some from Amazon. I thought who knows might prove useful on other projects in the future, the metric 2.5 x 5 worked well. To be honest at first I thought it was just my mistake, so that is why I did my own repair. I later found out there is a problem with the original threads have some glue or paint in them. Also normally it would not have been an issue since I rarely used belt clips, but the holder in the vehicles needs it.
    1 point
  7. I also snapped off a screw on one of my ext batteries, tried to drill it out, but that was not working for me, so just drove out the the brass nut insert with a punch and replaced it with a new one. Grabed a new screw and all is good. After I did this, BSR sent out a notice about a problem with the screw inserts, and a guide to help solve the issue, apparently Wouxun is aware of the problem and is working to fix it
    1 point
  8. JLeikhim

    More RT97

    I would rather be obsessive about maximizing reject notch as T-R isolation is the main goal of a duplexer. If you can keep the insertion loss in spec and not excessive, fine, but insertion loss is an expected feature of a duplexer. There is no free lunch.
    1 point
  9. Okay, I’ll bite here. I own a repeater (Rugged 575) in Naperville, IL at 250’. It’s on a commercial site with other UHF and VHF radio systems as well. Not only have I spent nearly 5 figures setting this up correctly but I monitor it as if it was my baby, cuz, you know, it *IS* my baby. I built it with no financial help from anyone else. Of course there was other help I received by LOTS of other commercial repeater owners (Those of you that are reading know who you are) as I’ve come a long way in the last year and some change here. I have my repeater system set up for several different private family usage cases and I also have a tone for public which I closely monitor as well and others that are out there do use it. As a repeater owner I’m super happy to turn my radio on and hear other people using it. As a matter of fact just yesterday some other licensed GMRS users were using my repeater and I needed to use it with my wife as I was at the grocery store and I broke in and said, “hang tight guys, I need to talk to my wife for a minute. I’ll let you know when I’m done”. Anyways, I flipped to our tone, talked with her about the particulars, then went back to the public side and said “Carry on guys! Glad to hear you out there using the machine”. That being said, mine is set to “Ask permission” as well because as others have mentioned, I want to know who is using it to verify their license and location because it’s my system and it’s my responsibility to make sure it’s up to par on the commercial shared site. I have sent an email back to EVERY! SINGLE! PERSON! As well welcoming them with the tones to use it! I haven’t had the need (yet) to ever reject anyone from using my repeater but I still keep a tab on who has access to it as in my opinion, it’s my responsibility to do so. Not only that, but I have my custom verbiage I send back with every request as well stating that this is a family repeater as well and to aid to traffic on the other PL tone. Heck, I’ll paste what I send you can see where we are coming from with this: “The tone for my repeater is XXXX (left blank) (N – normal, not inverted). When you key up for the first time please identify yourself using your call sign and call for ROB. I am regulating who is using my repeater as it is being used for my family as well. I have received an exceeding amount of requests to use my repeater. Originally this was set up for family only use but seeing as the range is far better than expected, I have opened it up on an as-requested basis to any licensed GMRS operator. PLEASE NOTE: ALL TRAFFIC MUST YIELD TO MY FAMILY. The tone for public use is different than family so if you see your radio lighting up receiving on 462.575 but no audio is coming through on your radio it's because my family is talking so please do not key up until that traffic has cleared. Thanks and I hope to hear you on the air!” That being said, sometimes users don’t understand what a multi-table is either so I will say this too: When you first use a new repeater you should ALWAYS call out for a radio check IMO because you don’t know how that repeater is set up and should NEVER assume anything! I was in Iowa once and I made contact to the owner on the traveler tone (I was travelling) and he told me that it’s linked to another repeater in California! NONE of this information was posted on mygmrs.com and upon googling I couldn’t even find it either!!! It was good to know that I was keying multiple machines too and me and the owner had a nice long 30 minute conversation and he was glad I keyed up and shouted out! To sum up further as a repeater owner: *MOST*, but not *ALL* repeater owners don’t mind you using their machine I’ve found. Now I’m in the Midwest mind you, so again, no assumptions would be made for other machines that I’ve never used, but around here most repeater owners are very happy to have you on their machine and it brings a great smile to their face to know that they are serving the public with a reliable communication system and growing the hobby as well! Remember that GMRS isn’t HAM and HAM isn’t GMRS. A *LOT* of people out there want GMRS for family use under one license and that’s what I’m doing but I’ve decided to open it up to the public as well as the coverage is fairly decent. I looked at getting a business license and could have easily done it too but I like the idea of being able to chat with my family *AND* other GMRS users so here we are! Thanks!
    1 point
  10. At the risk of sounding arrogant. I've said this before and will re post it again
    1 point
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