wbjohnston

I believe any antenna height regarding GMRS was rescinded after the 2017 revisions. Apparently there is a restriction that the FCC requires one to register height above 200’ from surrounding structures/terrain (not actually sure about that but the word registration is the key thing here) and of course there’s restrictions near an airport. Not withstanding HOAs can have very strict rules, but they’re being challenged. I think any of the break in the rules the FCC can take action usually in the firm of a letter that asked for compliance but historically, even after complaints, they rarely take any action, and usually start with a letter asking for your compliance. Unless it’s a significant interference or hazard, certainly if one is causing issues with emergency comms or aviation.

That’s the bottom line. We are sharing a resource and just because you can dominate a huge footprint in coverage seems selfish and plain egocentric. Given you likely have some latitude to improve your coverage to obtain a realistic goal the by all means go for it if pocketbook is accommodating. Unfortunately, there is no “frequency coordination“ for GMRS as there is for amateur radio bands. Fortunately, the FCC does not put restrictions on antenna height, the power that actually reaches the antenna after gains/losses, or the size of your footprint coverage. The FCC rules state that you have to work it out amongst yourselves if you’re causing interference (frequency coordination). I was running into the problem that any increase in coverage came with increase potential of interfering with other systems and therefore decided my current goal of coverage was adequate. Some guys gobble up as much coverage that is physically and financially possible but then cut anyone else out for using that pair of repeater channels. There is no way of controlling that given current FCC rules and many of us hope that there never is. Get respected frequency coordination groups going like Hams have to help sort things out fairly without stricter rules/laws. 710 you have the right attitude “…see if it covers the area I want to cover”. This hobby/tool will likely survive if we share this resource; imposed restrictions are not the solution.

I’m guessing these long range reports on VHF is likely ducting vs clear line of sight. Does occasionally occur on VHF.

You should have great coverage with minimal dead or poor coverage spots. Give that direct line of sight is the the thing that affects distance in said situations the most, you are just in the sweet spot (5 miles) considering the curve of the earth and a HT to a base station (repeater in your situation). If it was just HT to another HT you’d be lucky to go a block or two if houses or foliage was in the way. Remember, “height is might”. But only to a degree. Increase power, low loss and short run on coax, high gain antenna; they all help one to squeeze out a little bit more distance. GMRS is UHF and therefore has the advantage of penetration over VHF but VHF inherently does do better for distance. Regarding the height is might rule one can shoot themselves in the foot by running even low loss LMR 400 Coax way up high into a tree and the trade-off would be line loss that would be eaten up in that long run, and the height wouldn’t make up for it at some point. A 5W HT on a Ham Band can converse with the space station as it passes over, but there’s nothing in the way. In my situation, my repeater coverage goal was to be able to have at least 50% acceptable coverage inside a building and nearly 100% if I step outside and not in a shadow trees/near by houses. My system is an open system in a dense urban area that has a very advanced state of the art dedicated EOC & comms (always in a “warm state”) and a fairly large contingent of CERT members who have exclusive use of the GMRS repeater if the EOC becomes activated. EOC comms are man by licensed ham volunteers the very few of the CERT members are hans. All volunteers have family members and therefore in a grid down situation now have a means of conversing with their family in a grid down situation while out in the field/deployed. GMRS works great for this and the CERT in field can use it as a tactical form of communication. It sounds like your present set up is good, but you probably could squeeze just a little bit more out with some more height or high gain antenna &/or short as possible low loss coax.

New repeater owner (RPT-50) in the Seattle/South King County area. Given that there are only 8 pair of repeater channels I’ve found it difficult to find a pair that wouldn’t interfere with another repeater or their’s mine. The CTCSS tones do not resolve the issue of channel to channel interference. Main issue is that there 4-5 established repeater sitting atop high mountains in the region that broadcast & receive a very very large foot print of coverage. They are all legal as per FCC rules but it leaves only a few channels available for consideration which then increasing the chance of local repeater interference. As people point out, there is no established frequency coordination for this slice of the spectrum. To add to the confusing task of finding the best pair is the fact that there’s no rules that people should publish their repeater frqs/tones, regardless if closed or open. Many of these repeaters are very very light usage so monitoring for even a month could turn up zero hits. Also the process of reverting to monitoring as the best practice has high potential for false assurance of a potential pair. At the edge of my reliable foot print of coverage has proven to problematic because my fringe coverage locations a user configured for my system is frequently triggering a repeater that is out of range of my system and the user gets into my system as well as triggering a repeater on the other side of them and different tones don’t seem to screen out especially at the onset of transmission. What to do? Not even trying for great distance; just my city coverage / open unless EOC is activated then becomes closed and priority for FEMA CERT volunteers in the field.

I set up my 50 a month ago and as an experienced ham I’ve learned, like many of us, the art of interpreting Chinese produced manuals. I’ll play devils advocate here: They have come along way with providing manuals at some point that are more concise and clear. I guess they get tired of emails and telephone inquiries for clarification and decided to invest time and money and producing a manual that is more in line with what the customers need. As in the case of the RPT50 I guessing that it hasn’t generated enough sales/profit to invest in cleanup their operating manual. It is an art and there are people that make a living producing product manuals here in United States. It is expensive but well worth the investment and have been evolved with a big project that cost us thousands of dollars but in the end it was a manual written by native English speakers for native English consumers. The company that produces this repeater have apparently numerous variations planned. All pretty much are the same function (repeater), but different modes, i.e. VHF version, business, digital, etc. The build quality is excellent. Given that frequently repeaters are set up and operating in some harsh environments dealing with dust and heat the engineers took that into. consideration and made a good box. My concern is how well the internal duplexes will fair in time. This is new cutting edge technology, and has not been adopted by any other repeater builders that I know of so uncharted waters. Fortunately, their system is taken that into consideration and allowed for potential external duplicator implementation; smart. This system is basically a turn key, but even so there are many options with poor or no explanation in the present manual. For example, the ID/morse code option (every 15 mins if running an open system here in the US) has options that if set wrong would conflict and it’s poorly explained in the manual and it is not intuitive. That’s the only problem I’ve had with the system to date. I set it for 15 minutes and it’ll do that for several hours and then stop sending the ID. Many repeater owners just ignore that rule and I haven’t heard of anyone getting a letter from the FCC, but there is a potential. It’s a rule and not a law. In my case, I have to make it so that it abide by the rules given that the system is mainly provided for CERT teams (FEMA trained) but the system remains in a open configuration unless our Emergency Operation Center is activated. Given time I’m sure that if not the RPT50 team someone will produces a much needed clear precise manual. Present / temporary setup of RPT50 is in my ham shack. I’m getting 42 W output through a dummy load with a 2.1 SWR. Within the next few weeks, I’ll update after I move the system to the opposite end of the house to reduce potential of deceasing, adding much improved high gain omni directional antenna fed through a shorter coax run with LMR400. I will be gaining an additional 20 feet height off the roof from present system. Right now I’m able to pretty well saturate an area of 5 mile radius in a very densely populated urban area that a 5 W HT can hit with little problems. Amazingly, I live in a unique place that has a narrow geographical conduit going from the Valley floor (I5 / 167) that shoots northward into downtown Seattle that is 40 miles away. Same 5 W HT can work my repeater clear as a bell. Goes to show you that it’s all about line of site. One can hit the ISS with a 5 W HT and that’s 250 miles away but there’s no terrain. Regards, WRBQ468 / KD7GXN