davidotoole
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Posts posted by davidotoole
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I believe what the note about an external GPS is it means an external antenna connected to the tablet.
Well I have been looking at external ones that connect to Android via Bluetooth.
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Hey @WRWI380 that is good to hear. I don't know much about antennas, I bet someone here will though!
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I'm purchasing a waterproof/dustproof tablet with built in multi-satellite GPS for use on the trails along with our GMRS radios and geo-data recording with GIS software. But I've been told that for best accuracy it's best to use an external GPS unit. Are there any GPS experts here who might be able to recommend a good Bluetooth GPS that works with Android?
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@KAF6045 Thanks so much for your advice. Yeah, we've decided to drop the FRS idea for now. And I'll use Channel 4 instead.
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I’m just here looking for help.
HI @WRWI380, although I do not know how to use repeaters, I do have one general suggestion. It might be helpful if you made a new question in the "Technical Discussion" forum at the top level, with a link to the video or videos you are having trouble following, and a description of what goes wrong when you try to follow the video. As for the repeater problem, it could be that the people you were listening in on, were using a CTCSS/DCSS code that you weren't transmitting, thus they wouldn't be able to hear you. I hope you can find someone knowledgeable on the board who can help answer your questions about repeaters. Although I'm not terribly knowledgable myself, I would be happy to answer other GMRS questions that don't involve repeaters.
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1 minute ago, 73blazer said:
Elevation difference between radios of that magnitude (715') will change the game completely. Now your talking 10's of miles of range pretty easily. But yes, every terrain is different and you never really know what your gonna get.
Whoa. I just checked the map and the trail head I was planning to use for this test, is only actually about 175 feet lower than the peak. But if what you are saying is true, then I could possibly talk to someone at my house from Mt. Pisgah over 2 miles away. Since my elevation is about 400 feet lower than the peak, I might be able to make it happen.
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Even the GIS picture in the 1st post shows homes, and I would consider that alot more open (aka probably get more range) than what I listed and tested.
@73blazer Yes, this forest isn't so big or deep, encompassing about 100 acres, and the amount of wetlands means that some areas (particularly the area where we did our test yesterday) are partly devoid of trees. But at Mt. Pisgah here in town we should be able to separate up to about 0.75-1.0 miles in denser forest if we straddle town boundaries, and we'll explore transmitting from the 715 foot high peak to a trail head about 0.8 miles south as well. Nearby Upton State Park should be an even more more interesting testing ground... it's 2,600+ acres! I will let you know what happens.
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If you have true FRS radios in the mix, their power on the 15-22 channels (usually only newer frs radios have those) is 2w, that will reduce your range in heavy forest, couple with their usually crappy antennas, the range may be reduced significantly with an FRS. FRS radios are narrowband on all channels so yes, your GMRS radio should be set to narrow on those channels if communicating with them because there is some quality issues with narrow to wide etc.
Interesting. I'll have to choose my FRS model carefully then. Actually, I'm starting to wonder if I should even bother with FRS for this use case, because we only need one person on each squad with a radio, and we already have 3 GMRS licensees in the group.
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Hi and thanks again for your report. My Beofeng GMRS-9R radio complies with the regulations regarding power and bandwidth on channels 8-14, and we'll be using channel 18 on narrowband when 2-watt FRS handsets are in the mix. It is good to hear that range shouldn't suffer dramatically with narrowband.
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@73blazer One additional question: did you get a chance to compare narrow versus wide band?
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@Blaise I wish you the best for your group. I have put up our new web page here: Trails Adventure Team perhaps there will be useful information and ideas.
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This is super-useful! Do you mind if folks distribute it?
I'm trying to set up a local group too....Sure, go ahead. I'd like to give you Excel, ODF, and CSV formats as well so that you can modify or convert it.
GMRS and FRS radio regulations matrix - Main operational regulations.csv GMRS and FRS radio regulations matrix.ods GMRS and FRS radio regulations matrix (3).xlsx
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Hi @73blazer thanks so much for sharing this information! I really appreciate your help. I'm guessing we will need to plan to have our distance top out at about 1.25 miles when planning multi squad trips. I'm so happy I joined this forum and I hope to make a positive contribution. Nice to meet you.
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Hi everyone, first I just want to thank you for welcoming me to the site and for your help with my various questions. I thought I'd share our GMRS experience from today. My little group which I've recently started, called "Trails Adventure Team", made our first mission into a local trail system to clean up trash and report trail conditions. We hiked to the summit of Edmund Hill here in Northborough, Massachusetts, and then split up on two different trails on the way back down. While separated, we tested our new waterproof Baofeng GMRS-9R radios with our newly issued callsigns. Although Edmund Hill Woods isn't large enough to do a proper GMRS range test, we did find that transmissions were loud and clear in the forest at about 0.25 miles apart. In a few weeks we're going up to Mount Pisgah which is a significantly larger area and with more varied terrain. We are planning to conduct more tests then, using both wideband and narrowband modes (since we will be using the latter whenever unlicensed FRS users are in the mix, and we want to know how both perform) and will try to test reception at a distance of 0.5 miles or greater.
We also used QGIS and QField to record some GPS data points on the trails (see attached image), although a few of them were inaccurately placed; I think I need to buy a tablet with a more precise GPS than my low-end mobile phone.
Does anyone else use GMRS in woodland areas? What kind of range are you capable of getting with a 5 watt handheld? (Although, I've heard these GMRS-9R don't actually reach the 5 watts advertised.)
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So clearly you cannot spam listeners or charge to deliver messages.
Yes. Thank you for clarifying this. My imagined commercial use involves communicating between employees, paging and finding one another on site. No advertisements or common carrier.
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Thank you @Sshannon I wonder when this was changed? That language is present in the 2017 ruling, I still see some info online that says GMRS commercial use is verboten. Anyway thanks for clearing this up
I am so happy for everyones help and I hope I can make a good contribution to this forum.
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Here is an ODS version of the document.
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While reviewing the GMRS and FRS rules for my project I made a spreadsheet with all the relevant regulations so that I can see everything at a glance. I thought I would post it here in case anyone finds it useful, although I cannot promise that there are no errors. Perhaps someone knowledgeable could look it over and correct me! If you have time.
GMRS and FRS radio regulations matrix (1).xlsx GMRS and FRS radio regulations matrix - Google Sheets.pdf
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Just to clarify, it does say that only individuals and not businesses can have licenses. I am asking about whether individual licensees can communicate with each other for business purposes.
GMRS Education
in General Discussion
Posted
@WRVH932 hey there. My first advice is to study the FCC regulations themselves, here is the relevant subchapter: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-E and I also made a spreadsheet with an overview of the rules (see attachment.) The rules are going to be the foundation for everything you do, although it doesn't cover ins and outs of choosing equipment, etc. What kind of radios did you get? Anyway, I'm not able to help with repeaters, but hopefully someone else here will know what to do.
gmrs.pdf