Lscott Posted August 15, 2021 Report Posted August 15, 2021 Has anybody any experience with unlicensed use of European PMR446 and/or DPMR446 radios operating on the US Ham 70cm band? I would likely expect this around major international tourist spots like Disney Land etc. Apparently there are 3 different modulation types used depending on radio. Narrow band FM, TDMA (aka DMR), FDMA (similar to NXDN). https://en.wikipedia.org/wiki/PMR446 https://kenwoodcommunications.co.uk/files/file/comms/uk/pmr446/PMR446-White-Paper-V6_18AUG2016_JT_KB.pdf https://www.datamatik.no/media/produkt/tk-3701de.pdf Quote
WRNA236 Posted August 15, 2021 Report Posted August 15, 2021 Are you just wondering if anyone's heard it or considering trying? If you're thinking about using one it would be nominally legal as long as you hold a ham license but consider that their channelization is probably inconsistent with your local band plan. Here in Colorado the simplex channels are all aligned +/- with 446.000.000 Hz as that's the suggested ARRL 70cm calling frequency. The simplex channels are 16K0F3E set on 25 KHz steps from that starting point covering 445.700 to 446.300. Within that channelization we have some suggested digital narrowband (8K0F3E) on 12.5 KHz steps that would work for PMR but they start at 446.200 and go up, so 446.2125 and on. Which is unfortunately just beyond the top of the PMR channels. Some of the PMR channels would I think nearly fall as interstitial where a wideband user probably wouldn't even hear it. Some would almost certainly interfere with other traffic being just 6.25 KHz off center. There's nothing requiring you to use the band plan. They are just for convenience and to be considerate. And simplex is not technically coordinated anyway. So if no one's using the simplex channel(s) potentially affected then who would know or care? It would be pretty insulting to step on repeaters, SSTV, weak signal, etc. But sticking within the plain simplex, meh, using the spectrum is better than not. Quote
Lscott Posted August 15, 2021 Author Report Posted August 15, 2021 I was thinking if I could get one really cheap to experiment with it might be fun. I looked on eBay to see what a high quality dual mode analog/digital PMR radio costs. In this case a Kenwood. The only one I found was pretty expensive. https://www.ebay.com/itm/Kenwood-pro-talk-radio-pmr-ProTalk-is-a-tk-3701d-radio-/304087133273?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=724-127637-2357-0 My main point is has anybody stumbled across these radios being used in the US? The European 70cm Ham band runs from 430 to 440 only. Above that are other services. The PMR446 service is the equivalent to our FRS service except they can use digital voice modes. This point should be considered whenever the idea comes up to allow digital on GMRS. The Europeans have shown it can be done and exist along side the analog only FM mode. I’ve read on other forums warnings against US tourists from taking their FRS radios with them while visiting other countries where it isn’t legal. But some do anyway. I assume foreign visitors to the US have done the same with their PMR446 radios. I was questioning if anybody has run across an instance where this happened. And, in that area is it a big problem. Quote
MichaelLAX Posted August 16, 2021 Report Posted August 16, 2021 I was against using D*Star originally as it was ICOM proprietary software. Back in 2016, I became aware of DMR and its use of public domain TDMA digital communications. Having a couple of Baofengs already, with matching accessories, including the high capacity batteries, I sprung for the "low-cost" Radioddity RD-5R: a GD-77 in a Baofeng format and have enjoyed using it ever since. I see some information about D-PMR here: https://dpmrassociation.org/dPMR-446.html I see lower cost HTs on eBay including a Midland model for about $70 but of course with shipping from Europe! But I am not sure where else you are heading? US Amateurs being able to communicate with a PMR446 HT here in the States? But as a hobbyist, include me IN! Quote
Lscott Posted August 16, 2021 Author Report Posted August 16, 2021 2 hours ago, MichaelLAX said: I was against using D*Star originally as it was ICOM proprietary software. Back in 2016, I became aware of DMR and its use of public domain TDMA digital communications. Having a couple of Baofengs already, with matching accessories, including the high capacity batteries, I sprung for the "low-cost" Radioddity RD-5R: a GD-77 in a Baofeng format and have enjoyed using it ever since. I see some information about D-PMR here: https://dpmrassociation.org/dPMR-446.html I see lower cost HTs on eBay including a Midland model for about $70 but of course with shipping from Europe! But I am not sure where else you are heading? US Amateurs being able to communicate with a PMR446 HT here in the States? But as a hobbyist, include me IN! I thought getting one would be interesting to play with on the Ham 70cm band. I found two more models from Kenwood in addition to the TK-3701. http://www.walkietalkie.eu/documentos/catalogos/cat-en/Cat_KENWOOD_TK3401D_en.pdf https://bhvtotaal.nl/media/productdownloads/t/k/tk-3601d_brochure.pdf I have a TK-D340U that does analog/DMR (TDMA) and a NX-340U that does analog/NXDN (FDMA). https://comms.kenwood.com/common/pdf/download/DMR_TK-D240V_D340U_K_letter_1124.pdf http://comms.kenwood.com/common/pdf/download/05_nx240v_340u_K_1117_typeD added.pdf Either one of these two radios could be programmed to communicate with a PMR/DPMR radio on the Ham Band. What I’m not sure about is if the FDMA digital mode out of the two apparently different digital PMR modes is compatible with NXDN. Anyway has anybody noticed these PMR radios being used by unlicensed people in the US, likely tourists visiting here? Quote
MichaelLAX Posted August 16, 2021 Report Posted August 16, 2021 7 minutes ago, Lscott said: Anyway has anybody noticed these PMR radios being used by unlicensed people in the US, likely tourists visiting here? It is hard enough for me to drive into a Walmart parking lot here in the City of Los Angeles and listen to MURS Channel 5 (Green Dot) conversations (Walmarts are frowned upon here, and there is only one in the city limits)! But maybe a trip to Disneyland's parking lot is in my future! hahaha Quote
Lscott Posted August 16, 2021 Author Report Posted August 16, 2021 4 minutes ago, MichaelLAX said: But maybe a trip to Disneyland's parking lot is in my future! hahaha That’s one place I would sort of suspect to find that kind of activity. Since PMR is right there on the Ham 70cm band with the channels starting at almost the calling frequency of 446 I think it would get noticed. Things like foreign language use, no call signs, kids screaming/babbling and general screwing around on the air would be clues to unlicensed use. Since you mentioned you’re are in the LA area I’ve read recommendations not to take your Ham or FRS radios to Mexico. At least where I’m at here in the Detroit area there is a reciprocal agreement between Canada and the USA so operators from either country can use their radios in the other with certain ID requirements being met. As far as I know cross boarder communications on GMRS is not allowed either between Canada and the USA. Of course there is no issue with Hams doing it on the Ham bands. Quote
WRNA236 Posted August 16, 2021 Report Posted August 16, 2021 3 hours ago, MichaelLAX said: I was against using D*Star originally as it was ICOM proprietary software. D-STAR is actually an open standard paid for by the Japanese government and owned by the Japanese Amateur Radio League. Icom and Kenwood are the only to have ever implemented it but anyone can. It's not really any different than DMR, which is an open standard controlled by ETSI. It was originally intended as an extension to analog FM PMR as I understand it. I'm all for experimenting but I guess I don't see the point to buying a radio that can only ever be what it is when you can take any radio capable of tier 1 DMR and program it to do the same thing. It would be like using an FRS radio for 70cm ham and that would be at least a relatively interesting challenge to hack and re-tune it. Quote
tweiss3 Posted August 16, 2021 Report Posted August 16, 2021 I hadn't really looked at it before, but its kind of interesting. Check this document out: https://kenwoodcommunications.co.uk/files/file/comms/uk/pmr446/PMR446-White-Paper-V6_18AUG2016_JT_KB.pdf So they have 18 analog channels in FMN (12.5kHz), DMR T1 on those same 18 channels, or the dPMR which is 6.25kHz within the same bandwith, which is like the ultranarrow FM that is available on all new commercial Part 90 that came out of the T-Band narrowband/rebrand mandates. They don't have repeater usage available, and they are cut at the knees at 0.5W power. It would be a novelty to buy a few of the radios and play with, but unless you can get them for less than $50/each, I would think its too costly to play with. If I was interested, I'd spend a few more bucks and get something you can use no matter what. Look at a NX5300 Type 2, covers ham, GMRS and will do P25, NXDN, DMR and Analog all in 1 radio, plus 5W power. Then you could put the dPMR and DMR frequencies in there. Quote
MichaelLAX Posted August 16, 2021 Report Posted August 16, 2021 13 hours ago, Lscott said: As far as I know cross boarder communications on GMRS is not allowed either between Canada and the USA. Of course there is no issue with Hams doing it on the Ham bands. Some years ago I worked a Montana repeater from The Bob Marshall Wilderness with my Kenwood TH-22a on 2 meters and had a conversation with a Canadian Ham. My then wife, a Montana native, never took me camping again! I brought both TH-22a's to Cannes France back in 1996, so I could stay in touch with my daughter during the Film Festival, but I "forgot" to get preapproval from the French Radio authorities that time! Ooooops! It fit easily in her purse with the rubber duck unscrewed and they worked quite well for the purpose needed! Quote
MichaelLAX Posted August 16, 2021 Report Posted August 16, 2021 12 hours ago, WRNA236 said: It would be like using an FRS radio for 70cm ham and that would be at least a relatively interesting challenge to hack and re-tune it. Yes: it would be fun to get them working on 70 cm repeaters! Quote
MichaelLAX Posted August 16, 2021 Report Posted August 16, 2021 13 hours ago, WRNA236 said: D-STAR is actually an open standard paid for by the Japanese government and owned by the Japanese Amateur Radio League. Icom and Kenwood are the only to have ever implemented it but anyone can. Well that is not how it was presented to me back in the early days of D*Star, but a quick "google" indicates that your presentation is correct. Thank you. WRNA236 1 Quote
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