Is there someone who could PM me ref NXDN for amateur, I have some questions...
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mmckenna
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What's your question? You can PM me, or just ask it out here in the open.
No not PM!!! I'm very interested in NXDN for ham use...specifically simplex/direct.
gracias gents...
gracias gents...
FWIW, I got into VHF NXDN to listen to our local public safety repeaters that went NXDN 2 years ago. A lot of us in a local ham club have been using mostly Kenwood NEXEDGE mobiles/portables as scanners. They don't cost anywhere near the NXDN-capable scanners and they're great as amateur radios.
The Kenwood NX-200, 210, 220 HT's and NX-700, 720 mobiles are usually available on the used market. The software and programming cables are easily found on Ebay. The audio, like most digital, is very clear... to me it's much better than D-Star by a longshot. We did play with some Icom IDAS radios, too. They have great audio but on NXDN they didn't have the same capabilities while monitoring the local public safety Kenwood NXDN repeaters. Since monitoring those was our priority, we migrated to the Kenwood radios. Another issue with the Icoms is that a lot of them won't do wideband analog which limits their use for hams.
We programmed in some simplex VHF amateur digital channels (as designated in the Frequency Use Plan by the Southeast Repeater Assn.) and use them in our base stations as well as mobile/portable. The NXDN at 6.25 kHz bandwidth outperforms wideband analog simplex VHF in our mostly mountain terrain. The NXDN often gets through with clear audio when the same radio/antenna can't do it on analog. This class of radios is capable of analog wideband so they work well on our analog repeaters as well. The commercial radios IMHO have hotter receivers and transmitters than what we're accustomed for amateur equipment.
The Kenwood KPG-111D and KPG-141D software for these models wasn't too tough to learn and there are only a few screens you have to use as a lot of the Kenwood features aren't needed for ham use. There's a group in FL that uses a lot of UHF NXDN with linked repeaters. Those guys are at a level way above what we use them for.
I'm not sure what the Original Poster was looking for but thought I'd just throw this out there. If you decide to get into NXDN, I hope you have as much fun with as we are having.
Keep in mind, that like most things in amateur radio, this is a "gateway technolog". Once you start playing with NXDN you'll likely get hooked. I've moved up to a couple of Kenwood NX-3000 series and NX-5000 series radios. They cost considerably more but come with a lot more features!
73 de Vern
The Kenwood NX-200, 210, 220 HT's and NX-700, 720 mobiles are usually available on the used market. The software and programming cables are easily found on Ebay. The audio, like most digital, is very clear... to me it's much better than D-Star by a longshot. We did play with some Icom IDAS radios, too. They have great audio but on NXDN they didn't have the same capabilities while monitoring the local public safety Kenwood NXDN repeaters. Since monitoring those was our priority, we migrated to the Kenwood radios. Another issue with the Icoms is that a lot of them won't do wideband analog which limits their use for hams.
We programmed in some simplex VHF amateur digital channels (as designated in the Frequency Use Plan by the Southeast Repeater Assn.) and use them in our base stations as well as mobile/portable. The NXDN at 6.25 kHz bandwidth outperforms wideband analog simplex VHF in our mostly mountain terrain. The NXDN often gets through with clear audio when the same radio/antenna can't do it on analog. This class of radios is capable of analog wideband so they work well on our analog repeaters as well. The commercial radios IMHO have hotter receivers and transmitters than what we're accustomed for amateur equipment.
The Kenwood KPG-111D and KPG-141D software for these models wasn't too tough to learn and there are only a few screens you have to use as a lot of the Kenwood features aren't needed for ham use. There's a group in FL that uses a lot of UHF NXDN with linked repeaters. Those guys are at a level way above what we use them for.
I'm not sure what the Original Poster was looking for but thought I'd just throw this out there. If you decide to get into NXDN, I hope you have as much fun with as we are having.
Keep in mind, that like most things in amateur radio, this is a "gateway technolog". Once you start playing with NXDN you'll likely get hooked. I've moved up to a couple of Kenwood NX-3000 series and NX-5000 series radios. They cost considerably more but come with a lot more features!
73 de Vern
I guess my interest is in the TG usage. I'm a little confused, to have multiple TGs, don't you need a repeater for each TG?. I thought this was one talk path per frequency? How hard is it to get on the national networks?
mmckenna
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It depends on how it's set up.
If it's a trunked system, the individual repeaters that are part of the system get used when traffic requires it. Doesn't matter which talk group it is, it just gets assigned. Talk groups are usually not assigned to one specific repeater.
If it's amateur radio, then it's not likely a true trunked system with control/home channel and multiple repeaters. It may be some sort of pseudo trunked/one frequency trunk where they split up groups using the same repeater.
"National Networks", as in amateur radio? You'd have to link into a bridge with the repeater over IP.
Ok I get the whole commercial trunked system, multiple repeaters at each site TG assigned, I work for the army we have a moto system
I was thinking about this: Kenwood NXDN Log Does this setup work like Mototrbo on amateur where some TGs are permanent and some are on a timer? My understanding is that NXDN can be set up with 12.5 or 6.25 so am I allowed 4 talkpaths <Amateur 25k> because I'm running 6.25k? My issue with DMR is there are frankly too many talkpaths, some basically made up so you can use more than 2 talk paths per 12k pair.
My understanding was that there was one talkpath per frequency and multiple repeaters can be linked IP just like ALLstar except digital emission.
To have multiple talkpaths you needed a trunked type system, multi repeaters per site etc
I was thinking about this: Kenwood NXDN Log Does this setup work like Mototrbo on amateur where some TGs are permanent and some are on a timer? My understanding is that NXDN can be set up with 12.5 or 6.25 so am I allowed 4 talkpaths <Amateur 25k> because I'm running 6.25k? My issue with DMR is there are frankly too many talkpaths, some basically made up so you can use more than 2 talk paths per 12k pair.
My understanding was that there was one talkpath per frequency and multiple repeaters can be linked IP just like ALLstar except digital emission.
To have multiple talkpaths you needed a trunked type system, multi repeaters per site etc
mmckenna
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I don't know, but see my comment below:
NXDN is FDMA, so each talk path requires it's own frequency.
DMR is TDMA, so by alternating back and forth between the two talk paths, you can put two audio paths on one 12.5KHz channel.
Theoretically, if you had enough money, yes you could cram 4 6.25KHz NXDN paths into 25KHz, but I don't know of anyone who has done that. I have heard of 2 6.25KHz channels, however.
But I doubt that is what they are doing. It would require some very expensive filtering and design to work.
NXDN can run in two modes:
12.5KHz channel width, which gives ~about~ 9.6kb/s data rate.
6.25KHz channel width, with gives ~about~ 4.8kb/s data rate.
* there's some overhead for packet addresses, etc. so you don't get the full 9.6kb/s or 4.8kb/s data rate on it.
Right, that's an overall system design issue, not an issue with DMR. Hams trying to cram as much in as they can. Sort of like trying to drink from a fire hose.
For NXDN?
Correct. While DMR can put two talk paths in per repeater, thanks to TDMA, NXDN only allows one talk path per repeater.
Both can easily be linked over IP, either to link repeaters to make a wide area system, or two bridges to combine systems.
So, for amateur use, it's likely they are running one talk path per NXDN repeater, and you select the talk path using talkgroups.
Is there a default RAN for ham simplex use?
mmckenna
I ♥ Ø
0 or "None" would be the same as carrier squelch.
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