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Which digital voice mode do you prefer?


Lscott
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2 hours ago, MichaelLAX said:

I've heard of a Prolific chip in USB cables, but not prolific mode.

Is that the same as Promiscuous Mode in DMR?

If so, for $69, hard to beat the Radioddity RD-5R DMR/analog HT, which is their GD-77 in a UV-5R style case and now there is the OpenGD77 Firmware project that supports this radio, too.

Unfortunately that isn't really available, promiscuous mode, for some digital systems. That would be very handy for monitoring things like NXDN and P25 trunking systems. The protocol is written such that when a digital transmission is picked up, and its tagged as from a trunking system, unless the radio has a valid "system key" loaded, not an encryption key, for that system the data is not decoded to audio and the radio stays muted. At least that's my understanding.

https://forums.radioreference.com/threads/for-simply-receiving-nxdn-digital-audio-do-i-need-to-use-the-nxdn-trunking-system-feature-when-programming-my-radio.402726/

For my NXDN radios, NX-300's, the programming software won't even show the NXDN network info window without a valid system key loaded in to the software. Kenwood keeps a fairly tight lock on the software for these system keys. It's the KPG-110SM.

https://comms.kenwood.com/en/products/model.php?ID=KPG-110SM-a

I have a buddy the does use a XTS-5000 P25 radio on 800 MHz to monitor his local public service agencies. He used what was called an "non affiliated" mode but still had to fudge up a system key for the radio to get the thing to work.

http://www.mtolab.com/howto/non-affiliation-scanning/

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On 2/1/2022 at 10:33 AM, MichaelLAX said:

I've heard of a Prolific chip in USB cables, but not prolific mode.

Is that the same as Promiscuous Mode in DMR?

If so, for $69, hard to beat the Radioddity RD-5R DMR/analog HT, which is their GD-77 in a UV-5R style case and now there is the OpenGD77 Firmware project that supports this radio, too.

Thank you, that's the word I was looking for!

Mine just came in the mail.  :D  Do they actually use the same software and codeplugs as the GD-77?

Oooh, I'll have to check that out, thanks!

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Oh as a side note it seems the ITU is considering going digital for the VHF marine band. On another forum site some are guessing it could come down to a choice between NXDN or dPMR.  Both are very closely related.

https://csrc.nist.gov/csrc/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp2200.pdf

Myself I’ve been looking around for a relatively cheap dPMR radio to add to my collection. The one I would like to get is the TK-3701. It’s only 1/2 watt but would be fun to play with. Just one problem. They’re expensive.

https://www.connect.fi/images/docs/TK-3701D_20192511_LR.pdf

Supposedly there are cheap Chinese radios that do dPMR but from what I’ve read they use some weird version the AMBE  vocoder chip which isn’t compatible with the one used by the standard for dPMR. 

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1 hour ago, Ian said:

Thank you, that's the word I was looking for!

Mine just came in the mail.  :D  Do they actually use the same software and codeplugs as the GD-77?

Oooh, I'll have to check that out, thanks!

I’m not sure if it’s exactly the same software but I know that GD-77 codeplugs can be easily converted. 

Let me know if you need some help programming one, but I only use repeaters so I do not know much about hotspots. 

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I've never used a hotspot either.  Right now I can't get my GD-77 to talk to my PC, so I'm in a bit of a pickle as updating it goes.  Still, this bad boy has more than enough memory slots for all the weird stuff I could possibly need to scan!

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I've been trying to track down info on how to convert a Kenwood NX radio form NXDN to dPMR. I got a very brief message from Kenwood tech support the radio has to be sent in to have the "enhanced" feature function activated besides any firmware/protocol updates could be done. I would rather try it myself.

There is a brochure for the NX-220E/320E which says it can be done. The "E" versions are for the European area.

https://www.kenwood.it/files/catalog/it/Brochure-NX-220E_320E.pdf

In the programming software there is a advanced "special" feature check box under the mode section, which I suspect is what Kenwood support was talking about, that doesn't appear unless you have a hacked version of the software or a special install key to unlock a lot of the engineering functions. Anything with that asterisk next to it is a special advanced engineering function. There are bunch of these through various menus with this version I have.

 I suspect their tech support would simply ignore any requests for help trying to use any of these advanced features since they are intended for dealer/depot use not end users.

dPMR is primarily a European thing and is very closely related to NXDN, they use the same modulation type but the protocol is different. I haven't seen much if any mention of it being used here in the US.

 

KPG111D.jpg

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10 hours ago, Ian said:

I've never used a hotspot either.  Right now I can't get my GD-77 to talk to my PC, so I'm in a bit of a pickle as updating it goes.  Still, this bad boy has more than enough memory slots for all the weird stuff I could possibly need to scan!

Does the GD-77 come with its own programming cable, like the RD-5R does? And the RD-5R cable does not contain a chip, so there is no driver to install.

Maybe you are using a USB cable with a chip?

Once we get your GD-77 talking to your PC and programmed normally,  we can then start talking about the OPENGD77 Firmware which I learned about after being posted one year ago on a public forum! 😉

UPDATE: I found this comment on an old Reddit post:

Quote

The programming cable is different because, like all the other inexpensive DMR radios from China, the cable passes the USB signal directly to the radio rather than using a USB-serial converter in the cable. It's the same cable that is used for the MD-380, GD-77, or Anytone AT-D868UV.

Also:

Quote

The RD-5R uses an "MCU MOUSE DEMO" direct USB device connection not serial - if you're not using the supplied cable rather one from another rig that needs a serial to USB conversion, that's probably why you are having issues. Windows 10 should just see it - Linux could be a problem or anything earlier than Windows 7. 

NOTE: I use Windows XP to program my RD-5R

And:

Quote

Somebody discovered that the RD-5R code plugs are identical to the ones for the GD-77 except for a few radio ID bytes. A GD-77 code plug can be converted for use on the RD-5R with a hex editor.

I have access to some GD-77 codeplugs which can be easily modified for your situation, once you get your PC to talk to your GD-77.

Can you link me to a DMR repeater near you?

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I’ve been doing some research looking into some very rarely used digital voice modes. One that has my interest peaked is dPMR. So far it seems it’s an European thing. It’s very closely related to NXDN, uses the same RT modulation, the the CAI, common air interface, is different. I don’t see any mention of it being used in the US commercially or by amateurs.

https://en.wikipedia.org/wiki/Digital_private_mobile_radio

https://kenwoodcommunications.co.uk/files/file/comms/uk/pmr446/PMR446-White-Paper-V6_18AUG2016_JT_KB.pdf

Apparently at least one model series of Kenwood radios can be modified to use it. See link to brochure, first page in the middle on the right side. I’m not sure if it’s limited to just the”E” versions or not.

https://www.azqartelecom.az/pdf/p1_3_1.pdf

The software to enable it I discovered is KPG-97FW. The few European radio dealers I’ve contacted haven’t replied and Kenwood support in the US hasn’t been helpful on this topic either.

I’ve only found one site that has it, Russian of course, but you either have to pay them a bunch of money for access to their collection of radio software, it’s very extensive, or contribute stuff they don’t already have, which isn’t much. 

So does anybody have any experience with dPMR and the above software/hardware?

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  • 4 months later...

I have several DStar radios and have focused on that. A couple big reasons...locally, there is considerable infrastructure supporting DStar (and all of it links, which is probably what everyone wants to do with digital repeaters). Two, the low speed serial function can be fully used (unlike Fusion) and can fully function as a sort of more sophisticated packet channel along with voice. We use it for Emcomm with D-Rats software. It even does internet email like WinLink.

As far as voice, I had a Fusion radio and I didn't think the audio was any better. The re-sync WAS better on Fusion, no question. The other stuff like GPS was the same. D-Star pumps DPRS into the APRS-IS system (as about all repeaters are connected to that). You cannot message each other, but you can do position (which, honestly, is 99 percent of APRS om actual use). Yeah, DStar is long in the tooth as far as digital modes go. Still works, though. And we have a real Icom repeater here connected to a cross-mode gateway so we talk to DMR (mainly), Fusion, P25 and NXDN all on the same repeater. Requires a couple higher-end AMBE chips but it really works well. The other modes come in via a hotspot or a linked repeater native to that mode. 

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I’ve been picking up some commercial Kenwood NXDN radios, several different models. They seem to be cheaper than the DMR ones. They are also far cheaper than any P25 radios I’ve seen. I have radios for D-Star, DMR, P25 and NXDN. Nothing yet for YSF.

Around my area D-Star, DMR and YSF seem to be popular. There are a few P25 and one NXDN repeater near me. There is a fairly large NXDN linked system in west central Florida. I think there are a few other areas where NXDN is seeing some activity around the country. I heard there are some pockets of P25 use in California.

For Ham radio I think DMR works better. I don’t think it’s a great fit when considered for other services. For example the ITU is looking at moving towards digital voice for VHF marine radio. The paper I read mentions DMR likely won’t work well. They seem to be leaning more towards FDMA modes like NXDN or dPMR. NXDN by the way is already used by the railroads in the US.

https://cirm.org/documents/position-papers/CIRM Position Paper - Digital voice over VHF - November 2021.pdf

You can search for who is licensed for which of the big three, DMR, P25 or NXDN at this site.

https://digitalfrequencysearch.com/index.php

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10 minutes ago, Lscott said:

 I heard there are some pockets of P25 use in California.

Definitely some in central CA. One network covers a good chunk from Sacramento down to around Bakersfield (N6LYE). Another, the central valley out to the coast, mostly around Monterey/Santa Cruz, with around half the nodes being P25/analog mixed (Salinas Valley Repeater Group). One of the local clubs also (K6ARP/CARP) has a standalone p25/analog machine.

SVRG and the K6ARP standalone are UHF, N6LYE is mostly UHF with a couple VHF.

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The attached file has more info on the proposed switch to digital on the marine band. It looks like they are leaning towards dPMR, and possibly NXDN. 

dPMR isn't really used in North America. However if the marine band does switch to dPMR it's very likely other services may start using it as well. If NXDN is modified to increase it's address range and can overcome the licensing questions it might be select as well. 

1467189228_ImplementationofdigitalvoiceradiotelephonyintheVHFmaritimemobileband.pdf

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