Just getting into DV. Questions

[razorseal]

Hey everyone,

After being out of the game for a while (but still remembering how VHF/UHF works) and breaking my Wouxun radio, I decided to get something with digital capabilities. I was looking into D-Star as that was something gaining popularity when I was active in early parts of this decade.; Fast forward 7 years, it seems like D-Star did not end up where I thought it would have been by now, with only more competition...

I've always liked HAM because you had HF, VHF, UHF... now there is D-Star, All-Star, Fusion, DMR and none of them are compatible with each other.

Anyways... I was bidding on a Icom ID-51A on ebay until I realized I have 1 D-Star repeater near me, but ton of DMR. Luckily I was outbid and now rethinking my game..

I see Plenty of affordable DMR radios for 80-220 range or a used D-star for 250 to 500 for the new Kenwood D-Star.

Looking for advice on what everyone is using these days... Seems like DMR is the new norm...

Some videos suggest DMR programming is very complicated and similar to tuning trunked systems for commerical use. D-Star is fairly easy (especially with GPS nearest repeaters list)

I was thinking of getting the new TYT MD-2017 (prefer a dual band, I don't like single banders)....

Couple questions I have are -

Even though DMR is meant to be used with repeaters/talkgroups (I think?) what is the simplex DV range? How about simplex DV for D-Star?

I like that you can communicate with people all over the world using reflectors etc with IRLP, Echolink, D-Star... how does this work with DMR? Can someone in Florida talk to someone in say TX, or even another country/continent?

What happens when a repeater goes down with D-Star vs DMR? Will ton of other connected repeaters be affected?

I think DMR relies too much in internet gateways etc it seems. during a big catastrophic event (like hurricane irma that hit us in S FL) I would think your only option is simplex, or repeaters that might have generator power.

 

[N8OHU]

Okay, a couple of things I can answer from my own personal experience with DMR.

1: Simplex is possible, though I'm not sure of the range you'll get there, since in many cases you're near ground level and there will be obstacles between two or more folks at long distances. set up whatever local simplex option exists as time slot 2, talk group 99; this is the standard that is used in the US and likely elsewhere in the world in Ham Radio.

2: Yes, you can talk between states and countries, if you use the correct talk groups for each. One thing to not, though; you can't use a timeslot that has activity on it, so if both slots are in use, you're stuck listening if the channel in use is audible on your radio. The links are handled by the repeater trustee, so you can't change them, like is done in D-STAR.

3: If the Internet goes down at the repeater site, all you loose for either mode is signals from the networked repeaters; local use is unaffected as long as the repeater antenna is intact and the site still has power available.

As far as programming them, I suspect the videos exaggerate the difficulty somewhat. Each DMR repeater will go in its own zone, though some may require two if you want to use all of the available talk groups on them. It does involve a lot of copy and paste of the repeater information, but that is fairly easy. What can get complicated is the contact list, but really all you need in that are the Group contacts (aka talk groups).

 

[razorseal]

Where do you get all the talkgroup information etc? I hear "codeplugs" on the videos, but search of google didn't really show me any codeplugs (if I understand right, it's a already set file for a specific area?)

With analog repeaters (or other DV repeaters), I just got to repeaterbook and pull up the repeaters and program them in. How does this work with DMR? you have the frequency, and then talkgroups. How does one know what talkgroup is for what?

I started watching some youtube stuff and kinda understand what the timeslots are (allows you to carry two transmissions in the frequency if I understand right since it's a 30ms on off tx) then talkgroups are almost like PL tones (same for color codes)

 

[N8OHU]

Where do you get all the talkgroup information etc? I hear "codeplugs" on the videos, but search of google didn't really show me any codeplugs (if I understand right, it's a already set file for a specific area?)

With analog repeaters (or other DV repeaters), I just got to repeaterbook and pull up the repeaters and program them in. How does this work with DMR? you have the frequency, and then talkgroups. How does one know what talkgroup is for what?

I started watching some youtube stuff and kinda understand what the timeslots are (allows you to carry two transmissions in the frequency if I understand right since it's a 30ms on off tx) then talkgroups are almost like PL tones (same for color codes)

Repeaterbook has this information for DMR repeaters, if the trustee has listed them there. And, talk groups are listed in the radio code plug as Group Contacts.

 

[razorseal]

Repeaterbook has this information for DMR repeaters, if the trustee has listed them there. And, talk groups are listed in the radio code plug as Group Contacts.

Can you explain what the codeplugs are? (or group contacts)

I'm looking at the TYT MD-2017 and the Radioddity GD-77 which are both T2 and dual band. that GD-77 is pretty affordable. Not sure how necessary is the color screen

 

[N8OHU]

Can you explain what the codeplugs are? (or group contacts)

I'm looking at the TYT MD-2017 and the Radioddity GD-77 which are both T2 and dual band. that GD-77 is pretty affordable. Not sure how necessary is the color screen

Code Plug = list of repeaters and related information stored in the radio. Usually in a binary format that cannot be edited outside of the radio manufacturer's specific software, though some may have a way to export the information to a comma separated value text file.

In DMR, Contacts can either be other users (for the purpose of text messaging) or common channels for communication (group contacts/talk groups). There may be other uses for contacts, but the two most common as used in Ham Radio are the ones I listed above.

As far as the radios you're talking about, I don't personally have any experience with them; I have an older mono band Motorola XPR6500 that does quite well for me.

 

[razorseal]

That's what I thought then. Thanks!

now where do I download codeplugs? I would assume they are radio and model specific.

 

[N8OHU]

That's what I thought then. Thanks!

now where do I download codeplugs? I would assume they are radio and model specific.

Yes they are; the best bet to find a sample version is to use Google to search for one for your chosen radio model.

Sent from my XT1080 using Tapatalk

 

[AK9R]

I think DMR relies too much in internet gateways etc it seems. during a big catastrophic event (like hurricane irma that hit us in S FL) I would think your only option is simplex, or repeaters that might have generator power.

That's true of any Internet-based repeater linking scheme. If the repeater site loses access to the Internet, the repeater is no longer linked until Internet access is restored.

 

[razorseal]

That's true of any Internet-based repeater linking scheme. If the repeater site loses access to the Internet, the repeater is no longer linked until Internet access is restored.

Isn't there some C-Bridge though for DMR? (DMR-MARC) if that fails, all repeaters connected to it are now delinked.

with D-Star, if ABC123 repeater goes down, you can just connect to XYZ789 repeater down the road and get your message through from FL to NY

 

[W2PDX]

Amateur Radio Guide to DMR

http://www.dmr-marc.net/media/Amateur_Radio_Guide_to_DMR_Rev_I_20150510.pdf

Give this a read, it will give you a better understanding of DMR and how TDMA works.