DMR - It's Not Personal

I don’t know why, but some people take criticism of technology personally. Maybe its because they spend money on some technology product and if someone else makes negative comments about it, they feel they must defend it as if they have to defend and justify their financial investment.

Take my comments on DMR. I have people, one in particular, that attack my comments on DMR as if I am personally attacking them. How silly.

Yes, I use DMR. I also use DStar. Not using any other digital (primarily) voice technology right now because it gets too costly to get one of everything. My real criticism of digital technology as it relates to ham radio is that the manufacturers could not decide on ONE technology to use. This fragmentation is frankly keeping a lot of hams from adopting digital and thus they are staying on FM. So while a town like Cincinnati has two DMR repeaters, two DStar repeater stacks, a P25, and a couple of Fusion systems, there are just a few hams on each system. Most are still on FM. So instead of the digital users expanding, you find most of the digital users using FM.

I did buy a couple of DMR radios because we got a few DMR repeaters and the radios were CHEAP! Had it not been for CHEAP, I would not have branched out into DMR.

But that has not changed my basic beliefs too much about DMR. Yup, sounds a little better than DStar but not overwhelmingly better. If you have the latest generation DStar radios, they should very good. So does DMR.

It is still difficult to find a conversation on DMR compared to DStar. Even on the DMR North American talk group at times.

Yeah, DStar has that R2D2 noise when the signal gets weak. When the DMR signal gets weak it also distorts but sounds different, so the only difference between the two is the sound of the digital signal when it gets weak. That does not make one better than the other.

The DMR networking is nice, but it is not as flexible as DStar. If the DMR repeater owner does not offer a talk group, you cannot connect to it yourself. With DStar you can connect to any reflector you like. Just program it into your radio.

With DMR you must use a commercially manufacturer repeater. I’ve asked many times, and there is no way to home-brew a DMR repeater. With DStar, a hundred dollar board, a computer and a couple of FM radios, you can build your own DStar repeater.

DStar has all sorts of applications that allow you to send text and files over the radio. I have not seen anything like this readily available with DMR. I think Motorola might offer something, but not something that is open source and could be used by anyone without a license fee.

DStar requires you to register a call sign. DMR requires a registration/serial number. To get a call and name to show up with a DMR transmission, you would have had to program a person’s registration/serial number into your radio along with that person’s name to get it to display. With DStar, when a person transmit, it comes with their call automatically. The DStar user can also program his radio to display on your receiving radio something like “Bob in Detroit” or “Bob on ID51A.”

With DStar, if your radio has a built-n GPS, when you transmit your position is sent and also sent to the APRS network. Have not seen that capability with DMR.

So it all comes back to this DMR is a commercial standard that hams are trying to make work in amateur radio. But as of yet, it is still lacking what DStar has now. Will it get to the same point as DStar is at now, I don’t know, we’ll see but the current state of the DMR technology does not seem to allow that kind of flexibility.

If you don’t agree with me, fine. You don’t have to attack me personally over my comments. If you have better information like “there is now a DRats-like program for DMR” then let me know about it. If DMR moves to registering call signs and they display with each transmission, let me know. If you can easily home-brew a DMR repeater, tell me about it.

However as of now, DMR is a digital voice system, sounds nice, is networked and any ham can use it inexpensively with the Chinese radios; provided you have a local DMR repeater.


Blog Responses

I know some people don't always agree with my blog posts, especially when it comes to the DStar, DMR, Fusion, P25, etc. discussions. Everyone has their own favorite digital voice method.

Now I approve or reject the comments people make not because they disagree with my opinion, but because they may not really add to the discussion, they are promoting equipment purchases from a particular vendor, or they are offensive.

For example, the other day I received a post that referred to the users of a particular digital voice method as.....well let's just say, that person referred to them as participants in the Special Olympics.

This is so wrong on so many levels. First, just because you do not like a digital voice method does not mean you have to make fun of those users with derogatory comments. You can rip up on the digital method, but making fun of people and tearing them down because they use something they like is really sick in my opinion.

Second, it was extremely offensive to those with disabilities. My wife works with special needs children and making fun of them was very offensive to her.

I understand that not all amateur radio licensees have the proper maturity to conduct themselves appropriately, but let's try not to make personal attacks and make fun of people going through life with severe challenges.

DMR in North Carolina

Well I decided to bring the DMR radio with me to Surf City/Topsoil, North Carolina during vacation. I elected this radio instead of DStar since there are more DMR repeaters in North Carolina than DStar repeaters. In fact, with the number of DMR repeaters shown in this and the surrounding state, I thought DMR must really be popular.

I had all the DMR repeaters programmed into the CS750. So I was well covered. While I thought I would be able to hit Jacksonville, NC and Wilmington, NC repeaters from the beach area, I was only able to hit the Wilmington repeater.

The first night I got here, I had a brief conversation with a couple of gentlemen on the Southeast talk group. But since then, in spite of repeated calls on Southeast and the local talk groups, I have not received any calls or heard but a few brief conversations.

I really thought there would be a lot more activity on DMR in this area given the number of repeaters.

Continues to demonstrate that if you want to get into digital, and actually have someone to talk to, get a DStar radio for now.

DMR so far

I have had DMR for almost a week. A big thanks to Dan, KC8ZUM, for helping me get started with a simple code plug (radio programming) that got me up and running on one local repeater. It helped me understand and learn to program these DMR radios.

I have now programmed in all the Ohio DMR repeaters and posted my code plug on the CSI DMR radio groups on Yahoo in order to help others. I will continue to program in repeaters in other states as I get time. Frankly, DMR programming is a bit laborious.

In any case what I can say is that DMR has advantages and disadvantages to other digital voice modes. When I get some time, I intend to create a spreadsheet outlining the pros and cons as I see them.

Here is my biggest disappointment. It is hard to find anyone on the radio to talk to. The North American timeslot I was told is the busiest. It is very quiet. For a mode that proponents claim is exploding with growth, it is awfully quiet. I've even called on the Worldwide and Worldwide English timeslots without success. Called on local, not a soul responds.

Now I have had a few conversations on North America, but if I were creating my own impressions of DMR on use alone, my guess would be that only 20 to 30 people even owned a DMR radio.

Where is everyone? Maybe I just cannot hear them over the sounds of crickets chirping.

DStar versus DMR - First Impressions

Well I like to experiment with new things in amateur radio. While I continue to voice my disappointment with the lack of a united digital standard in amateur radio, I have resigned myself to the belief that we are going to have multiple digital methods in use for sometime until the market, if ever, determines which digital method will win out....which of course may never happen in the foreseeable future.

Since the price of new DMR radios has come down quite a bit, mostly because of the cheap Chinese radios, I decided to order one. I did not actually place an order until we had a few DMR repeaters in the area. I mean why buy a radio without anyone to talk to?

I ordered a CS750 which is a Chinese built radio by Covalue and marketed by Connect Systems in California. Connect Systems is also the company trying to produce the CS7000 which promises to support both DStar and DMR. The reason I purchased this radio is because it is low cost and second, because Connect Systems will service it if there is an issue with it.

So here are the first impressions with a radio and digital method I have used in less than 24 hours.

First, I have been told that DMR adoption is exploding with repeaters and users. Not my experience. I was told by a current DMR user that the North American talk group was one of the busiest. Not many people answering calls and not a lot of activity. I had a few QSOs, but compared to DStar Reflector 30 (which is just a regional reflector), there is no comparison. I have not found any activity yet on the DMR Midwest talk group or any of the local talk groups. In other words, where is everyone?

Second, audio quality between DStar and DMR is about equal. I really do not hear any significant difference. I will give to DMR that it seems to recover faster than DStar which means you do not hear the "R2D2" sounds when DMR becomes marginal.

Third, programming DMR is laborious in my opinion compared to DStar. With the newest generation DStar radios, about the only thing you need to program is your call. All the current DStar repeaters are pre-programmed into the DStar radios and the newest DStar radios have a GPS which will locate the closest DStar repeater for you. No guessing when traveling. DMR does not seem to have the ability to have such a function. I do not see anywhere where you can store the GPS coordinates of the DMR repeater.

The software that came with the CS750 is not nearly as easy to use as the Icom DStar programs or even Chirp. When I tried to import repeaters and contacts into the CS750 software, instead of appending the new contacts and repeaters to the existing contacts and repeaters, it just overwrites what was already there. This means I have to really do the cut and pasting with Excel first before trying to do the import. Yikes, more work.

Fourth, DMR does not seem to have the ability to let users build their own repeaters like you can with DStar. So as I understand it, the cost of a DMR repeater is about $1,800 minimum. I am not sure if that includes the networking gear to allow it to connect to all these various talk groups. Yes, you can easily build your own DStar repeaters and some have done it for a few hundred bucks.

Fifth, as far as I can determine, I also do not see an ability to use an external program like D-RATS to send digital messages and data through the radios. Maybe that is coming. We'll see.

Sixth, there does not seem to be a way, or maybe any availability, to provide hotspots. This would allow someone who does not have a local repeater to still be able to access talk groups from home, car etc.

Finally the biggest issue is the use of a registration number instead of a callsign. So when a user is transmitting on DMR, you do not see his or her call, you see a number. We are hams, we have calls and we use our calls. Surprising that DMR could not be modified to use a call instead of these registration numbers. Now you can get the call to display instead of the registration number, but that requires you entering in the user call along with the registration number into the contacts list. It's all manual. With DStar the call is always displayed.

So in quick summary, while DMR is useable, it is not nearly as ham friendly as DStar. That's because DStar was created for hams, but hams. DMR was created by commercial interests for commercial users and we hams are trying to make it work for us.

I will continue to use both and report on my experiences and findings in the future.