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Kenwood APRS vs Icom D-star? Which to choose?

Discussion in 'General Technical Questions and Answers' started by KC0BUS, Aug 18, 2009.

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  1. KC0BUS

    KC0BUS Ham Member QRZ Page

    Which VHF/UHF mobile transceiver should I choose: Kenwood TM-D710A or the Icom IC-2820H? Both are practically the same exact price. Other than D-star, what can the Kenwood TM-D710A do that the Icom IC-2820H transceiver can't be made to do and vice versa?

  2. AJ4FJ

    AJ4FJ Ham Member QRZ Page

    I have never used the Icom, but I own a D710 and have been very happy with it. In addition to APRS, there's Echolink, of course the built in TNC, dual VFOs, wide band rx, cross-band repeat, and SkyCommand II (really cool if you have other Kenwood gear).

    I've used a 706MkII and some Yaesu stuff and the Kenwood stuff has definitely been the easiest to operate and configure. But that's just me.

    I'm sure both rigs are fine radios.

  3. KA9MOT

    KA9MOT Ham Member QRZ Page

    Apples and Oranges. You have 2 different things here APRS and D-Star. You are going to have your APRS fans (of which I am one) saying one thing and your D-Star fans (of which I am not) saying another.
    Personally I own 2 of the Kenwood TM-D700 and love them.
  4. N0AZZ

    N0AZZ Ham Member QRZ Page

    I have used the I-2820 for over a year and have been very happy with it and all of it's features. I do have the D-star with GPS also a very handy tool I like being to connect very easily with other hams in other cities so painlessly


    73 de N0AZZ Fred
  5. K0RGR

    K0RGR Premium Subscriber QRZ Page

    It depends.

    If you have DSTAR in your area and don't travel much, the ICOM might be the best answer for you.

    However, DSTAR isn't that common, and APRS is. Indeed, there are very few places you can go in the U.S. and much of the civilized world and not be in range of the APRS network.

    I have both the TM-D710 and the older TM-D700 and they are both excellent radios that just happen to do first-class APRS, too.

    I had the ICOM 2720H and I am a little gunshy about ICOM VHF/UHF mobiles right now, because that radio had problems - the addition of a $100 outboard filter to cure the intermod problem made it a pretty nice rig, but without the filter it was useless here. There was another workaround that would put the rig in 'half-crippled' mode to get around the intermods, but I didn't consider it a viable option. The D710 will suffer a little intermod if I'm sitting right under one of the KW paging transmitters here in town, but it's very easy to live with.

    See the September issue of QST for an article from WB4APR about 'Universal Text Messaging for Hams". He details all the many ways of sending text messages to and from ham radio and APRS. Also, his website has lots of information on other APRS-based applications.

    As yet, only two people here in town own DSTAR radios. If I find the kind of money it takes laying around, I might make it three. But as my main VHF/UHF mobile rig, I like to travel, and APRS is everywhere.
  6. KB1NXE

    KB1NXE Platinum Subscriber Platinum Subscriber QRZ Page

    I own both APRS and D-Star. As said, these are different animals. APRS is for position reporting and does text messaging as a side. It is an analog medium (inasmuch as the data is modulated into analog sounds for transmission and demodulated from the analog to digital). It is a wide bandwidth method of transmitting up to 9600 baud with 1200 typical. It is relatively slow in it's transmission speed.

    D-Star is a digital encoding method for voice (using a VOCODER). Since it is a digital medium, it lends itself to digital message transmission at a higher rate of up to 128Kbps. Some have experienced 196Kbps. It is possible to 'surf the web' using a D-Star system. It is a narrow bandwidth system

    Both can connect via GPS receivers and relay their position. The APRS system typically need outboard equipment (laptops, Packet TNCs, GPS) in order to do both text and position reporting. D-Star may need external GPS inputs with some rigs offering all in one solutions. The closest I know of in an APRS system is the aforementioned 710 has a built in TNC, but requires an outboard laptop (I may be wrong here, someone correct me if I am) to do messaging. I own a 708 that does not have the built-in TNC (only difference as I understand it from the 710). The D-Star can send text using a method similar to cell phone texting. With an outboard laptop on a D-Start rig, you have many options for chat, messaging, E-Mail, file sharing, etc.

    As I said, I own both. I think the D-Star solution is a much easier and less cumbersome approach. It is not widely available as a digital repeater system, but becoming more and more so. Use of a D-Star rig does not preclude you from using analog systems (repeaters) with the exception of the Icom ID-1 which is a 1.2GHz digital only rig. By digital only, I mean it is incapable of working analog repeaters.

    If you want a recommendation - go with the D-Star system. It will grow (is growing) and it is still usable as an APRS system in much the same way many of the available rigs are today. With a D-Star rig, you can have them both, but not the other way around.
    Last edited: Aug 18, 2009
  7. KA9MOT

    KA9MOT Ham Member QRZ Page

    Consider yourself corrected.
    My only problem with D-Star is it is proprietary. And that is why I think D-Star is a passing fad. There are folks who are trying to get computer based D-Star working and Icom won't play. Seriously big bucks are involved as well.
    I gave up on Icom a couple of years ago when they tried to sell me a relay for $78. I bought it from RF parts for $9.99 plus shipping.

    Do you have D-Star in your area?
  8. KB1KIX

    KB1KIX Ham Member QRZ Page

    DSTAR is growing quite a bit here. Even when you check online, there are DSTAR repeaters going online almost just about weekly (here in the US). They do have a decent footprint and there is a lot going for it - if you like that sort of thing.

    We have 4 DSTAR repeaters in my area now with a few more going up (that is 4 sites, not just 4 repeaters if you count the different bands).

    As for the price of the two radios being the same..... Me don't think so! The 2820 is the same price WITHOUT the DSTAR module!

    I think the biggest mistake Icom made with the DSTAR rigs is not allowing standard APRS to be used. The DSTAR version works.... but it's not really compatible unless you have a net connection with other non-DSTAR APRS setups.

    I actually like both of those rigs quite a bit. A friend has the 2820 and been using it for almost 2 years and really likes it.

  9. KB1NXE

    KB1NXE Platinum Subscriber Platinum Subscriber QRZ Page

    I think the point I was trying to make, and may have clouded in my comments is you CAN do APRS via standard analog methods using the current offered D-Star rigs.

    You'd use it like a standard Analog setup with external TNC, PC, software and cables. You CAN also do Digital APRS (some call it DAPRS) using a software package over Digital (D-Star) repeaters and the Internet.
  10. WA6MHZ

    WA6MHZ Subscriber QRZ Page

    Dstar, while there may be instances of OPEN repeaters, is primarily used by special interest groups. Here in SoCal, there is a D-Star group that has an excellent repeater system. But they charge something like $100 a year to be a member!!!!!!!!!!!!!!!!!

    Meanwhile, APRS is 100% free.
  11. K0RGR

    K0RGR Premium Subscriber QRZ Page

    Uh, no... the D700 and D710 as well as the older THD7 handheld and I believe the new Yaesu VX-8R can all do text messaging without an outboard PC. It's almost exactly like 'texting' on a cellphone - you use the DTMF keys on the mike to do the letters. They both have a lot of other 'built in' APRS functions which make them convenient to use in that mode.

    Another thing to note is that the digital speed for APRS is actually faster than for D-Star on 2 meters or 440. But, on the 1.2 Ghz. band, the D-Star ID1 provides a much higher speed connection.

    There is a D-Star gateway that can be used like EchoLink to connect your D-Star mobiles into the wider D-Star network via the Internet, but I understand the functionality is somewhat limited.

    I'm really glad to hear that D-Star is growing rapidly.
  12. N3OCQ

    N3OCQ Ham Member QRZ Page

    This is one misconception that I try to correct every time I see it...

    The D-STAR Specification is NOT proprietary.

    In fact, you can download the entire specification that contains all the information you need to build your own D-STAR equipment and/or software from the ARRL (who translated it from the native Japanese document published by JARL):

    Now there is one proprietary component of a D-STAR equipped radio - and that is the chip that does the actual analog to digital conversion. The D-STAR specification (as authored by JARL) indicates that the voice encoding will be done via the AMBE protocol. And that protocol is proprietary.

    It is the choice, for whatever reason, of JARL to specify a proprietary (and expensive to licence) encoding standard that makes it impossible for amateurs to experiment with D-STAR. The company that owns AMBE, Digital Voice Systems, will only licence AMBE software for 6 to 7 figure licence fees. If you want low-quantity or prototype licences, they will sell you a chip that does all the AMBE in hardware, so you can't reverse engineer it.

    Icom gets a lot of bad press in the Ham-verse for DSTAR, but NONE of it is Icom's fault. Icom pays Digital Voice Systems a licence fee for every D-STAR equipped raido they sell - just like everyone else. The only reason that nobody else is selling D-STAR radios is that they aren't willing to take the financial risk of licencing AMBE.
  13. WW5RM

    WW5RM Ham Member QRZ Page

    APRS vs D-Star

    OH no you dont need a laptop or keyboard to send MSG over APRS. All the Kenwood APRS radios have everything you need to send MSG and why they didn't add this to D-Star I don't know. But the MSG and tracking features of APRS isnt all you can do! You can send Email, Text MSG to cell Phones, Winlink2000 Email, See local Objects such as Repeaters, Weather Stations, Hospitals, Traffic Jams, Club Meetings, National Weather Service bulletins which includes Watch Boxes and Warnings. And the list goes on so why there is even a question of which one to use I really dont see a comparison. They are two different birds. APRS uses old technology to see and use modern features. Such as AX.25 Protocol at 1200 BPS. It is a little slow but hey it works and quite well actually and I always believe in the old saying of "Why fix what isnt broke?"

    I think the one difference between the two is the speed. If you are going to be doing RACES and your local RACES uses D-Star then you may want to go that route but dollar for dollar you get 10 fold the features with APRS as you do with D-Star. Plus you can add a base APRS Station without buying any new equipment and isnt that what Ham Radio is all about? Making some old stuff do new tricks? That is what I was told it was all about by my Elmer in 1992. So just drag out the old TNC or find one from an O/M and put it to use!!!! Along with a PC of course. Then you not only have a Mobile you may have spent some money on but you also have a base station too capable of doing APRS with very little money if you have a 2Meter Radio, a TNC laying around and an old PC. Or you could run one of the Sound Card Interfaces will work too instead of using a TNC is another option at the house.

    But either way it is very easy to set up a Base Station on APRS to keep in touch with or watch the Mobile with. So I am sorry but other than the reason of being able to provide an Internet connection with D-Star Radio there is just no comparison of the two! And why anyone would want D-Star other than to do RACES with a group because they already have the very exspensive Repeater and Radios already I really dont know why anyone would want D-Star because you can use ECHO-Link or IRLP with an APRS Radio at the push of a button. Which is basically the same as the D-Star Link features.

    So from where I stand D-Star is just like someone already said. "A passing fad." Unless of course they make some major changes to its features that is.

    Enjoy and I hope to see you on my map. =]

    DE WW5RM


    Last edited: Sep 19, 2009
  14. G4ILO

    G4ILO Ham Member QRZ Page

    Boy do I agree with that! D-Star is a solution looking for a problem. It is not, as has already been pointed out, a proprietary system. But the prime reason for its existence is commercialization. It is a technology developed by the JARL that has been seized upon by Icom as a way of selling more radios. Through marketing and offering cheap deals to repeater groups they are setting up D-Star repeaters in areas where there is already existing repeater coverage, in the hope that people will buy D-Star radios to try this out. But we should all resist D-Star because its ultimate result, if it becomes successful, will be to make a lot of existing equipment obsolete that would otherwise have years of useful life left.
  15. N0AZZ

    N0AZZ Ham Member QRZ Page

    It seems in our area that the only ones that are interested in APRS is the EComs. In fact most of our state there is D-Star coverage around larger cities and that goes for APRS as well.
  16. KA9MOT

    KA9MOT Ham Member QRZ Page

    You live in the state of Misery. I live close to your state and travel through all the time. Nice state, even nicer people...and friendly hams.
    Repeater coverage is adequate (my 5th grader spelled that for me), and the only large cities you have is St. Louis, Kansas City and Springfield. You have many areas between them that don't have any repeater coverage. Very spotty D-Star coverage I would say.

    APRS is not primarily used by EMCOMM. I have noticed a bunch of ECOMMERS using it in the KC area, but the primary users are hams just like you and I.

    Travel around some more before you make broad statements like the one I quoted. I think your statement could be better made about D-Star.

    Yes, I am anti D-Star and pro APRS
    . I use APRS because it is fun and it works everywhere.
  17. KA9MOT

    KA9MOT Ham Member QRZ Page

    Exactly how I feel!
  18. NE3R

    NE3R Ham Member QRZ Page

    I put together my first APRS station for about $100 :) I haven't been able to do that with DSTAR! One of the early responders was right, it is really apples and oranges.

    The thought has crossed my mind of converting the club's lightly used 70cm repeater (on a mountain with 5 other 70cm repeaters) to DSTAR just for something different, but the idea really hasn't gone anywhere. Chicken and eggs, nobody has the radios so why bother, but there is no repeater so why get the radios.

    73 de Joseph Durnal NE3R
  19. ZL1UZM

    ZL1UZM Ham Member QRZ Page

    Very well put! I totally agree!
    D-Star is not what ham radio is about. Might just as well use your cell phone. Everybody has one.
    It creates a US and THEM mentality. It splits the ham community.
    Resist D-Star!!!
  20. AB0WR

    AB0WR Ham Member QRZ Page

    No one has pointed it out yet but D-star is a technology just waiting to be made obsolete.

    What happens to your D-star system when the next generation of vocoder comes out? What happens when the next generation of digital transmission technology comes out (e.g. a high speed PAM system)?

    We've already been through wnat? 3 generations of cell phone technology? Wait till that happens with amateur radio. Talk about a lot of wailing about money having been wasted.

    Digital technology just absolutely lends itself to a host of Tower of Babel problems. Plain old analog FM technology does not.

    tim ab0wr
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