APRS and DMR Radios

Discussion in 'Ham Radio Discussions' started by KC1MUU, Apr 24, 2020.

ad: L-HROutlet
ad: l-rl
ad: Left-2
ad: L-MFJ
ad: Left-3
ad: abrind-2
ad: Subscribe
  1. KC1MUU

    KC1MUU Ham Member QRZ Page

    I have been looking at getting into digital communications. I know very little but have been reading more about it lately. I think the best way to get into it is to just buy a radio and learn by doing. I am not looking to spend a fortune since it may not even be something I keep up with. That being said, I am interested in using APRS with the system if it comes with a GPS. Many of the radios with GPS say they do not support APRS however. What would the GPS even be used for then?

    Anyway, anyone have any luck running APRS on some of the cheaper digital radios like the ones I linked below? I did find one article from 2017 (also linked) that explained how to get it to work through a hotspot. I think this kind of defeats the purpose of APRS. Has anything changed since then?




    I guess I could always spend $100 more and get one that has the feature built in but that almost doesn't seem necessary to me. Any advice would be appreciated!
  2. N1YR

    N1YR Premium Subscriber QRZ Page

    APRS requires:
    - a satellite GPS receiver
    - some kind of terminal node controller software to correctly assemble the data, add callsign, map icon code, and status bits into message 'packets' and generate modem tones
    - a radio in analog mode

    Some things are integrated, like a handheld with all three built in, or perhaps a TNC with GPS. Or, you can acquire the individual parts and interface them. This may mean buying or making custom cables to match the models of the devices you choose. Almost any radio with external mike and speaker connections can be adapted to send and receive the packets. Finding custom cables off-the-shelf may limit your options on choice of radio, if you do not make your own cables.

    Some APRS usage is transmit-only, such as a hobby balloon launch, or a tracker put on the tail-end vehicle serving a bicycle/foot race. Other devices will also decode beacons direct or through digipeaters in range.

    Some people operate gateway stations that take position reports, and send them via the internet to websites APRS.fi or FINDU.com. I understand that there are even smartphone apps that report the phone's position using cellular data, bypassing ham radio entirely.
    Last edited: Apr 24, 2020
  3. KD4UPL

    KD4UPL Ham Member QRZ Page

    APRS is not done with "digital" radios. It is transmitted using analog FM. I know nothing about the cheap Chinese junk radios. I have a nice Yaesu FT1XDR that has APRS built in. It is a 2m/70cm dual band radio that also includes C4FM digital capabilities. If using C4FM mode the GPS is used to figure the distance between you and the station you're talking too. This information shows up on the screen of the radio. The newer rigs from Yaesu, the FT2 and FT3 are even more advanced.
    Kenwood's TH-D74A also includes APRS and has DSTAR capabilities. However, APRS is not transmitted over DSTAR (nor C4FM). There are gateways to take DSTAR location information and move it over to APRS servers but that's got nothing to do with the radio.
  4. KC1MUU

    KC1MUU Ham Member QRZ Page

    Thank you all for the replies. I guess I was not too clear with the question. I’m familiar with how APRS works, I have been using it on my analog HT with my phone without issue. What I would like to be able to do is eliminate the phone. Seeing these DMR radios with GPS but no support for APRS is confusing to me. What is the point of the GPS on a ham rig if you can’t run APRS with it? I thought there would have to be a way to get this to work.

    I don’t consider the cheap radios “junk” in fact I think they are a great way for people on a budget to enter into a new part of the hobby. Not everyone has $500 to spend on the latest Yaesu DMR rig, nor would I want to before I know if it is something I will stick with.

    Right now, it looks like I can buy a fairly cheap DMR radio and use my phone as the GPS/TNC as I have been doing.

    But that still leaves the question: why even put GPS on these radios if you can use it with APRS?

    Thanks again for the comments
  5. N1YR

    N1YR Premium Subscriber QRZ Page

    DMR, also known as MotoTrbo, was developed for business. A few Public Safety agencies also use it, as the business radios are about half the cost of radios using the approved P25 Public Safety digital format. Unlike DStar or System Fusion, DMR was not originally developed for amateur radio.

    There is an ability to send a radio's GPS location in a DMR data stream. I don't know if it is sent before, during, or after the digital voice data streams. Location information can be useful for businesses to track their deliveries or service calls. The location information is not in APRS format. If I recall correctly, amateur radio repeater operators in the past generally asked that this feature be left turned off.

    So I think the answer is that the GPS is carried over from the business standard.
    Last edited: Apr 25, 2020
    AI7PM likes this.
  6. N5AF

    N5AF Premium Subscriber QRZ Page

    Spend the extra money and get a quality DMR rig. The Anytone 578 / 878 series are very nice. Yes, they are Chinese radios, but the build quality of the Anytone rigs is quite good. The manuals are "properly translated" and the programming software is very easy to master. I own both radios and have no regrets on the purchases.

    The 878 & 578 have GPS and APRS support. Link below to a good video review of the 878.

    KB0RTQ likes this.
  7. KC1MUU

    KC1MUU Ham Member QRZ Page

    I appreciate all the help. I ended up ordering the Btech 6X2. These are made by Anytone and are essentially the same radio as the 878 but have a few more features. I think you were right that spending the extra few dollars will make a difference.

    Looking forward to getting involved!
  8. N0DZQ

    N0DZQ Ham Member QRZ Page

    Nor was... CW, AM, SSB, FM, & GPS.

Share This Page

ad: chuckmartin