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DMR for Emcomm

Discussion in 'Ham Radio Discussions' started by KG7LEA, Dec 14, 2019.

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  1. K4AGO

    K4AGO Ham Member QRZ Page

    It seems to me that if cell towers are down, radio towers are down and electrical grid towers are down too. DMR would be useless without towers, repeaters and computers. Simplex will work until batteries die. Then you will need solar chargers.

    I am talking about a REAL emergency like earth quake, hurricane, tornado or major fire (as in Calinfornia). Not a minor emergency like a thunderstorm.

    Coordinating life saving medical supplies, potable water and food... among the MAJOR reasons for being able to communicate with someone counties or states away.

    But, again I say; DMR will be of no use if electric, internet, towers and repeaters are down.

    The Native Americans used smoke signals because they could not depend on DMR.
    KY5U, WA9SVD and (deleted member) like this.
  2. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Why do you think that people who've spent years, untold man hours, and large amounts of money making a failure-tolerant, infrastructure independent multi-state network somehow didn't consider backup power?o_O
    NQ1B and (deleted member) like this.
  3. AG4RT

    AG4RT Platinum Subscriber Platinum Subscriber QRZ Page

    I believe our EMS repeater has a generator. Mobile rigs should still work if you can get gas. Inverters for the HTs. Many ways to skin a cat.
  4. K0RGR

    K0RGR Premium Subscriber QRZ Page

    It does indeed, exist. I happen to have one of the cards with the code I need to use it in a disaster. A local FEMA official issued them to our ARES leadership.
  5. KG7LEA

    KG7LEA Ham Member QRZ Page

    Who cares? I think there are other parts of the community that will value amateur radio such as NGOs providing relief and spontaneous neighborhood groups needing to coordinate with each other. If they have the right cell or copper phone numbers and the systems are not overloaded, that might work.
  6. N6TDG

    N6TDG Ham Member QRZ Page

    I wasn't a ham back in '89, but I was a News Director in Watsonville back then. Looking to today, there have been issues in the Bay Area of cell phone towers down both due to fire and PG and E Shutoffs. Evidently and I didn't know this, a lot of land lines are now handled by the internet versus copper wire. Not a good thing. Luckily, where I now live up in the northern end of the gold country, the phones are still copper wire and an old rotory phone got me out.

    For local neighborhood communication, the area has initiated a GMRS net and funded a repeater for emergency uses by the local civilians.
  7. W5TTW

    W5TTW XML Subscriber QRZ Page

    We had 5,000,000 using their celphones here in the Houston Metro during Harvey. Everything was fine. Internet speeds didn't suffer either. Cable TV was fine as well. The Cajun Navy didn't rely on radios to assist. Moreover, they didn't arrive in whacker wagons or wear ridiculous uniforms.
    Last edited: Dec 15, 2019
    W0FS, WE4B and KB0RTQ like this.
  8. K0RGR

    K0RGR Premium Subscriber QRZ Page

    Some groups in our region have adopted various digital voice and data modes for EMCOMM and Public Service. The most impressive of these uses the 1.2 GHz Dstar equipment to blanket the Twin Cities. Each portable 1.2 GHz radio becomes a terminal node controller for multiple dumb terminals, which connect through the network to hardened, redundant servers running various applications for different needs. The multiple repeaters are tied together via non-ham microwave. Sadly, since ICOM stopped making the 1.2 GHz gear, they are moving now to AREDN-based ham microwave instead. They are doing it all via radio - an intentional design objective.

    I'm aware of one group in south central MN that has adopted Yaesu's Fusion. Several have Dstar. I'm not aware of any using DMR that way, but we have mature networks of all three kinds around here. The DMR repeaters are linked via low speed cell data. Our local group has Dstar radios at all of the main sites in town. The idea is to use them for coordination on UHF without interfering with the analog traffic on VHF. Dstar also enjoys some 'security by obscurity' as scanners for that mode are virtually non-existent.

    Personally, I know analog is going to be the main event, but DV might have it's place. It doesn't have to involve the Internet, and probably shouldn't, though the Internet is much more resilient than most people think it is. I think we are missing a few other options that might serve us better. Weak signal stuff on VHF and UHF provides all the range you probably need unless you live in Texas, Alaska, or California and need to communicate with your state capital from anywhere. We struggle to work our state capital here on both VHF FM and HF, while I know that 100 watts and a small yagi on each end on any VHF or UHF band would provide a solid link over that 75-100 mile distance, 24 X 7. With all the FT-8x7s, IC70xxs and other rigs out there with SSB capability on 6, 2, and 432, all you need are some horizontal antennas to try it out!
    AI7PM and N0TZU like this.
  9. WA9SVD

    WA9SVD Ham Member QRZ Page

    And that, my friend, ASSUMES (on YOUR part) that the other EOC's use DMR. Or do they use P25? or Winlink? PacTerm? D-Star? Or anything else??? How does THAT allow connection between each other?:confused:
  10. W4EAE

    W4EAE XML Subscriber QRZ Page

    In South Carolina, we have a network of link-able (over microwave, not internet) analogue and DMR repeaters that are integral parts of the state's emergency response plan. VHF, UHF and DMR repeaters each serve a distinct purpose.

    In our state within the last year, we have had flooding that eliminated power, cell phones and internet is specific areas. We have also had the Palmetto 800 system go down statewide (P-800 is the first responder radio network used by police, fire, and EMS).

    The amateur radio network I mentioned could certainly fail, but it hasn't yet--even when all the other alternatives had.

    Every part of the county is different.
    AI7PM and KG7LEA like this.

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