Results 1 to 11 of 11

Thread: Search and Rescue drone repeater set up

  1. #1

    Default Search and Rescue drone repeater set up

    New to radios so looking for advice

    Alright, we are having a problem and have always had a problem with our radios losing reception in difficult terrain like in the sand dunes and canyons and such with the search and rescue.

    So, Iím trying to pretty much replicate what they did in this you tube video where we hook a cross band repeater handheld radio to a drone, fly it to 400 feet, essentially making a 25-minute cross band repeater for clear communication.
    you tube link https://www.youtube.com/watch?v=JwVcJAbqCmY

    Could something like this work? They guy in the video says it may be illegal so wondering if you know any legality on the issue. Currently most of our search guys have the baofeng bf-f8hp radio. So also do you have a cross band you would recommend that is under two pounds? Flying it up with a mavic pro that will take about a pound and a half

  2. #2
    kc5fm's Avatar
    Join Date
    Nov 2011
    Location
    Altus, Oklahoma, United States
    Posts
    77

    Default

    As you have mentioned, weight is going to be a problem. It's not one that can't be overcome, but a tethered ballon would be a better option.

    Something built around the Pi would be possible.

    As for legality, why is a crossband repeater in space legal and one on the ground not?

    73

    Lloyd, KC5FM

  3. #3

    Default

    Thanks for the reply Lloyd,

    The benefit with the drone over the balloon is that everything I need for the drone setup is about 4 pounds and can easily be packed in on long hiking search and rescue operations. Also the drone has the ability to position itself in wind where the balloon would be subject to wind direction.

    I am considering the "TYT UV8000E 10W High Power Dual Band Two-Way Radio, Walkie Talkie with Cross-band Repeater Function,VHF 136-174/ UHF 400-520MHz Transceiver" to be the one ascending with the drone. The radio itself weighs about a pound and is an easy payload for my drone for about 20-25 minutes of flight time. I am new to radios and wondering if that setup would be decent for my goal of a 20 minute clear line of communication back to our staging point.

    I guess the questions I had with legality are more to do with ID requirements with using cross band repeater function and if it would be possible to do through with the radio airborne. As you can tell I am way out of my league and will do some more reading.

    Thanks again

  4. #4

    Default

    In the UK, a cross band repeater that can be accessed by users unattended - isn't permitted. The killer term in the licence in Europe is this one:

    9(3) Without prejudice to Clause 1 of this Licence, the Licensee shall not establish or use the Radio Equipment in any Aircraft or other Airborne Vehicle.

    Here, operation of airborne radio equipment is very, very tight. Private Pilots cannot even fit their own radio equipment, it must be done by authorised and CAA licensed engineers. I'm pretty certain that the FCC has an identical system where any airborne vehicle with radios is regulated.

    Crossband repeaters here are a fairly new addition to the rules - but the key feature is they MUST be controllable by the licence holder. One sitting at 400ft retransmitting anything it hears might stretch that. If some idiot or just interference is re-transmitted, then the licencee is responsible and they have no simple way to kill it, other than landing the drone and switching it off. Drone battery life also reduces seriously when the motors are working hard. 20 mins is typical on a low/no wind day. I've nearly lost mine multiple times when you don't realise there's a serious headwind on the return flight, and you have to use full power to get the thing home, watching the battery meter tick down, and the alarms kick in, then hold your breath that it can get home before the battery dies. If you can take off, just - then your controller is going to be running considerably higher power to maintain altitude and position. 10 minutes is typical on my DJI phantom in high wind conditions.

  5. #5

    Default

    Paulers thanks for the reply

    The drone itself is the mavic platinum with a 30 min flight time, ive sent it up a few times with a 1.5 lbs weight and it seems to last 20 min. with wind about 10-15. Even 10 minutes is enough of a window to get back to our base camp to request medical supplies, life flight, additional gear, gps coordinates, ect.

    Thanks for the clarification on the legal points.
    Tested it out today and descending 400 feet took about a minute, form 200 feet about 30 seconds. I wonder if 30 to 60 seconds is considered quick enough to be in "control" and kill it.

    Also did have not find anything like this in the FCC but i'm sure its in there somewhere. "9(3) Without prejudice to Clause 1 of this Licence, the Licensee shall not establish or use the Radio Equipment in any Aircraft or other Airborne Vehicle. "
    any way to get around this? This project would make a huge difference in the way we did things if we were able to do it.

  6. #6
    travis.farmer's Avatar
    Join Date
    Jul 2017
    Location
    Farmington, Maine, USA
    Posts
    120

    Default

    Part 97 : Sec. 97.11 Stations aboard ships or aircraft.
    (a) The installation and operation of an amateur station on a ship or aircraft must be approved by the master of the ship or pilot in command of the aircraft.

    (b) The station must be separate from and independent of all other radio apparatus installed on the ship or aircraft, except a common antenna may be shared with a voluntary ship radio installation. The station's transmissions must not cause interference to any other apparatus installed on the ship or aircraft.

    (c) The station must not constitute a hazard to the safety of life or property. For a station aboard an aircraft, the apparatus shall not be operated while the aircraft is operating under Instrument Flight Rules, as defined by the FAA, unless the station has been found to comply with all applicable FAA Rules.
    this is all i could find, that may be relevant.

    ~Travis
    PASSED Tech exam on 09-09-2017 (awaiting callsign)
    Equipment:
    Kenwood TS-430s, Bucket-base 20 foot vertical antenna
    Kenwood TH-K20a, HYS NA771 antenna

  7. #7

    Default

    The UK licence terms are easy to find, but the US ones don't seem to be anywhere easy to find? Odd that!

    Here in the UK - drone radio links are just not allowed - the US seem more willing. There used to be an old exception to radio licensing for use in an emergency here - something along the lines of in a genuine emergency, ANY available radio system can be used, but I can't seem to find that anywhere current - it was so that in an emergency situation anybody on a ship or airplane or similar could grab the mic and call for help?

  8. #8

    Join Date
    Nov 2017
    Location
    With my wife
    Posts
    81

    Default

    I suppose you could get around the whole control op problem by having a quick release for the BaoFang so it would drop to the ground if control was lost somehow...

    Just coloring outside the lines fellas!

  9. #9

    Default

    I'm not going to add much here except this: Thanks to the FAA becoming involved in drones and requiring a license to operate as a commercial endeavor, it opens a whole new can of worms for what the OP wants to do. Better bet would be a tethered helium balloon that would then fall under "experimental" for a licensed ham. One has to remember there are coordination issues for commercial frequencies and GMRS will require users to have licenses and antenna height for a small station is 20 feet.

  10. #10

    Default

    I think I found the solution,

    Just a simplex repeater plug and play box. If we loose radio connection with the team, send the box and a radio up with the team, then we have radio back on just with an echo.

    A simplex repeater simplifies things tremendously. Instead of having to receive and transmit at the same time, using frequencies on 2 bands, the unit will receive, record, and retransmit all on one frequency.


    We have a few part 107 pilots, and as long as we are under 400 feet and stay within line of sight(with binos I think were good.

    Thanks all.

  11. #11

    Default

    Quote Originally Posted by Tempstar View Post
    I'm not going to add much here except this: Thanks to the FAA becoming involved in drones and requiring a license to operate as a commercial endeavor, it opens a whole new can of worms for what the OP wants to do. Better bet would be a tethered helium balloon that would then fall under "experimental" for a licensed ham. One has to remember there are coordination issues for commercial frequencies and GMRS will require users to have licenses and antenna height for a small station is 20 feet.
    There was actually someone commenting on the video that hydrogen would be better than helium because it costs less and will lift more. I only have one word for him: "Hindenberg..."

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •