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Antenna and weatherproofing

Discussion in 'Hardware' started by Mathew Day, Nov 26, 2017.

  1. Mathew Day

    Mathew Day New Member

    Ok, so I have decided Im going to start this whole process and learn as much as possible
    I will be ordering the pi today and all the goodies that go with it
    I checked out some antennas and it was recommended to use the flightaware 26 in 1090 antenna.....would you guys recommend that as well? if yes, why? and if no, what other options would you suggest?
    I am also curious about how this works , so 1090 is above 18000 feet. Will this antenna still be able to pick up any lower levels or should I also get a 978?
    I am a military aviation nerd and around here we do not get alot of military planes but when we do they tend to be below 18 000 feet unless we have a kc10 with some f15s or f22s flying up to alaska.
    Should i be getting a 978 antenna too?

    I also live in a climate where we get snow, rain and lots of sunshine. And obviously, I want the pi closer to the antenna so does anyone have any suggestions how to set this up?
    Im going to try and put the antenna on the top of the house but because it is already icy that may have to be in the spring as the roof is quite slippery now.

    Thanks guys

    Looking forward to getting started
     
  2. MDA

    MDA Administrator Staff Member

    Hi
    I will try to give you some answers:
    1. "flightaware 26 in 1090 antenna": It can be very good choice, antenna was tested by many users in completely different weather conditions. I haven't got this one but very similar one "ADSB A3" from jetvision.de .
    Of course you can buld your own, G7RGQ or coax collinear, both are performing very well (if you have luck), many design descriptions are available.
    2. "1090 is above 18000 feet": that's not true, from ground to sky limit :)
    3. "should I also get a 978": this question I can't answer, not available in Europe :(
    4. "I want the pi closer to the antenna": good idea, Place your Pi in IP68 box on antenna mast (with FA sticks antenna cable 5m/15ft is not a big issue - If you haven'got professional crimping tool order preassembled cable. Cable quality is very important).

    IMO best sticks are: FA ProStickPlus (1090 only), FA ProStick (1090&978 both).

    Success

    Marcin
     
  3. JoePPi

    JoePPi New Member

    I am currently using a Bulgarian antenna stick from Ebay with FA pro stick, sticking just above the chimney (27ft ASL). Abt 4ft vy good quality cable with abt 1ft adapter cable feeding into the bottom of a freezer box taped and ty-wrapped to a small mast besides sat TV dish (dish support supports the box from sliding). The thick (abt 3/5" dia) coax goes into the bottom of the box, adapter cable connects to it & FA stick. Also contains Pi-3, power-adapter & hookup to mains voltage. Box is actually a little to small but sofar it fits. Been hanging there a few weeks now in nasty, windy and rainy/misting weather. Most connections taped with Scotch-33. If you are really worried get some Scotch-44 self-amalgamating tape.

    My only worry right now it the danger of something overheating especially when the weather gets hotter. Today's max temp was 8C, Pi core temp was max 48C. There is NO ventilation in the freezer box, any solution with a waterproof box with ventilation would be better. I often see NEMA-4(or 4X) type enclosures recommended however, the freezer box was available...

    Heat and humidity is what you should be watching out for but both can be dealt with. Add ventilation to prevent overheating when it gets hot is an entirely different beast especially for my clear plastic box.

    Now to the performance: the FA prostick + with stick antenna above the roof perform substantially better on number of positions (500.000) compared to a cheap $9,- RTL-SDR (160.000) with standard (not cut to size) short antenna mounted to an outdoor light on one side of the house (9ft ASL). However, the number of planes counted (3.000/day) is only about 30% more (cheapo = 2300). Decide wisely and consider the effort to get your antenna high and the potentially needed maintenance access. Having the electronics low might be a maintenance consideration.

    No comments on 978MHz as not relevant in Europe. Military uses ADS-B as well but without position so MLAT setup needed except when Apache's are hopping trees behind the backyard. Then I hear & see their positions....

    Good luck!
     
  4. evangel

    evangel New Member

    hi Mathew and welcome in this forum

    I am near (1.7nm) CYUL, in urban area. I use just a home made Cantenna from a tuna-can, with very good results, from my corner balcony 3d floor.
    the range exceeds 250 nm. System RPi3 indoors connected with 5m sat coax good quality.

    for Cantenna check the following: forum-planefinder-net-threads-three-easy-antennas-for-beginners

    I would try this option first before I commit to a more expensive antenna if I were you. I put the antenna inside an inverted, transparent Tim Hortons coffee cup
    to protect it from the elements, tied it to a broomstick and voila !
    this works from ground level to 43000 feet at 200 nm, provided there are no other nearby obstacles/obstructions.
    978 is for private aircraft. Also if you get a 978 you'll need a second RPi.
    In any case both GenAv and Mil aircraft do not show on ADS-B display.
    MLAT is needed for that and it depends on how many other receivers have enabled MLAT near you.

    HTH
    evangel in CYUL


    vrs max ac581 29nov2017 4.jpg modex loc range 28nov2017.jpg
     
    Last edited: Dec 2, 2017
  5. TXMike74

    TXMike74 Member

    I don't think you need a second RPi, just a second SDR. The key would be to make sure you can assure that 1090dump and 978dump talk to the right dongle every single time (I am sure there is a parameter for that).

     
  6. xJMV

    xJMV Member

    As nobody talked about weatherproofing the antenna, use di-electric grease inside the connection and self-fusing tape from the cable to the top of the threads on the antenna. This way it will be very resistant.

    If you put the Pi out of the house make sure you use a very resistant case like Pelican, UK or Nanuk. And remember to seal properly whatever hole you punch in the case and to add some desiccant inside to remove humidity and eliminate condensation.

    Some antenna like the JetVision might need some marine silicone sealant (UV resistant) to be put over the actual seal between the fiber stick and the stainless base. My first one has been good for 4years before the seal cracked and water has been able to ingress and ruined reception. The water also got into the coax and broke it. In the end a new coax and a new antenna has been needed.
     
    Freqman and MDA like this.
  7. MDA

    MDA Administrator Staff Member

    Same experience with JetVision A3, but my antenna survived (it happened in the winter), quick drying, cleaning, re-seal and OK.
     
    xJMV likes this.
  8. xJMV

    xJMV Member

    I always get on the roof once during summer to ensure all my antennas are ok (physically, self fusing tape is still ok, no water ingress traces, coax are still well attached and show no signs of use, caulking is in good condition...). Last winter just got the antenna... going on the roof by -30c was out of question.

    So I ordered a new cable and antenna to be ready when weather would be allowing me to go in the air and change what is required. The old cable has been cut a bit and a new connector has been installed.

    It is now a spare and testing cable. The antenna has been disassembled and cleaned with alcohol. It did not come back to 100% but it came back good enough to use for testing purpose. From that point, I decided to add sealant right out of the box for antennas showing "weak" waterproofing design.
     
  9. Stephen Sprunk

    Stephen Sprunk New Member

    I've got the FA 26" antenna, and it works very well. I consistently pick up planes at FL300 out to 120nm, FL350 out to 160nm and FL400 out to 200nm; at the other end, I can pick up planes down to about 500ft AGL at two major airports ~20nm away. And that's with the antenna inside my attic rather than outdoors (to be fixed soonish). I'm considering getting a second SDR stick for 978, via a splitter on the same antenna.

    There are higher dBi antennae on the market, but they're also a lot more expensive; the FA one struck me as a good balance of cost vs performance. I don't have the patience to make my own, but if you do, that's definitely worth investigating, both for the education aspect and the cost; google around for various hams that have come up with designs tuned specifically for 1090.
     
  10. James

    James Administrator Staff Member

  11. James

    James Administrator Staff Member


    There is. Mess it up and you brick the SDR -- careful ..

    rtl_eeprom

    Windoze
    http://www.cloud-sdr.com/tutorial-sharing-two-rtlsdr-receivers/
     
  12. Rick

    Rick Member

    James: You spray that stuff directly onto the electronic components? Never used it for that purpose.
     
  13. James

    James Administrator Staff Member

    Placed whatever heat sinks we need to attach then coated them when unplugged, let it dry, plug it in and go.

    Leaves a waxy film, can also use silicon that doesn't cure with acetic acid. I was going to test potting epoxy but forums seem to say it flexes and can bust things up.
     
  14. Rick

    Rick Member

    OK. Excellent. One of my locations could use that treatment. I'll give it a try!
     
  15. James

    James Administrator Staff Member



    I watched a bunch of videos these drone guys are posting about waterproofing a drone for all weather use, and if they crash in a fountain or the ocean. :D

    CRC-400
    WD-40 Silicone
    Corrosion-X

    They all protect. WD-40 probably the most widely available and easy to use. CRC SP-400 and Corrosion-X (used on aircraft) can be bought off amazon.
     
    Last edited: Nov 13, 2018
  16. janrinok

    janrinok Member

    I've had a lot of success using standard plumbing pipes for constructing outdoor containers for both the RPi and the antenna. A short length of 100mm or 120mm piping with a cap on the bottom, and a reducer to, say, a 30 mm pipe at the top provides loads of space for the RPI / amplifiers, SDR etc and I place the antenna in the length of 30mm piping which is cut to the length of the antenna plus a small margin. Being pipes they are completely waterproof, and the screw-on end cap gives easy access to the contents for repairs or whatever. Another advantage is that there are numerous additional fittings available so that the whole thing can be easily attached to a mast or wall . All available from any DIY or builders' merchant, at least here in France, and relatively cheap.
    Currently my 3 receivers are powered by ethernet PoE (5v easily available) or via a home-made power supply that uses the coaxial cable for the antenna to deliver the power to the system when mounted.
     
  17. James

    James Administrator Staff Member

    That's actually genius ... you've given me an idea ..