ADS-B decision

Discussion in 'Avionics and Upgrades' started by MountainDude, Feb 28, 2019.

  1. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    Yes, there were several new products that started broadcasting this past June, including the first two in your list. Towers have been visible on charts in ForeFlight for a long time, though I think you might have to switch that on. Hiding distant traffic has been there for a long time.

    ADS-B Out equipped traffic is always transmitting position... But not necessarily on both bands. If you have a dual-band receiver, you should see all other Out-equipped traffic. If you have a single-band receiver, you're relying on the towers to re-transmit traffic that's on the other band (I think this component is called ADS-R as in Rebroadcast).

    In addition, non-ADS-B Out equipped traffic that is on radar will be sent to In-equipped traffic if it's within their "hockey puck" (±3500 feet and 15 miles, IIRC) (TIS-B).
     
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  2. MBDiagMan

    MBDiagMan En-Route

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    Oh! I get it about the ADS-R! Now that I have focused on this I am learning all kinds of stuff. Thanks.

    I read somewhere and maybe don’t yet have it right, that if you are transmitting OUT, the ADS-B traffic around you will transmit directly to you. I still need to study that one. I don’t have that concept in my head correctly yet. Anyway if you have OUT, it somehow effects what you are receiving on your IN.
     
  3. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    ADS-B Out equipped traffic is always transmitting to everyone, whether you're equipped or not. That's what you see when you have a Stratus or similar device.

    What having your own Out will get you is that non-equipped traffic that's on radar only. The ground stations will transmit the location of that traffic to you if you have Out *and* In and there's traffic in your "hockey puck".
     
  4. MBDiagMan

    MBDiagMan En-Route

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    Got it! Thanks cheesehead!
     
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  5. MountainDude

    MountainDude Pre-Flight

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    I tried to order SkyBeacon today, but it only allowed me to pre-order (which I did). I called them to ask them about the status of my order, but only got voice mail. Does anyone know how soon I will get the unit?
     
  6. kgruber

    kgruber En-Route

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  7. MountainDude

    MountainDude Pre-Flight

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    They don't have the adapter (just called them and they did not even know about it till my phone call).
    :(
     
  8. MountainDude

    MountainDude Pre-Flight

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    The SkyBeacon is backordered for 2-3 weeks, so we just need to wait. They are slammed with orders, apparently.
     
  9. MBDiagMan

    MBDiagMan En-Route

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    I am puzzled by some things I have read, but I don’t know where so I can’t go back and confirm.

    I read that over 200, something like 240 Watts are required. I read elsewhere that the SkyBeacon transmits much less than that. So... if both of those tidbits are correct, how is the SkyBeacon legal? I tried to become enamored with the SkyBeacon, but just could not get there for several reasons. I see why people, especially those on a limited budget are going with it, but I am just not yet convinced it is a good long term choice.

    My $0.02,
     
  10. Ryan Klems

    Ryan Klems Pre-Flight

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    The SkyBeacon is not a transponder, it is a UAT device. Transponders have higher wattage requirements than does a UAT device.

    https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC 20-165.pdf

    "For the UAT link, 16-watts minimum transmit power at the antenna output is required. For the 1090ES link, 125 watts minimum transmit power at the antenna output is required."

    If you look at their manuals, the Stratus ESG has a 310 W nominal output, and a Trig TT31 has a 240 W nominal output, in order to make sure it gets to 125 W minimum at the antenna. The SkyBeacon has 25 W, it's not required to have more.
     
  11. MBDiagMan

    MBDiagMan En-Route

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    Thanks for the explanation Ryan.
     
  12. Matthew Rogers

    Matthew Rogers Pre-takeoff checklist

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    And you know in my 150, I probably don’t want more than 25 watts in case my small alternator starts to go bad. After replacing nav lights and taxi lights with LED, it would be a shame to then have to pump out another 125 watts just to satisfy the FAA. This way with the Skybeacon, if my alternator goes bad at night, I could reasonably leave the ADSB on until the battery fails and have more of a track for people to find me.
     
  13. ahypnoz

    ahypnoz Pre-takeoff checklist

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    The skyBeacon uses .5 amps max about (5 watt power draw) with a 25 watt output.
     
  14. Matthew Rogers

    Matthew Rogers Pre-takeoff checklist

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    Can someone please explain how you can get 25 watts of power output from 5 watts of power input? What am I missing here?
     
  15. MBDiagMan

    MBDiagMan En-Route

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    That is intermittent peak power. I expect energy is accumulated in a capacitor over time then a high power burst is discharged for a short duration of time.
     
    Last edited: Mar 20, 2019
  16. Matthew Rogers

    Matthew Rogers Pre-takeoff checklist

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    Good answer. Now I don’t have to go finish my perpetual motion machine using a skybeacon as the power source.
     
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  17. MBDiagMan

    MBDiagMan En-Route

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    Well, if you could make it work as a perpetual motion machine, then I might consider buying one.
     
    Last edited: Mar 21, 2019
  18. ahypnoz

    ahypnoz Pre-takeoff checklist

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    Not only do they operate with only 3 watts and transmit at 25 watts but it also produces 40 candelas of light intensity.

    From the skyBeacon install manuel
    UAV-1002305-001 2 Rev C
    5.1 Physical Specifications:
    14V Current 0.5A Max
    And Transmit Power at 44 dBm or (25 Watts)

    From one of their advertising adds (a little more generous with the numbers)
    • Weight: 90 grams
    • Dimensions: 124 x 116 x 48 mm
    • Input voltage: 11-31 VDC
    • Operating power: 3 W
    • Operating temp: -45 to 80°C
    • LED position light: Aviation Red / Intensity- 40 candelas
    • Power classification: 978MHz UAT Transmitter- DO-282B Medium Power
    • WAAS GPS: Tracking- 166dBm, Reacquisition- 160dBm, Cold Start- 148dBm
    • Power transcoder: decodes Mode A,C and S via DC input
     
  19. chartbundle

    chartbundle Cleared for Takeoff

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    The same way your transponder outputs 200+W without needing a 10 or 20 amp breaker. GTX 335: 14/28VDC (15/17W Max) ; Transmit power 200W minimum
    Behold, the magic of capacitors.
     
  20. Mark B Schick

    Mark B Schick Filing Flight Plan

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    Great looking panel. Pure art!
     
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  21. MBDiagMan

    MBDiagMan En-Route

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    Thanks Mark! That little highly modified 140 is my baby.
     
  22. weirdjim

    weirdjim En-Route

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    Ah, the magic of PEAK power. Capacitors have little to do with it. An integrated circuit pulse generator (yes, a small capacitor is required for the timing, but the duration of the pulse is determined by the rest of the circuitry) fires the transponder to urp up a few microseconds of peak power a few times a second. To the radar at the receiving end, whether it is peak power for microseconds or full power transmitting continuously, it makes not a whit of difference. Call it persistence of the receiver if you will.

    Same for lighting. The eye responds to persistence of vision. If you are caught outside in a thunderstorm and you see a lightning bolt flashing across the sky, if you shut your eyes, you will see that lightning bolt for the better part of a few seconds. If I pulse a high power LED on for a few milliseconds and then off for a few hundred milliseconds, all your brain says is that the LED is continuously on, even though it is off for a hundred times longer than it is on.

    Jim
     
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  23. IK04

    IK04 Cleared for Takeoff

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    DC current in watts and RF output as a function of dB gain is how we come up with "transmit power" in Watts.

    44 dBm out of 0.5 amps current draw is very efficient. Modern microelectronics at work!
     
  24. MuseChaser

    MuseChaser Pre-takeoff checklist

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    The EchoUAT is for LSA/EX and is not tso'd for certified aircraft. I almost got caught by that myself, since "2020 compliant" is plastered in big print at the top of the page. My apologies if you already knew that and it doesn't matter in your situation.
    Glad I found this thread...been wrestling between SkyBeacon, Stratus ESG (w/ or w/out 3i option...already using Stratux I built and not sure I want to spend the extra $500 for convenience when I already have ads-b-in on a box that cost less than $150 to build), and Garmin GTX335. My transponder is ancient, and I'd like 1090 as I live near Canada, so the additional $1k spent on the Stratus or Garmin over the SkyBeacon seems more than justifiable since I'd also be getting a new transponder.
    Now, deciding between THOSE two.. Garmin is a little more money, and i get the sense that Garmin kind of locks you into buying more Garmin stuff if you want your boxes to talk to each other. However, it comes with a new altitude encoder, while the Stratus uses your existing one. For me, that's a tough call. Plane is a '65 PA28-140, no panel gps, single narco navcom, glideslope.
    Further thoughts/advice between those two units? Benefits of the 3i option, other than convenience, over my current Stratux? Other less expensive options still worth considering? Best prices on these two boxes? How much to budget for installation costs?

    Thanks. Feel free to point out any stupidity...
     
    Last edited: Mar 29, 2019
  25. MBDiagMan

    MBDiagMan En-Route

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    What panel GPS does it have?
     
  26. MuseChaser

    MuseChaser Pre-takeoff checklist

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    Sigh...typo...meant to write NO panel gps.. just Fltplan go and Stratux on android tab. Sorry for the screwup.
     
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  27. MBDiagMan

    MBDiagMan En-Route

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    I had a similar situation with my Cessna and really like what I ended up with. It has an old, but very nice IFR panel, with no panel GPS. No GPS in the plane beyond an EFB. I went with the Stratus ESG and the permanently mounted 3i. It comes with antenna and AHRS sensor for permanent mount. Once installed it gives me a modern transponder with key entered sqwauk, AHRS on Synthetic Vision and reliable GPS receiver and reliable ADS-B IN without wires strung throughout the cockpit to get tangled in something. It makes for great functionality and a neat, solid cockpit and panel.

    Just because it works for me, doesn’t mean it’s best for you, but I am very pleased and it was relatively economical.
     
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  28. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    I dunno, it seems to me like you would benefit from the Garmin GNX 375. You'd get a panel mount GPS, ADS-B in and out all in one.

    Of course, that "single Narco nav/com" likely isn't going to last forever. Hell, Narco didn't last forever. :rofl: So maybe it'd be better to put in a GTN 650 and a 335/345, if you're planning on keeping the plane for a while. If you're not planning on keeping it, you can either leave it for the next guy, or get the 375 and make your plane pretty attractive when it comes time to sell.

    Yeah, they had a pretty pathetic useful load. Maybe 400 pounds. Put in the 24 gallons of usable fuel (144 pounds) and you're left with 256 pounds total available for people. Want to get checked out? You either need to weigh well under the average, or have Tinker Bell as your flight instructor.
     
  29. MuseChaser

    MuseChaser Pre-takeoff checklist

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    I appreciate the advice. Those units look wonderful and would certainly go a long way towards future-proofing my plane, but my pockets aren't anywhere near that deep, and the second option would represent at least 50% of the value of the plane. The sad truth is that, as great as a panel GPS would be, it's just not in the budget. Heck, jumping from the $1850 SkyBeacon to approx $3200 for buying and installing a 335 or ESG makes me sweat a little.
     
  30. MBDiagMan

    MBDiagMan En-Route

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    I understand perfectly Muse. My flying budget is no longer significantly limited, but it has not always been that way for me. Thinking it through thoroughly is the right thing for you to do. Been there, done that. Keep thinking it through and bouncing things off of us. Research thoroughly, but budget wisely. There are times when you can pinch the pennies TOO hard and end up spending more in the long run.

    Keep thinking it through and you will come up with the best decision for you. Those of us on the forum find it very easy to spend other people’s money. I guess we could be politicians.
     
  31. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    What the 335/ESG gives you is a new transponder, really. Do you need a new transponder?

    If not, get the GDL-82 or Skybeacon and a portable In device (like a Scout, Stratus, GDL39, etc) and be done with it... If it's a bird that isn't going to be used for IFR, and you're just looking to keep flying inexpensive, that's all you need, and it's more than most people had 15-20 years ago.
     
  32. MuseChaser

    MuseChaser Pre-takeoff checklist

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    Exactly. My transponder is ancient, and I'm concerned that going the cheapest route (SkyBeacon) might mean that in the near future I might need a new transponder anyway, which would cost more than the money I'd save with the SkyBeacon now.. and I still wouldn't have 1090 capability.

    See above.. :)

    If I went w/ the SkyBeacon, I'm giving up a new transponder for $1000 (the difference between the SkyBeacon and the 335/ESG options) and 1090. I live about 90 miles from Canada and, although I haven't flown there yet, I definitely see it happening in the near future. Other posts have said the necessity for 1090 in Canada isn't in place quite yet, but this may very well be time when penny-wise/pound-foolish kicks in. I'd hate to spend $1850, only to find out I need to spend another couple grand any way in a year or two.
    Right now, my plane is IFR capable for VOR and ILS approaches, but I know GPS is slowly eating away at the maintaining of those facilities. I've completed about 1/3 to 1/2 of the IFR syllabus with my instructor in the plane, and am planning on continuing, if that helps shape any further advice.

    I DO very much appreciate the thoughts.. thank you!
     
  33. hindsight2020

    hindsight2020 En-Route

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    what kind of airplane?
     
  34. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    Hmmm.

    Right now, we don't know what Canada is going to require. Almost certainly 1090, but possibly antenna diversity as well. Right now, the diversity solutions are quite expensive - The only ones I know of are the NGT-9000D and the new Garmin GTX 345D. So, savings plus equipping for Canada right now is going to be difficult, and you will over-spend if you equip with antenna diversity and it turns out you don't need it for the flying you plan to do there.

    I'm glad to hear you're working on your instrument rating - That really opens up a lot of possibilities to use GA for travel... But travel usually makes people want a faster airplane, too. ;) How long do you plan to keep your plane?

    If you're at the limits of your airplane purchase budget already and you plan to keep it a long time, then I'd go back to suggesting the GNX 375. Not being able to fly a GPS approach at all is already very limiting, and in the next 10 years it will likely be severely limiting. For example, the last place I flew to was KSPW. It's a rare non-towered field with an ILS, but it has four runway ends. All four have GPS approaches, one has the ILS, and there's a VOR approach to the end opposite the ILS.

    I landed, at night, opposite the ILS, with a pretty hefty wind. Because of the wind, the only two runway ends viable for landing would be the one I used, and one of the RNAV-only ones. Without any GPS capability, I would have had the option of a straight-in VOR approach with 800-1 minimums, or a circling ILS at night (see the "Lear down at TEB" thread for some discussion of why that's a bad idea) with 500-1/2 mins. With a non-WAAS GPS, the other runway became an option at 500-1, and the runway I landed on had 400-1 minimums. With a WAAS GPS, I could land on either one, with mins at 250-3/4 or 250-1.

    And that's in the flatlands. The minimums can differ by a lot more at airports with more vertically developed terrain. Another recent example like that for me would be 1400-1 1/4 on the VOR approach, 1000-1 for LNAV (non-WAAS) minimums, and 200-3/4 for LPV (WAAS) minimums.

    It's a HUGE difference in capability, even over a plane with WAAS GPS. Before I got my panel upgraded, I had a non-WAAS GPS and more than once I was the guy going missed when others with WAAS were getting in. And we haven't even talked about how much money being able to go GPS direct will save you over time. And if you end up deciding to sell your plane after all, it'll likely be a lot easier to sell, and fetch more money, if it's fully IFR equipped with a modern GPS and ADS-B In/Out.

    Now, If you might be able to sell your plane and pick up a Comanche or something like that for better traveling capability, I'd probably go a different route, just finish your IR without a GPS and get the GDL-82 or Skybeacon. If your transponder happens to die before you sell the plane, you can get a nice GTX 327 pretty darn cheap these days. (I sold the one I pulled out during my upgrade for $250.) Since a nice, newer used transponder like the 327 is quite a bit cheaper than the difference between the GDL 82/Skybeacon and the GTX 335/Stratus ESG solutions, unless you expect to own the plane long enough that you're sure your existing transponder isn't going to make it that long, you're probably better off taking your chances and hoping it lasts until you sell the plane.

    If you're keeping the plane "forever" and can't afford the GNX 375 right now, I guess the 335/Stratus ESG option, with a potential later addition of a GPS 175, might be the ticket... But it will cost more in total if you're doing two separate installations like that.
     
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  35. MBDiagMan

    MBDiagMan En-Route

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    I am pretty sure that the ESG/Stratus would not feed ADS-B IN to the 375. It would take a Garmin transponder to do that. There might be others that would, not the Stratus.
     
  36. MuseChaser

    MuseChaser Pre-takeoff checklist

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    Sorry.. Thought I had mentioned it. PA28-140 Cherokee, '65.
     
  37. flyingcheesehead

    flyingcheesehead Touchdown! Greaser!

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    The 375 has ADS-B In and Out already built in, why would it need a feed from another transponder?
     
  38. hindsight2020

    hindsight2020 En-Route

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    Meh, maybe if an ArcherII. But a 140? Odds say you outgrow that thing. Yeah put a skybeacon and get your flying in. Then sell that thing and get yourself an EAB if your mission is two seater, or get a higher powered cherokee or C-182 or the like, and sink avionics money on an airplane that will take you a little longer to outgrow. I know where you are at, I used to own a C-150.
     
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  39. murphey

    murphey Final Approach PoA Supporter

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    "vertically developed terrain"

    gotta love that description! Goes right along with "cumulo granite".

    Must remember that for the next YE ground school.
     
  40. murphey

    murphey Final Approach PoA Supporter

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    Guess what? I've owned my Cherokee 180 for almost 20 years...as much as I'd like a faster airplane, it's just dandy, thank you. Not terribly expensive to maintain, everyone knows how to fix them, and there's always parts. If the OP is happy with the 140, and doesn't expect to need more airplane, then add whatever upgrades and be happy.

    Why the 180? Because I live in Denver, and want to be able to take off in the summer. If the OP doesn't live in high altitudes, then the 140 may be just fine.
     
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