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Newbie question on technical FPV stuff

Discussion in 'Pilots Lounge' started by K_Note72, Feb 6, 2013.

  1. K_Note72

    K_Note72 Studio Forums Elite
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    Hey so at this point in time I'm doing some research into flying kits so someday I might be able to take to the skies. One major factor affecting my choice is the future possibility of flying FPV. In my studying into FPV I started coming across mentioning to make sure whether the FPV system's frequency is legal or not in one's own country, and I'm curious about what's legal in the US (I know that some of these frequencies are used for aircraft, military, law enforcement and other "authorized" sources). Obviously the 5.8ghz and 2.4ghz bands are legal (or else the whole rc industry would be under fire O_O), and from what I know there's 900mhz, 1.2/1.3ghz, 2.4ghz and 5.8ghz frequencies. Since I can't seem to find any internet resources clearly stating regulations, most of what I've learned is from random others on the topic. Most claim 900mhz is flat out illegal, some say 1.2 & 1.3 require a permit accessible to civilians, others say 1.2 is totally free to use. Some claim that many including themselves just 1.2 anyways but "use it responsibly and exercise caution.

    I live way out in the boonies and am surrounded by mountains covered in tall evergreens, making 5.8 only useable down in the valley. 2.4 would face too much interference from outside sources, including the transmitter. That leaves 1.2/1.3 and 900 to get decent object penetration. Since 1.2/1.3 is the one up in the air, can someone definitively tell me whether it's legal or not?
     
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  2. K_Note72

    K_Note72 Studio Forums Elite
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    I finally got somewhere with this topic. I found a US frequency allocation chart on another rc forum (was told that the green sectors are "amateur" and considered legal for civi use).

    [​IMG]

    By the looks of it, 902-928mhz, 1.24-1.3ghz, 2.3ghz, 2.39-2.45ghz, 3.3-3.5ghz, & 5.6-5.9ghz are all fair game. Most of these are shared with govt. radio-location, but other uses I think are fine to use.
     
    #2 K_Note72, Feb 11, 2013
    Last edited: Feb 11, 2013
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  3. K_Note72

    K_Note72 Studio Forums Elite
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    With an extra paycheck coming, I keep feeling the urge to explore a little into an fpv system. With something like this, I'd be doing a lot of testing with it before I trust it with a plane, so the right system is crucial. My first thought is, what frequency? 1.3ghz or the ever-popular 5.8ghz? Most of what I hear is the 5.8 doesn't like losing line-of-sight, and in an area with lots of tall trees and few open areas in between that can be a problem. I live in the boondocks with miles upon miles of open public forest, so FPV is a little bit safer than say in town. My only concern in this scenario is the powerlines, what frequencies do they emit interference at? The 1.3 becomes my main option, with a 433mhz uhf for the radio, and I don't know whether loggers or truckers use uhf. I did a check on various rf uses in the county, all main services (fire, forestry, ranger, police) operate on 150-175mhz and 450-460mhz. I'll figure out the situation with the ham license, but for now I'll stick with my better judgement and just ride on common sense out where no one can get hurt if something ever did go wrong. I'll start by having a friend positioned on one hill and see the reception I get from another hill, and go from there. Any input?
     
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  4. K_Note72

    K_Note72 Studio Forums Elite
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  5. Chunder

    Chunder Fixer
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  6. K_Note72

    K_Note72 Studio Forums Elite
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    I heard through the grapvine the RTH systems don't work without an active failsafe, is that true?
     
  7. Chunder

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    Depends on the system you use. Nazas and Wookongs work best with a receiver with a smart failsafe built in, but they also have a "Receiver Advanced Protection Function" which will work, but not as well and has some disadvantages such as a delay before activation and is a bit trickier to turn off.
     
  8. K_Note72

    K_Note72 Studio Forums Elite
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    Well for example, let's say that it was to be paired with an open LRS uhf system, and said system was running custom firmware that had an in-flight failsafe function programmed into it. And let's say the preferred rth system was an Arkbird................
     
  9. K_Note72

    K_Note72 Studio Forums Elite
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  10. K_Note72

    K_Note72 Studio Forums Elite
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    Sad news. I finally crashed the bixler.........

    I was in the middle of a roll to do an inverted pass when the plane started rolling back the other way, like something was pushing down on the wing. It was headed straight for the ground and I tried to recover but to no avail.

    [video=youtube;QMnKuexm6ZA]http://www.youtube.com/watch?v=QMnKuexm6ZA[/video]

    Last night I scavenged out all of the parts, surprisingly everything fared well except the plane itself. The spar in the wing snapped like a twig, next time I'm going for a solid spar like CF or a dowel rod.

    [​IMG]

    Next paycheck I'll order a kit version, since the fuse halves are left unglued it'll be easier to make a hatch into the side and turn that empty inner area into future FPV space
     
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  11. K_Note72

    K_Note72 Studio Forums Elite
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    I have a list of parts for a future fpv setup, they're not firm options and may change if more suitable options emerge

    -BevRC 1.3ghz 800mw video tx&rx Best FPV and UAV device: BEV 1.3G 800mW [BEV 1.3G 800mW]- US$74.99 - www.bevrc.com

    -Cyclops Storm OSD/GPS/RTH Best FPV and UAV device: Cyclops Storm OSD 2013 version v1.03 firmware--the best-value AHRS based OSD with RTL/RTH fucntion [Storm OSD]- US$140.00 - www.bevrc.com

    -ReadyMadeRC cloverleaf antennas

    -Orange OpenLRS 433mhz radio tx&rx https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=27095
    https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=27096

    -ReadyMadeRC Whip and dipole antennas

    -HD FPV monitor w/ shroud (non-bluescreen)
     
  12. K_Note72

    K_Note72 Studio Forums Elite
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    So it's been a whole 1/2 of a year since I last commented on this topic, and I'm still at the same point I was when I made that post (of course with the exception that i finally bought a new bix shell and performance motor). Things for me the past months have been kinda rocky, dealing with life in general, and my RC stuff in general has been cold & dried up on the back burner. So now that I've finally made that step, I'm glancing back at the FPV situation to see what's new. This was originally gonna be my planned fpv setup:
    -BevRC 1.2ghz 800mW tx/rx set
    -1.2ghz cloverleafs and helical antenna
    -Cyclops OSD/RTH
    -HD camera (similar in weight to Gopro)
    -Turnigy 9XR
    -100 mWOrange openlrs UHF tx/rx set (now offered in 1W which borders legal US boundaries)
    -Dipole and Whip antennas

    One dilemma I face: calculating flight times based on battery specs, esc and motor draw. I have three 2200mah 3s lipos and an older 5000mah 3s (3-4 years old and made for cars so heavy and not intended for flight). My esc can handle up to 60A continuous and my planned motor draws 35A. I know the video tx draws 12V 300mA, I just don't know how that translates to overall operation time. Assuming low wind conditions, to get maximum flight time I want to find out my options:
    -Run the whole system (power and video) off just two 2200mah packs in parallel (makes 4400mah)
    -Run the whole system off the one 5000mah pack (weighs more than the two 2200mah packs)
    -Run the whole system off three 2200 packs (weighs a bit more than 5000 pack, reach threshold of having to choose between lower weight or more mah)
    -Run the power on two 2200s and video on the third (dependent on which runs out first, power on two packs or video on one)

    So far, with the Bixler not being built for payload, the second two aren't really looking like viable options. After I crashed my bixler and scrapped the shell I planned out how to make a side hatch for it (like on the skywalker) so I can have a decent payload. Even having most of my weight near the CG I'm not so comfortable putting so much battery weight on it. One thing I know: I have an HD camera similar in weight to the gopro hero3, mounted on the hatch cover with a 2200mah right inside, and after adding a AAA battery counter-ballast to the tail it flies unaffected (two factors affect a seesaw's balance at the fulcrum, the weight of the rider at each end and each rider's distance from the fulcrum).
     
  13. K_Note72

    K_Note72 Studio Forums Elite
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    [video=youtube;O_e1KQPtZcE]http://www.youtube.com/watch?v=O_e1KQPtZcE[/video]
     
  14. TracaR

    TracaR MASTER BUiLDER
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    to put it lightly, there is no way to accurately figure out your flight times, since your amp pull at any given time will fluctuate while flying.. but there are things out there that can help with this issue,
    i use rvosd g6 . it has a live flight time estimator built in and will tell you how far you can fly at that current moment, based on the telemetry and flight parameters, ( gps info/amp draw )
    its a fully autonomous RTH system too ( auto pilot )
    half my wings have a minimum of 10,000mah battery's which works out to roughly 100kph flights and 30 mints in the air, i have one that will do a max of 82kmph and has much longer flight times, my larger wings can hold alot more battery's ;)
     
    #14 TracaR, Feb 19, 2014
    Last edited: Feb 20, 2014
  15. K_Note72

    K_Note72 Studio Forums Elite
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    do flying wings generally get more efficiency and flight times than gliders like the bixler 2? Given that with mods I can now fit in my 5000mah pack while still maintaining CG, I just need a chance to take it out and fly it but february in Oregon is anything but suited for that!
     

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