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Discussion in 'Introductions' started by VenomBallistics, Aug 30, 2018.

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  1. VenomBallistics

    VenomBallistics

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    I see a few familiar names from the dutchforce forum ... your probably rolling your eyes seeing me again.
    In the course of migrating to a new computer, I found the old DF electronics forum to be inaccessible.
    anyone have any insight?
     
    abeluna likes this.
  2. Harald Kapp

    Harald Kapp Moderator Moderator

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    Welcome to EP.

    Harald
     
  3. kellys_eye

    kellys_eye

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    Hi there - you'll recognise my name then! I left DF a while ago after frustration with the site being permanently trolled/spammed and the owners reluctance to upgrade it to both stop that happening and also to allow posting of images (imagine not being able to do that on a modern site!).

    Found this forum and discovered it to be very friendly and supported by some very astute and intelligent members. You made a good choice to join here...
     
    abeluna likes this.
  4. Cannonball

    Cannonball

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    Hello and welcome.
     
  5. VenomBallistics

    VenomBallistics

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    Looking pretty bleak for DF ... every time I've checked, I see internal server error.
    I'm thinking its toast.
    I miss some of the crew. Tekwiz, CWB and others. I think we will need to find CWB's Slys Snake Oil pic on a few of these threads ... but thats par for the course till they see how the laws of physics apply
     
  6. kellys_eye

    kellys_eye

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    Tekwiz left DF quite a few years ago and CWB had medical issues that raised some concerns (and I don't recall seeing him post for a good number of months prior to my departure).
    Tim was always a valuable source of knowledge and would be very welcome here - amongst many of the regular posters there. The community at DF was great in its hayday but the owners lack of support/input for the site meant it was always doomed to eventual collapse.

    Even when I was prolific there, people were 'losing interest' and drifting off (Tommy aka J0Ongle for example). Shame - as it is for any site that started in the early years - but times move on (as do people) and you go where the flow takes you.

    Electronics Point is (personal opinion) the most friendly of places for such subjects and is particularly well run by the owner and moderators. I can see it going for a lot more years than DF managed and I plan to be part of it - usual disclaimers apply of course :D
     
  7. VenomBallistics

    VenomBallistics

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    I never heard of it before I let the search engine guide me here to be honest.
    I see Tommy on YouTube showing off his various scores. He seems to ignore the comments section though.
    My interests have morphed some since the hayday of DF. I've migrated back to RC aircraft and took up homebrewing I can see some of the new age woo woo over in the general topic ... reminded me of the reoccurring topic of the Rodin coil. I guess that cannot be avoided, but it can be laughed at
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    We have a special section for that :)

    It is a dimension as vast as space and as timeless as infinity. It is the middle ground between light and shadow, between science and superstition, and it lies between the pit of man's fears, and the summit of his knowledge. This is the dimension of imagination. It is an area which we call... The Twilight Zone.
     
    Last edited: Sep 2, 2018
  9. VenomBallistics

    VenomBallistics

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    well ... that'll serve to brighten my mood in the days to come :D
     
  10. abeluna

    abeluna

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    Nice to meet you :cool:
     
  11. hevans1944

    hevans1944 Hop - AC8NS

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    Welcome to EP @VenomBallistics. Looking forward to your posts here.

    Is the vignetting of the aerial image in your avatar deliberate, or just a result of how you had to mount the camera?

    I am looking into either purchasing an inexpensive drone to take aerial photographs of my property here in Florida (for the purpose of locating amateur radio antennas), or to find someone with whom to contract for those images, perhaps a hobbyist nearby in Venice or Sarasota. I haven't tried to find any local clubs catering to drone operators yet. Google Maps provides fairly decent rectified overhead images, but real-time and higher resolution would be nice.

    It is amazing how far drone technology has progressed in the last twenty years... or RC fixed-wing airplanes for that matter. All driven by the availability of LiPo power cells, dirt cheap microprocessors, inexpensive accelerometers and rate gyroscopes, and some very spiffy (mostly) open-source software. I've not tried it yet, but I am told the modern drone craft practically fly themselves.

    Might have to add a 3D video camera-pair in the air, plus a pair of head-worn stereo video goggles on the ground, to finally capture the "real" experience of flying. Well... I am 99 44/100 percent sure this has already been done, by professionals, if not yet a common amateur or hobby practice.

    73 de AC8NS (Hop)
     
  12. VenomBallistics

    VenomBallistics

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    What you've herd is somewhat mixed.
    Some of the DJI drones do pretty much fly themselves ... for about $1000
    How I go about it, you can have a fleet for the price of a single DJI phantom 4 Pro ... but you're going to need to earn some pilot cred.
    The Avatar pic is from a Mesa RC design F15 .. airframe less hardware is $4, the camera is simply hot glued into a slot hacked into the dollar tree foamboard nose section, just ahead of the canopy.
    it's taken from an FPV vid making a 100+ mph pass on a party.
    For what you seem to want to do, You might want a multi air frame approach
    A good twin motor fixed wing for scouting and a quad for detail work.
    You're not limited to a single camera ... thus a stereo HD solution could be set to record to storage onboard while a CMOS FPV co-witnesses for flight operations. You can even set up for a two man crew where one flys the drone and the other runs the high res camera.
    About the only issue remaining is that one seems forced to build wiring harnesses between the various video components. The industry has thus far refused to settle in on any sort of standard plug
     
  13. hevans1944

    hevans1944 Hop - AC8NS

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    @VenomBallistics, thank you for the informative reply. I didn't want to hijack your introduction thread, but it appears from some of your other posts that you have considerable knowledge and experience vis a vis RC flying machines, so I just waded on in...

    Years ago, about 1958 or so in the previous century, my father and I became interested in building small, fixed-wing, single-engine, control-line flown airplanes. Dad started off by gifting me with a Spirit of St. Louis balsa wood kit airplane, powered by a mighty .049 glow-plug IC engine, and flown in circles with a U-Control line that adjusted the pitch or angle of attack of the airplane. Dad was in the Air Force and stationed at Lowry AFB in Denver, CO at the time. Lowry had a pretty good base hobby shop and a Base Exchange that sold kit models for very reasonable prices. Add some "dope" and some paint and some decals and head off into the wild blue yonder. Or not. I never did learn how to fly model airplanes using the U-Control cables, and RC was a hobby best left to the "big boys" with deep pockets full of cash. So, after a period of time Dad lost interest and so did I. I continued on with my electronics hobby, scrounging used parts (dumped in the back of radio and TV repair shops) to "play" with.

    That hobby continues to this day, and it eventually led to a bachelor of electrical engineering degree after an initial preliminary career as an electronics technician. Now that I am a little older and have an amateur radio license again, I think I will investigate the modern world of radio-controlled flight.

    If the OP of the original thread that you responded to wants to extend his control range beyond the visual, I would suggest he carefully investigate the laws, rules, and regulations governing and limiting this sort of activity. Drones are drawing a lot of attention now days, not all of it favorable.
     
  14. VenomBallistics

    VenomBallistics

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    Yeah ... technology has exceeded legislation.
    The mighty .049... I've designed around them, but never really used them. I was ether early electric power or using a more upscale glo engine. It's honestly not a bad time to revisit the hobby, Between the scads of cheap and remarkably reliable hardware available and the ridiculously cheap and simple methods brought to us by the fine folks at Flitetest, the whole show has come within reach of the common man.
    The legal side of things ... we have piles of long range radio stuff. Most of the FrSky gear can easily clear line of sight even before we jump over to 900 MHz modules for "Obstacle penetration" nudge nudge wink wink.
    Really, what needs to happen is for the laws to conform to our reality. 100 MPH is not a realistic limitation, 400 feet AGL only looks good on paper. a good quad can hit that in a few seconds. and line of site ... I still have 80% signal strength on my Wonkavator.
    its an awesome way to explore the world around you for as long as you don't impose yourself upon the worlds of others.
    But, you should be aware of all the laws your probably going to violate in the first few hours. Especially multirotors. There is no safe way to fly them within the law. after about 50 feet distance, you cannot determine direction with any certainty, so you have to fly them FPV. When and if your ready to try ... feel free to ask.
     
  15. hevans1944

    hevans1944 Hop - AC8NS

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    Thanks. It may be awhile. I was out of ham radio and "off the air" from 1967 (when my non-renewable Novice license expired) until April 1, 2013 when my Amateur Extra license, call sign AC8NS, was issued by the FCC. I half-jokingly say the "NS" part of my call sign means "No Station," but that isn't entirely true. I bought an Elecraft KX3 HF transceiver to celebrate my re-entry into ham radio, and later added a KXPA100 linear amplifier. What I don't have is a permanent antenna to transmit and receive with.

    Before retiring to Florida, we lived on a small lot in Dayton, OH with virtually no room to erect an antenna. We now have a largish corner lot with no HOA or antenna restrictions, but also no amateur radio budget for antennas. I went to the Orlando Hamfest last year and came back with a set of nesting aluminum poles, originally intended for the deployment of camouflage netting. Each pole is a bit over four feet long, so I figured to stack five or so of them to make the end supports for a dipole antenna... or maybe stack ten of them to support the center of an inverted "V" and then use three or so on opposite ends to support the lower part of the antenna a few feet above ground. Easy peasy, I thought, until I realized we now live in the lightning capital of the world. Those aluminum poles will have to come down before and during every thunderstorm. I still plan to eventually erect a dipole antenna, but Plan B is to build a magnetic loop antenna that sits only about ten feet or so above ground, supported on PVC pipe, and ground the copper loop of the antenna during thunder storms.

    Thanks for the encouragement and the good news that your RC hobby is finally within reach of the common man. I thought for many years that hobby electronics was out of reach of the common man, but that is no longer true today. Of course my notion of the electronics hobby as being component-level design and experimentation has yielded to the availability of inexpensive modules that the hobbyist simply wires together. The same appears to be true with RC models. As you stated in another post, no one messes with the radio-frequency "nuts and bolts" part of hobbyist RC design. Well, almost no one. As a retired electrical engineer with a hobbyist amateur radio license I am free to legally delve into that realm. Perhaps someday I will.

    Hams are heavily involved today in digital communication modes that offer increased range of communication at quite reduced power, or "QRP" operation as it is known by its Morse Code "Q" signal designation. This is mostly used in the hobby to pursue QSOs (two-way conversations) with distant worldwide (DX) stations, "just because" it can be done using various propagation modes such as ionospheric reflection, meteor scatter reflection, and moon-bounce reflection... to name just a few methods to wrap a radio-frequency signal around that pesky globular Earth. Hams also employ line-of-sight public repeaters that receive signals on one frequency and re-broadcast them on another different frequency. This would not be a reliable method of extending RC range, though, because the repeaters are shared and may not be continuously available. Less well known, at least in the amateur radio community, is the application of digital techniques to ensure error-free transmission and reception of data. Some form of digital error detection and correction is probably incorporated in the the latest RC electronics, unless youse guyz are still stuck on PWM analog controls, which I seriously doubt but haven't investigated yet.

    I was a bit confused about your statement regarding multi-rotor aircraft not being safely controllable beyond about fifty feet without using a FPV camera for visual feedback. Until I realized that beyond fifty feet you can hardly see the darn things, much less control them! Then I visited the dji.com website to learn about their Phantom Pro series of quad-copters with high resolution camera and imaging collision avoidance system. Wow! The more than a thousand bux "entry level" price seems to be quite reasonable given the performance capability, but your inexpensive approach seems more in the "hobbyist" spirit to me.

    I think I will start off with a small, inexpensive, electric airplane with a FPV video camera for visual flight control and obtain some "pilot creds" before even thinking about moving up to a multi-rotor platform. And I will certainly try to find a local club or organization with someone willing to mentor a newbie. That was a huge problem in the 1950s: newbies learned by the "crash and burn" method of flight instruction, just as the Wright brothers did at the turn of the century. It was pretty discouraging to wreck a model you had just spent months building (or re-building) and preparing for flight. Having an experienced "co-pilot" to fly the plane while I select still images to store on-board sounds like a good idea too. We happen to live on one of the approach paths to Venice Airport and see a lot of low-flying aircraft every day. Surely we don't want to compete with any of them for airspace.

    In an earlier life I worked with the intelligence and reconnaissance community to support digital image processing. Back in those days the buzz words were "sensor fusion," meaning the combining of data from various imaging sensors into a coherent whole that humans (or machines) could use for decision making. My first attempts at this were rather mundane. We had purchased a (then) brand new mechanically scanned forward-looking infrared imaging (FLIR) system with two focal-plane, liquid nitrogen cooled, photoconductive IR detectors, one doped for 3μm to 5μm infrared and the other doped for 8μm to 12 μm infrared.

    A beam-splitting mirror directed the scanned image field to both detectors simultaneously, a scanning procedure known as image dissecting, but only one of the two IR detector outputs could be displayed on a TV monitor. As it turned out, the horizontal scan rate was not up to NTSC standards, being only about half as fast and sinusoidal rather than a linear sawtooth scan. Also, because miniature galvanometer mirrors performed the scan resonantly, the scan was sinusoidal in velocity. The OEM digitized the sinusoidal waveform, representing horizontal scan position, and used the results as an address into a random access buffer memory into which the sampled and digitized video was stored. This occurred during both the left-to-right and the right-to-left scans. Now the tricky and clever part: to make NTSC compliant video, the buffer memory was read out twice in the period occupied by two NTSC scan lines. No one seemed to notice that each consecutive pair of horizontal scan lines displayed on the monitor contained exactly the same data, obtained from a single horizontal scan of the galvanometer mirror.

    I, OTOH, realized that if the data were being duplicated every other scan line, maybe we could just switch back and forth between IR detector outputs every other scan line to display both IR bands simultaneously. That turned out to be almost ridiculously easy to do with a high-speed video switch and some minimal logic. The results were impressive, and since the switching was all controlled by logic gates, it was easy to implement A-B comparisons at the flip of a toggle switch. Management was happy and I received either an "attaboy" or a "brownie point" for my efforts.

    But I couldn't just leave "well enough" alone. For my next "trick" I tried to combine a CMOS CCD camera image with the FLIR images so we could see the infrared image superimposed on a visible light image at the same scale. Now this is pretty much normal practice today, but in the early 1980s it was apparently considered sensor fusion and classified at a level above Top Secret, for which I did not yet have a "ticket" to be privy to. Management quickly shut me down and assigned me to another project. It turns out that there are many imaging sensor platforms whose data can be combined in a similar manner to produce a result that has more information than any individual source... radar (including ground-penetrating and back-scatter radar), sonar, laser Doppler interferometry, hyper-spectral imaging and probably some I don't know about yet. The process of sensor fusion is all very math intensive, especially if real-time results are needed as, for example, on the battlefield. Even the method of results presentation is open for further consideration as technology evolves. Fascinating work, and too bad I am retired and so not involved any more.

    Hop
     
  16. VenomBallistics

    VenomBallistics

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    In no particular order of discussion .... LOL
    https://www.flitetest.com/articles/ft-bushwacker-build
    Having been tasked with finding entry points for noobs ... this one floated to the top of the pile.
    It's slow and docile enough to learn fixed wing piloting, but still has enough performance to deal with the wind.
    Flaps option is brilliant. just 1/4" flap deployment can slow it to a near hover and makes landings a snap.
    I used it as my FPV training platform when FPV was new to me.
    After you get some pilot cred, try this one.
    https://www.flitetest.com/articles/ft-guinea-build
    It's a $6 bombtruck of a plane, so you can get obscene with your battery packs and hardware load out.
    Also, being a twin engine, the props are not in your forward field of view. In fact, it even allows a good amount of panning before the props are in the shot at all.

    You seem to have a fairly good grasp of radio as it applies to us.
    the hobby is dominated by various flavors of 2.4GHz spread spectrum systems.
    Its a high speed psudo random frequency hopping approach that uses the whole 2.4 band. What we end up with after error correction is just a reduction in range as the band gets more populated and the rate of dropped packets rises.
    It's not like the good old days of 72Mhz FM where anyone switched on a TX on your channel, you were boned. It was largely PPM / PCM. PPM is still in use inside the radio as a default serial data system.
    It may or may not remain PPM past the transmitter block
    A fair number of skills converge in RC.
    My main draw was aerodynamics and engineering and electronics was somewhat secondary.
    as the hobby evolved, Ideas outpaced product availability so you often had to roll your own solutions as things changed.
    The advent of electric propulsion often meant a crash course in MOSFET H bridges until the industry caught up.
    I do often think about getting a HAM ticket now as the prospect of extreme range exploration does pique my interest. but I think I'd return to Legacy 72MHz and just run higher power as allowed with a license. I have a box full of 72MHz RX's from the era to use for it.

    Sensor fusion ideas sound kinda fun, but there's a reason we tend to favor somewhat lower res CMOS cameras at 600 to 700 TVL.
    Latency is a killer of airframes. I'd probably want to play with fusion concepts as a secondary vid system, non essential to aircraft operation. Processing takes time.
    which brings us to the DJI offerings ... take a look at the Inspire.
    its way more than a phantom but the design concept knocks it out of the park.
    it revolves around a concept of a two person team. Pilot and cameraman.
    DJI has a lot of good ideas at an exorbitant price. but truth be told, their collision avoidance tech isn't that great. It might manage to stay out of a brick wall but it seems to still allow bad haircuts and transformations into tree ornaments. there's no replacement for pilot skill. Careful selection of your flight control board can give you access to all the user friendly features of a DJI product well under budget. The roll your own drone route also frees you from DJI's proprietary batteries and chargers. $120 for a battery pack is ridiculous. Study the stuff out there.
     
  17. hevans1944

    hevans1944 Hop - AC8NS

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    Absolutely good advice! And thanks for the two Flitetest links.

    A Technician-class ham license could provide you with an overwhelming advantage in radio control, but 72 MHz is outside the amateur radio spectrum allocation. Other amateur radio band possibilities are 6 meters (50.1 to 54.0 MHz), 2 meters (144.1 to 146.0 MHz), 1.25 meters (222.0 to 225.0 MHz), 70 cm (420.0 to 450 MHz), 33 cm (902.0 to 928.0 MHz), 23 cm (1240 to 1300 MHz) and a dozen or so bands from 2300 Mhz to 250 GHz plus everything above 275 GHz. The band from 2300 to 2310 MHz or 2390 to 2450 MHz looks promising as you may be able to re-tune or re-purpose 2.4 GHz spread-spectrum transmitters to this band of frequencies. Might be worth investigating to see if hams have done this.

    The amateur radio community is in a constant battle worldwide to preserve their spectrum allocations against incursions by commercial interests. There is a "use it or lose it" attitude, and some of the currently available microwave frequencies may be/are shared with other licensed as well as un-licensed radio services. The American Radio Relay League is the ham spokesperson for USA amateurs, but not every ham is a member of the ARRL. Visit the ARRL website for more information.

    If you are serious about obtaining a ham radio license, it has never been easier than it is today. The Morse Code requirement has long been eliminated and the written tests consist of multiple-choice questions administered by volunteer examiners or VEs, under the auspices of a volunteer exam coordinator or VEC approved by the FCC. Both the questions and the answers are published by the FCC, and test questions are randomly selected from the "pool" for each of the current three license classes: Technician, General, and Extra.

    It is theoretically possible to memorize the entire pool of questions and answers, but of course you don't want to do that. You begin by sitting for the Technician class, and if you pass that you can sit for General in the same test session. If you pass the General test you can sit for the Extra class, again in the same test session. That's what I did after about two months of on-line study. I recommend an on-line study program called Ham Test On-line. You can try it out for free, and if you like it you can purchase a two-year "subscription" for the class of license you are seeking. Usually, most folks will be ready to take (and pass) their chosen exam after a month or so of on-line study, drill, and "trial" exams. The two-year subscription provides more than ample time to prepare for the real FCC exam by a VE team near you.

    Technician class is all you need for full-legal-limit power (1500 watts) on frequencies above 50 MHz, but it is worthwhile IMHO to study for the General and Extra classes too. Of course, for RC flying, a few tens of watts should be more than enough power. I think it is legal for hams to experiment with spread-spectrum transmissions, but even if it is not, a suitably encoded digital signal with error detection and correction at the receiver will "punch through" the noise at any reasonable range and power. However, to take advantage of what is commercially available "off the shelf" you should endeavor to make or modify transmitters for amateur radio bands that are compatible with current packet encoding technology even if not "spread spectrum" per se.

    On video cables... one of the "best" small coaxial connectors is a Microdot connector. They are very small and rugged screw-on coaxial connectors, but they also require an inexpensive special tool to assemble properly. We used them, with special coaxial cables containing graphite-impregnated shields, for piezoelectric strain gauge signals. The graphite "shorted out" any triboelectric noise generated by cable flexing. The connectors may or may not be suitable for HD video however. One would have to try them to find out.

    Roger the experience with MOSFET H-Bridge drivers. Gate timing was critical to prevent shorting the positive and negative rails together, destroying the MOSFETs. I plan to use integrated circuit MOSFET H-Bridge drivers for largish stepper motor controls, with pulse-width modulation of the stepping waveforms to enable micro-stepping with current feedback. One application is to slew the vacuum variable tuning capacitor between minimum and maximum capacitance to tune the 80m/40m magnetic loop antenna I am building. That would have been a real PITA for a discrete component design just a few years ago, but COTS (commercial off-the-shelf) modules are now available at reasonable cost. Some do require external MOSFETs for higher voltages and/or currents, but the high-side gate drivers are already implemented with charge pump technology.

    I will keep you posted on my next great adventure in RC flight!

    Hop
     
  18. VenomBallistics

    VenomBallistics

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    Aug 30, 2018
    I am fairly serious about HAM. I have to be really due to power level constraints.
    My 5.8G video is limited to 25mW without a HAM ticket. However, that presents a fairly short leash, even with practical finesse solutions like antenna selection.
    It would be nice to operate the "Oh how did THAT get here" collection of 5.8G vid TX's with the peace of mind afforded by a HAM license, without adding any real complexity while making a jump to 100mW to 1.5W.
    Better still would be a portable relay tower with an RX at 1.2 - 1.3G that feeds to a 5.8G @25mW TX to be received by my 5.8G goggles. The airborne side could have some serious legs with as little as 5W .... This is obviously HAM territory.
    While we are there .. the control band would need to follow into HAM levels as well, to keep up with the video.
    If the act of exploring ones world from the air, in real time wasn't so magical, I probably wouldn't be in this mess :D
     
  19. hevans1944

    hevans1944 Hop - AC8NS

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    Careful! You are gonna make me an addicted RC UAV flight enthusiast before my first drop of hot glue has congealed! But it's a nice mess to be in, given the current state of technology. No one needs to be on the bleeding edge anymore, either. Thousands of hungry but well-educated Asian engineers have already paved the way. We Americans just need to now pick the low-hanging fruit of their efforts.

    The idea of a portable repeater tower is immanently practical. This has already being done for the cell phone spectrum to improve communication in densely populated "steel and concrete jungle" areas. The concept should work fine for RC data links, too, using ham radio spectrum allocations, but I don't think a repeater is necessary for RC. See 802.11a discussion below.
    This is true, but with a Technician license you can use a goodly part of the 5.8 GHz amateur radio band with up to 1500 watts of transmit power, not that you would ever need this much power. See this Wikipedia article for some of the details. It is my understanding that COTS 802.11a (5 cm) access points, with appropriately chosen channels, can be used for this purpose. Since these are just digital data packets that are being transmitted, you could interleave real-time digitized video with real-time digital telemetry and control on the same channel. Some high-speed buffering of video may be required to allow the low-bandwidth interleaving of telemetry and control signals. A patch antenna mounted on the fuselage or a wing surface should be adequate for two-way communications with, say, one to ten watts of transmitter power. The ground half of the link could use a higher power, but this is probably not necessary for good results. These figures are just rectal extractions right now, so some experimentation is necessary to define how much power you really need on each end for reliable control at whatever distances you want to fly the UAV from ground control point. Note that FCC regulations require amateur radio operators to use the minimum amount of power necessary for communications. So, even though 1500 watts is the maximum allowed, that doesn't mean it should be the amount of power actually used. Common sense will always prevail because higher power becomes very expensive at higher frequencies, even with gallium arsenide heterojunction bipolar transistors providing the power. You may be able to salvage GaAs HBTs from discarded cell phones if you want to "roll your own" RF amplifiers.

    Other than the fact that COTS equipment is available, I am not sure why you would even bother using the 1240 to 1300 MHz (23 cm) amateur radio band for control and telemetry. Given an available 802.11a channel, say, channel 180 on 5.905 GHz, I would do everything... video, telemetry, control... on one channel. I haven't tried it yet (being a noob in this area), but any decent microprocessor should be able to multi-plex and de-multi-plex a serial data stream of packets. I would be very surprised if this isn't already a fait accompli in the amateur-radio-enabled UAV community.

    In the meantime, I have found a DIY UAV group that I have asked to join. And there is a Google group in the Orlando area that I have also asked to join. So far, nothing in the Venice, Florida area, but I am still looking. We are currently visiting my oldest son in Atlanta, Georgia but will be back in Venice next week. I haven't learned enough yet to actually purchase any parts, but hope to do that sooner rather than later.

    Hop
     
    Last edited: Dec 15, 2018
  20. VenomBallistics

    VenomBallistics

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    Aug 30, 2018
    Explore flitetest.com too. They put in a remarkable amount of work to help make RC tangible for all.

    As a fixed base HAM, you've probably just accepted atmospheric events imposing their difficulties upon your transmissions.
    RC is a dynamic environment where your conditions are subject to change with your position and orientation.
    For example, you're making a pass at tree top level to get a closer look at some new discovery. As the craft travels along its flight path, the line between you and that craft are intermittently separated by trees.
    Lower frequencies tend to penetrate leaves and such better than higher ones . While a single channel duplex project sounds interesting and probably worth developing, the mix of equipment tends to dictate a two band solution. Control TX brand A is not compatible with brand B, thus its impossible to develop such a system for the general market. Bear in mind, many practitioners of the hobby probably had their VCR's flashing 12:00 through the 80's
    so the typical approach is something like a 2.4G control with a 5.8G vid or a 900MHz control with a 2.4G or 1.2G 1.3G vid
    It has the advantage of giving you a visual cue (snow) ahead of losing control contact ... not that I think its particularly far behind.
    That aside, there are those that seem to build with and axe, and paint with a mop. These folks are a source of amusement and inspiration. it's best to keep things simple enough that they don't get lost under the bar.

    Perhaps conventional links user to repeater ... Long range multiplex repeater to craft.
    It would allow the Hobby industry sourced COTS to live on unmodified.
     
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