Tested.com was at the Drone nationals and they interviewed the curator of the event, along with the top pilot, Chad Nowak.
Checkout what they had to say here: http://www.tested.com/tech/535073-fpv-quadcopter-racing-2015-drone-nationals/
If you have a specific question about the Drone Nationals, or a particular quad setup, Please post it in our Q&A
A Guide to FPV SMA & RPSMA Connector ends
What happened to make the SMA connectors that we use on our FPV Transmitters and antennas so confusing? I have struggled for the longest time trying to figure out some sort of rhyme or reason to these connectors, and hopefully this post will help you wrap your head around it.
To think about RP-SMA and SMA adapters, I have developed this method….
First, think conventionally. Forget about RP-SMA for a minute-because it goes against normal convention, which is what makes it so darn confusing.
So the basic thing to remember about connectors is that (usually) if there is a center conductor sticking out in a manly fashion, then you have a male connector. If there is a hole in the center conductor, then you have a female connector.
So the convention is: SMA Male looks like this:
SMA Male Connector quadcopter antenna vtx help
SMA female looks like this:
SMA Female Connector quadcopter fpv antenna vtx help
So that is pretty easy to remember….. I like to think of the cable box or Satellite receiver (or VCR for you mature folks….lol)
Female connectors are on the cable box, males on the cable.
how to connect your SMA cables together
SMA connectors do the same thing…. females have threads and holes, males have collars and poles.
Along came the FCC, that’s right, another government standardizing agency that has good intentions, but those intentions sometimes don’t make any sense without knowing the history behind the regulations. You do have your ham license right? Right?? It’s time to get one if you don’t…ARRL…
The FCC mandated that the standardization for newer WIFI devices be made so that high-gain antennas couldn’t be put onto newer Wifi devices. Manufacturers of these Wifi devices had to make a new non-standard antenna connector that was hard to find replacements for (as they were all regular SMA before that). The aim was to prevent consumers from connecting antennas with gain and therefore breach compliance (from Wikipedia).
We all know that Wikipedia is a terrible source of credible information, so to dig deeper, this change was implemented to meet the requirements of 47CFR15.203:
“…a permanently attached antenna or of an antenna that uses a unique coupling to the intentional radiator…”
so, yes, the reason was to limit the options for alternate higher gain antennas used on part 15 (unlicensed) equipment.
Think “reverse polarity” RP-SMA…..REVERSE POLARITY-SMA. Take the Female RP-SMA adapter for instance. Start out thinking about what a normal Female SMA connector is like….. A normal female SMA adapter has a hole in the middle and threads on the outside……… NOW an RPSMA female is the same connector with threads on the outside, but the center conductor has a sex change….so it is like the SMA female, but with a male center conductor…….That’s not confusing is it??
RP-SMA Female How to think about it connector
Lets try again….
Male RP-SMA……. Think Male SMA…. collar with pole for center conductor………now RP it! Swap the male middle for a female… and you end up with a Male RP-SMA.
RP-SMA MALE How to think about it connector
The RP-SMA connector……It’s the transvestite of the Sub-Miniature Version A world!
There is one consistency; all antennas, cables or anything was being attached to a potential stationary object used an outer nut or inner thread design and all stationary devices should use the outer thread design.
We are working with our manufacturers to try and make sure that video transmitters have a female SMA connector, and all Antennas have a male SMA, but it is going to take a while to get everyone to catch on! If ordering a transmitter, make sure that you look at the connector to make sure it will work without the need for SMA adapters.
SMA Connector Selection Guide SMA VS RPSMA
If you still can’t wrap your head around it, just print this image and put it in your tool box!
A Guide to FPV SMA & RPSMA Connector ends
All too often, people that are new to the fpv hobby tend to have a misconception about the actual range of fpv. Technically, line of sight (LOS) Is supposed to be maintained when flying fpv. This automatically limits the realistic distance that you are supposed to fly fpv.
Technically you are also supposed to have a spotter when flying fpv. This way you can maintain line of sight while flying with googles.
So what kind of range can you expect? Well nothing is Perfect, but each frequency has advantages and disadvantages. This post can help you decide.
On 5.8 ghz (the ideal mini-quad frequency ) the range that can be expected is LOS MAYBE 1500′. Less if you add obstacles to the mix such as trees, hills, buildings, or bodies. For this reason,5.8 just isn’t really ideal for long range flying.
When flying on 5.8. I tend to find my flying area, center myself within it (use omnidirectional antennas) and then fly all around myself. I have learned that video cuts out pretty bad beyond any trees or buildings and therefore my 5.8ghz crafts naturally limit themselves to Los. 5.8 is good for its portability (no ground station, small antennas) but for better range something else has to be done.
To fly further, you have to change your methodology.
So my method is to bring a spotter, binoculars, and a ground station, and fly on a frequency that works better beyond trees, over hills, and through the woods.
The key here is the ground station.
I prefer to fly on 2 frequencies for long range flying, 2.4 ghz and 1.2ghz with the former being my favorite because of it’s legality and the availability of equipment.
When flying long range, you have to change your antenna scheme. In order to get the range that you want, you have to get a good directional antenna array. When using 2.4ghz video, I fly with a tbs GROUNDSTATION coupled with an 11db 2.4ghz yagi antenna. The tbs GROUNDSTATION is a really nice unit because it has a video screen for redundancy, built in 2.4ghz receiver, antenna mounting areas, tripod mounting holes, a rugged metal case, connections for goggles (power and video cables), and a USB port to charge a camera.
So the tbs GROUNDSTATION makes it very easy to have a reliable unit on the ground to help you tune in your fpv and give your spotter something to do and look at. The screen also doubles as a redundant backup in case you have an issue with your goggles.
TBS Groundstation Fully Setup showing Yagi antenna and tripod (not included)
There are other, cheaper ways to build a GROUNDSTATION but the TBS has it all built for you already. You just add a hi capacity battery and you are set and ready to power your rx, spotter screen, goggles, and whatever else you need.
When flying on 1.2ghz I use a separate receiver, antenna and tx to rebroadcast the video at 5.8.
1.2 1.3 Ghz RHCP skew planar and Cloverleaf antenna set.
1.2ghz is a great frequency for fpv in urban environments. I typically use omni-directional antennas with this frequency, or use a helical on the ground with a cloverleaf in the air.
900-1.2ghz fpv video rx receiver with Digital tuner video connector view
When flying on 2.4ghz video, one downside is the fact that you can’t also use 2.4ghz control because of the interference that is caused by running 2 systems on the same frequency. This isn’t so bad because there are other radio systems out there that are a much better choice for long range control.
Radio systems other than 2.4ghz such as the old school 72mhz systems or a 433mhz long range system. (LRS) are a better choice for long range fpv.
I am a big fan of the openlrsng long range equipment. It is open source and easily configured via a chrome app very similar to baseflight. It even acts as a beacon in the event of a crash so that you can find and recover your aircraft.
I currently use a DTFUHF hawkeye XJT module which drops right into the back of the Frsky Taranis and Turns the radio into a 1w 433 MHz transmitter with telemetry.
DTF UHF XJT Module for Taranis x9D
I also use the dtfuhf hawkeye deluxe 1w transmitter on a Turnigy 9x for long range. The dtfuhf deluxe tx can be retrofitted onto any radio that outputs a ppm signal.
On the other end of things, i have found that there are several different receivers in the market that work with the openlrsng software.
The brotronics broversity receiver is a good one with diversity and a backup battery charger for a beacon battery (so you can find your craft long after it’s main battery has died.)
Other good led receivers include the small dtfuhf 6 channel receiver, and the dtfuhf 1w long range receiver.
Telemetry is something to consider when flying long range as most receivers have a 100mw tx for telemetry built in which isn’t enough power for when you start getting into longer range flights. This means that you lose telemetry before you lose video or control. If telemetry is important to you than the 1w rx is a must. (It has a 1w rx built in for telemetry back to the controller)
For most fpv pilots though, telemetry doesn’t matter because important craft information is overlayed on the video feed with the use of an on screen display.
Even with a proper video and control system, long range fpv success can vary with atmospheric conditions, physical environment, radio environment, antenna selection & aiming, and more.
Other tips:
When I travel for long range fpv I make sure to bring these essentials beyond the normal gear:
A Toolkit that includes:
Even with all of the above, sometimes you can just loose a craft, or have a bad crash so I always go with the preparedness that I might loose my aircraft. Crashing, finding, & rebuilding is part of this hobby. With the right equipment, it’s easy to be successful but even then, things can still go wrong.
The Naze32 Flight controller comes in an acro version and a full version. How to tell the Naze32 Acro Apart from the Full version?. This guide should help.
The Naze32 Acro vs the Full? which one to choose from?
The Naze32 comes with 2 variations. The boards come in many different colors and the color is not an indication of whether the board is an acro or a full. The only way to tell is by looking to see if the components on the board are populated or not.
The “Acro” model for acrobatic flying & The “Full” version for more advanced quads.
Naze32 Acro
Flies amazing. Great for acrobatic sport fliers on a budget.
A Naze32 multi rotor flight controller
In addition to all of the sensors and features of the Acro version, the Full has additional sensors that make it more capable. These sensors include:
The acro can still work with GPS, but you must use a magnetometer equipped GPS which is considerably more expensive than the cost of upgrading from an acro to a full.
The difference between the Naze32 Acro and Full version and how to tell them apart
In a pinch, it is possible to upgrade an Acro to a full version if you are an expert at electronics repair as shown on this page. However, the cost of the components is more than the cost of the upgrade.
I hope this helps you make an educated decision!
[wolf_column col=”col-6″ first=”yes”]GET THE FULL VERSION HERE![/wolf_column][wolf_column col=”col-6″ last=”yes”]Get the ACRO version here[/wolf_column]
We are pleased to have more of these flight controller boards available for you at competitive prices.
Naze32 Acro
Afromini32 Flight controller from abusemark. a mini naze32 size
Get them while they last!
So you have started building up your quadcopter, read through the blog posts on our site, scoured the web for hours, and still cant figure out FPV. Well the purpose of this guide is to help you understand the anatomy of the FPV side of your quad, and help you make some better decisions about how to wire it all together.
Please read our blog post (FPV Video Transmitter Selection Guide) as a prerequisite to this article.
The FPV system of a quadcopter can be as simple as a camera with a video transmitter attached. There are systems that make this possible. There are even video transmitters that attach to a go pro for a modular FPV system. The problem with this type of system is that while the GO-Pro and other cameras are very good at making amazing video, they are not very good for FPV systems.
The problem with this type of system is that while the GO-Pro and other cameras are very good at making amazing video, they are not very good for FPV systems
The main reason the go-pro is bad for FPV is the fact that these cameras take some time to transition from light to dark areas.
This creates a safety problem. It means that you cannot see what is in the shadows, and you essentially lend yourself to flying “blind” while the camera transitions.
The other problem with the cameras is that although they record HD, we still have to down-convert the video signal to work with analog video transmitters. Analog video transmitters are currently the only choice for FPV. The idea of HD FPV is an exciting one, but the limitations of such are latency (a delay between what is actually happening and you see in your goggles) There are some systems that are coming out that do HD such as the CONNEX by Amimon,
Amimon-Connex expensive & Heavy
but this system is prohibitively expensive ($1600 at the time of this writing April 2015), Heavy &
It requires an HD camera to work such as the Go-Pro, which has the transitioning problem as stated above.
So if you are really excited about FPV and want to be serious about it, The best thing to do is to get a matched setup for your quad, using a proven system that is designed specifically for FPV. It is the safest and most cost effective and most functional way to go.
Once you have determined which frequency to use for your FPV setup and what power you need(you should have made a decision after reading the FPV Video Transmitter Selection Guide) you should be ready to get started.
My recommendations for a sure fire 5.8 ghz setup are:
TS58500 Video Transmitter mini Long Range FPV front
5.8ghz FPV RHCP antenna set skew planar and cloverleaf
Skew Planar W/ TBS patch antenna (not the best for flying behind you, but better for distance in front of you.
or
Skew planar & Cloverleaf antenna set (better for all around you flying, not as good for distance)
Sony Superhad CCD FPV camera for QAV250
The Sony Superhad II ccd board mount camera is superb for FPV. It has excellent color reproduction, fast change from light to dark areas, adjustable shadow contrast (you can see in the shadows with this camera) and a high contrast low light mode (black and white) It also accepts different lenses for those that want to better customize their field of view (2.8mm standard)
The important thing to remember when choosing a camera is that there are board mounted cameras and there are cameras that come installed in housings. You will have to make sure that whatever camera you choose fits your airframe. You will also need to make sure that you choose a high quality camera with a CCD for the best transitioning.
The Sony Super Had II is also nice because it comes with a whole array of software features that enhance it’s performance. These are all adjustable via an ON SCREEN MENU.
This is an integral component for FPV setups. A good on screen display can unlock your quad, giving you video overlay that displays information such as angle to the earth, altitude, battery voltage, current, speed, GPS coordinates and more.
There are several OSDs out there to choose from. It can be difficult to pick the right one.
teamkvosd QAV250OSD
I fly the Naze32, and therefore I use a Minimosd flashed with TeamKVosd firmware. This makes for an extremely versatile little board for under $30.
The TeamKVosd firmware allows this little board to communicate with the Naze32 via multiwii serial protocol. It makes for an excellent addition to the Naze32 flight controller.
It will even read GPS data from the Naze and give you speed data and a return to home arrow that points back to your home location.
If you are flying with a DJI Naza, or a CC3D, you will need to flash this board with appropriate firmware to make it work, which is beyond the scope of this article.
The nice thing about the minimosd board is that it is open source and you can usually find a firmware variant out there that will make it work with your flight controller.
TBS Core OSD and BEC rear view
There is also the option of going with an OSD such as the TBS core. The TBS core is a bit more expensive than the minimosd with less features, but it is nice for the builder that doesn’t want a clutter of wires and who doesn’t want to think too much about their wiring setup.
From the Manual:
TBS has put the bare essentials that every FPV pilot needs – voltage, current and relative signal strength indicator (RSSI) – in an OSD that sits right on the TBS CORE
This OSD has just the bare essentials, and it can really simplify a setup for the first time user. The core doesn’t have any GPS support and is a standalone type of OSD that doesn’t communicate with your flight controller at all.
There are other OSDs out there that are equally suitable and will be added to this article as time goes on. One OSD in particular is a micro version of the Minimosd that we have been using to really clean up our builds such as the one shown in the featured image. It is exactly the same as the standard minimosd but 1/4 of the size. It is difficult to solder and therefore only recommended for expert builders.
You will need to provide power to your camera, OSD, and video transmitter. The TBS Core takes care of this. If you are going with the minimosd, you will need to provide it with 5v. You will need a:
QAV250 miniquad voltage regulator BEC
This takes care of voltage regulation. You need to provide your camera with 5V or 12V depending on it’s requirements. a 3S battery outputs around 12v, so you need to step it down to get 5v.
We recommend the adjustable Micro BEC for low amperage applications. (<2a)
Our Board mount Sony Superhad CCD cameras are 12v, whereas other cameras (such as the one that comes with the FatShark Attitude goggle set) are 5v.
LC FIlter FPV
It is a good idea to add an LC filter after your voltage regulator to take out any noise that it may induce into the system. This noise can be apparent after the motors spin up, showing up as horizontal lines across the video screen.
We sell PreMade LC Filters and ferrite beads if you want to try to make one yourself.
One major thing to consider is that some components requirements 12v and if you run 4 cell batteries (4S) you will surpass your voltage requirements for these items. In which case, 2 BECs should be used, one for the 12v items, and one for the 5v items.
The TBS Core OSD takes all of this work out of it, providing regulated 5 or 12v power to your video camera and VTX and supplying a but is less functional than the minimosd and more expensive.
You can see from the image to the that the core has a selectable 5v or 12v output for the video camera, and for the video transmitter, and a built in OSD which can be disabled if using a separate OSD. It also has a current sensing input and RSSI (received Signal Strength indication) input.
The minimosd is extremely susceptible to ground loops. One example of this is powering your mimimosd from a bec and grounding it that way, and grounding your camera directly to your battery ground. The ground after the BEC will have a different potential than the ground after the battery and it will cause the OSD to not work when you connect it to your camera because it will be out of sync with the camera’s ground. This has caused many users problems that seem frustrating, such as the OSD working until the camera is connected, then upon connecting the camera, the osd info disappears.
When I wire in minimosd OSDs, I always make sure to connect a common ground to the ground after the LC filter. This ensures the elimination of ground loops.
So How to wire? Here is the diagram:
Fpv wiring diagram for Naze32 Minimosd LC filter TS58500 TS5823 and MinimOSD
These tips should help you get flying, and with a sure-fire system in the sky!
Stay tuned for part II
How to set up FPV on the Ground for the best experience possible. Getting your on-aircraft system working is only half of the battle. Goggle choice, antenna selection, and other factors effect performance on the ground and we will cover those in the next post.
Ultimate Naze32 User manual
I have found a really good manual for the Naze32 and decided to post it here. I am not taking any credit for this, but the creator of the board and my self both think that this guide is a really good starting point for the noob.
I didn’t write this so I am not taking any credit for it, but I think that you will find it useful if you are setting up a Naze32. A big thanks to Dlearnt for this guide:
[su_document url=”http://quadquestions.com/wp-content/uploads/2014/11/acro_naze32_guide_5th_ed.pdf”]
OK, I sent this off to a customer this week and I decided that the world should have it. No, It’s not pretty, but it should help you get your wiring done. Ive even included a pdf so that you can print it off and put it in your notebook… You do have a quad notebook, don’t you?
This is how you should be wiring your QAV250 with Kiss Escs and a QuadQuestions Bec.
Notice the signal wires and ground reference wires. The exact naze32 pinouts are listed in the naze32 manual which is here
I will probably make a few more of these. You could in theory substitute the kiss escs out with any esc and the same conventions apply. When was the last time you saw handwriting on the net?
Click on the image to see the hi-res PDF.
Lumenier QAV250 Wiring diagram for use with Naze32, Kiss Escs, and BEC regulator. You’re welcome!
Please comment if you have questions or suggestions.
Did this help you? Please contribute to my coffee fund!
[coffee]
Lumenier QAV250 Video Build Manual
This is the missing manual for the QAV250. It walks through the entire build process, with a timelapse and stops along the way to explain what is happening. If you find it useful, please subscribe to my channel!
This is the complete video showing a build of a QAV250 Quadcopter. I tried to cover everything in this video but I know there are things I forgot to say. Please be sure to ask questions on our Q&A page, and subscribe to my video channel.
The build features Lumenier QAV250 carbon fiber frame
SimonK 12a blue escs with build in BEC,
IBcrazy 5.8Ghz RHCP antenna set
& more
Some of the challenges that I faced while building this quad we’re trying to fit everything into such a small package. The QAV250 doesn’t leave much real estate in terms of mounting options, but it is a light and nimble QUAD for it’s size.
There are some nice options in terms of video transmitters such as the TS5823 that would allow for more real estate, and make the build process a little bit easier.
I modified the Fatshark LC filter to work with this quad.
I also installed a ferrite ring to minimize RF-Interference.
We used an IBcrazy 5.8GHz antenna set with this build.
I custom made all of the wiring for the FPV stuff and I am sure that I will be making a video on the exact procedure soon. This video is more of an overview of the process. More on this build can be found in my build portfolio.
I hope that this helps you with your quadcopter build! Please comment, subscribe, and leave me questions!
-Anthony
The video transmitter is a very important component to consider when building an fpv quadcopter, plane, or drone. It is visual link to your aircraft. And choosing the right one for the application can mean the difference between success in FPV and failure.
There are many choices available and trying to choose the right one can be daunting. After reading this post you should be better informed to make a decision regarding your FPV (Vtx) video transmitter.
choosing the right one for the application can mean the difference between success in FPV and failure.
electric vs magnetic field [1]
All wireless devices transmit electromagnetic radiation at a specific frequency range. They use this frequency to transmit information by carrying signals on top of these frequencies.
Using a 5.8GHz transmitter, for example, means is that the radio frequency of that specific transmitter oscillates at a frequency of five point eight billion times a second. 900 MHz means that the frequency oscillates at nine hundred million times a second.
These frequencies (e.g. 5.8, 2.4, etc) actually indicate that a range of frequencies can be used, and “5.8GHz” for instance means the center frequency of the band.
The 5.8Ghz ISM frequency band has a width of 150 MHz with 5.8 Ghz at the center. This means that video transmitters that are 5.8 GHz actually operate between 5.725 GHz and 5.875 GHz. It is this bandwidth that allows us to have separate channels on our 5.8 Ghz video transmitters.
If you look at a video transmitter, such as the TS58500, you will find that there is a way to change the channel that corresponds to different frequencies within the 5.8ghz band.
You can see from looking at this video transmitter’s frequencies that it is possible to use a frequency that is not in the ISM band, such as 5880, therefore it is important to make sure that you select a legal band that you have a license for when using this type of equipment. More information about getting a ham license can be found here: http://www.arrl.org/getting-your-technician-license
Frequency determines what part of the electromagnetic spectrum the radio signal is in, but to understand why different frequencies act differently, we have to understand wavelength.
The wavelength determines several things such as how much energy is contained in a transmission, how the waves react with the environment effecting things such as range and penetration of radio signals, and whether or not the radio waves bounce off of the ionosphere around the earth, or just go off infinitely to space.
I like to think of radio waves as a form of matter that takes on the same characteristics as light, except in a form that our eyes weren’t designed to see. (this is why radio is invisible)
Try to imagine antennas as giant flashlights to understand how radio waves work. Think of high gain antennas such as microwave antennas as focusing a beam of radio frequency “light” towards another tower. Think about a a low gain antenna such as a router with dipoles attached, spreading radio waves “light” in a more general, broad fashion, similar to a flashlight with it’s beam spread wide to illuminate a broad area.
The high gain flashlight can allow you to see further, but only in a narrow spot, however, the low gain flashlight allows you to see a broader area, but you can’t see as far in front of you.
This “light” can carry information in the form of digital and analog signals. These signals are sent by coupling information onto the frequency of the particular “color” (wavelength) of the “light” (radio wave)
Pretty much all FPV video transmitters at this point are analog, and they transmit video signals in analog.
Radio waves travel at the speed of light and we need to know the speed of light and the frequency to determine the wavelength.
To figure out the frequency of a wave
$latex \LARGE f=\frac{C}{\lambda}&s=4$
where:
f=frequency in cycles per second, C=speed of light (299,792,458 m/s), and $latex \lambda$=wavelength in meters
converting this formula to figure out $latex \lambda$, we can arrive at the formula:
$latex \LARGE \lambda=\frac{C}{f}&s=4$
so, for 5.8GHz we can plug in our values to figure out $latex \lambda$
$latex 5.8 GHz(\frac{1,000,000,000 Hz}{1 GHz})=5,800,000,000 Hz&s=3$
-WOW! That is a very high frequency! five billion eight hundred thousand cycles per second!
Using the formula and the HZ calculation, we can determine:
$latex \LARGE \lambda=\frac{299,792,458}{5.8*10^9}=.05 meters&s=4$
$latex .05M (\frac{100 cm}{1m})=5cm&s=4$
The full length wave of a 5.8GHz frequency radio wave is about 5cm long.
That wasn’t to hard was it?
If we do the same for a 1.3GHz wave,
$latex \LARGE 1.3 GHz(\frac{1,000,000,000 Hz}{1 GHz})=1.3×10^9 Hz$
$latex \LARGE \lambda=\frac{299,792,458}{1.3*10^9}=.23 meters&s=4$
$latex .23M (\frac{100 cm}{1m})=23cm&s=4$
So the 1.3GHz wavelength is 23cm or nearly five times the size of the 5.8GHz wavelength.
This explains antenna sizing, and there is an obious advantage to 5.8ghz over 1.3GHz, The antenna size is much smaller (it is proportional to the wavelength)
Trying to understand how these different wavelengths effect the way that the signal interacts with the environment is a little bit more complicated. Many things effect these signals and how they propagate. Higher frequency tends to be more sensitive to reflections and have a harder time penetrating things like buildings and trees vs. lower frequencies. At the same time, the higher frequencies leak through holes a little bit more easily than the lower ones.
Further reading here: http://www.dxfm.com/Content/propagation.htm
The Electromagnetic Spectrum in terms of radio waves for R/C and FPV frequencies
The electromagnetic spectrum is the spectrum of radio frequencies that include Bluetooth, wifi, television, am fm radio, cellular, and all other radio communications. Light is also part of the electromagnetic spectrum. The reason that we can have all of these communication technologies; wifi,video satellite, fpv, etc is because all of these technologies operate in a different part of the electromagnetic spectrum, on a different frequency and therefore do not interfere with each other. If they were all operating on the same frequency there would be terrible interference and communication would be shotty at best
This image shows all of the radio frequency allocations in the USA as of 2011. As you can see, the electromagnetic spectrum is a very crowded natural resource [2]
Luckily for us today, we have radio technologies such as accst frequency hopping that allows many pilots to fly in the same frequency band without the need to worry too much about who else is flying.
When it comes to fpv though, we encounter the same problem that those early r/c pilots encountered. FPV video is an analog signal and if there are multiple pilots in the same area flying on the same video frequency there will be interference.
Follow this link for an excellent introduction to how wireless devices work: http://www.wired.com/2010/09/wireless-explainer/all/
Video transmitters for fpv quadcopters transmit an analog television signal. This signal includes video and audio. There is a lot of hype right now about HD goggles and high definition feeds, but the reality is that we are transmitting an analog tv signal and therefore any HD that we use will get downgraded to analog tv.
I’m sure that the future of FPV will involve some digital transmissions of tv signals through the same frequencies as the analog counterparts thus allowing for HD FPV but we aren’t there as of 2015. (note to self… consider doing this for a senior project)
Different frequencies have different characteristics and there are pros and cons to each frequency range for fpv video.
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Fatshark Attitude Camera & VTX top
A TS58500 5.8ghz FPV Video Transmitter for Drone or Quadcopter
TS5823 mini fpv video transmitter for mini quad such as the Qav250
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Power levels:
Power output for video transmitted
1.2Ghz FPV TX 800mw Transmitter shown with and without heatsink
for most fpv, a ham license is required.
There are many different frequencies to choose from.
5.8ghz is an excellent frequency for park fliers and noobs Because of its open channels and small antenna size.
Lower frequencies such as 1.3will have better penetration through objects and will travel further vs 5.8 ghz on the same power level.
Please leave comments to let me know how I can improve this article and subscribe to the blog for future updates.
sources:
1 http://sunearthday.gsfc.nasa.gov/2010/TTT/71.php
2 http://www.arrl.org/getting-your-technician-license
3 http://www.bb-elec.com/Learning-Center/All-White-Papers/Wireless-Cellular/10-Commandments-of-Wireless-Communications.aspx
4 U.S. Frequency Allocation Chart – National …