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Hi, first I must say that I’m writing from Poland and my English isn’t too good.

I understand the general base of working wireless video, but what does the range of working of system depend? I understand that the range is connected with power. Why 1000mW system has range only up to 2500ft (800m) and 200mW system has range up to 1500m? This has not sense. What transmitter/receiver system you can recommend? AMW633 looks good but I seen it only in one shop – here. If I buy the AMW 633 transmitter than what receive I will need? Are those 1000mW and 200mW systems with camera are good? There are on 9-12V how I can change the voltage to 5V?What antenna will be the best to this kind of use. Now the video glasses, are 320x240 is enough or better buy 640x480?

I apologize for errors :)

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Concerning the range, it really depends on many things and many of the given estimates are just that - estimates. Basically, good range depends on frequency, having line of sight, antenna (including type, orientation, polarization), good and stable transmitter, sensitivity of the receiver, interference and noise, and so on (maybe even humidity if you're on 2.4GHz). So generally as a rule 200mW under normal to ideal conditions is likely to get you out as far as 1km and beyond. 500mW almost surely will do that if you get the rest of the configuration right. I think for most people 500mW or 200mW is more than enough unless you're attempting some long distance flight. I've seen systems with a lot of power but poor antenna feed solutions, wrong polarization and orientation, and the resultant video link was very poor. You also have guys running 10mW and getting very good distances. Many of the estimates are conservative because they're thinking of room-to-room and ground distances, rather than ground-to-air and line of sight distances. It's not a simple relationship between power and distance. As an extreme example, back in my amateur radio days, I managed to have a radio conversation from Singapore to Equador (about 20,000km) on just 5W on 14MHz.

Usually on the transmit side, you will use some form of omni-directional whip - normally 3dBi. On the receive side you have several options. If you have a 500mW transmit power, then probably the same whip will work quite well on the receive side. If you're going further or using low power (10mW or 50mW), then you will probably need a more directional higher gain antenna such as one of the patch antennas. These you can either buy or make yourself following plans available on the related websites. With the directional antennas you will have to point it a bit or fly within the antenna cone so as not to lose the signal.

It's hard to tell if the system is good just based on the power rating - some use cheap CMOS cameras and those don't perform as well as the CCD cameras. Between CCD cameras there are higher resolution ones, and lower resolution ones. And then there's 1/4-inch CCD or 1/3-inch CCD. There's also the AGC and colour performance to think about. On top of that, there's also the type of lense - pin-hole, standard, wide-angle, fixed focus or vari-focal, fixed iris or variable iris, etc. You will have to do your own research and investment to figure out what works best or just follow the recommendations and get what has been tried and tested by the guys here.

The voltage you can use depends a lot on the equipment design itself. the KX-131 camera runs on 5V but apparently will tolerate up to 7V or so. If you're running from a 12V power source, you will need to use some kind of regulator to step the voltage down to the operating voltage. There are several ways of accomplishing this - you can just make the regulator circuit yourself, which is quite easy to do - using one of the 3-pin linear regulators such as the venerable LM7805 or the newer LM2940-5.0 and so on. Alternatively, you can use a UBEC or something similar to do the job.

Of course the higher resolution goggles are better and I think VGA ones will be considerably better than the QVGA ones because the QVGA (320x240) is lower than your camera's basic resolution so you lose detail. However, VGA ones will be more expensive than the QVGA ones. If you're feeling rich, you might even go for the SVGA types. As with all the other components, there is no simple best solution. Each one has it's own compromises, be it, build quality, features, image size, image resolution, etc.

To cut a long story short - you should take a month to read through all the threads on this site to get a better feel of what is really involved before running out and buying things.

Daniel

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Regarding the video goggles I compared "cheap" i-glasses with 320x240 to the io-display HR versions and found that the resolution is worse, of course, BUT: when your radio signal gets weak or when you get dropouts, the extremely expensive HR-glasses just blank the screen and need a couple of seconds to resync after the signal gets good again, whereas the low res goggles alwazs stayed in tune and showed me the noise when the signal is bad.

So, because of this fact I chose the Olympus Eyetrek FMD-200 goggles, for I know I can rely on them! You will get them on Ebay.

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As far as power goes, you need to use 4 times the power to double the distance. eg a 400mW TX will give you twice the range of a 100mW TX.

Terry

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I think about the goggles blanking out, this is not a case of hi-res vs. lo-res. It's more a case of one design vs. another design. You can have lo-res goggles that blanks out, and you can also have hi-res goggles that do not blank out. In my case, my VGA goggles has good resolution and it does NOT blank the screen when the signal gets weak or noisy - I see the weak noisy signal without blanking. It would not be right therefore to generalize that hi-res goggles all suffer from this blanking issue, as the post above (Hartwig) may seem to suggest.

Daniel

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OK. Is this antenna is good ? VGA glasses are expensive I don’t see any under 280USD and I want buy glasses under 200USD (I searching for new ones not used). You say to buy a checked transmitter and receiver, so maybe AMW633 Transmitter but I don’t know what receiver. What equipment you use (transmitter, receiver, antennas, cameras and glasses)? :) I do not hurry, I usually think twice before I will buy something :D

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I think about the goggles blanking out, this is not a case of hi-res vs. lo-res. It's more a case of one design vs. another design.

Daniel

Of course. I have goggles of all resolutions (from 266x225 to 800x600) and all work perfectly well regarding dropouts. Definitely some bad designs from some manufacturers.

I want buy glasses under 200USD

That is not a lot. You will find some, but don't expect anything great in terms of quality.

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Well, I got my VGA goggles new on e-bay for US$265 so it's possible. You just need to restrain yourself and be patient - wait for the right offer and don't be in a hurry to buy things. While you're researching - read as much as you can, and then wait some more. A lot of guys just want to go out right this moment, buy all the stuff and start flying. It's not that easy, truth be told. You will need to put in some study and research to be successful.

While it is fastest to go with tried and tested, and recommended, equipment, that should not replace gaining proper understanding of the operation of all the equipment. If you don't understand your equipment, how it works and which one works best and for what reason, then you will be flying with undue risk. So, someone could point out brand XYZ antenna and you can buy it and use it but you really should try to understand why that antenna works and what it's limitations are before you actually fly with it. That comes from reading.

As for goggles, I would actually not start with goggles and FPV. You should start with just a good camera such as the KX-131, and maybe a 500mW TX and RX combo from one o the better shops, and make sure you have all the right voltages etc. And then try to record your flights to a camcorder and review your recordings. This way you get to iron out all the glitches in the links before committing your money and plane to full FPV, and you'll be safer to yourself and others too. If you can't get the camcorder setup to work flawlessly, you probably don't want to get with the goggles yet. This also provides you the opportunity to learn more about how the various systems work. THEN after you've done all that, it may be time to start thinking about goggles. To put it another way, don't jump into the deep end of the pool to learn to swim, start at the shallow end first, even if it's not as exciting.

The antenna you linked to is a regular 3dBi whip. Usually if you buy the transmitter and receiver, it already comes with similar antennas and there is really no point buying another whip unless your module doesn't come with antennas. It's probably best to go with ready to use TX/RX rather than modules unless you are quite proficient with soldering and have some rudimentary understanding of electronics (actually maybe more than rudimentary, intermediate would be more like it).

If you read the various threads here, you should find links to various sites and recommended equipment. There is a FAQ (sort of) somewhere which should answer all your questions.

Daniel

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