Legal Radio Frequency Bands In Thailand?

[AleG]

Let's see if someone here knows the answer to this one. Perhaps a HAM radio...

I'm thinking about building a FPV (First Person View) model airplane, basically it's radio controlled electric plane with a camera mounted on a swivel that tracks the movements of the head of the pilot on the ground, pretty cool if I can find some nice video goggles.

So far so good, the thing is that the video transmitters and receivers come in three flavours, 900Mhz, 1.2Ghz and 2.4Ghz. Different countries have different regulations concerning the use of the radio electric spectrum and I'll be darned if I can find the Thai regulations for this. Namely, which one of those frequencies (and perhaps among those, which channels) are legal to operate in Thailand without the need of a license.

So, any idea?

[Maizefarmer]

The R/C frequencies here are the same as those elswhere in the world - with 2.4Ghz now fast becoming the preffered choice - and so too are the ISM bands, which means: so long as you stay within the max radiated power limits you can use any of the ISM frenquencies for your intended purpose without having to worry about licensing. Go over the max radiated power limit and licensing becomes an issue.

The other point to keep in mind is modulation - what type of modulation do you intend to use - analoge or digital, and if digital what type of digital mod do you have in mind, QPSK, spread spectrum, QAM, DVB - S or S2 (which is common when it comes to digital video/audion content). Some mod techniques can be used on certain frequencies and bands within the ISM rules & regs, and some can't. 2,4Ghz ISM for model radio controll can be one of 2 different types of digital modulation, but 2.4Ghz as used for IP content (e.g. WiFi connections) is a different type of digital mod compared to R/C flying and control.

You best bet - touch base with one of the guys who fly R/C heli's for filming (there are a few of them in Thailand) - they'll be the best folk to guide you through all the rules and reg's. Unfotuneatly I fly/control my R/C model plane with Silverstone R/C gear from Australia - which to the best of my knowledge is not legal.

PS ..... I saw a couple uTube vid's the other day on the exact subject you are talking about. Looked pretty impressive. That guy was using 2,4Ghz IP type modems (Wifi type links) - with a tripod mounted servo driven 2.4Ghz patch antenna which followed the plane flight path. He just sat back on a beach chair with a pair of goggles on. Looked impressive - I dont belive for one moment it's as striaght forward as it looked though - lots of rf data travelling back and forth and lots of scope for things to go wrong. One big plus point you will have in Thailand (especialy if you go out to the rural areas) is that the rf specturm is nowhere near as crowded as it is in Western countries.

[AleG]

Thank you, Maizefarmer. I've already looked those people you mentioned but their webpage doesn't say what sort of frequencies they use for the video.

I suppose 2.4Ghz should be fine, since it's used for radio control transmitters everywhere, however that's the problem since a video transmitter using the same frequency as the control signal would interfere with the receiver on the plane... So the solution would be to use the old, trusty 72Mhz RC frequency.