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Helix1

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About Helix1

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    RC-Cam'er

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  1. The skew planar antenna is not to be sneezed at – it’s been a long held theory that on balance circular polarised antennas are the best on ground type antenna’s to use in RC/FPV flying scenario’s – despite the -3dB loss incurred when matched with a linear type antenna mounted on the airborne platform (which can largely be negated using a second antenna or designing in an additional 3dB gain in the first place). However, I don’t believe the skew planar to be the best circular polarised omni direction to use – for 2 reasons: firstly, some 50% of it’s potential usable radiation pattern/gain is
  2. None - I see no reason at all why the products you have suggested can not or should be used. I haven't looked in any detail at either of those products, so they could be better suited. Been designed for RC model plane use (specificaly?), chances are theres' a bunch of reasons which would make them preferable options. Fair comment. Secondly, and I can't speak for mrfliboy either, but from my perspective the comments shared were not in any way mean't to suggest or reccomend one product over another - only to share with the OP some ideas regards the product he had and was asking about
  3. mrfliboy Mmmmmm …. that’s not a bad idea. I tried to chase this product up on the FCC website, and I couldn’t find the exact same product, but I did find a very similar product – bearing an almost identical brand name ("Luggage Locator" - but not including the "Pro" word) using identical type-face, and bearing an identical trade mark (a solid colored central dot surrounded by 3 concentric circles). The molded plastic packaging of the "Luggage Locator" on the FCC website is different – so what do we have(?) - a knock off, or an updated version of the same product in revised packaging? My
  4. http://epubl.luth.se/1402-1617/2005/296/LTU-EX-05296-SE.pdf ..... good read - has some interesting info in it
  5. Noman - also not sure what you mean, but I suspect you are talking about using a constantly on rf downlink of some type? What signal type did you have in mind, if any? - a dedicated rf signal of sorts (modulated with a "beep beep ..."?), or an existing modulated signal(e.g. if you have video transmission onboard?) - or some other kind of rf signal? Using a received rf signal [strength] is not the easiest way to go about pointing an antenna if you are centering everything around a single ground station. There are a few issues that have to be factored for to get such a system working as relai
  6. Who is the manufacturer? If it’s Far East manufactured there’s a good chance it is a generic circuit/pcb and a close look at it could well show a number of vacant component places – components that are not “essential” (at least by their standards) and/or not in stock at the time the board is populated. A good example of components that get left out are the output filters. So many 900Mhz (and to some extent 1200Mhz) video boards from the far east don’t have filters on the Tx output or the Rx input – just a pair of component holes, which are patch across with a wire where required. I don’t k
  7. Hannibal Could you be a little more specific regards what you'd like some more info on - quite happy to help if I can. Patrick
  8. sigma_fr Possible option ...... if you can open up the metal box that contains your video transmitter electronics and take a high res/close up digital photo of the circuit board, I may be able to point out to you exactly where you can solder on a surface mount component type filter. Many analogue video transmitter-receiver kits are based around the same or very similar generic circuitry & boards, and from manufacturer to manufacturer you often find certain components deemed not essential for the application the product is designed for left off the circuit board to save production time a
  9. I made it clear earlier that to tackle a digital HD system for ones self is not the same as tackling the project – especially as a “proof of concept” project - from a retail ready perspective. Putting together this system, as explained in earlier, is not only a technical exercise but needs to be cost conscious. I may source one or other component as a used component from a specialist dealer e.g. the codec engine (Black Magic H.264 Pro Recorder) I sourced today as a used part from a specialist broadcast equipment dealer in London – saving the equivalent of just under $100 (retail price in t
  10. Okay – OMM, now I’m with you. I’m not sure though I concur with you that there is anything unique about AMP’s COFDM modulators, and with great respect OMM, that this isn’t apparent to you suprizes me somewhat in view of your 25yrs experience with SS. Actualy there is one thing unique – it’s the price (mind you, so to are L3-com’s small/portable COFDM modulators - in fact L3-com’s products cost even more!). I’ll explain myself. Off the top of my head I can name a half dozen or so brand-name pro-spec clip’on sized COFDM modulator manufacturers – the small modulators that broadcasters
  11. No Terry, it isn’t worth it financially. The costs and technical barriers over-ride the advantage in all but a few cases – which is why the few low latency HD video streaming hardware packages that do exist and are small enough to squeeze into a model (and it would need to be a model of fair size) cost so much (economies of scale). I don’t know what the policy is in other companies, but EADS sees video sensor systems and links for UAV platforms all been HD within 3-5 years, and in a broader context, trade publications for the digital cam & image sensor markets by and large concur that w
  12. Sorry Mike - I'm obviously missing something in what you trying to share with me. What is it about DVB-T (as opposed to say DVB-S, or any other transmission standard/modulation that could be applicable to HD video) that you feel I don't understand, or have failed to keep in mind with respect to the notes I written regards HD video? ..... and the point regards AMPS products - I'm missing on that as well? Thanx
  13. Kilrah ..... indeed, the OP was looking for a practical solution. Off the shelf solutions to implement "connect & fly" HD streaming video are thin on the ground so far as finished products suitable for hobby use go. Most of what does exist (currently) is either too expensive or too bulky. A possible way forward would be to seek out suitable parts at a component level i.e. put together ones' own system from separate off-the-shelf parts. To do that successfully would mean keeping in mind the points I raised. As far as HMDI goes, the points I raised are as applicable to HDMI as they
  14. I can’t help but think at times the powers to be deliberately imposed all the restrictions they have regards RF power outputs and frequency options when it comes to video (tongue in cheek). Of course, as most folk on this and similar forums will know, the higher your transmit frequency the greater the required output [power] needed to cover a given range/radius, and the harder that becomes to implement the more bandwidth one needs to use (as is the case with video content – analogue or digital). Likewise, on the receive side, the harder it becomes technically to realize receive sensitivity
  15. Hi Henrick HD quality video – this is a project I am currently working on – let me share with you some of the issues that need to be thought through if you hope to implement HD quality video streaming successfully from a mobile platform (air or ground – makes no difference) to a fixed location ground station. This is a bit of a mouthful these notes, but they will once and for all cover the issues you need to bear in mind and think through if you hope to implement an HD video stream with any degree of real world usability on a moving model. Camera Camera selection: HD video means a camer
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