title_body: Is it possible to transmit a high-resolution image over an analogue signal? As digital video signals become more popular, there is a growing question; Why can't we just create a higher resolution analogue system? Are there actual limitations of the technology that prevent it?
  So far, I have thought of a few potential reasons why analogue transmissions remain low-resolution:
  
  Existing equipment (people already have goggles/cameras with set resolutions)
  Not wanting to give up bandwidth (racers in particular need to have enough bandwidth for multiple pilots)
  Lack of interest (people might just not care enough to change analogue)
  Cost (depending on what would have to happen to create a high-resolution analogue system, it may end up being even more expensive than digital)
  Not possible (it might just be beyond the capabilities of current technology)
  
  Several of these reasons, however, would also prevent people from changing to a high-resolution digital system. They would need new (expensive) equipment for digital, and most digital systems have less available channels because they use more bandwidth.
  Would it be possible, though, to create a new analogue system that transmits a high-resolution image? Even if it took so much bandwidth that only two people could fly simultaneously and it required new cameras/goggles/VTXs, it could still be worth it.
  And if it was possible, would it actually be worth it, or might it be better to go digital?
upvoted_answer: Bandwidth is the main issue. An HD signal has about four times as many pixels as an ordinary TV picture, so you'd need most of the range of FPV frequencies just for one pilot. I think that would also require four times the transmission power to get the same range.
  Then the problem is that all the gear we use is based on old CCTV chips rather than having been developed specifically for FPV (which is one reason the channel allocations are such a mess). I guess no one built a CCTV system for just one HD camera - multiple cameras are important in CCTV, and lag isn't an issue, so they could use digital compression.
  So, I guess the cost to develop a custom system is the big issue, especially if it might have a limited market, or become obsolete in a few years as faster, cheaper processors allow digital systems to overtake it.