At 11:01 4/6/2009, Chuck Kelsey wrote: >Digital appears to work well only in a "controlled" environment where there >is very good signal-to-noise ratio. This leaves, for the most part, RF paths >out of the mix (excepting microwave since it has good S/N). >Will we see the day that digital two-way and digital TV works really well, >all the time? Maybe some of us will, but I think it's many years off.
Chuck brings up the central point. I happen to live 1mile line of sight from Sutro Tower (San Francisco's biggest roach clip). I get 39 OTA HD channels. In this I am fortunate. When signals are weak, analog gets noisy, digital gets dead. But the hope for processing very weak signals is greater for digital that analog, consider PSK31 that reliably transmits data using signals that cannot be heard AT ALL because of excess noise. What digital needs is to go to character rather than audio messages when the noise gets too high, using mod/demod techniques for low rates in high noise as "Plan B". This will make digital much better than it is now and much better than analog. Until then, weak digital will be nearly useless, meaning anyone who wishes to use it reliably will need GREAT NEARBY repeaters. Same for digital TV (except the Internet is probably TVs "Plan B"). And folks in very remote areas will NEED satellite (or to stick to DVDs and the mail). -- Dave Gomberg, San Francisco NE5EE gomberg1 at wcf dot com All addresses, phones, etc. at http://www.wcf.com/ham/info.html -----------------------------------------------------------------
