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???
02/08/05 08:06
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 		 #86868 - Confusion
Responding to: ???'s previous message
Hi Paul,

Where to begin. The basis of your thought seems to be the idea that you can
...turn it on and off 44 million times a second...
No, you can't. The most you could turn it on and off is 4000 times a second. That's what the upper limit of the bandwidth means. For AM (amplitude modulation) the maximum bandwidth is twice the modulation frequency. In the case of FM (frequency modulation) it can be even larger. This means that using AM you can not modulate any signal of frequency greater than half your bandwidth, in this case (4000 - 400)/2 = 1800 Hz. It is even lower if you use FM. Even if you tried something like SSB (single side band) transmission, you're not going to get an NTSC television signal (which includes both video and audio) through a dial up phone line. Sorry.

List of 26 messages in thread
TopicAuthorDate
sending high frequency signal over phone            01/01/70 00:00      
   sending high frequency            01/01/70 00:00      
   High Freq            01/01/70 00:00      
   A low-pass filter!            01/01/70 00:00      
      Why oh why            01/01/70 00:00      
         a possible why            01/01/70 00:00      
            Unfortunately not. :-(            01/01/70 00:00      
            Annoying telemarketers            01/01/70 00:00      
               Special Information Tone - SIT            01/01/70 00:00      
   oh no            01/01/70 00:00      
      CMX850            01/01/70 00:00      
         this is what i am pondering            01/01/70 00:00      
         this is what i am pondering            01/01/70 00:00      
            that is called a modem            01/01/70 00:00      
               im not wanting to get on the net            01/01/70 00:00      
                  modem and the net            01/01/70 00:00      
                  Modems and Video            01/01/70 00:00      
                     56K            01/01/70 00:00      
                     Video            01/01/70 00:00      
                        details            01/01/70 00:00      
            Yes, it *is* a modem!            01/01/70 00:00      
   ok there is some confusion            01/01/70 00:00      
      confusion all right ...            01/01/70 00:00      
         suggested texts            01/01/70 00:00      
      Confusion            01/01/70 00:00      
      Watching movies over the phone            01/01/70 00:00      

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