it depends on how you systems was designed...
first think of cable as a very large radio... ie you fm radio goes from 88mhz to 108mhz.... extend that frequency range from 5mhz to 1000mhz and you have cable. depending where the modems recieve frequency is dictates wether or not you'll be able to watch tv on it. if you cable company uses a very high frequency(550mhz+) for the recieve then you'll prolly be able to watch all the non scrambled channels.. OTOH if your cable company uses a lower freq like say 115mhz your SOL, since they can put a "trap" on your line without effecting the modem. (traps will block all freqs/channels above a certain range)
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In other words, they didn't use the same line my cable tv was coming from >>
that line has the cable tv and cable internet signals in it... it is the same "line" that tv uses. ie if you had no cable line in that room, they would have run the same wire to the same spot.
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Just for the heck of it, I tried plugging in my tv to the internet line, and I could get hbo, showtime, and cinemax. I was kinda surprised >>
if you did that without a cable box you live in the ohh so easy to steal service "non addressable" systems.. i envy you
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what i was told by the at&t people is that they send two completely diffrent signals through the the line >>
thats got a hint of propaganda to it, but you could strecth that the TV is analog and the modem signal is digital, hence the completely different thing.
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plus at&t can tell when u have been ussing ur cable. >>
anyone with access to the CMTS(cable modem termination system) can tell when and if you altered the amount of signal going to the modem.(all we have to do is check the return power level) you can try this yourself if you have any GI/motorola cable modem just remove the proxy settings from IE and type 192.168.100.1, then click on the signal tab and look for the bottom number in Dbmv.(35-55 is safe)