bkamen at benjammin.net
Thu Jan 14 19:04:04 UTC 2010
On 1/14/2010 12:52 PM, Brian Wood wrote:
> Close, the upper end of frequency response of cable systems does keep going
> up, and the reason is the additional services being carried, but many digital
> services are carried well below the top end of the system, especially the
> return (upstream) portion of cable modems.
> All that matters is the frequency response of the passive devices, the word
> "digital" really means nothing, though it might be easier for the installers
> to understand than an actual frequency rating.
Ultimately, all the "digital" services on the cable are delivered in the analog domain in an RF fashion.
Interestingly, if they delivered CAT5e to your house and plugged right into an Etherswitch and gave you a special network tuner, I could see that as being more "digital" (even though the higher speeds of ethernet use an "analog domain" style of transmission to deliver the bits).
Even now, HDTV still only consumes only 6MHz of bandwidth like the old analog stations did.
Cable systems have been going up no matter what.. digital or not. So as Brian mentions, it's probably easier to
print "digital" on the silly thing than try to train some of these guys as to what "bandwidth" in terms of Hz (Hertz) really means.
I used to work in CATV (fixing old OAK TC56 STV's when I was 17 and our system was a staggering 450MHz!) and some of those guys should have never been given a crimper.
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