Author Topic: Digital TV  (Read 5837 times)

Offline Synbios

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Digital TV
« on: September 16, 2008, 03:17:16 am »
I just did a autoscan on my digital TV, and it found a lot of channels in the notation 102-2, 102-3, 103-3, etc.  What is the meaning behind this notation ? Why not just have sequential numbers?

Offline fuzzytomcat

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Re: Digital TV
« Reply #1 on: September 16, 2008, 05:28:39 am »
I just did a autoscan on my digital TV, and it found a lot of channels in the notation 102-2, 102-3, 103-3, etc.  What is the meaning behind this notation ? Why not just have sequential numbers?

Hi Synbios,

I think what your talking about are "side bands" for multicasting here in the Portland, Or area channel 8 KGW (NBC) is using 8 for programming analog and 8-1 for digital programming and 8-2 for 24hr weather, the same with OPB (Oregon Public Broadcasting) is using 10, 10-1, 10-2, 10-3 each with diffrent programming.

8-VSB (8-level vestigial sideband ) is the FCC standard radio frequency ( RF ) modulation (a process of adding data to a signal carrier ) format chosen by the ATSC for the broadcast of digital television (DTV) to consumers.
The 8-VSB mode includes eight amplitude levels that support up to 19.28 Mbps of data in a single 6 Mhz channel (there is also a 16-VSB is mode that has 16 amplitude levels and supporst up to 38.57 Mbps of data on a 6 Mhz channel). 8-VSB is perfect for the simultaneous transmission of more than one DTV program (multicasting) and the transmission of data along with a television program (datacasting) because it supports large data payloads.

Hope this is what your looking for ...

Regards,
Fuzzy
 ;D

 
« Last Edit: September 16, 2008, 05:41:31 am by fuzzytomcat »

Offline Synbios

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Re: Digital TV
« Reply #2 on: September 19, 2008, 05:13:59 am »
pretty confusing but I kinda get it..

Although I'm still kinda confused as to why I only have a 103-3 channel for instance. I don't have a 103-1 or 103-2.

I did a little research and apparently (I believe) my TV has a QAM tuner. This allows me to accept a pretty much random set of channels without paying for service from my provider. What channels I get depends on what channels are not encoded by the provider in my area.

My setup is:
I pay for cable internet, nothing else.

I put a spliter on my cable going to my modem and attached one to my TV and the other back to my modem.

A alas, I get a bunch of random channels on my TV that my QAM tuner is picking up.

Offline fuzzytomcat

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Re: Digital TV
« Reply #3 on: September 19, 2008, 10:04:44 am »
It is very confusing -

The digital ATSC format "over the air" broadcasting channels 2 thru 13, and the QAM is a simular but diffrent in that part of the number is the cable providers assigned program frequency and part of the providers converter box channel. The feed thru channels are cable providers digital broadcast programming that is in the clear usually local channels but ends up with a strange number mixed around. This is I guess an attempt to have to get a cable providers black box for easy viewing, the new numbering is going to be a big pain hooking cable direct to the TV will be a thing of the past with the new mixed channels with HD programming now.