tv frequencies

[Onceler]

I need to know what frequencies are involved for channel 21 1-4
I can't seem to find this nfo with google
A chart showing all the audio and video frequencies would be great and how their transmitted.

 

[PottedMeat]

http://en.wikipedia.org/wiki/North_American_broadcast_television_frequencies

http://en.wikipedia.org/wiki/Digital_subchannel


actually you should look up the station - i'm not sure if a tuner really assigns the title 'channel 4' to frequency channel 4

 

[Lemon law]

Potted meat is correct, your local channel 21 1-4 is merely a virtual channel, to find the real channel its broadcast on, go to www.TVFool.com , input your address and out should come the real channel your local channel 21 is broadcast on. Plus other information to delight any geek.

Once you have the station call letters, you can goodle that and get even more information.

 

[exdeath]

Somewhere around 165 MHz (166.75 channel center?) for North American QAM digital cable. All sub channels are digitally multiplexed and compressed into the 6 Mhz analog bandwidth assigned to that real channel in the analog domain.

Not going to be able to get a chart showing the bandwidth allocation of the 6MHz channel, its all digitally encoded and multiplexed in various ways. Analog was easy to see.

As you can see digital makes far better use of the available bandwidth and is able to transmit much more info (multiple channels etc) but as result is not "human readable". Its just a digital bit stream, so you aren't going to see sub carriers for individual video and audio sub/virtual channels. At that level a digital tuner is selecting data packets belonging to different sub channels, its not tuning to a sub carrier frequency for .1-.4 like you would with analog.

 

[Onceler]

Thanks all