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Curious About Digital Television Airwaves

Lone Stranger

Lone Stranger

Well-Known Member
I did a search about digital television broadcasting and found nothing. Here in Canada we are finally ditching the analog broadcast August 31st. I will keep one of my old CRT models since I use it for movies only and do not have cable or satellite subscriptions. I did recently buy a cheap 19 inch television for my bedroom just because I would need a digital tuner to watch anything off an antenna.
What I would like to know just for kicks: How does the digital signal get carried over the air? I know that with the analog signals the audio travels on FM and the video on AM. What about the digital?
 
It is a simple FM signal using a smaller bandwidth than a standard video signal. It can use less power because the signal can be decoded with a mere 3dB of S/N (though that is a threshold, not a target). As such, moving to digital frees up massive amounts of spectrum for other applications, like LTE and WiMax.

Really, it isn't very complicated at all.

Do a search for ATSC for the North American standard for broadcast digital television.
 
Thanks Flint. I did look up ATSC and did find the info about using less power and bandwidth. I just did not see anything about the FM waves. My house is in a valley with a major electrical transformer nearby so signals are weak to non existent. Interestingly enough one local television station switched over to digital several days ago and when doing a channel scan the television cannot find it even though it finds a very crappy analog signal from farther away. I will have to upgrade my antenna. I cannot put one on my roof so I will compromise and put an amplified higher quality antenna in my attic at the peak. I have ordinary asphalt shingles and no electrical wires within a couple of feet so I hope that will yield better results than a lousy set-top antenna currently hanging up in the attic.
 
Why can't you put an antenna on your roof? In the US the FCC has mandated that NO ONE can prevent you from putting up the right technology to receive commercial broadcasts. While my HOA has a policy against antennas, they cannot strictly enforce it. They can insist that someone who needs an external arial antenna use only what they need and make all reasonable effort to hide it from street view, but they cannot stop one from having an antenna at all.
 
It is not a matter of not being allowed but with the tall trees nearby and the sometimes violent storms causing damage it will never last. I also do not watch television frequently except during the Olympics so I also do not want to put a lot of money into it either. I know it is not ideal but If I can pick up a handful of channels with a unit in the attic I am happy. If it works out I can try hooking my clock radio and a stereo receiver up to it as well.
 
When stations go from analog to digital, they have to invest lots of money on their towers & equipment. If you got the analog channel that doesn't mean you will get the digital signal until they have updated their towers & equipment. Even then they may not go full power for some time. Contact all the local broadcasters & ask questions.
Example, my local Fox (owned by Fox) replaced their tower etc. It took a long time to do this & even then it took longer to go full power. for awhile I sometimes got Fox & sometimes not. I'm 12-16 miles by way of how the crow flies to the towers. I use indoor antennas.
Another example about digital channels. My local PBS just had 2 analog channels. During the change over they dropped one. The analog channels cost alot of money in power bills to broadcast. But when going digital those bills drop & most broadcasters broadcast more channels. My PBS now has 4 digital broadcasts, ABC has 3 etc. I also got a firmware update on my Sony LCD while watching PBS (they piggieback info on their broadcast----manufactures pay them to do this).
 
Lone Stranger said:
Thanks Flint. I did look up ATSC and did find the info about using less power and bandwidth. I just did not see anything about the FM waves. My house is in a valley with a major electrical transformer nearby so signals are weak to non existent. Interestingly enough one local television station switched over to digital several days ago and when doing a channel scan the television cannot find it even though it finds a very crappy analog signal from farther away. I will have to upgrade my antenna. I cannot put one on my roof so I will compromise and put an amplified higher quality antenna in my attic at the peak. I have ordinary asphalt shingles and no electrical wires within a couple of feet so I hope that will yield better results than a lousy set-top antenna currently hanging up in the attic.
Click to expand...


Same as me. Though it was with a set of powered rabbit ears, I was only able to get one analog PBS station. That was about 3-3.5 years ago.
 
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