Problem with hdtv cable

[cactus_74]

Hi I was wondering if someone could help me. I notice with hdtv or regular digital signals that the horizontal black bars for widescreen programming are two different sizes. what I mean is that the black bar on the bottom is a different size than the top one at times. I was wondering if this is normal or is there a problem or any kind of solution I could do for it?

Thanks

Cactus_74

 

[cactus_74]

Oh yeah I forgot to mention that I own a Toshiba 51" 51H84C CRT rear projection TV.

 

[SATMAN]

Cactus......I beat cable television into the ground......Cable is the biggest joke when it comes to High Definition......How in the world can you receive digital signals through analog cables..i.e. cable tv...Cable is just a modulated satellite system..they will set the aspects and ratios for you. Those black bars will be a common place with cable tv.

 

[MDS]

How in the world can you receive digital signals through analog cables..i.e. cable tv...Cable is just a modulated satellite system..

You answered your own question - modulation. The M in PCM, PAM, PWM, etc stands for modulation. You send bits, zeros and ones, over a cable using some modulation scheme of which there are dozens.



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[SATMAN]

Modulation would not cause high def to be converted from analog to digital. An analog signal is just that...analog.. You show me true high definition thru a cable television coaxial ? It will not happen.
Now, taking a digital signal and converting it into a picture is another story..i.e. high def satellite..It is converted from signal to pic in high def, never being an analog signal. I know this is an audio forum, but for all you audio buffs...I know your monitor is also somewhere in the mix..If you are running cable television (any format) your wrong. You are missing so much...

 

[MDS]

Modulation would not cause high def to be converted from analog to digital. An analog signal is just that...analog.. You show me true high definition thru a cable television coaxial ? It will not happen.

The HD signal was digital in the first place. I thought you were remarking that there is no way to transfer such a digital signal over an analog cable, which is false, happens every day; in fact there is no such thing as a 'digital' cable - only cables that meet the specs for reliable transfer of digital signals; eg 75 ohm coaxial cable.

I suspect that the 'modulation' you are talking about is modulating an analog signal on a carrier frequency as the analog cable system does. That has nothing to do with transferring a digital signal on an analog cable such as coax. Digital signals are a stream of bits - one or zero, on or off, high voltage or low voltage etc. There are various modulation schemes for doing that to transfer the digital signal over an analog cable (basically a wire). If it were not possible, which it is and always has been, you would not be able to connect computers together in a network with cat5 cables and send data between them.