Sanjay, a thought just occurred to me. None of the TV companies have any direct link to a cable operator. So the cable operator also has to receive the signals through a satellite. Though the cable TV operator who came home also told me that with a set top box his signals will be better, I don't see how unless he has some equipment to boost the signal strength or filter the signals of noise.
Cheers
Actually there is one major reason for the difference in quality, between cable operators and the DTH companies. The difference lies in the quality and extent of compression being used. To understand why the difference is there, we need to understand the entire path the signal covers, before the original channels' uplinked signal, reaches the final customer / viewer.
First the original channel compresses, encodes and uplinks it's signal to a satellite. This signal, is in turn received and decoded by the cable operator and the DTH companies. Up until this stage, both, cable operators and the DTH companies, have the same, relatively good quality picture. But from here on, things change and the quality starts differing.
In the case of The DTH operator, they now re-compress and encode the signal before uplinking it to their DTH satellite. But, for cost cutting reasons, they put more channels on a single transponder. This is achieved by using very low bitrates while compressing the signal, this results in a very poorly compressed and heavily pixelated picture in addition to several other digital artifact problems. Bottom line, the originally good picture, reaches the final customer in less than even VCD quality picture at times, let alone DVD quality. By the way, using MPEG4 does not in any way help make the picture any better, for instead of using the better compression abilities of MPEG4 for better picture quality, the greedy DTH companies use it to further increase the number of channels being carried on a single transponder. Therefore the move by a few DTH companies from MPEG2 to MPEG4 only benefits them and not the customer, as their ads would have you believe. In fact this is the very basis on which Tata-Sky has filed a case against Airtel's ad campaign, which highlights their using of MPEG4. Personally I feel the courts should show Tata-Sky the mirror in answer to their complaints. After all, their marketing campaign, claiming "DVD quality picture & Sound" too, is nothing but false advertising.
The cable companies on the other hand do not have the same limitations of transponder costs or anything to gain by using low bit-rates while compressing and encoding. Thus, they use much higher bit-rates for their compression, which ultimately results in a relatively, far superior picture quality, without the horrible pixelisation and other compression artifacts that is so common with all the DTH companies.
Also, very importantly, none of the cable operators superimpose 'watermarks' of their crappy logos on all the channels, whereas DTH customers have to not only bear with them but also have to put up with numbers flashing accross their screens in random spots on the screen at random times.
