I’m guessing that if you don’t have a cable box, then you probably have analog cable. There are all kinds of things that they can do to scramble and or cause copy protection with analog.
Be aware of the difference. Scrambling is designed to completely mess up the signal to where it won’t show on anything. The descrambling hardware used would often be on the pole outside, typically in the form of a simple filter. There were several kinds of these filters. Different channels would use different methods of scrambling. It was the channel that mandated what kind of scrambling was used, not the cable company, so whatever method the channel (like hbo or cinamax) wanted is what was used. In fact, people learned how to make and or what to buy to use as filters to unscramble many of these channels. I remember years back, it was as simple as winding copper wire around a tube (it had to be certain dimensions constructed in a certain way), to descramble hbo. You could build a descrambler for a few dollars. I also seem to recall that hbo changed what type of scrambling they had more than any body else. Later on (even while still analog), cable boxes were used and the box descrabled it. there was eventually intelligent descrambling where the cable company could change the descrambling as often as they wanted. They would send a signal to the cable box instructing it on how to descramble the signal each time it was changed. I suppose its feasible that there is a unit like this that is outside on the line somewhere?
Copy protection is different. It is generally intended to allow it to play on a tv, but prevent copying. One of the early ways that macrovision used for vhs tapes was to make one of the video channels weak. It would generally play fine from an original (most of the time and unless the tape was old), but copying would further weaken the signal to the point the video got messed up. I’m not sure how they do/did it with cable (I’m sure that there were several ways used, especially with channels like hbo). I guess that it is feasible that there is a similar weakness in the signal somewhere. It might mess up the picture to the tv, but to such a small extent, that its not very noticeable. When a computer trys to digitize it, it gets confused or has problems with the bad parts, and further messes up the video (preventing you from digitizing it to record it). I do know that some channels would have the cable box apply some sort of analog copy protection. The signal was scrambled, and the scrambling would change so you couldn’t just build/buy a descrambler. The cable box would get updates from the cable company so that it could descramble it, and then it would apply copy protection to the signal before it left the cable box. Fyi, better capture/tuner cards and or ones with stronger tuners tend to do better with copy protection. I’m not familiar with the brand you have as it is not common here though (not sure about the quality). There are video signal enhancers that can take care of some of the copy protections (and I do know for a fact, that at some point in time, they have been effective with copy protection that hbo used).
I think you are just going to have to find out what copy protections are used there. Perhaps you could set your google search filters for local web sites only and try searching for terms like hbo copy protection etc. Do it for the various channels and see what you find. Perhaps someone on this forum from India might see your post if you are lucky too. Here is a hack that worked back in the day (it probably wont help you but it might be interesting to read about using a tin foil slider to tune the descrambler, lol).
I would imagine, that others there have already dealt with this issue so there has got to be some known ways around it somewhere?
You might also try googling terms like india cable tv hack and look for sites like this.
In fact that second link might be a good place to ask your question (I don’t know anything about the forum, I just found it googling). Let us know if you find anything.