Greetings all !
      This is off-topic, but I love reading your forums, because of the many intelligent people that seem to be on this site
My question is centered toward people who live in the US and have Comcast as there TV/computer connection.  I received 1 of their new boxes which supposedly enables an old tv to receive their new digital signals.  In general there was a lag (screen would pop up that says contact comcast blah blah)  before the channel would appear.  and it seemed as though many other channels were no longer available.
       This is the tech part of the question - they sent out a repairman when my wife was at home (I was at work) who immedately said Ah your need to replace your cheap coax cables with the new cables.  I did notice that the cable that came with the converter box is much heavier.  But I have splitters running through the roof of my house which would mean I would have to replace over 300ft of cable.  None of my TV's are HD and I have the on-demand box in the living room.  I guess my misunderstanding is that does the cable coming out of the box at your house need to be replaced with "new coaxial cable) or only the cables that lead from the new digital converter box ?
    As I said this is off-topic, but  if anyone can EXPLAIN any differnces in coaxial cable,  I think a lot of us could learn form people who know vs people who sell.
    Thanks to all.  CH rules the universe !Well,  I used to work in that kind of stuff. In general, Coax cable does not last a s long as you want it to. And every spice and tap is a potential source of trouble. But it affects the quality of your reception, it does not cut off any channel just because of poor quality.
Your TV set should be set to 'cable', not 'antenna' to receive all cable channels. But some  cable systems now require every TV set to have a converter box. It is a real PITA.

My advice, do not replace the cable until you know that is the real problem. I think they want you to have a box on top of every TV.

You could, of course, break your contract and get another company. The fact that they do not give you the service outlined in the contract is a valid reason to break it.
And no, the coax cable does not belong to them. It becomes a permanent part of your home.

BTW, you can make a deal with you TV provider for internet service. So it does become a topic for this FORUM. To date, a cable modem is the way to go. If it is done right.
There are dozens of different types of coaxial cable used in homes, usually referred to as drop cables.  At one time RG-59 was the standard and that's what it sounds like you have.  For a number of years now, RG-6 has been the standard and it is LARGER than RG-59 and therefore has LESS signal loss which is very important at higher frequencies.  Like in anything there are good drop cables and cheap drop cables.  If you have that much RG-59 in your house I would guess it's over 20 years old and could be a problem.  Although, there is nothing wrong with RG-59 in it's self other than excessive signal loss, although really old RG-59 wasn't designed for the higher frequencies in use today.  If you have a mashed cable maybe only that one piece of cable needs to be replaced.

The first thing I would do though is check the splitters in the attic.  Most splitters have markings on them to show their upper frequency limit.  Today, the upper limit on splitters should be 1GHz.  Anything less could cut off upper channels depending upon the bandwidth of your cable system.  I would also check the cables in the attic and make sure there is no damage to the cables.

BTW, legally, if Comcast installed the cable, it is their property until you disconnect.  Then they have 15 days to retrieve it (which they almost never do) and after 15 days it is your property.  If the cable was installed by a builder, it is your property.

Cable companies are going digital because they can fit many more channels into the space one analog channel takes up.  Many cable systems have already gone all digital, which means a box on every older set.  Almost all newer TVs can display unencrypted digital channels without a box.  At some point in the future all cable channels will be digital.  People seem to get upset about cable channels going digital, but they forget all satellite channels are digital and that doesn't seem to bother anybody.I'm going through the Comcast changeover now.  If your signal is clear on the analog TV's without the converter, new cable drops are not required.  My house is full of RG-59 & the signals are good to all the TV's (mostly analog with DTA's) and the cable modem.  The Comcast technician should have measured the signals at the end of the drops (right at the TV's).  If he did not do this, he's not doing his job properly.

The little DTA's actually work quite well, but I just had a 3mo old unit lose sync and could not be rebooted by the CSA's, the little green light just kept flashing.  New one had to be activated even after the exchange.  I think Comcast is pretty overwhelmed with this changeover & few CSA's or techs know what to do.Thanks for all your replies,
      Have yet to decide as to what I am going to do, as I need to replace over 300ft of cable.  rthompsonwon80819 - if rg-569 was the old standard is RG6 the new standard. - As I stated before no HD TV's involved.
RG-6 has been the standard for a number of years.  There are larger drop cables, but they are very difficult to work with inside the home.  It doesn't matter if you have HD or not, it's the higher channels that are affected by excessive cable signal loss.  If you have a staple or nail through the cable in the attic any channel could be affected.Reference.
http://en.wikipedia.org/wiki/Coaxial_cableGeek, I just read the Wikipedia article on coaxial cable, and normally I consider Wikipedia a reasonably good source of information, but the article on coaxial cable was horrible and outdated.  I'd edit it tonight, but it's after 1am and I've had several glasses of wine, but I plan to work on  it tomorrow.  It's just got too many misstatements and unclear facts.

It starts off with a picture of RG-59 with two center conductors.  There are some video cables with two center conductors, but it's not RG-59. Quote

It starts off with a picture of RG-59 with two center conductors.

...It starts off with a picture of RG-59 with two center conductors.  There are some video cables with two center conductors, but it's not RG-59.