Better cable for cable connection

[Magnum]

I have a friend who has cable and there are problems with the cable going to his HD TV.

It's the old coaxial cable and oftentimes he has to rescan the channels.

I think the cable is probably not doing a good job of carrying the signal about 75 feet.

What could it be replaced with.

Thanks.

[clive]

Personally I used RG-6 to replace all the cheap/old crap in my house. Good for cable, or sat-tv

http://en.wikipedia.org/wiki/RG-6

[dedndave]

RG-6/U is probably what it already is
actually, that is good cable, electrically speaking - it is double shielded
the problem is, they make it as cheaply as they can
after a time the outer insulation develops small cracks and/or becomes less supple or even brittle
Beldon is a good manufacturer if you need to replace it

the shield in RG-6/U is aluminum - no way to solder to it

it's possible to replace it with RG-59/U
they are the same impedance (75 ohms), but RG-59/U uses single copper braided shield which can be soldered
it is slightly smaller in diameter, but retains flexibilty longer

[GregL]

I agree, use RG-6.  I wouldn't use RG-59 though, too much signal loss, especially at the higher frequencies.  The old stuff may be RG-59, and that could be a big part the problem.

[dedndave]

that is absolutely true, Greg
Rg-59/U drops out around 200 or 300 Mhz
cable TV goes up to about 800 Mhz, i think

what is bothering me about the problem described is...
if you have to re-scan TV channels, it tells me the TV isn't remembering them or something
i am not sure that is necessarily related to the quality of signal

also, there are pre-amplifiers available to help overcome long cable lengths and poor signal strength
most of the time, i have too much cable signal - lol - but, i live in a big city

[clive]

Depending on the connection, the cable company may be able to increase/reduce the gain at the pedestal. Other things to consider would be the number of splitters you have off the main feed into the house.

[Magnum]

There is one splitter and a total of 3 TVs that are connected.

2 analog and one HD.

First set is about 20 ft. away, second is another 30 ft., and the third is about 60 ft. away from where the cable comes in from
the pole.

The 2nd TV has bad reception on Channel 11, other channels are O.K.

Maybe all I need is something to boost the signal.

[joemc]

can you split digital signals? i would think you would need to repeat them.

Also read whats on the "splitter" there are many different things that all look the same. some split the frequencies between 2 cables, some split the power of all the frequencies to all cables.  diplexers bump the frequency up or back down to share the cable for 2 uses.

[donkey]

I have a Motorla BDA-4K-RA broadband drop amplifier to boost the signal because of multiple cable runs in my house (5 outlets) solved all of my problems. I agree with Dave about the rescanning channels, I can't see that being the fault of the cable signal attenuation.

[clive]

can you split digital signals? i would think you would need to repeat them.

They are modulated onto a carrier frequency (probably phase/amplitude encoding multiple bits). There are multiple channels, with significant bandwidth. An amplifier with enough bandwidth might be considered a "repeater", but we're not talking 0's and 1's

Some of the cable systems are pushing multiple compressed digital audio/video streams over a single "channel" to balance the compression ratios across the multiple data streams while maintaining a uniform bit rate for the channel.