Home Automation - signal loss in digital cable?

Hi there,

I was wondering if digital cable TV suffers from the same signal degradation problem that analog cable does when it is split multiple times througout one's house? Theoretically, the cable box just has to detect a one or a zero, and even a very week signal will be able to communicate these bits fairly successfully. I just don't know if digital cable is truely digital in the way a CD or a computer disk is digital. For all I know, cable companies could use the term just to sound impressive and back it up by putting some digital switch on the line somewhere.

So, I guess the true question in all this is: if I have a digital cable subscription and converter boxes for each TV in the house, do I have to worry about signal amplifiers or how many times I split the cable?

Thanks!

The signal is carrid analog on the cable, if if the receiver
finds it hard to distinguish the bits, you will have trouble.

Yes, it is a true digital signal. Signal loss due to splitters or cable length is still a factor. It is likely that you cable signal is supporting both digital signals and analog. If your analog channels are getting snowy, digital will eventually be affected. An analog channel may get snowy with low signal, a digital channel will either be on or off completely ...no gradual degradation.

Thanks for the info. Sorry I took so long to respond...I forgot to subscribe to the thread.

I guess I'll go ahead and wire my house without amplifiers. If I find that a lot of channels don't work or if I get that blocky digital cable effect a lot, I'll add an amp where I split the line coming in to the house.

Thanks again for your input!

I changed my mind.

Today, I bought a 25 dB signal amplifier. I opted for this over the 4-output amp because that one was only a 10 db amp (it wasn't clear if that was 10 total or ten per out). The 25 dB amp also had a FM trap to, supposedly, remove FM interferance.

I'd like to wire 7 rooms with CATV. Not all rooms will have digital converters, so it's important to get a good signal to each. The largest splitter I've been able to find is a 4-way. I've been told that you never want to split a signal twice, but I'm basically forced to do it in order to get 7 outs.

The way I look at it, if I put a 2-way splitter right at the amp, then each out will have a signal that's 12.5 dB stronger than what the cable company is piping me. Then each of those will be split and sent to the individual rooms.

Does this sound like a problem to anyone? Can I really get away with breaking the 1 split rule?

Sidebar question: has anyone had a good or bad experience using wall jacks that basically just have 2 male adapters end to end and accept female cables coming from the source and to the TV? Seems like it introduces a lot of extra connections. It would be nice if you could just crimp the cable onto the jack and have one male instead of a female, male, male.

'nother question: Do individual cabling tool companies (such as Ideal) use proprietary cable ends with their crimpers, or will a RG-6 quad-shield end work in any RG-6 crimper?

Thanks everyone!

lifos - You can split the signal as many times as you like. There is no rule. The splitter should be labeled with the loss per leg. For example, a two way splitter may attenuate the signal by 5 db per leg (not half the 25 db gain, as you noted).

It is a good idea to place your amp and splitters is an easily accessible location.

The wallplate and jack with a female F-81 connection should be ok. That's what the pros use. There are differences between manufacturers of connector and crimp tools. I suggest you buy a matched set... whatever one or the other recommends. A bad crimp could result in all kinds of problems.

If you are still having problems when you are all done, contact your local cable company. Service is free in most areas. They have the test equipment and training to determine if everything is installed and adjusted properly.