Yesterday I wired a relatives house for cable. The analog cable works
fine, but when I plug in the digital cable box supplied by the cable
company it doesn't work at all. Is there anything special about
splitters for digital cable? I use Dish network, and I've really been
out of the loop as far as cable TV stuff. This is not Comcast, but a
small municipal cable company.
Splitters are not one-way or two-way, they all will pass signals in
either direction with the same predictable loss of 3.5db per split.
Where the cheap splitters have problems is with shielding and bandwidth.
You shouldn't be using any splitters not rated for at least 1GHz
bandwidth and 110db shielding on any cable system these days, and a few
cable systems as well as satellite may require a higher bandwidth.
Also, older analog cable boxes did indeed sent return data to the
head-end for things such as pay per view buys, things that far preceded
"digital" cable where the A/V is transmitted digitally.
Another thing to keep in mind is that many of the digital cable boxes
need to be plugged in and receiving data for quite some time before they
will work properly.
Yes, they are combiners or splitters, it doesn't matter which way the
I'm pretty sure now that there's one of two problems. They may have been
distributing the digital boxes to all customers in advance of the
disabling of analog cable, even if the customer didn't sign up for the
more expensive digital service, or I didn't leave the box plugged in
long enough (about 5 minutes).
5 minutes probably wasn't long enough. The data channel used to update
the box is pretty slow, and the longer the box has been offline the more
updates it may need. I had a digital box here that sat disconnected for
about a year, and when I hooked it back up it took sitting overnight
before it started doing the digital channels properly. Presumably the
updates include things like CODEC software which could take a while.
I hooked up the same type of box at another relative's house in the same
city, and the digital cable worked right away. But I'll still have them
try just leaving it plugged in. I do all this on the weekend, and it's a
small municipal cable company with no one to call on the weekend for
It's always possible that the cable box is bad, or that there is a
problem in the cable plant itself, like the closest amp to the house
that is preventing the return signal from going back to the head end. If
the cable system just started doing interactive and digital that
possibility is greater.
did you use RG6 or RG59, any screw on connectors?
you shouldnt use RG59 or screw ons for digital cable installs..
both are way too lossy, and this applies to satellite tv as well.
how many splits do you have? might need a distribution amplifier
The wiring from the street is RG59, probably about 20'. All my wiring is
RG6, about 60'. One of the existing outlets has about 4' of RG59 from
the splitter, but the outlet that I tried the digital box on was all
RJ6, except the old RG59 from the street. I could change the outlet with
the RG59 to RG6 if necessary, and I suppose I could also change the
wiring from the street.
There are two splitters. The splitters I used are
"http://www.hometech.com/video/splitters.html#PI-DSU2 " so there is 9db
of insertion loss. The RG6 connectors are crimped, and the RG59
connectors are press-on, not crimped (I couldn't find RG59 crimp-ons
yesterday when I first realized that the existing wiring was RG59).
When the HDTV went through the set-up where it finds all the channels,
without the box in place, it did find a bunch of "digital channels.
What I'm wondering (and can't find out until Monday) is if my relative
actually has subscribed to digital cable, or did they just send the
boxes in anticipation of their shutdown of analog cable.
Next I'll bring a small TV and try hooking up the digital box in the
garage, directly to the incoming line.
First, you better have used RG-6 coax rather than RG-59. Second, you'll need
splitters rated @ 1GHz bandpass. The cheap rat-shack ones you may have lying
around won't cut it. Also- make sure you make proper fittings *use a proper
crimp or compression fittings* do not use twist-on's, and do not try to cheat
and use pliers as a "crimper" if you go with crimp fittings. Signal leak is
I kill all Google Group posts, you can too.
Take back Usenet <--> http://improve-usenet.org
I agree with Reed. For digital you usually need two way. We have
Cablevision here. They have these channels for car shopping and house
shopping. From the remote you can request new data. You can also
request movies etc. This requires two way communication.
If you have multiple TV's, and have alot of cable runs then a
amplifier that enables you to split off each feed may be useful. You
need a amplifier which allows two way communication. I got mine from
here http://www.cabletvamps.com /.
I have an Electroline EDA-FT-8100 and it works for me.
All the best, Mike.
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