"Splitting" the cable w/minimum loss

[JonUrban]

I currently have Charter Cable coming into the house. Up until a few weeks ago, I had the BASIC package, with the High Speed Internet, and that was that.

The cable came into a single splitter (3.5 dB each output), one line went to the Cable Modem, and one went to a video distribution panel that I installed (A Channel Plus box) that included a 4 channel modulator that I have attached my two Dish Network receivers, a DVD player and a VHS machine, which allows me to watch either receiver, the DVD, or a VHS tape on any TV in the house on Channels 81,83,85,&87. This setup has worked fine for years.

Well, since Dish seems to be lagging in the local HDTV scene, I upgraded my Charter Cable service to a Charter HDTV DVR, and got the HDTV package. (I must admit that the Dish HD looks better than the Charter HDTV, but that's for a different post in a different forum)

Anyway, Now, I installed a 3 way splitter that the Charter guy gave me. It has 3 outputs, a 3.5dB and two 7 dbs. He told me to use the 3.5 db output for the cable modem, and the other two for the cable TV output. However, I want to split one of these into 2 to drive two more locations.

So, I am stuck. Is there a 1 in, four out splitter that anyone could recommend to do this job that would A) Not screw up the cable modem and B) Not screw up the digital cable?

What would be the preferred way to accomplish this? The Channel Plus unit amplifies the signal, but on the input to that I have a filter and a trap so the modulated channels in the 80s are clear of the cable channels.

Would it be best to take the cable from the street into an amplifier with 4 outs? How would the cable modem deal with this?

I really am not up on my technology when it comes to cable modems and digital cable HDTV signals.

Can anyone help????

THANKS

:-jon

 

[cablewithaview]

A 5meg-1gig four way splitter should do the job. with that type of spectrum it should clear everything for your return on the modem and digital products. I recommend putting the 4 way in place of the main splitter there now at the point of entry. no under the house, in the attic, behind a tv, etc. make sure you you use waterproof connectors. some type of grease approved to go inside the connector and tighten it up, should be good to go. (no sleeves over the connector or electrian tape which will trap in moisture and cause problems down the road!!!)

 

[sam6405]

What I would do is Take the line coming in to the house into a two way splitter. From one of the legs of the two-way I would run my cable internet outlet. The other leg of the splitter I would run to the input of a 3-way splitter and then run the outlet with your digital (HDTV Box) off the of -3.5DB leg and the other two outlets off the -7.5DB legs.

By doing this your cable modem is sure to get the signal and return levels it needs to stay online. Your HD box will also get ample signal and return provided the signal is their when it comes in the house. Make sure all your splitters are 500-1000MHZ

 

[cablewithaview]

if the splitter is 500-1000 then what do you do with channels below ch.70? return in the modems runs below 54 mhz. 2 way has -3.5 db lose to each leg, 3 way as either -5.5 across or the one -3.5 w/ 2 -7 legs. -3.5 through a two way minus -3.5 through a 3 way he looses -7, include -2 more if you use the -5.5 across 3 way on one leg and gain 2 on the others. 4 way splitter has -7 on all 4 legs. I don't believe the 4 way will make that much difference on the modem but with extra splitters, it could make the difference on the digital platform. no difference ??? more splitters more trouble !!!!

 

[sam6405]

if the splitter is 500-1000 then what do you do with channels below ch.70? return in the modems runs below 54 mhz. 2 way has -3.5 db lose to each leg, 3 way as either -5.5 across or the one -3.5 w/ 2 -7 legs. -3.5 through a two way minus -3.5 through a 3 way he looses -7, include -2 more if you use the -5.5 across 3 way on one leg and gain 2 on the others. 4 way splitter has -7 on all 4 legs. I don't believe the 4 way will make that much difference on the modem but with extra splitters, it could make the difference on the digital platform. no difference ??? more splitters more trouble !!!!

Meant to say 5-1000 Mhz splitter.

The cable modem should have a signal level between -4.0 DB to +4.0 DB preferably 0.0 DB on channel 107 or 693 mhz to work properly. With a return level of 47-51. The digital box including digital channels is going to work if channel 107 is somewhere between -15.0 DB and Positve 15.0 DB. The closer the signal gets to -15.0 DB the more tileing you are going to see.

Depending on the levels at the tap, length of drop cable, size of drop cable (ie. RG-59, RG-6, RG-7, RG-11), type of fittings etc his signal level at the ground block on channel 107 could be good coming in at about +5.0 DB or terrible coming in at +2.5 DB or lower. If channel 107 is low at the ground block and then you take -7.5 DB off for a 4-way split you are at negative - 5.0 DB which will cause your modem to act up.

If this is the case and you go with my suggestion 107 is going to be - 1.0 DB at the modem and -4.5 DB at the digital box, this providing your cable runs are not huge and the cable is of good quality. Both items should work fine.

As far as losing -3.5 DB and then -7.5 DB for the two tvs that have analog you should not see a problem. Channels below 107 have much higher signal levels at the tap therefore better signal at the tv.

 

[cablewithaview]

I know what your saying, just buy or have installed a Motorola or Scientific Atlanta drop amplifier and just be done with it.

 

[sam6405]

I know what your saying, just buy or have installed a Motorola or Scientific Atlanta drop amplifier and just be done with it.

Agreed Amplfiers are awesome!