Trouble with HD signal, lots of noise, need help

[uconn99]

Unfortunately my first post on this board is about a issue I am having with my Cox cable HD service and hopefully someone can help me out. It is more an issue I believe with the way the condo was wired than with Cox cable. Here is a overview on how things are setup, sorry about the long nature of this post.

I am a renter and live in a nice condo in Phoenix, Arizona. However, who ever bought the condo either cut costs by having their cable daisy chained or that’s how the builder decided to do it!

Currently in the condo there are 3 cable jacks, one is in the Master bedroom, another in bed 2, and finally one in the family room.

Cable feed comes in from the street to a Phone/Cable closet on the bottom floor which houses all the cable and phone for the building I am in, only community staff and cable/phone providers have access to this room.

From this closet/room, there is a cable feed running up to my condo unit directly to the Master bedroom outlet. After unscrewing the plate I noticed that this line coming from the downstairs utility room is being split using a standard non-amplified 5-1,000mhz 3.5 GHZ db splitter into the master bedroom plate and then running into bed 2.

From bed 2 it repeats itself, using the same splitter and then running it into the family room where it directly connects to the cable plate. In the end the family room is the last line of the daisy chain, you think they would have done it reversed!


The issues I am having is that the TV signal on my Samsung 56'' 1080p display in the family room looks bad during most HD programs. I am seeing a lot of digital noise, lots of image bleeding and simply not the picture quality I should be seeing.

I am using the standard Cox HD scientific Atlantis HD8240 box with a monster 800 series 1 meter cable running to the Samsung.

I know there is really no way of getting around the daisy chain setup the builder has done, and there is also no way of me doing a direct feed from the first spit that’s located in the master bedroom and running that into the family room because I am on floor 2 of 3.

Is there a good way I can boost that signal into the family room from the incoming line in the master bedroom? Some kind of good amplifier anyone recommends? Or am I out of look with the way the condo was wired?



Thanks for the help on this issue everyone!

 

[branchbouncer]

Follow this link and see what your levels are for the signals the the rooms
http://www.dslreports.com/faq/sciatl/3.1_Using_diagnostic_screens

 

[Todd Humphrey]

You first must learn if you have enough signal at any point in your home, and also if the picture you are seeing is the best it can be. Access the CATV at the first point you can in your home and run a coax from that point straight to your HD CATV box. This will give you the best picture you could ever expect. If that picture is still not clear, then call the cable company and see what they can do.

If your picture does clear up then still call the cable company and ask them to provide an amplifier. Those two splitters are only dropping your signal level 7 db. The cable box needs 0 db (1000mv) and many homes use four way splitters with no problem, which also has a 7db loss per port.

Don't try to use a cheap VHF/UHF amp. They will not work well on a large channel capcity system. A good CATV 0-1000 Mhz amp runs at least $85 to $150. Let the cable company provide it.

 

[djjolietjake]

You first must learn if you have enough signal at any point in your home, and also if the picture you are seeing is the best it can be. Access the CATV at the first point you can in your home and run a coax from that point straight to your HD CATV box. This will give you the best picture you could ever expect. If that picture is still not clear, then call the cable company and see what they can do.

If your picture does clear up then still call the cable company and ask them to provide an amplifier. Those two splitters are only dropping your signal level 7 db. The cable box needs 0 db (1000mv) and many homes use four way splitters with no problem, which also has a 7db loss per port.

Don't try to use a cheap VHF/UHF amp. They will not work well on a large channel capcity system. A good CATV 0-1000 Mhz amp runs at least $85 to $150. Let the cable company provide it.

Motorola makes a good 15 db gain amp that passes the reverse. Also, you shoud ask the cable co. to switch the splitters to DC 6'S. THIS will give more signal at the end of the run.

good luck!

 

[branchbouncer]

Motorola makes a good 15 db gain amp that passes the reverse. Also, you shoud ask the cable co. to switch the splitters to DC 6'S. THIS will give more signal at the end of the run.

good luck!

We are using the Motorola here works better than the one the cable co gave us

 

[Todd Humphrey]

Motorola makes a good 15 db gain amp that passes the reverse. Also, you shoud ask the cable co. to switch the splitters to DC 6'S. THIS will give more signal at the end of the run.

good luck!

A 6db directional coupler, or Line Tap, ( I assume this what you mean by DC6) will have the same through loss, or more, as a 2 way splitter. Only a tap value around 10db or higher would have significant less signal through loss then 3.5 db, but to use a 10 db tap would mean you had at least 10 db available. If we had 10db, there would not be an issue.

 

[stevenl]

A 6db directional coupler, or Line Tap, ( I assume this what you mean by DC6) will have the same through loss, or more, as a 2 way splitter. Only a tap value around 10db or higher would have significant less signal through loss then 3.5 db, but to use a 10 db tap would mean you had at least 10 db available. If we had 10db, there would not be an issue.

The "Through" leg of the DC (tap) has aprox < 1 db of loss the "TAP" or "DC" leg of the device will lose the most signal depending on the size of the DC dc6 = 6db loss dc9 = 9 and so on.. and i answerd this in antoher thread as to how it will only gain u 1 db at the last tv but lose 3db more at tv1 and 2db at tv2

 

[Todd Humphrey]

The "Through" leg of the DC (tap) has aprox < 1 db of loss the "TAP" or "DC" leg of the device will lose the most signal depending on the size of the DC dc6 = 6db loss dc9 = 9 and so on.. and i answerd this in antoher thread as to how it will only gain u 1 db at the last tv but lose 3db more at tv1 and 2db at tv2

Sorry, but you are not correct.

The through loss of a tap increases as the tap value decreases. A 4db tap has no throughput and terminates. An 8db tap has about 3.7 db through loss. A 6db tap would have about 4-5db+ of loss.

The through loss of a tap is only < 1 db once your tap value reaches about 23db or higher.

Note: The specs I have mentioned above come the spec sheet for Toner brand 2-port taps, models TMXT102-4T, TXMT102-8 and TXMT102-23. There may be small differances from one brand to another, but in 25 years I have found no more than a 2-4% variance from one to another.

 

[Todd Humphrey]

If you had 5db of signal to a house and ran it through 2-2-way splitters,

TV1 would have 1.5 db
TV2 would have -2 db
TV3 would have -2 db plus the line loss from the 2nd splitter to the 3rd location. Say another 2db for a total of -4db

Using 6 db taps at a through loss of 4db (conservative value) you would get these results

5db to tap 1 = TV1 would have -1db (5-6) and the throughput loss would be 4db.
1db to Tap 2 = TV2 would have -5db (1-6) and the throughput loss another 4db.
This gives you -3db plus the cable loss of 2db for a total of -5db at the last TV

TV1 looses at least 2.5 db
TV2 looses at least 3 db
TV3 looses at least 1 db

Taps are only usefull when used with at least 15 db of line signal.