Which splitter?

MadDad2 · 01-01-07, 11:51 PM

I have a Motorola 3416 HD DVR sucessfully running a HDTV. In the menu system for the 3416 the signal strength is listed as fair to good. right now the SNR: is 21.5 and listed as good, but most of the time it's in the low 30's and listed as fair. The main line in is RG6 to a 4 way 5 to 900 MHz splitter. The TV reception is good on HD channels and the lower analog channels. BUT: in an effort to get the best signal I put a 5 to 2300 MHz splitter in. Well the HD channels espicially OnDemand ones had a real bad pixilated lines all over the place problem. I went back to the 5 to 900 MHz splitter. Why would the newer splitter cause that problem?? Also would a 5 to 1000 MHz splitter make any improvement? Most of the cable after the splitter to the Motorola box is RG6 with the last foot RG59. That will be replaced as soon as I can get some decent RG6 cable and connectors, etc.

Thanks for any help.

MadDad

RCbridge · 01-02-07, 10:16 AM

Quote:

the signal strength is listed as fair to good. right now the SNR: is 21.5 and listed as good, but most of the time it's in the low 30's and listed as fair.

That is odd!!
It should be the opposite. Higher SNR should reflect better signal quality

About the splitter: For cable you only need to 5-900mhz perhaps that other splitter has a bad port or you have a bad connection.

RG59 should be fine for cable TV!

Mallego · 01-02-07, 06:20 PM

Mad, the 2300MHz splitter is built for satelite signal splitting. It probably isn't as efficient as a CATV splitter. Most cable systems are at 750 MHz, some go up to 870 MHz. Your 900 MHz unit should be just fine. Your signal is obviously marginal. Call your cable company for a trouble call.

If that is not productive, look on the internet for a CATV quality drop amplifier. Units made by Motorola, S-A, Electroline, etc are good. They can be had with builtin splitters or without.

Make sure it is bi-directional, passive in the return.

A couple of feet of RG59 isn't going to make any difference one way or the other.

GeekGirl · 01-03-07, 08:19 PM

This is a 4-way splitter? In theory, a 6 dB signal drop (most likely close to 7 dB with insertion loss). With a long cable run, it can be marginal. However, if you are replacing a 4-way with a 4-way, then there should be minimal difference.

Let's try something else: Are all 4 ports (outputs) of the splitter terminated? In other words, do you have an input attached to each of those 4 outputs? If not, there will be reflections due to the open port on the splitter (no 75 Ohm load, high VSWR) and cause interference. It may explain the "oddity" of the SNR.

MadDad2 · 01-04-07, 12:07 AM

Thanks all for the assistance.

Mallego: Thanks for the info on the MHz.
GeekGirl: All outlets are used, cable run to the HD Box is about 20 ft. Now all RG6 quad shield. Which by the way made no difference, but I had it so I used it.
RCbridge: I may have got that SNR backwards. Gettin old don't ya know.

Guess I'll just leave well enough alone, or might get Comcast to check it out one of these days.

CableTool · 01-04-07, 01:50 PM

Quote:

Originally Posted by MadDad2

RCbridge: I may have got that SNR backwards. Gettin old don't ya know.

You might have been checking a different channel or diagnostic page. The inband status will read different then the out of band status.

Each QAM has a different threshold for SNR. Whats GOOD for one would only be FAIR to POOR for a higher QAM channel.

01-01-07, 11:51 PM	#1 \| Link	<a href='http://rev.avsforum.com/phpAdsNew/adclick.php?n=a4ac4393' target='_blank'><img src='http://rev.avsforum.com/phpAdsNew/adview.php?what=zone:30&n=a4ac4393' border='0' alt=''></a>
MadDad2 New Member Join Date: Dec 2006 Posts: 3	Which splitter? I have a Motorola 3416 HD DVR sucessfully running a HDTV. In the menu system for the 3416 the signal strength is listed as fair to good. right now the SNR: is 21.5 and listed as good, but most of the time it's in the low 30's and listed as fair. The main line in is RG6 to a 4 way 5 to 900 MHz splitter. The TV reception is good on HD channels and the lower analog channels. BUT: in an effort to get the best signal I put a 5 to 2300 MHz splitter in. Well the HD channels espicially OnDemand ones had a real bad pixilated lines all over the place problem. I went back to the 5 to 900 MHz splitter. Why would the newer splitter cause that problem?? Also would a 5 to 1000 MHz splitter make any improvement? Most of the cable after the splitter to the Motorola box is RG6 with the last foot RG59. That will be replaced as soon as I can get some decent RG6 cable and connectors, etc. Thanks for any help. MadDad

01-04-07, 12:07 AM	#5 \| Link	<a href='http://rev.avsforum.com/phpAdsNew/adclick.php?n=a591f81a' target='_blank'><img src='http://rev.avsforum.com/phpAdsNew/adview.php?what=zone:36&n=a591f81a' border='0' alt=''></a>
MadDad2 New Member Join Date: Dec 2006 Posts: 3	Thanks all for the assistance. Mallego: Thanks for the info on the MHz. GeekGirl: All outlets are used, cable run to the HD Box is about 20 ft. Now all RG6 quad shield. Which by the way made no difference, but I had it so I used it. RCbridge: I may have got that SNR backwards. Gettin old don't ya know. Guess I'll just leave well enough alone, or might get Comcast to check it out one of these days.

01-02-07, 06:20 PM	#3 \| Link
Mallego Member Join Date: May 2005 Location: Seacoast NH Posts: 143	Mad, the 2300MHz splitter is built for satelite signal splitting. It probably isn't as efficient as a CATV splitter. Most cable systems are at 750 MHz, some go up to 870 MHz. Your 900 MHz unit should be just fine. Your signal is obviously marginal. Call your cable company for a trouble call. If that is not productive, look on the internet for a CATV quality drop amplifier. Units made by Motorola, S-A, Electroline, etc are good. They can be had with builtin splitters or without. Make sure it is bi-directional, passive in the return. A couple of feet of RG59 isn't going to make any difference one way or the other.

01-03-07, 08:19 PM	#4 \| Link
GeekGirl Señora Member Join Date: Jan 2005 Location: Yardley, PA Posts: 1,510	This is a 4-way splitter? In theory, a 6 dB signal drop (most likely close to 7 dB with insertion loss). With a long cable run, it can be marginal. However, if you are replacing a 4-way with a 4-way, then there should be minimal difference. Let's try something else: Are all 4 ports (outputs) of the splitter terminated? In other words, do you have an input attached to each of those 4 outputs? If not, there will be reflections due to the open port on the splitter (no 75 Ohm load, high VSWR) and cause interference. It may explain the "oddity" of the SNR.