1. First and most important split the incoming signal as few times as possible. Signal loss occurs at the splitter, not at the consuming device. As with the water supply in your house the more taps you open up, the less water pressure you will have. A splitter leg, in use or not, is a constantly open "tap".
2. If absolutely necessary (more than say, 4 legs on the splitter) try this to improve cable modem performance Buy two GOOD QUALITY splitters one two-way, the other a 3 or 4-way (again as few as possible). Put the cable modem on one leg of the 2-way and use the other leg to feed the other splitter. That way the cable modem gets the best possible signal.
3. Check the connectors. By far the most common cause of poor reception is a bad connector. Make sure that the center conductor or "stinger" is not too long or too short. 1/16 to 1/8 beyond the rim of the connector body is correct. Make sure that none of the aluminum braid in the cable wire is wrapped around the stinger. Note Some older installations will use wire that has copper braid rather than aluminum. This type of wire causes "ingress" (extraneous signal leaking in) and should be replaced if possible. The connectors should also be firmly crimped. I've seen wires that slide freely in an out of the connector. This will cause ingress and/or a "noisy" connection. For the same reason the connector should be firmly screwed down.
4. If all else fails have the Cable Company check the incoming signal. While different Cable Companies will have different technical standards, the incoming signal should be about +10 to +15 dBmv at the point where it enters the house or at the local distribution point, that is BEFORE ANY SPLITTERS. If this is not the case the situation should be corrected. BTW... if the signal is to strong, more than say, +16 dBmv, damage to the Cable Modem May result.
It should also be noted that a good TV picture isn't necessarily an indication of good signal for Cable Modem purposes. If your cable modem performance seems poor get it checked.
Credits - Mike Regan
LangaList September 03, 2003
Even more helpful information can be found at the link below
