I just had the cable tech come out because my broadband cable modem would not sync. Looking at channel 2 on analog cable it appears the signal strength was too low. I connected it directly to the incoming line and it sync'd just fine.

I have a Monster 5-1000 khz (or is it mhz?) 8 way splitter. It's been working just fine like that for 3 years. I have 6 active connections right now (used to have 7 but I used one for satellite. My electrician used rg-6 through the entire house and I thank him every day.) I use terminators on the unused outlets.

He said signal strength coming in was fine but the splitter was degrading it too much so he put a 2-way splitter in front with one going to the 8 way and one going straight to the cable modem and now it works fine. He told my wife that a 2 way splitter with 2 4 way splitters would work better than the 8 way. I bought the 8 way because I thought it would be better to split it 8 ways once than to split it 2 and 4 ways twice.

So what's better? How do you tell - are there specs for signal loss that you can compare? Are there general rules for splitters? Note I do not have digital cable, only cable modem. But I might in the future. I used to have a line amplifier but that caused too much noise and the installer said i didn't need it so I took it out. Again - it was working fine with the 8 way splitter until Tuesday so I know they changed something. Or can a splitter just go bad and degrade over time? This one is about 8 years old I think.

I was having quite a bit of trouble with signal strength. Same thing as you, good coming in, but I was losing it somewhere. I went to good ol Radio Shack, and they suggested trading my Moster splitter for an RCA Sat splitter that went to 2200 mhz. Problem solved.

Your installer had a good idea to do a 2 way split for the modem, a 1GHZ splitter for cable applications is good enough, most upgraded cable systems top out at 750 or 860Mhz. The quality of the splitter can vary from brand to brand,
In general you lose about 3-3.5db for each split. (half power). If you choose to use an amplifier put it after the modem split (the modem needs the return band to send signals back). If you have any unused ports of your new splitter terminate them with loads.

Thanks. But is there a difference in signal loss between a 2-way, 4-way and 8 way splitter? If not then one 8 way should be a better signal than a 2-way into a 4-way, right? Or is this monster splitter just not very good to begin with?

Just trying to understand the factors for future reference.

In theory, assuming each splitter turns 10% of the signal into heat, a 2-way into two 4-ways would throw away 20% of the signal. (Most of this loss occurs in ferrite.) So I tend to regard this as bad advise.

In fact, as I have discovered by taking apart some splitters, the circuits inside them vary a lot. Their performance as a function of frequency thus varies a lot, and it is dangerous to assume that there are simple rules about what to expect. Is a wide-band splitter more efficient (as many people think) or is a narrow-band splitter more efficient (as I tend to think)? You just have to try it and see.

There is nothing in a splitter that degrades over time, except maybe the mechanical connector.

How does one measure signal strength? I'd like to do my own experimenting and troubleshooting if they're not terribly expensive.

This is a thorny issue. Despite the simplicity of what you want to do, the pitfalls are so many and so invisible, it will severely test your diligence as an experimenter. Professional equipment with characteristics linear enough for useful results tends to be expensive. Unless you have an engineering degree, you likely won’t see all the pitfalls.

I bought a variable attenuator from Radio Shack and then reconstructed it with a large dial and painstakingly calibrated it. I found I could use it to measure noise figures to plus or minus 0.1 dB. In some situations it will measure power and other things. It was not expensive, but it took a lot of time. Unless you are retired, your time is probably better spent on other things. If you still want to pursue this, you can email me directly.

Thanks - I'm not THAT interested. I think what I have now is working fine so I'll probably leave it that way until I have a future problem. If it ain't broke......