Entertainment Center: TVs, Stereos, VCRs and DVDs - Snafu

My cable service had been fine for nearly 2 years, good picture no outages. My provider recently rolled out On Demand service in our area and almost to the day since, the picture on many channels has been choppy or even nonexistent, just a message saying the channel should be available shortly.This seemed like too much of a coincidence.

I called support, they swore the new On Demand service had nothing to do with it, suspected the cable box, and sent a technician out.

The technician said the box is fine and proceeded to replace a tap at the front of the house with a splitter, and another older splitter with a new one ( I can't complain he did this for no charge). He was satisfied this fixed it. 5 minutes after he left I had the same old problems. The technician kept hinting I should sign up for their linebacker program, I think he suspected many more problems with the way the cable is wired in my house.

I can't understand how everything could be fine one day and not the next. If all of a sudden I don't have a strong enough signal isn't that the cable company's problem and not mine.

Any thoughts?

Here are some thoughts that may or may not apply to your situation:

Standard cable uses the frequencies between 55 and 550 MHz. Digital cable uses higher freqs from 550 to 860 or so.
-- Older in-house cabling used "passives" (taps & splitters) that weren't rated for signals higher than 550 MHz. New passives are rated from 5MHz to 1GHz. The freqs between 5 and 54MHz are used by the cable company as a "return path".
-- Degraded passives, cables, and connectors can cause problems at the higher frequencies. Check to make sure the connectors are solid and the cabling hasn't been kinked or damaged.
-- Higher frequencies are attenuated more than than lower freqs over distance. RG59 wiring will attenuate more than RG6.
-- Daisy-chaned splitters can lower the signal to below the digital threshold at the far end of the run. How does the picture look at the first TV where the tech replaced the passives?
-- Pull the cable off the box and connect the cable directly to your TV. See if you can get the analog signals on Channels 2 through 78. If those pictures look good, it probably is your home's wiring that's causing the issue.

Thanks for the info, I saw bits and pieces of everything you said in various places but I was confused, you summarized it nicely for me.

The line leading to my TV had two two way splitters in it, I removed one splitter that fed a room that does not have a TV in it. The TV I use is working for now.

Its just irritating that nothing seemed to change on my end and now I have signal problems. There are three other cable outlets in my house for a total of four, I have seen houses with an outlet in every room probably 6 or 7 drops total, having five doesn't seem too much to ask for.

It's not a good idea to daisy-chain splitters. Five daisy-chained splitters will attenuate the signal by -15dB to the last TV in the chain. That's pretty much all of the signal that enters a typical home. If your house is getting less signal to begin with (but still within the cable company's tolerances), it could be the fourth, third, or second TV that suffers.

It's much better to split the signals at a single point (usually near the demarc where it enters your home) and home-run the cables to each TV drop. The signals will be evenly distributed to all of the TVs. If the signals are weak, you can insert a broadband TV amplifier before the main splitter.

The problem with inserting an amp into your system is, the first TV may get too much signal. Signals over +15dB can damage the TV's tuner or cable box.

How could this happen overnight? Digital signals are typically 10dB lower than their analog counterparts on the same cable. When you switched from analog to digital, your home's system may have caused the signals to be below the threshold.