My cable company has been happy to give me the appropriate splitter rather than me buying a rat-shack one. They don't like bad parts in their system. It can cause problems on your neighbor's reception.
Bob
Sure, but 0 dBm is a robust signal and that level is supplied to many homes ... 0 dbm is a milliwatt (that might not sound like much, but is a huge signal given the sensitivity of modern television receivers).
Using say an old 500MHz rated splitter on a current 1GHz cable system will knock out half your channels, probably cable modem, etc.
Pete C.
Actually, analog television is more dependent on a clean strong signal than Hi Def. This is because Hi Def is a digital signal, as long as there is enough signal to work with it will work. Basically it either works properly or not at all.
well then, with very good splitters and a signal amplifer, he should never have a problem no matter how many tv sets he wants to set up.
mike...........
If you install a new (additional) splitter (before the cable modem) you attenuate both the upstream and downstream signals to/from it by 3.5db or more. A cable modem should be at the start of the system in your premises, ideally at a first two way splitter and any additional splits needed will be on the other output from that first split. This insures a maximum 3.5db attenuation from the cable drop.
It makes a difference - really, even bending the coax makes a difference.
Back when I worked for the cable company we took all the new installers into the converter and line gear repair room where we had a sweep tester. We would cut a fresh piece of coax from a spool, install F connectors on it and connect it to the sweep tester.
A sweep tester injects a test signal into the coax that sweeps from low frequency up to high frequency and it monitors this signal from the other end of the coax and displays a trace on the screen in real time showing the signal strength received. A nice 10' piece of coax gives a nice flat line normally.
After noting the flat line we would then start to flex the coax and start to kink it a little, squeeze it a bit with pliers and whatnot. The trace on the screen would go nuts showing all kinds of odd signal attenuation at different frequencies due to the cable damage.
This demonstration did a good job of convincing the new techs that the coax was not like an extension cord and damage to it made a real difference. They were much more careful to avoid damaging the coax when installing drops.
Pete C.
As our cable company updated hardware... they came to my house when called. and up-dated a previous company splitter. I had it reduced from a 4-way to a 3-way. I can always add the 4th run in again, but not necessary now.
People think going to rat-shack for a "dumb passive device" is cheaper or best. No one has explained to my understanding how a "dumb passive device" fails; nor would I understand it.
-- Oren
"Well, it doesn't happen all the time, but when it happens, it happens constantly."
Two "failure" modes, one representing a real failure:
The first possibility is you use a cheap splitter that is rated for say
500MHz. The cable company has been installing 1GHz rated splitters in preparation for their planned system upgrade. You splitter works ok now, but when the upgrade comes through the new channels are all snowy because your splitter can't pass the higher frequencies without excessive attenuation. This is not an actual failure, it's a mismatch between your older splitter and the newer cable system.The second possibility is that a cheap splitter is built poorly, has bad solder connections, flux wasn't cleaned of the PC board, contacts weren't plated properly, etc. Over time the connections deteriorate and eventually fail. This is a real failure of the passive device.
Pete C.
Did you make sure he used a compatible splitter? :-p
Not really, if the gain is adjusted improperly he's just as likely to have a signal overload at the receivers and poor quality.
We once had a more dramatic case of signal overload at the cable company on some satellite receivers. Late one evening we changed out the LNBs on the big 10m satellite dish with newer, better ones with lower noise figures. We went back in to the head end and noticed that the AGC LEDs on the 8 satellite receivers fed from those LNBs were all red. Investigating further we found that the new LNBs were so much better that they were providing a signal too strong for the AGCs on the receivers to compensate for. We had to install something like a 6db attenuator on the feed to make the receivers happy.
We also had to delete a half dozen voice mails complaining about the hour long loss of a pay per view channel, a channel where we had checked the pay per view computer and determined there were no buys. Amazing how people stealing cable are dumb enough to complain about it. If we felt like it we could have saved those voice mails and let the security folks track down and prosecute the offenders.
Pete C.
Not entirely true. First off all of the lower tier channels on most cable systems are still analog so they will be pretty sensitive to signal strength. Secondly, while digital signals don't gradually degrade in picture quality like analog ones do, there is still a threshold point where reception will be marginal and the picture will show significant digital artifacts due to dropouts.
Pete C.
I'd be better to keep the amplifier separate, so you get to use only what you need. A too-strong signal is as bad as a too-weak one.
well i have no clue what any of that means, but i'm running pretty much the same set up as he is and what i described to him, and have never had a problem. when i've disconnected the amp. i've noticed a difference in the picture. reconnect the amp and the picture is great. Comcast is our cable provider and we're not in a rural area or have issues like that, but i'm running 5 tv's off the regualr feed.
mike.........
Really the device has not failed; only limited by it's ability to pass the frequencies? (cable company)
I can see how quality assurance failure would make a dumb device "stupid".
Thank you...
-- Oren
"Well, it doesn't happen all the time, but when it happens, it happens constantly."
He did. And I greased his palm.
-- Oren
"Well, it doesn't happen all the time, but when it happens, it happens constantly."
Agreed, although that cheapo RCA didn't seem to overamplify. If you go with an amplified splitter, it should be a close to the cable box as possible. If you've lost your signal by running splitter after splitter, using an amplifier won't recover your signal from the noise.
I had a multimedia computer with 3 video inputs (three capture cards); add to that a VCR and TVs in three other rooms and I had 7 devices that needed a signal. I ran a three way splitter at the cable box, and then two runs each to a four way amplified splitter. The third run went to a cable modem.
Why then do some homes have a picture that in all respects is near to perfect as analog gets and other have snow and ghosting. In other words what is the range for analog signal strength between best case and drop out. You say pretty sensitive and visually one wouldn't guess that not to be the case.
Secondly, while digital signals don't gradually degrade
Isn't the threshold between digital signal showing macro blocking to drop out pretty small and effected by other factors other then simply the signal strength. Can't a digital signal be effected by the tuner and reciever components to a degree that will effect the minimum signal strength it will work at?
Right. The amplifier needs to be connected at a point BEFORE the signal loss occurs. That is, before the splitters.
A cable modem (and/or digital cable box) are best connected before any amplifiers (and with minimum splitters) because these devices also send signals to the cable office.
OK, if you have nothing against them messing with your system. This might be a problem if you have some special requirements (like an IR distribution system requiring DC bypasses around splitters).
Compatible with the frequency range used.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.