coax spliting 101

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Matt, I didn't respond to the comment because I took it to be sarcasm. I, too, have been doing LV wiring for at least as long as I've been doing power wiring.

In fact, longer. I started building crystal radios when I was six, and running phone lines in our house soon after that, and wired our shed when I was around 10.
 
around here we do all the low voltage installations, from fiber to CATV, fire alarm, burglar alarm, CCTV, network, and telephones and whatever low voltage needs. if it needs electrons to flow to work we do it. some electricians have no business doing it if they dont know what they are doing but to me its just another part of the job that needs to get done. LV is pretty simple to do. some low voltage systems can get pretty complex
 
mdshunk said:
Any minute now, Hal will post that electricians have no business installing TV cable. Love you Hal. :)
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He's right, unless, of course, you have the right equipment.

Here's my offering:

fotosMedidor-sadelta.JPG


If you can't measure, hoiw can you know your installation is correct...?
 
dbuckley said:
If you can't measure, hoiw can you know your installation is correct...?
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You can't, but do you measure Z's when you get done installing a row of receptacles or switches? I would think not, because you attend to good installation practices. I have a Sadelco meter to measure levels, but I hardly use it except on trouble calls. Use good materials, good tools, and good installation practices, and measuring levels when you're done is largely unnecessary.
 
dbuckley said:
Thought I had a good chance of stumping you on this one, but no, you've got one of them too.....
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He's like Sears: he's got everything. ;)


What ever happened to Roebuck? :confused:
 
mdshunk said:
For cable, just think about a few simple things.

As a simple rule of thumb, figure the signal is coming in at +8dB, and don't let it go under +3dB. Every splitter has losses, written right on the splitter. For instance, a 2-way splitter has a -3dB loss per leg, so you'd be down to 5dB using the rules of thumb.

If you have a cable modem, split the incoming cable line with a 2-way immediately, and run the cable modem on one port of that 2-way splitter. Take the other leg to go to your TV's. If you need to run 8 Tv's, for instance, you're going to need an amp. Amp it first, before you split it! In our example, with a cable modem and 8 TV's, you'll run from that 2nd leg of that 2-way splitter to your amp. The amp will probably add +15dB. From the amp, run to your 8-way splitter. Each leg of that 8-way will go to each of your tv jack plates. Each port of an 8-way splitter has a -11dB loss. In our example, you'll likely have +9dB at each jack. (8 in - 3 for the 2-way + 15 for the amp - 11 for the 8-way = 9dB)
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Be careful with TV amps! I've had a cable guy chew me out for having the amp my brother put in hooked up. He said something about the COAX cable being used for two way transmission of signals. Of course, that wasn't the cause of the problem we were having...nor was it the gold connector/shielded COAX cable he tried to tell us had to be ripped out and re run with "their brand" copper. I felt like smacking him and telling him to check the signal where it came into the house and follow it back to the box at the end of the street with the Cable Co's amp in it...again...
 
steelersman said:
mdshunk said:
Yes, if you order movies through the remote control and such, you will need a bidirectional amplifier.
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I thought that was why you connect your receiver to a phone line?
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The former applies to cable, and the latter to satellite.

The cable company can communicate 2-way over the coax.
 
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