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Jerry wrote: A question from a lay person. I'm looking for information on what kind of CATV splitter to buy. I have Time-Warner analog CATV and don't use any cable box. All my devices use coaxial RF cable as input. Here's my setup... Cable comes into my house's outside junction box into a 4-way splitter with each output saying 7dB (whatever that means), then goes to four rooms. That means that the RF signal level at each output port is 7 dB below the level being fed into the input. That's not too bad - a perfectly lossless 4-port splitter would divide the power four ways, resulting in an output level at each port which was 6 dB below the input level. This splitter has 1 dB of additional loss. Room 1: Bedroom without any TV. Coax not terminated. Room 2: Office with cable modem and TV. Cable company used a 2-way splitter with each output saying 3.5dB. Again, that's not too bad - 3 dB of reduction per port (50% of the power going each way), plus an additional .5 dB of loss in line with each port. This means that your TV and cable modem are seeing signal levels 10.5 dB below the level that your cable company is feeding your house. Room 3: Bedroom with a TV. Room 4: My main media room. Here's where I need the right coax splitter. I currently have a 2-way splitter connected to a VCR and a TiVo. I'd like to add a DVD recorder with a cable-ready tuner. All 3 devices would have coaxial RF cable input. My two questions: 1. Should I get a 4-way coax splitter with each output at 7dB and terminate the unused output? This would leave an output free for future expansion in Room 4. I saw such a splitter at Radio Shack. Is there a better brand? You could do that. You'll be wasting some of the RF power fed to that room, into the termination resistor on the fourth port. Or, you could daisy-chain an additional 3.5 dB splitter off of one of the two ports on the existing two-way splitter. This approach will give you three outputs, two of which have lower RF levels than the third. Use the third port (the one coming out of the first splitter) to feed whichever device seems to need the strongest signal for a decent picture. 2. Should I terminate the cable in the unused Room 1? Generally a good idea, for several reasons. RFI is one such reason... unterminated ports can "leak" RF, and some of the cable-TV channels overlap with amateur bands (e.g. 2 meter) and aircraft/public-safety bands. Cable companies are required to [try to] keep their cable plants leak-free, due to the interference that these cable channels can cause. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
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