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Moving the modem

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Since moving into my home, I’ve had my cable modem in our office. A room above our garage that has coax run to it from the garage, which is where the CATV coax enters the house. Coax enters the house through a wall, goes into a splitter, and heads from there up to our office. Total run length from the splitter is about 30ft. With the modem in the office, and then in the garage, the data for the modem follows (Update 5/26/11: After a couple days, the signal levels changed a bit in its new location. I’ve found online that 6 dBmV is actually a bit on the high side for signal strength, but within acceptable limits):

Office Garage Garage 2
Downstream Freq 567.00 mhz 567.00 mhz 579.00 mhz
Downstream Power 3 dBmV 4 dBmV 6 dBmV
Downstream SNR 36 dB 36 dB 35 dB
Modulation QAM256 QAM256 QAM256
Upstream Freq 32.400 mhz 32.400 mhz 22.800
Upstream Power 44 dBmV 43 dBmV 42 dBmV
Channel Type DOCSIS 2.0 (ATDMA) DOCSIS 2.0 (ATDMA) DOCSIS 2.0 (ATDMA)
Symbol Rate 5120 kSym/sec 5120 kSym/sec 5120 kSym/sec
Modulation QAM64 QAM64 QAM64

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RadioShack Deluxe Cable Stripper

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Radioshack Deluxe Cable StripperOn the heels of my post relating to grounding your CATV, I thought I’d do a brief review on this inexpensive, capable coax stripper. I’d been looking online and at local hardware stores for a good quality coax stripper, and any of the really good ones were at least $30. Which, I’d be happy to pay if that’s what it would cost for a good stripper, but on a whim, I looked at RadioShack’s site, and found this, which gets decent reviews, and at the local Radioshack, was only $15! In my few tests, it does a great job, and quickly. After reading in depth about coax the last few days, I’ve read that nicking the conductor of coax when stripping it is bad, which I’m sure I’ve done on some of my crimps. So, over the next few days, I plan to redo several of the terminations in my house to perhaps improve my signal quality to my cable modem (the local demarcation point for CATV is about 10 feet from my house, so all my TV signals look great. I just hope to slightly improve my cable modem signal).

All and all, if you’re going to be doing anymore than a one off coax termination (in which case you might be able to get a friend, or a friendly cable installer to do), I’d highly recommend this stripper. Much cheaper ones are almost as expensive (I have one), and do a MUCH worse job. This one performs as well as any $25-30 I’ve seen.

The old downside being getting replacement blades. The local Radioshack I bought this from didn’t seem to have them, but from reviews, the blades should last some time, and replacement blades can be purchased online here.

[xrr rating=4.75/5]

Ground your cable TV coax!

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Ungrounded CATV coax connections can cause some rather bad speaker hum (at 60hz here in the US), and horizontal lines in your picture. Grounding your coax connection can help alleviate these problems, though it may not fully solve your issues. To demonstrate, here’s some backstory.

We have a older CRT TV in the garage that we use to play DDR/Stepmania, as well as have a TV going when working in the garage. I recently hooked an old computer up to the TV for a permanent Stepmania machine. Right after hooking this computer up, I started getting a really bad ground hum on the TV, which could be quickly fixed by installing a ground lift (Cheater Plug) on the computer power connection, but this is generally a bad idea (computers like being grounded). After doing some research, I found out that an ungrounded CATV connection can cause ground hum. Checking it out, I removed the CATV connection from the TV, and viola, the hum was gone. Okay… so, now to actually FIX the problem.

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