You might think the extra bandwidth isn’t worth the extra $10 per reel or so, but remember with fast broadband, the signals have harmonics in them. The lower the grade of cable, the more that digital signal comes out looking like a pure sinewave and stripped of all data. Better cable will give less dropped data.

Incidentally, rewiring as much as you can to cut out every possible joint or connection might bring a speed boost, since most people never bother checking the specs of connectors/cable. EVERY SINGLE CONNECTION attentuates your signal by 1.5 to 3dB. So one single joint to lengthen a cable can in theory attenuate a signal by up to 9dB (-3dB at the cable-to-connector junction, another -3dB in the coneector-to-connector adaptor, the final -3dB is lost in the connector-to-wire junction).

Do you know that every sharp bend in the cable can drop another -1dB? The reason is that a sharp bend “crushes” the cable internally, so the shield layer gets closer to the central core and this increases the capacitance. Since you are working at high frequencies, this increases impedance (by how much, depends on the frequency you are working at, but remember the harmonics go MUCH higher than your base rate). This is another reason for choosing CT-100, since the insulator between the central core and the shield is foam, not the simple (and easily-crushed) air-celled polyethelene/polypropylene construction of the RG series cables.

Finally the outer shielding is MUCH more effective at shielding the signal-carrying core from RFI/EMI interferance, since it isn’t just the open-weave strands of the RG series cables, but open-weave strands over copper foil. For sat-comms you usually use crim-on F-Connectors, but it fits into the normal plugs and sockets used for RG series cables usually, as it’s almost the identical dimensions of RG series cables.

I’ve come across a lot of eye-opening specification sheets and mis-information in my 25 years on L, S, C, Ku & Ka-Band frequencies.

Just remember stick with the RG6 cable with good shielding and good connectors on the ends.
“don’t use those cheap screw on connectors you buy from radio shack” they will pop right off. get some good compression fittings

and one last thing
Chris mentioned that your modem might have a self diagnostics test built into it.
if you want to access it. just type this into your web browser
192.168.100.1
that should work if you have a motorola modem or scientific Atlantic Webstar modem. and maybe some others. if it doesn’t work. just do a search for your brand. most of them have it built in.

1. Ideally you want to have the cable come into the house and split once at the entry point. One feed goes directly to your modem – straight shot, no splitters, no “barrel” connectors/extenders, good quality cable, no kinks. The other feed can then split to feed all of the tv’s in the house. TV’s aren’t as picky about signal strength.

2. You also want to make all your splits at the entry point. You shouldn’t have it go the the living and then have a splitter there that goes up to the bedroom, then splits from there and feed the other bedroom etc. Unfortunately many homes are already wired this way as they were wired as the need arose. But if it is new construction or if you’re doing it yourself make sure it’s done this way. Makes it much easier to troubleshoot and things will just work better.

3. If you need an amplifier you want it AFTER this initial split on the TV leg. Most amplifiers are only unidirectional (this may have changed in the past few years) and they will mess up or totally block the outgoing connection on your modem. Also, an amplified signal may be too “hot” for your modem and fry it.

4. Some low quality splitters filter out signals below 900MHz. Make sure yours doesn’t. This is where your Internet is transmitted. Filter that and you are off the ‘net.

5. Some splitters – usually ones that are more than one-to-two – have one leg that has less attenuation than the others legs – 3dB vs 7dB. Use the one with the lower attenuation to feed your modem.

6. If you make your own coax cable, make sure when you attach the ends that the hot wire sticking out isn’t too long or it could kink inside the connection and short it out by hitting the ground, or even damage the equipment.

7. And you want RG59 cable. If you can easily coil it around your arm in a circle smaller than a couple feet, it’s too flimsy and doesn’t have proper grounding. Those old cables you’ve got lying around with the frayed ground wire sticking out and all the kinks and no threading on the connector – throw ‘em out!

8. Throw ‘em out because they’ll degrade the quality of your signal. They may leak and interfere with other equipment. The cable company does periodic drives around their service areas with detection equipment checking for leaks. They will leave a notice at your house if they detect leakage. If you do not respond and let them check the wiring inside your home they will disconnect you. One of the reasons for this is that aircraft use some of the same frequencies and if there is leakage it could interfere with their equipment. Not sure if I totally buy that, but that’s what we were told. But I know I wouldn’t want a plane crashing into my house just because I was too cheap to throw away that 99 cent RatShack cable!

I hope that helps.
~Matt

also if you have multiple splits, there is signal strength loss each time you do it. A cable company serviceman told me try for no more than 4 devices on one cable.

Have any doubt of signal strength? get your cable service guy to check it.

They CAN boost signals but this is usually done in remote areas and is always hard to get them to put it in.

Sorry to poke a little fun, but it would seem that your specialty is more along the lines of software, something I’m a major moron at myself. But I have practically lived and breathed “coax” for well over 25 years and I think I can add a little clarification on that subject.

Simply put, your cable probably had a broken and/or damaged center conductor. It was just old. Even the cheapest length of RG-59 coax will do a superb job, given the short length you were using. I always use RG-6, cut to length, and attach my own ends. RG-6 is heavier and better shielded than RG-59 and the price difference is negligible (about 35 cents/foot vs 25 cents)

Just don’t waste your money on those “monster” cables and the like, especially when it comes to coax, which is plentiful and cheap!

While you are at it, you can consider running a conduit (plastic tube) so you can then thread wires in as needed (fiber, ethernet, whatever comes next)