Coaxial cable

[nizak]

Is there any performance difference between RG6 and RG6 Quad Shield?

Does the box store cable perform as well as what would be provided by say Charter for example.

It all appears to be 18 gauge.

Thanks

 

[LarryFine]

Quad shield is overkill.

 

[Geber]

Is there any performance difference between RG6 and RG6 Quad Shield?

Does the box store cable perform as well as what would be provided by say Charter for example.

It all appears to be 18 gauge.

Thanks

What is Charter? Is that a brand of cable, or the name of a cable TV company? Is the application cable TV or something else?

Can't say I have much experience testing cable; usually I just transmit into a dummy load and measure power at the near end and far end, plus check the SWR.

 

[Speedskater]

RG6 is an ancient generic label. All it indicates is that the cable has a nominal 1/4 diameter and a 75 Ohm Radio Frequency Characteristic Impedance. There are many different RG6 coax cables optimized for different parameters. Some are good at low frequencies and others are good at cable TV frequencies. A heavy braided shield at low frequencies and a foil shield at cable TV frequencies.

 

[zbang]

"Preform" is too vague a word. If you're roping a house for cable TV, any decent quality 75ohm cable and matching connectors will do the job; the runs won't be long long.

Charter is one of the large cable TV companies, and seems to get all the respect they deserve .

 

[LarryFine]

The last time I looked, the cable company's coax had one layer of at best 75% braid coverage, no foil.

 

[electrofelon]

I will say that in the late 90's I helped a friend out pulling new RG6 quad to replace non quad cable and it definitely made a difference. So I have always preferred quad, buy may e today with digital and what not it doesn't matter as much

 

[curt swartz]

The last time I looked, the cable company's coax had one layer of at best 75% braid coverage, no foil.

Even in the 80's cable companies used RG59 with foil and at least 1 braid. I can't imagine any of the using an cable with less than 100% shielding.

If you tried to use a cable with less than dual shield (foil & braid) today your service will get cut at the tap very quickly.

RG6Q is over kill for most areas but has become a common standard for most LV contractors. Most cable companies use dual shied or tri shield RG6.

 

[LarryFine]

Even in the 80's cable companies used RG59 with foil and at least 1 braid. I can't imagine any of the using an cable with less than 100% shielding.

If you tried to use a cable with less than dual shield (foil & braid) today your service will get cut at the tap very quickly.

I should have said that this was the underground cable feed to a house.

It had coverage equal to or less than this cable, and no foil shield. I looked at it closely.

 

[hbiss]

The reason for cable shielding is twofold. First, it has to be sufficient to keep the RF from leaking out. Cable companies are required to monitor "leakage" because some of the frequencies they use are the same as those used over the air for such things as aircraft navigation and emergency communications services. Insufficiently shielded cable and poorly installed connectors allow the cable signal to radiate like an antenna and jam the over the air signals. Cable companies face stiff fines if they are found in violation of leakage levels.

Second, cable systems can be thought of as operating in duplex mode. Data is sent to you but it also has to send data back from you to them. Certainly, this can be understood for internet, but it also applies for TV and phone service. The cable boxes and modem constantly send data back to the cable company and this is why the same system integrity needed to prevent leakage is needed to prevent interference (called ingress) from entering the system and disrupting the return channels.

Cable companies have adopted their standard cable that they tested to meet leakage and ingress and that depends on the location of the system. Quiet locations can get away with an RG6 that has a foil shield covered with a 100% braid. That would be minimum. If you are in an RF noisy urban area and particularly those near transmitters you need to up the shielding to stop ingress, and quad shield may even be required. But I will agree that QS is overkill in most instances.

The good news is that fiber to the premises and Ethernet within the premises is replacing coax as streaming is becoming more and more popular.

-Hal

 

[CurrentFlow]

I recommend using RG6Q with Compression Connectors for best performance especially if you are using the coax to connect to a modem. Terminate all unused ports on a splitter/combiner etc with a 75ohm F connector terminator. RG59 is way too leaky and will underperform if used for anything other than connecting to a tv antenna. If it is a long underground span use RG11.

 

[LarryFine]

RG59 is way too leaky and will underperform if used for anything other than connecting to a tv antenna.

Isn't RG59 50 ohms? I use an all-copper (not clad) RG59 for the five RGB-HV signals to the CRT projector in my home theater. I use analog component video, and a transcoder to drive the projector.

 

[hbiss]

RG59 is way too leaky and will underperform if used for anything other than connecting to a tv antenna.

RG59 comes in many of the same shielding variations as RG6. But the problem with RG59 is that it's loss makes it impractical for use at cable frequencies. Check the loss between RG6 and RG59 at 1Ghz and see for yourself.

-Hal

 

[hbiss]

Isn't RG59 50 ohms? I use an all-copper (not clad) RG59 for the five RGB-HV signals to the CRT projector in my home theater. I use analog component video, and a transcoder to drive the projector.

No, RG59 is 75 ohms. Your application is baseband video that doesn't exceed 6Mhz and that is where RG59 with a solid copper center conductor and copper braid shield has always been used.

RG58 is 50 ohms. One use is for CB and other low power transmitter connection to the antenna.

-Hal

 

[infinity]

IMO you don't need quad shield. I've even used copper clad RG6 without any issues.

 

[egnlsn]

I always use Series 59 cable for jumpers. At 10', the difference is ~1.5dB, and 59 being more flexible than 6, it's lower profile and looks better. The construction's the same - same shielding, same bandwidth, etc.

 

[Craig Maes]

In a previous life I was a CATV engineer. Quad shield cable has its place in urban areas that are close to television transmitters. We had tremendous issues with signal leaking into the cable, especially when we could see the transmitter tower from the customer’s house. Quad shield and non-quad should have the same loss properties. I would always wire a house with RG6 not RG59; same labor but the loss could just make the difference, especially if they have many outlets. Leaks in the cable (out or in) are caused by impedance mis-match, which is caused by improper connector installation or improper "hammering" the cable with staples. Impedance mis-match used to also cause ghosting in the analog days before everyone went 100% digital.

 

[cabledawg]

IMO...For residential, most RG6 will do. Just get a decent Compression tool(like 45$) or so and some compression fittings and a good quality strippers.