What is the maximum length of an RG6 cable?

[lord_erico]

I have seen a lot of information on this subject over the Internet. The conclusion I came to is, "it depends on your use of the cable". Well, I need to hook up a very cheap CMOS video camera to the cable using an RCA to coax converter, then send it through the line. How far do you think I could go before the signal becomes unrecognizable? Would a repeater fix that problem? If so, are there any small, cheap RG6 repeaters?

Thanks for your input,
Eric
Now that I look at it, RG6 might not be the right choice. Ideally, I would want this to do down 1000' into water (does the water make a difference?). Would RG58 be an option, because 110base2 can go 185 meters, or is RG59 better?

Thanks again,

Eric

 

[m~Michael~m]

The systems are designed to tolerate roughly 200ft of cable, but that will vary based on the condition of the cable and whether and of what type any multiswitches present are.

In-line amplifiers powered from the coax can indeed be used for longer lines, but remember that amplifying after the signal is too weak does no good -- the amplifier should be within the first 100 feet of cable, where the signal is still solid, then the boost will keep it so over the remaining cable run.

If you have more specifics I can address specific solutions.

A stronger satellite signal will not materially affect how long the cable can be -- once it is too long it rapidly degrades the signal far more than a strong signal or bigger antenna can overcome.

 

[lovs2jokearound@yahooecom]

The highest video resolution currently possible is HDMI, but one of the drawbacks of this technology is that the HDMI cable is not suggested for long cable runs, due to the fact that HDMI cable is manufactured out of twisted pairs of copper conductors that are small-gauge, instead of the usual coaxial cable, and this can cause problems when the HDMI cable needs to be run over 50 feet in length.

With twisted pairs cable, impedance can not be kept under strict control. Without this strict control, the signal may be reflected along the length of the cable between the source and the sink of the signal. This can cause interference with the source bit-stream.

The usual specification length of maximum run for HDMI cable is normally about 50 feet, or approximately 15 yards. The maximum cable run that will be efficient will be different for each individual cable, depending on the quality specifications of the cable manufacturer. A higher quality cable will cost more, but will also run further before any additional devices and technology are needed. Generally, the thicker the copper wire is in the pairs, the more costly the cable is, but the longer that cable can be run before experiencing signal problems.

To have HDMI cable that runs over the maximum effective length, 50 feet to 60 feet, will require additional technologies and devices. There are several excellent ways to extend your HDMI cable run and keep the signal effectiveness.

When an HDMI cable length gets too long the signal loses strength. This results in picture distortion, sparklies (where single pixels drop out of the picture), or no picture display at all, only sound capabilities. If any of these problems occur than the cable length is too long, and the signal needs to be adjusted by additional devices.

The available options to extend the HDMI cable run and still have a usable signal are various. There are signal restorers, signal boosters, signal extenders, signal equalizers, cables with thicker conductors,and fiber optic cables. The cost and effectiveness of these methods vary according to the method used.

 

[sullivan]

Your CMOS video camera emits baseband video at a max of about 4 MHz, not RF (radio frequency).

Given that, you should be using RG59, not RG6. Most of the RG6 you find for sale has a copper-clad steel center conductor, and this gives it a *lower* bandwidth limit of about 50 MHz (due to skin effect introducing group delay distortion).

In addition, the shielding on RG6 is much better suited for VHF frequencies (50 MHz and up) than for baseband.

So, buy RG59 cable. It's cheaper than RG6, too.

Baseband video over RG59 should be good for at least a few hundred feet. I recently ran a hundred feet with a couple of adapters and barrel connectors in the path, with no visible problems at all. At three hundred feet or so I would start thinking about a repeater.