Shielding help

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tipster67

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I have 4 scanners in my office. I am forced to run the antenna cables behind a TV, Printer, Router, switch, 2 PC's and a DVR for my security cams. Yes I know, but I have no real choice. Is there a way to help shield those cables. I have one channel that seems to be getting interference.
 

jonwienke

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Use good quality coax and it isn't an issue. Where are the antennas?
 

jim202

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There are several brands of double shielded coax cables on the market. Some of them require special connectors designed to handle the slightly larger OD of the cables.

But my gut feeling here is that you will not have enough separation of your antenna away from the noise generated by those RF noisy devices. If you can't get your antenna far enough away from the electronic devices that are generating the noise, the double shielded coax cables will not provide any solution.

The other issue here is that you probably have no way to effectively ground the coax cables that help mitigate the noise issue. The same goes for grounding all the electronic devices. Trying to rely on the ground supplied by the power cord is like just putting a long antenna on each of the devices.

You might do better to locate just what is causing the RF interference and look at trying to reduce it or shut it off until it's needed.
 

prcguy

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If the antennas are only 10-12ft away there could be more interference pickup by the antenna than through the coax shield. One way to find out is leave the antenna in its current location and move the coax and radios well away from the computers, etc. If your noise is still there then better shielded coax will not help.

In my situation the antennas are far from the radios but the coax runs right through a bunch of computer and router stuff. I found the coax was picking up interference onto the outside shield and carrying it up to the antenna where it was picked up and sent back to my radios. Some good common mode chokes on the coax as it exits the building and more at the antenna made a very noticeable difference.
prcguy
 

jonwienke

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I agree that the shielding in the coax is unlikely to be the problem. Whatever noise and interference you're getting is being picked up by the antenna(s).
 

Rred

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Kill power on the "devices" one by one until you find the one that is making interference. Then you can worry about how to mitigate it.

In today's market you can almost guarantee that not all the devices are FCC Part15 compliant, and there are many devices that only meet the "office use" standard, which are guaranteed to create problems in a home, and technically illegal to sell to home users. If you've got one of them, sometimes the only solution is to replace it.

Either way, you need to figure out which device it is before throwing money at random fixes.
 
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