Ethernet Interference how to filter

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  • Updated 1 month ago
Hi All

I seen a post somewhere recently explaining that it was a waste of time putting ferrite on either utp or stp Ethernet cables, I can't remember which, or where I read it, I am trying to remove some birdies on 2m caused by home network,

Anyone have any pointers, I have a large amount of cat cable around my house so don't want to replace it with the wrong type,

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Posted 1 month ago

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Neal - K3NC, Elmer

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Trevor, how long is your ethernet cable? You might consider putting an optical link in the middle.
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Ron / K4XRF

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Michael Walker, Employee

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I had the same thing happen with the Cisco router

I replaced the router. It solved the problem perfectly. 

Ethernet cable is generally pretty good as it is twisted pairs that do a good job of not radiated signals.  

Are you sure your cables are properly made with the connectors on correctly?  The twist is key and part of the design.

In all seriousness, not all Switches/Routers are created equal.  In my Cisco case, the 64 port device as actually wiping out 2M.  You could hear it in a 2M handheld in AM mode. (VX7R).  

I did replace it with a $50 device from TP-Link and the effect was amazing.  I suspect the switching power supply in the Cisco that had gone noisy as it was pretty old.

Switching power supplies are a dime a dozen today and there is no thought given to RF immissions anymore.  

Good luck and let us know how you make out.

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Michael N3LI

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I had a router that would reset when I transmitted on 40 meters. I used a honking big ferrite on it at both ends of the ethernet cable. It cured the problem. So probably not a waste of time.

Computers and their associated peripherals don't really like RF. I've graduated from troubleshooting out the problems, adding a ferrite here or there,  to simply putting a ferrite on every cable going into the computer, router and keyboard.
Overkill? Perhaps. But after you troubleshoot the same problems over and over on several systems, it's really nice to have things work the first time, every time. 

A huge number of "faulty' Flex radios are just RF getting into the wrong place on the other items. 
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20 turns thru material #43 will cure your problem.
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Lawrence Gray

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I replaced all Ethernet cables with CAT 7, which solved my Ethernet noise issue.  As mentioned above, cheap switchers also cause issues.  I have a Cisco IP phone which had a noisy wall wart.  I also, as mentioned above, put ferrites on every cable.  Easier than trying to find noise sources, as pointed out above.