Router Noise

I just discovered my router a Linksys WRT54GL induces quite a lot of noise on the Cat5 cables coming out of it. It sounds kind of like UFO noise on my shortwave radio, and it travels very far through the cabling.. In fact, it goes to another router, and then to my computer, and then in my keyboard!.. And also in all the wiring in the entire house. I can hear the noise at other wall outlets very far away.

I have an older TP-Link WR941ND, and it has less than half the noise on the radio, sounds different too.

My latest Asus RT-N12 doesn't make almost any noise on the same band. The power adapter also has very low V/M readings on the DC wire, unlike any other switching adapter I have. I think Asus has done a good job filtering this router, amazingly.

It looks like newer electronics could be better filtered than older ones.. Lesson learned for me, if you feel something is causing you problems, perhaps you should try changing it. I've had a bad feeling about this router for a long time, ever since I measured very high V/M readings on Cat5 from it.

Most people say wired is much better than wireless, but wired can be bad also if you have a bad router, especially one with high electric fields. I think wireless is still worse though.. unfortunately.
Also most routers are not grounded. I am still trying to find a good grounded one that would make less noise, but for now the Asus seems good.

You can usually solve this by using shielded (and grounded) Cat7 cable: https://lessemf.com/computer.html#703

Thanks Emil,
I will be trying.
It seems that actually even the Asus router makes some noise also, but only when it has cables plugged into it/it's working. It must be the CPU or something.
On the radio, it is so silent without any router on, it's amazing the difference.

That's why I suggested the Jameco linear regulated power supplies.

(For anyone else reading this, here's a 12 volt one: http://www.jameco.com/z/DDU120100H4480-AC-to-DC-Power-Supply-Wall-Adapter-Transformer-Single-Output-12-Volt-1-Amp-12-Watt_170245.html)

Unfortunately this noise is from the router itself. It's 12V and I battery powered it. Same buzzing. I'm starting to think it's impossible to not have this noise though, I think it's simply the communication on the wire between the router and the computer.  If I unplug all wires out of the router, the buzzing stops. Also, on the computer side, if I disable the network card in device manager, the buzzing stops.

Yes, there is inevitably some emissions just from the modem/router doing its job.  I once did a big trade study on DSL modems and cable modems, trying them out and seeing how I felt, and there was definitely a difference between models/brands.  And that was mostly using linear power supplies, and modems/routers that had no wireless capabilities at all.

Marc

 

Well, the buzzing I'm hearing from each router is quite different, so that's not surprising that some may be better than others.
I guess I just have to buy a few and try them out.. but I'm not sure if it will help. I think my laptop network card will be making it's own buzzing as well, which I can't change unless I try a different computer.

I just got a switch, Netgear FS105NA, it has a "green" feature where it reduces the energy in the cable if it's shorter.
It definitely reduces noise, I can hear it loud like my other routers when it first turns on, then then noise goes down quite a lot. It comes with 12V switching supply, but I substituted with a linear and that cleans up the noise even more. It's the lowest amount of noise of anything I've tried yet. Being a switch, it has even less electronics than a router as well.
The power usage is not even 1 watt. My power analyzer doesn't measure lower, so I would have to use a voltmeter. I'm guessing 12v /50ma but I'll have to test exactly.. I think lower powered electronics are better for ES.

I still have to see how I feel with it. I hope it helps. Good thing is, I can return it.. so that's the best thing to do I would say, buy returnable electronics and try them out.

After some hours of testing, the switch is a no-go.. It felt much worse than anything I had previously.
It also seems shielded Cat7 cable is consistently worse than unshielded Cat5.. I even tried grounding the Cat7, no help.

Yes, I also found shielded ethernet cable to be much worse than unsheilded.  I am using switches in my house, but also discovered that some switches are okay, while others aren't.  Right now I'm using two Netgear GS108 v3 switches.  Turns out that I can't stand the later versions, but v3 is okay.  I'm also using these with older Netgear linear power supplies, as I believe these originally came with switched power supplies.

I tend to buy things used on eBay, and if they don't work out, I resell them on eBay.  When you take into account eBay fees, paypal fees, and shipping costs, I usually suffer a bit of a loss doing this, but not too bad.  

Marc
 

You could try Amazon too, returns were easy and free for the items I tried, but not sure if they are all free to return.. maybe just the Prime ones. I only buy Prime anyway.

I returned the Netgear and back to the Asus, it is definitely much better.  I had a TP-Link before and it was pretty bad. I am very surprised that this little router is worse than my entire laptop.

I am going to try a Cisco Catalyst 2950, it's a huge box that could be much worse, but it has a 3 prong adapter with built-in supply, and it's made for commercial use. I think it could have better filtering.. plus it's old, so maybe the less CPU power is better. The supply is switching probably though.

I don't notice any help by changing switching to linear supply on the routers I'm trying.. Only the Netgear had a very small reduction in noise. The rest sound the same on the radio. Maybe an oscilloscope would reveal more.  But only this Asus switching supply is good, others I have put out big E fields, up to 100v/m, that end up spreading everywhere.

> You could try Amazon too, returns were easy and free for the items I tried,
> but not sure if they are all free to return.. maybe just the Prime ones. I
> only buy Prime anyway.

The problem with doing that is that Amazon bans customers for doing too many returns.  So there was a time when I returning lots of stuff, but then when I learned about that, I decided that I didn't really want to be banned from Amazon.

Marc

is the router wireless? you have cat cable, is your connection wireless?

bums me out that you would have problems even with non-wireless.