Routers and modems - good and bad?

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Routers and modems - good and bad?

Romana
This post was updated on .
Some are really terrible, so if we could make a list of which of the routers and modems thats good and which are bad. Of course this is indiviually what each one can take, but it's a start.

Safe for me:
Router Asus RT-N12 D1
Router D-link Dir-655 if 2 meters away.
Cablemodem Cisco EPC3925

Bad, causes various symptoms:
Router Netgear R7800 x4s even with wifi turned off.
Router D-link Dir 842 even with wifi turned off.
Modem Sagemcom docsis 3.0 24/8 ch.- even with wifi turned off.
Modem Arrow Docsis 2.0 modem
Router Buffalo Whr G54S even with wifi turned off.
Multimodem Zyxel P8702N v2
Fibermodem Genexis Platinum 6840 even with wifi turned off.

So if you have your own experiences with modem/routers pls post.



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Re: Routers and modems - good and bad?

Karl
I wish that I could offer suggestions, but I don't have any that I like particularly. Sailplane posted some of his personal experiences:

http://es-forum.com/Router-Noise-td4030413.html

He likes grounded power supplies, too.

I find that using a non-switching power supply helps a lot, and I've done side-by-side comparisons using my AM radio. There's a very big difference in the noise on the ethernet cables connected to one of the switches here depending on whether I use the AC adapter that came with it (very loud on the radio) or a Jameco linear regulated power supply (less than half the noise).
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Re: Routers and modems - good and bad?

Karl
In reply to this post by Romana
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Re: Routers and modems - good and bad?

earthworm

Why the ac-dc linear wall adaptor was not good enough ?
No stable voltage, too much loss ( thinner coils ) or to much noise on the input-line ?
In the latter case one of these filters you suggested earlier would be an anternative and for some a more easy solution.
One of my modems has a switching mode power supply delivering 12 volt / 2 amps, probably 2 amps is never used though.
I thought of replacing it with one similar to these :
https://www.jameco.com/z/DDU120150-AC-to-DC-Wall-Adapter-Transformer-Single-Output-12-Volt-1-5-Amp-18-Watt_101291.html
Running it on a car-battery is another option but i am afraid that the voltage may drop too low one day or the cable gets disconnected, possibly damaging the modem ( perhaps this is nonsense ).
The modem came with the internet-contract, i do not know if just any other modem could replace it.
To ground it, can you just open it up and connect earth to a main metal part ?


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Re: Routers and modems - good and bad?

Karl
The Jameco power supply works very well and I still use two of them in other locations.

I replaced the one powering the switch because I wanted to reduce the 60 Hz magnetic field in that area. A toroidal transformer should be better in that regard.

Have you found a linear regulated power supply that's compatible with European power? The Jameco model was well worth the money, but it only runs from 120V.
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Re: Routers and modems - good and bad?

Karl
In reply to this post by earthworm
I don't know the best way to ground a modem. The modems and switches I've taken apart had plastic enclosures with molded tabs and pins to hold the circuit board. There were no obvious ground connections and they had ungrounded power cables.

The rectifier/regulator board that I linked to above uses a rectification circuit similar to this one:



Because the capacitors on the + and - wires are connected to ground, small fluctuations in charge on them can escape before they get into your modem. So you could call it a 'partial ground.'

You're right that running from too low a voltage can harm electronic equipment, but I don't know which types are most sensitive. (A term to search for is "brownout.")
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Re: Routers and modems - good and bad?

earthworm
In reply to this post by Karl
I keep modems always in some distant corner because these emit a lot of emf-s, also without wifi enabled and whatever powersupply is used, partly directly and unfortunatedly also partly through the ethernet cable.
Regarding the latter, people have reported worse experiences with shielded cat 7 than with unshielded ones, and Charles wrote if i remember it well that the pollution should be able to bleed out.
Therefore, in case the computer sits within say 5 meters from the desk it may be a good idea to use the first so many meters from the modem an unshielded ethernet cable and for the last few meters to the compter a shielded one.
The same idea may apply video- and usb-cables.
Anyway, back to the topic of powersupplies, smps-s do pollute the electricity cables all over the house, so a linear adaptor would be always preferable.
A toroidal transformer is something to keep in mind for nearby use, these sometimes sit in halogen office lamps and old car-battery chargers for instance.
I usually find stuff like this second-hand, often even in the trash ( not exactly the right place for recycling ), and that happens to be usually european, with the right input voltage and plugs.
However ordering the mentioned adjustable regulated power supply board might be a could idea one day and connect it to a strong 13-15 volt toroidal transformer in order to get a 12 volt DC output.
Although i would prefer a better one similar to the large one inside the linear power supply that came with my low-emf monitor, but beggars can't be choosers, we'll see what opportunities will appear.
 

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Re: Routers and modems - good and bad?

Karl
I think that most store-bought shielded ethernet cable has only a thin metalized plastic sheath - a bit like aluminized mylar.

I installed some tinned copper braided cable sheath on the longest section of ethernet cable here, and one of these days I'll get a small section of shielded cat-6 and compare the two. (The stuff I got was from Jameco and was a bit expensive. If you have the space, steel or aluminum conduit will probably be cheaper, although I haven't checked prices in the EU.)

Here's a forum thread about how to properly crimp shielded cable: community.ubnt.com/t5/About-the-Ubiquiti-Community/Request-Proper-shielded-CAT5-STP-grounding-install-HOW-TO/td-p/118635

What I like about the copper braid is that you can expand or shrink its diameter by compressing or extending it axially, so it should be easy to install small toroidal chokes inside the shielding on the ends facing computers or switches/routers/modems. You can then ground the shielding to the router through a shielded RJ45 jack, or you could buy a large electrical box to house the router and ground to the box instead (using something like this, for example: www.amazon.com/Sigma-Electric-C-500-8-Inch-Connector/dp/B006VWY4K8).
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Re: Routers and modems - good and bad?

Romana
As some say shielded cable is worse, are there difference between the different shieldtypes like standard ftp, f/ftp(2x foil), stp (braid), s/ftp(braid and foil). I have no problem with s/ftp but neither with utp. Whats your experience?
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Re: Routers and modems - good and bad?

Marc Martin
Administrator
I have had symptoms from shielded ethernet cables, but I do fine with UTP  (unshielded twisted pair).

Specifically, this is what I have in my house:
https://www.amazon.com/gp/product/B00AJHC32C/

My wiring I have for my computer speakers is also twisted-pair, as this caused me less symptoms than regular (untwisted) wiring.

Marc
 
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Re: Routers and modems - good and bad?

Karl
In reply to this post by Romana
My experience is limited. Most of the ethernet wiring here is unshielded Cat-6. I found it hard to sleep with the network running and would often turn it off when my housemates were away.

Adding the copper braid seems to help a lot as far as sleep and ability to relax during the day, but I still need to do some side-by-side tests with the radio and other instruments.

Thanks for mentioning the braid-shielded cables. I wasn't aware that they were available, and it looks as though they would be a lot more economical per foot than buying the braid separately.
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Re: Routers and modems - good and bad?

Karl
In reply to this post by Romana
It turns out that I had a shielded ethernet cable lying around that needed its ends replaced (due to broken retention tabs), so I cut one of them off to take a look.

It was labeled as "ETL verified Cat.5e STP." The shielding is proper aluminum foil (not metalized plastic as I had thought), but it's 1/4th to 1/5th the thickness of kitchen foil (0.0002" on my micrometer vs. 0.0008-0.001"). It was wrapped around the entire 8-wire bundle (not the individual pairs) and was grounded at one end only.
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Re: Routers and modems - good and bad?

earthworm
So these shields are really thin and close to the wires, almost nothing compared to solid pipes.
Copper braided cable sheath on the outside is probably not that bad.
Shielding could be important because fields from lines diminish less than from objects ( like routers or computers ) along with the distance.
Therefore cables should also run in a direction away from where one usually sits.
I am told that letting the diverse cable cross each other ( at close distance ) is to be avoided.
Apart from crossing, running them parallel while almost touching is probably not a good idea either.
All this would then apply as well for some wires within a device.
Large desktops could be preferable above mini-pc-s and laptops because of that, although certainly many other factors will be relevant here of course.
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Re: Routers and modems - good and bad?

Karl
Shielding could be important because fields from lines diminish less than from objects ( like routers or computers ) along with the distance.
Therefore cables should also run in a direction away from where one usually sits.
Yep.

I am told that letting the diverse cable cross each other ( at close distance ) is to be avoided.
Apart from crossing, running them parallel while almost touching is probably not a good idea either.
I would be more worried about running wires in parallel.

All this would then apply as well for some wires within a device.
If you take apart a laptop or wireless access point, you'll see a separate metal shield where the wireless chips are.

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Re: Routers and modems - good and bad?

Romana
As my current router went out I need a new one without wifi. Looking at cisco, linksys, mikrotik, ubiquiti etc - anyone that are good emf wise? What to look for?
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Re: Routers and modems - good and bad?

Marc Martin
Administrator
You might also look at a single box that combines the functionality of a modem, a router, and a switch.  That's what I use.   But for these, you have to find something that's compatible with your internet provider (cable company or DSL company).

 
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Re: Routers and modems - good and bad?

Romana
What equipment can measure fully the smog from routers and network equipment?
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Re: Routers and modems - good and bad?

Marc Martin
Administrator
On July  6, "Romana [via ES]" <[hidden email]> wrote:
> What equipment can measure fully the smog from routers and network equipment?

The e-smog may be the least of your concerns.  For me, it was the ground loops that was causing me the most symptoms, solved by putting in a ground loop interrupter on the incoming coax cable from the cable company.
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Re: Routers and modems - good and bad?

Romana
If one want to minimize wifi radiation dose what settings would be best on the wifi part? B - g - n - ac standard, 20 or 20/40 mhz band, mimo disabled?, etc. ?
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Re: Routers and modems - good and bad?

Marc Martin
Administrator
To minimize wi-fi exposure, I guess you'd first put it a timer, so it automatically turns itself off during the hours of the day when it's not needed.

There is also a "beacon" pulse that occurs even when nobody is using it, but I believe that with some routers that this can be turned off altogether, or at least the frequency that it occurs can be reduced.

I also believe that in some routers you can turn down the intensity of the wi-fi, so you only use as much power as you need (although this may have the bad side effect that your wi-fi devices close to you have to turn their power UP to communicate with it, so that might be a bad idea depending on how much you use it).

It seems like some people react more strongly to the 5 Ghz version of wi-fi, maybe use a router that only supports 2 Ghz.

No real experience on my part for this advice, because my router has no wi-fi, and we just use ethernet (the best solution).

Marc
 
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