RF quiet network switch... do they exist?

[VK5ZEA]

Hi Everybody,

I am trying to do some research on replacing my current Linksys gigabit network switch.

I've been putting up with all kinds of musical interference on HF courtesy of this device and I wonder if anyone has found one that works... but is also quiet on HF.

Is is possible to make an RF quiet network switch... I've been asking some of the SDR guys who access their radios via Ethernet and they indicate that it is indeed possible for Ethernet to be quiet.

A DC powered switch would also be good... I run my current Linksys switch on an AC inverter (my wiring closet has a 250Ah gel battery for backup and the switch is the only AC device). The inverter is also a severe noise generator... getting rid of it would be good too.

Any ideas or suggestions?

Michael.
VK5ZEA

 

[n0nhp]

I have two of the Netgear Prosafe 16 gigabit switches in my setup and have not noticed any noise out of them. If it is the Router rather than just a switch, I am using the Dlink DIR-655 gigabit router and it seems to be quiet as well.
However, your installation and mine will be different and the best suggestion is to put the hardware on a credit card so you can put it in operation and find out if it is what you want.

Bruce

 

[VK5ZEA]

I've tried another switch... an older model Netgear 10/100 switch, to rule out any fault with my Linksys switch. I still get the noise on HF.

I uploaded a short video to my YouTube channel where you can hear the noise from the network switch in various places on the 20m band. I also turn the Netgear switch off remotely, you can hear the noise go away when the switch is powered off.

Noise on HF caused by Ethernet network switch activity - YouTube

It's quite pervasive all the way up to 10m. My next step is to get some mix 43 ferrite cores and clamp them on the Cat5 cables at the rear of my patch panel.

Michael.
VK5ZEA

 

[KZ9G]

Are you sure its the switch and not a device attached to the switch?

 

[Thunderknight]

I was getting a lot of noise on low band from my ethernet devices. I switched many devices to wireless (either with native wireless or with ethernet to wireless bridges) and I replaced all of my cables with shielded Cat 5 (STP). Didn't totally eliminate the noise, but it helped a lot.

 

[cabletech]

I have worked with a lot of network equipment around all kinds of radios, both commerical and ham and I have never found any of the network devices to cause any RFI on the radios.

What you may try, is remove the wall wort for the swicth/router and connect direct to a battery. The potenatil for interferance is more likely to be from the wall wort then the device itself.

 

[VK5ZEA]

Are you sure its the switch and not a device attached to the switch?

No I am not sure about this. I plan to spend a bit of time at my wiring closet powering off each device connected to the network switch in turn while listening to the noise on HF.

All my network gear (apart from the original Linksys Gigabit switch is DC powered. I have a 250Ah gel battery bank that keeps everything alive during power failures.

The power supply/charger I use is specifically designed for use around radio equipment (made for RF Industries in Australia)... it's VERY quiet.

I have two ADSL services (and two phone lines)... each with a Billion ADSL modem. My main router is a Snapgear/Cyberguard SG570, the 2nd router is a Mikrotik RB750.

I've also got a Linksys VOIP box, Dlink 802.11G access point, Clipsal C-Bus home automation system, Mikrotik 5.8GHZ link equipment for my D-Star repeater/IRLP/AIS receiver... and a whole lot of other stuff connected to the switch at the wiring closet.

You are right, I do need to determine if it is the switch or something connected to the switch that is causing the trouble.

 

[n0nhp]

I have not had trouble on HF, however on VHF I had a NAS device (that I cannot come up with the name of right now( edit; It was a Snap Server) knock out a channel. I was able to track it down with my hand-held. The IT folks were not happy (It was at a fire camp in Alaska) but nobody goes to fight the fire unless they can communicate!

Just pulling single lines from the switch might give you the device or cable that is causing the noise.

Bruce

 

[mtindor]

If somebody has worked with networking equipment for years and years and years and has never been aware of the internals of a network device / ethernet transceiver [or a wall wart for a router/switch/other device] causing any RFI issue, then somebody hasn't been tuning to HF bands.

The biggest offender is anything that is 10 mbit. Any ethernet transceiver manages to produce less noise when it's connected at 100 mbit. If you have a device that is 10 mbit only, or a device that'll do 100 mbit but for one reason or another [administratively locked at 10 mbit, or bad cabling forcing it to 10 mbit], then that's probably the first thing to look at. Unplug anything from the network that happens to be connected at 10 mbit and see if you can isolate that way. Those are usually the biggest offenders [in my experience].

Mike

PS: I switched everything to wireless to avoid having to deal with the ethernet issues. Ethernet cabling seems to like to propagate the noise all around, and likes to capture the RF your transmitting and cause network components to reboot / malfunction.

 

[SCPD]

I have a DLINK DIR618 and its noisy as ----------- (hash when plugged in with WIFI OFF!)
The router they give you free from Cablevision is quiet though.

SAGECOM 5260CV is the model