Microwave knocked out wi-fi to streamer. Solution found.

[Chazz6]

My Denon HEOS Link2 streamer receives from our router over the 2.4 GHz wi-fi band. When we run the ~1200W microwave, its radiation interrupts the stream.

I pass on a solution I found. The router was set on Auto channel, that is, its firmware algorithm chose from channels 1 to 11 in the 2.5 GHz band. Per advice I changed the router settings to use channel 1. That stopped the microwave interference. I'm told the microwave operates at 2.5 GHz and that channel 1 in the 2.4 GHz band is the furthest away from that band. Fortunately, neighboring networks are not crowded into channel 1.

The router also uses the 5 GHz band, and I left that one at Auto channel select. The Denon is only on 2.4 GHz.

 

[Blumlein 88]

I've run into this a couple times. Microwaves vary around 2.45 ghz which is closest to channel 9. Yes channel 1 is further from that than any other channel you can choose.

 

[Moonbase]

There is a lot of miss information around routers and channels. Definitely don’t change the 5ghz off auto. 2.4ghz may well be ok on channel 1,6,11 as they don’t overlap. I never like to use the
Microwave over 700/800 and that’s never caused issues for me.

 

[Chazz6]

I said above the Denon is only 2.4 GHz. I am wrong now, perhaps after some update. I looked on my router page at the clients on the home network, and there was the HEOS on 5 GHz, channel 149. All in all, the Denon streamer has been just fine, after the usual starting hiccups when I first got it.

In the interest of science, I should reverse the change I made to the 2.4 GHz channel setting and run the microwave, but in the interest of getting back to the music, I haven't done it.

 

[restorer-john]

You really should look at how much excess microwave energy is coming from your oven. How old is it?

 

[Chazz6]

You really should look at how much excess microwave energy is coming from your oven. How old is it?

About a year old.

True, we can just put the dish next to the thing. Convenient! </sarcasm>

 

[JSmith]

You really should look at how much excess microwave energy is coming from your oven. How old is it?

Exactly what I was thinking... sounds potentially dangerous. That said I suppose a microwave oven is around 10000 times more powerful than WiFi.


JSmith

 

[Roland68]

My Denon HEOS Link2 streamer receives from our router over the 2.4 GHz wi-fi band. When we run the ~1200W microwave, its radiation interrupts the stream.

I pass on a solution I found. The router was set on Auto channel, that is, its firmware algorithm chose from channels 1 to 11 in the 2.5 GHz band. Per advice I changed the router settings to use channel 1. That stopped the microwave interference. I'm told the microwave operates at 2.5 GHz and that channel 1 in the 2.4 GHz band is the furthest away from that band. Fortunately, neighboring networks are not crowded into channel 1.

The router also uses the 5 GHz band, and I left that one at Auto channel select. The Denon is only on 2.4 GHz.

I have many reasons why I haven't had a microwave in over 20 years and they just added another reason to my list.

 

[restorer-john]

All I know is my multi-field RF meter goes off the scale into the red from the other side of the room when I turn on the microwave. I no longer peer through the door anymore...

 

[Blumlein 88]

You really should look at how much excess microwave energy is coming from your oven. How old is it?

When I've brought up Wifi issues with microwaves I've been told the same thing. They make devices to test leakage, and I've had access to one. In both cases the microwaves were fine. No leakage at any level to worry about. Yet it effected wifi. In both cases the router was fairly close to the microwave on the other side of a wall. Moving the router fixed it.

 

[Blumlein 88]

Exactly what I was thinking... sounds potentially dangerous. That said I suppose a microwave oven is around 10000 times more powerful than WiFi.


JSmith

Microwave radiation is non-ionizing. So not the danger some imagine it might be to people. Don't feed the myth of worry over something harmless. I mean if it were dangerous and we are concerned because it is interfering with something(wifi router) meant to radiate it all over our house at the same frequency then something is daft. Neither oven leakage nor wifi is dangerous. Oh, and you (or most people) hold a source of such radiation next to your brain quite a lot.

 

[solderdude]

Consider that RF filtering of the mains cable from a microwave may not be good enough.
This creates an effective antenna for RF.
Microwave ovens have to be in a frequency band that is reserved for this.
Consider the huge power inside the microwave vs the very low powers used (in roughly the same band) in wifi where flea power and distances of quite a few meters are required ... again ... with very low power as mobile devices need to communicate as well.

So... we have the microwave in a band that was made long before the invention of wifi and and other low power remote control devices existed.
They have to occupy the same band. More and more communication in that same band as well.

Yep kW (that has to be reduced to uW emissions) and uW and nW high speed communication in the same band is asking for trouble.
I am amazed how well wireless communication still can work fine under these conditions.

In my repair days (Panasonic microwaves) we too had a sniffer (looked like a drainpipe, same PVC) wand with a styrofoam mushroom on top. It was used for detecting leakage through doors or the enclosure and mains cable but was not designed to test for wifi level signals, just for severe (dangerous) levels, at least that what was considered dangerous levels about 40 years ago.

 

[Blumlein 88]

One of the places I worked had lots of the old month long paper tape rolls that had ink graphing of equipment conditions. Inside each was a little short flourescent bulb. Some tech discovered it would light up dimly just about at the desired threshold of the expensive microwave sniffer. They were pretty consistent. Since we only had one sniffer, all the techs started carrying one of these bulbs. If it didn't light up, they didn't need the sniffer to get a reading.

There was a case of a satellite dish receiver that using the microwave would knock out. It was traced to microwave leakage over the power cable. Moved the dish a few feet and it was fine.

 

[voodooless]

Oh, and you (or most people) hold a source of such radiation next to your brain quite a lot.

Never mind that it about up-to 40x more power.

… get out your tinfoil hats!

 

[restorer-john]

at least that what was considered dangerous levels about 40 years ago.

3M away from my Panasonic inverter 1200W microwave on high.

1M away from the wireless router (dual 2.4/5.0GHz) when actively streaming data.

TM-190

 

[solderdude]

One of the places I worked had lots of the old month long paper tape rolls that had ink graphing of equipment conditions. Inside each was a little short fluorescent bulb. Some tech discovered it would light up dimly just about at the desired threshold of the expensive microwave sniffer. They were pretty consistent. Since we only had one sniffer, all the techs started carrying one of these bulbs. If it didn't light up, they didn't need the sniffer to get a reading.

There was a case of a satellite dish receiver that using the microwave would knock out. It was traced to microwave leakage over the power cable. Moved the dish a few feet and it was fine.

Yep, measuring distance is very important as is the frequency spectrum of the RF.
Each time doubling the distance makes a huge difference.
A handy that is being called that is lying on equipment can cause audible gremlins (the familiar tone bursts) but moving it away 30cm drastically reduces the field strength and may make the problem disappear.
Measuring under equal circumstances is paramount. Certainly with RF.

 

[voodooless]

3M away from my Panasonic inverter 1200W microwave on high.

View attachment 347223

1M away from the wireless router (dual 2.4/5.0GHz) when actively streaming data.

View attachment 347224

TM-190

FDA limit seems to be 5 mW per square cm at 2 inch from the surface (note the mixing of units ). A quick calculation shows that this amounts to 0.14mW per m^2 at 3m. So your Microwave seems way out of spec

 

[Deleted member 48726]

3M away from my Panasonic inverter 1200W microwave on high.

View attachment 347223

1M away from the wireless router (dual 2.4/5.0GHz) when actively streaming data.

View attachment 347224

TM-190

1 mW from the router vs. 87 from the oven. I'd ditch that oven in a hurry. Or place it in a Faradays cage.

 

[restorer-john]

FDA limit seems to be 5 mW per square cm at 2 inch from the surface (note the mixing of units ). A quick calculation shows that this amounts to 0.14mW per m^2 at 3m. So your Microwave seems way out of spec

I'm not so sure about it either - it is getting old but all the seals, panels etc are perfect to look at. Maybe I'll test a few friend's microwaves and see what the deal is.

The LF field detector pinned into the red when I took it under some local 275kV transmission lines and held it up. That was maybe 40M below the lines.

 

[restorer-john]

It'll be going in a Faraday's dumpster if it's bad.