Can a Factory built microwave oven have microwave leakage?

[Pommie]

Can anyone point me at a reference for phones working on 2.4GHz? Here in Australia they are more likely to work sub 1GHz (or above 2.4GHz) frequency.

Check your countries frequency here. Or am I misinterpreting this?

Mike.

 

[Externet]

Many flavors ----> https://powerfulsignal.com/cellular-frequency-bands/

 

[rjenkinsgb]

Can anyone point me at a reference for phones working on 2.4GHz? Here in Australia they are more likely to work sub 1GHz (or above 2.4GHz) frequency.

The cellular signal is not on 2.4GHz - but that's the commonest WiFi band still!

 

[Nigel Goodwin]

The cellular signal is not on 2.4GHz - but that's the commonest WiFi band still!

And as such is often unusable

 

[gary350]

Found something similar, but do not know why a second diode.
----> https://www.creative-science.org.uk/mobile_LED.html
Perhaps can work for oven leaks ?

I built the cell phone transmit detector circuit with 1 LED, I have no 0A91 diode, circuit does nothing with my cell phone is there a substitute diode?. I have some 1N5819 & 1N34 & 1N914 & 1N1007 diodes. This is the wrong frequency for our microwave oven but I tried it anyway and it does nothing. Information I read about cell phones it sounds like cell phone will transmit so quick LED won't have time to light up. This gives me something to do besides watch it rain outside.

 

[rjenkinsgb]

Normal LEDs have quite high capacitance and are slow turning off. At high frequencies they are pretty much a short circuit. A faster diode could provide the rectification needed for the LED.

All diodes take some time to turn off, which may be some microseconds or more - or down to picoseconds or less.

The diode needs to be fast enough to operate properly at the frequency being rectified. Small signal schottky diodes are quite good, though there are specialised diode types for really high frequencies.

 

[Pommie]

Many flavors ----> https://powerfulsignal.com/cellular-frequency-bands/

How does that demonstrate mobiles use 2.4GHz?
A quick screenshot,

As I stated above sub 1GHz.

The cellular signal is not on 2.4GHz - but that's the commonest WiFi band still!

So why do people keep suggesting putting a mobile phone in a microwave as the shielding will block 2.4GHz.

And as such is often unusable

Actually why I prefer 5G (5GHz not fifth generation).
As I live in a highrise the 2.4G network is so crowded it's practically unusable.

Mike.

 

[Nigel Goodwin]

How does that demonstrate mobiles use 2.4GHz?
A quick screenshot,
View attachment 147567
As I stated above sub 1GHz.

So why do people keep suggesting putting a mobile phone in a microwave as the shielding will block 2.4GHz.

Actually why I prefer 5G (5GHz not fifth generation).
As I live in a highrise the 2.4G network is so crowded it's practically unusable.

Mike.

It doesn't have to be a high rise, as I mentioned above, 2.4GHz is often unusable anywhere as the band is so narrow and so busy. Switching to 5GHz (if available) often works far better, even though it's range is shorter.

When I was eventually able to get fibre I added a three node mesh system, so I have one on each floor, and WiFi on the hub turned off. The mesh units are dual-band, so provide 2.4GHz and 5GHz seamlessly on the same Network Name.

I've been very pleased with them

 

[MrAl]

Hey, if you really want to test a microwave oven for leakage then unplug it and throw it into a tub of water. If you see bubbles coming up, then it leaks (ha ha). You can then take it out and see if the cavity is filled with water

Actually, there may be a screen you can put in front of the microwave oven that could attenuate any real RF leakage, if you are that worried about it. I would guess that most of the leakage, if any, would come through the front somewhere as that is where the door is.
They do make special materials for this I think originated with the military, but you can't see through them. There may be some now though that you can see through.

 

[ZipZapOuch]

If you want your cell phone to communicate on 2.4GHz, turn off your phone's wireless data, turn on WiFi and connect to your LAN. Then make sure your LAN router is set to 2.4GHz. Now, check if it communicates.

Better yet, program an ESP32 as a Bluetooth beacon and download an app from Nordic to scan for Bluetooth beacons - the app will show the beacon's signal strength (RSSi), test from the same distance when inside and outside the oven. Test from various angles.

Have fun - it's amazing what one can learn as they work through paranoid and/or hypochondriac fears. Enjoy your experimenting and learning.

 

[gary350]

If you want your cell phone to communicate on 2.4GHz, turn off your phone's wireless data, turn on WiFi and connect to your LAN. Then make sure your LAN router is set to 2.4GHz. Now, check if it communicates.

Better yet, program an ESP32 as a Bluetooth beacon and download an app from Nordic to scan for Bluetooth beacons - the app will show the beacon's signal strength (RSSi), test from the same distance when inside and outside the oven. Test from various angles.

Have fun - it's amazing what one can learn as they work through paranoid and/or hypochondriac fears. Enjoy your experimenting and learning.

Hey, if you really want to test a microwave oven for leakage then unplug it and throw it into a tub of water. If you see bubbles coming up, then it leaks (ha ha). You can then take it out and see if the cavity is filled with water

Actually, there may be a screen you can put in front of the microwave oven that could attenuate any real RF leakage, if you are that worried about it. I would guess that most of the leakage, if any, would come through the front somewhere as that is where the door is.
They do make special materials for this I think originated with the military, but you can't see through them. There may be some now though that you can see through.

The bath tub idea made me remember I have a parted out junk microwave case laying behind the garage it stays full of rain water all the time.

I inspected our kitchen microwave it has about 1000 small 1/8" vent holes on top for the vent fan. The right side has a fiber pad about 4.5" x 4.5" square with a 2" x 4" area of 1/8" holes. The magnetron is behind the fiber pad. Door appears to seal tight. It is water tight except for a few holes.

Years ago I worked in a place where people played pranks on each other all the time. People would drop a paper clip into someone's brown paper lunch bag when they microwaved the bag there was a loud buzzing and electric spark flashes and the lunch bag would catch on fire.

I know what a piece of wire inside a microwave will do.

 

[Nigel Goodwin]

The bath tub idea made me remember I have a parted out junk microwave case laying behind the garage it stays full of rain water all the time.

I inspected our kitchen microwave it has about 1000 small 1/8" vent holes on top for the vent fan. The right side has a fiber pad about 4.5" x 4.5" square with a 2" x 4" area of 1/8" holes. The magnetron is behind the fiber pad. Door appears to seal tight. It is water tight except for a few holes.

Years ago I worked in a place where people played pranks on each other all the time. People would drop a paper clip into someone's brown paper lunch bag when they microwaved the bag there was a loud buzzing and electric spark flashes and the lunch bag would catch on fire.

I know what a piece of wire inside a microwave will do.

Microwave ovens aren't supposed to be sealed, in particular the doors usually use what's called a 'choke seal', which means you can often actually see a visible gap between the door and the oven. If you hold a sheet of paper across the seal, and then close the door, it should easily pull out with no effort

It wasn't me, but one of my work mates went on a microwave oven course, and as part of a demonstration they made a hole in the 'window' of the door, about an inch across, cut through the internal mesh, and bent it outwards. They then leakage tested the oven, it still passed

The waveguide cover you refer to above isn't made of 'fibre', it's almost always make of mica - as in mica capacitors A very small number of ovens used various specialised kinds of plastic covers instead. You can buy sheets of mica and cut your own out (if you can't find the correct part for your oven), but generally the correct ones are freely available - in fact, as a Microwave Service Agent, it was one of the few parts we were allowed to sell to customers. We weren't allowed to sell anything that required the case removing (including fuse), as that would then require professional leakage testing - rather pointlessly, as with the case removed they don't leak anyway.

 

[debe]

In 1980 i built this kit & its served me well, & yes ihave never found a leaky oven since. Also a simple LED indicator would be next to useless.

 

[ZipZapOuch]

debe how does your sensor respond to cell phone or WiFi ? When placed right next to the WiFi router antenna?

 

[debe]

It varies from zero & small pulses. was able to capture a larger pulse. Beare in mind this is not in test mode so its not much more than what leaks out of a microwave door. If you push the test button it doesnt register.

 

[MrAl]

This thread begs the question: How much leakage would we get if we took the entire door off the microwave oven and fooled the electronics into turning on the power anyway. Yes it would leak, but what would be the effect say 1 or 2 feet from the front.

 

[Nigel Goodwin]

This thread begs the question: How much leakage would we get if we took the entire door off the microwave oven and fooled the electronics into turning on the power anyway. Yes it would leak, but what would be the effect say 1 or 2 feet from the front.

600-700W of RF pouring out the front, seriously NOT good even at a couple of feet.

 

[AnalogKid]

Deleted.

 

[ZipZapOuch]

[/QUOTE]

Yes it would leak, but what would be the effect say 1 or 2 feet from the front.

You would be...

Deleted.

 

[MrAl]

600-700W of RF pouring out the front, seriously NOT good even at a couple of feet.

Hi there Nigel,

Yeah you are right, that is a lot of power, and bad for the eyes if not anything else.
I could imagine a 500 watt white LED from 2 feet away. It would hurt the eyes very badly.
Conclusion: not a good idea to take the door off

This reminds me of an episode of South Park where one of the main characters, Randy, wanted to be able to buy medicinal marijuana but the doctor said nothing was wrong with him so he could not get a referral. Well, the next day we see Randy holding his mid section up near a microwave oven with the door open and it running full blast in an attempt to get testicular cancer so he could get a referral and then buy 'weed'. It was funny as heck, especially when his lower man parts both grew as big as basketballs, and he had to bounce around on them to get anywhere in town.
The writers of that show are truly the textbook examples of crazy (ha ha).