Trivia: magnetron damage

• Jan 17, 2015

• #2

ScottyUK

Electrical

May 21, 2003

12,915

DE

At a guess, either 'cooking' metal objects in the microwave, or running it empty.

 

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• Jan 17, 2015

• #3

Compositepro

Chemical

Oct 22, 2003

7,849

US

That is the antenna of the magnetron. Most likely some contaminant got on the surface which caused a hot spot by absorbing the the intense field energy at that location.

Contrary to common belief, metal objects can be placed in a microwave oven. The oven walls are metal. You just must lot allow metal objects to touch other metal objects or there will be sparks, nor do you want foil or thin metal plating which will heat-up and melt due to the eddy currents and low mass.

 

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• Jan 17, 2015

• Thread starter
• #4

sbkenn

Mechanical

Feb 22, 2010

64

IE

Thanks for the enlightenment. I was aware that it was the antenna, but a little puzzled about the shape, particularly inside the burned part. I guess that there is a 45degree plate/reflector in the waveguide too, but will have to wait to look ... it is someone else's unit. Is it a resonant cavity ... something similar to a LASER ?

 

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• Jan 17, 2015

• #5

Comcokid

Electrical

May 23, 2003

1,281

US

Did it also arc to the inside of the oven?

 

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• Jan 18, 2015

• Thread starter
• #6

sbkenn

Mechanical

Feb 22, 2010

64

IE

The closed end of the waveguide is discoloured. That is the only damage that I noticed beyond the antenna. The burned side of the antenna pointed that way. I am now concerned that there may be damage to the waveguide, and that a new magnetron will quickly follow the original.

 

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