I have take three microwave apart and purchased a new oven that is still intact. I was interesting to see how delivery of the microwaves have changed over the years. In the oldest oven the magnetron was mounted vertically in a waveguide that ran over the top edge of the oven to the top center. It had a large dimple about ¼ wave from the magnetron and the two slots letting the microwaves into the oven were trapezoids of different sizes.
The next oven had about the same type waveguide arrangement but the waveguide was used to move cooling air that ran a pinwheel type fan used to average out the energy density in the oven cavity.
The magnetron in next oven was vertically mounted into what looked like a square waveguide box in the side wall of the oven.
Now for my question, the purchased oven has the magnetron mounted horizontally. The walls of area that the magnetron is mounted looks like they are at about a 45 deg angle to the magnetron’s antenna. Looking at the magnetron from inside the oven you see two slots about the size of a waveguide separated by part of the oven wall. This separation is about the same as the smaller dimension of the slots. Does any one know why they use this design? Does the separator help prevent energy from being reflected back into the magnetron, or does it just help distribute the energy?
I want to know because I am using the oven to produce an atmospheric plasma in a quartz tube and need to get some idea of the best place to mount the tube. With the microwaves coming out of two slots I want to know if I should mount the tube vertically across one slot or horizontally across both slots? How far from should I be from the wall by magnetron? With the 45-degree side walls where would I expect to find a ¼ wave node?
The next oven had about the same type waveguide arrangement but the waveguide was used to move cooling air that ran a pinwheel type fan used to average out the energy density in the oven cavity.
The magnetron in next oven was vertically mounted into what looked like a square waveguide box in the side wall of the oven.
Now for my question, the purchased oven has the magnetron mounted horizontally. The walls of area that the magnetron is mounted looks like they are at about a 45 deg angle to the magnetron’s antenna. Looking at the magnetron from inside the oven you see two slots about the size of a waveguide separated by part of the oven wall. This separation is about the same as the smaller dimension of the slots. Does any one know why they use this design? Does the separator help prevent energy from being reflected back into the magnetron, or does it just help distribute the energy?
I want to know because I am using the oven to produce an atmospheric plasma in a quartz tube and need to get some idea of the best place to mount the tube. With the microwaves coming out of two slots I want to know if I should mount the tube vertically across one slot or horizontally across both slots? How far from should I be from the wall by magnetron? With the 45-degree side walls where would I expect to find a ¼ wave node?
