As a kid i remember always watching the tv get a distorted signal whenever my mom was using the mixer. Why is that?
In: Technology
A mixer is basically a fair-sized electric motor. Electric motors work in various ways, but they all utilize rapidly changing electric and magnetic fields. They tend to be “noisy” in terms of how much stray electromagnetic radiation they emit. And radio is just that, electromagnetic radiation. (In the case of radio, a color that is so deep red that our eyes can’t see it.)
Radios and TV can pick up these signals if the mixer is close enough, and try to turn them into video/audio. Of course, that doesn’t work well.
If a mixer is very close to an old CRT TV, the magnetic fields can directly impact the operation of how the tube gun shoots electrons at the screen. But it typically would need to be fairly close for that to happen.
Mixers, microwave ovens, and other appliances can give off radio noise that interferes with TV broadcasts. It doesn’t have anything to do with the old CRT TVs, it is just that they went away about the same time people were switching from over the air broadcasts to cable and satellite. Even if you still get your TV over the air, broadcasts are digital now. When a digital tuner gets a bad signal, it usually just blacks out rather than playing a distorted signal.
Finally, kitchen appliances are better made today and give off less interference.
It’s actually the commutators on the motors, old electric motors have commutators which are brushes that touch spots as the motor moves causing the wires to get connected and disconnected as the motor operates. When this happens there is typically a small spark (on many devices you can look in and see these sparks).
Anyways, sparks create broad range RF, [basically a spark gap transmitter](https://en.wikipedia.org/wiki/Spark-gap_transmitter), so these sparks act as small radio transmitters that interfere with all radio devices, with old TV being one of the common ones.
Now you probably use cable TV which shields the signal inside a wire so it’s not an issue. Also, more attention is paid to reducing the sparks, they interfere with modern circuit breakers that have spark detection (AFCI breakers). We have brushless motors that are truly spark-less, and these are used in most of the higher end equipment.
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