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A comment on You block ads in your browser, why not in your city?. Parent comment

Re:You block ads in your browser, why not in your city? by matheusmoreira on Sunday December 26, 2021 @05:10PM (#29696870)
> Each car radio sends out a signal at a frequency higher than the one it is receiving from the radio station.

Why would it do that? I thought car radios were merely receivers, not transmitters. This is insane...

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Re:You block ads in your browser, why not in your city? by xyzzyz on Sunday December 26, 2021 @05:58PM (#29697186)
It is a result of the mechanism used for operation. See https://en.m.wikipedia.org/wiki/Superheterodyne_receiver especially the section on Local oscillator radiation
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Re:You block ads in your browser, why not in your city? by dmm10 on Tuesday December 28, 2021 @03:13PM (#29717523)
Most radio receivers transmit a very weak signal slightly higher than the carrier frequency of the station tuned as a result of how they enhance received signals. Look up superheterodyne for details.
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Re:You block ads in your browser, why not in your city? by gruturo on Monday December 27, 2021 @08:38AM (#29702395)
It's a side effect of how tuning works (local oscillator), and the signal is extremely weak, very little of it radiates out due to some components / PCB traces behaving as an accidental (poor) antenna.

Still, with good enough equipment it can be detected even from some distance.

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Re:You block ads in your browser, why not in your city? by heavyset_go on Sunday December 26, 2021 @11:58PM (#29699440)
Check this out: https://scholarsmine.mst.edu/cgi/viewcontent.cgi?referer=&ht...
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