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Comment by xani_ | Hacker News Reader

The airplane pilots can't do shit about it, it's up to their parent company to pressure company (and pay $$$) that sold them planes to fix it.

From their perspective it worked for decades and now someone decide to jam it.

From engineering perspective, yes, they are defective and don't have enough filtering on the input to stay within its band

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From engineering perspective, the 5G equipment is not staying in its band, not radar altimeters. Remember that the regs for band usage are on transmit, not receive, and the physical reality makes radio altimeters especially hard to filter.

I don't think you understand FCC rules about communications at all. You can't just freely snoop on someone's cell phone call because you are just receiving. There are all kinds of regulations around reception.

And I think you do not get the rules about frequency allocation, which don't care about separate rules related to snooping communications.

No the altimeters are sensitive to frequencies outside their band. So 5g transmitting inside its band causes the altimeter to malfunction.

Many receivers can be affected by strong signals outside of their band. The strange analog world has effects like desensitization and intermodulation, which can produce in-band signals or attenuate the ones you intended to hear. The degree to which a receiver is immune to these effects is part of the engineering of the receiver. They likely didn’t consider strong C-band transmissions with a high duty cycle in their design at the time.

Also in multiple threads on this before, people more versed in analog radio electronics described how problematic it is to filter.

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