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Comment by nickysielicki | Hacker News Reader

Getting deeply into amateur radio in the past year has really changed my perspective on the world around me. You start to get frustrated by cheap power supplies ruining your reception, you start to curse plasma TVs and power lines, etc. It gives you perspective for how limited our senses truly are, relative to the insane amount of general noise that things make. This is especially illustrated by things like RF-Capture by some MIT students, see their paper "Capturing a Coarse Human Figure Through a Wall" [1].

Signals are going to be weaponized in ways that we cannot imagine, a very loud but humanly imperceptible transmitter is only the beginning.

[1]: http://rfcapture.csail.mit.edu/rfcapture-paper.pdf

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> you start to curse plasma TVs and power lines

Nah. What you need is a transmitter powerful enough that all the cursing is done by everyone else around you. :)

j/k - I guess I'm jaded because I live in a densely populated area, and there's no place nearby where there's no RF pollution all the time. And yeah, while my plasma TV is on, reception is junk on all frequencies.

You should build a personal faraday cage.

How am I going to get any reception from a faraday cage?

Yeah, I'm a little depressed to move soon from a S2 location to S5-6 if my shortwave radio is any measure.

Don't get me started about Powerline Ethernet. That shit is straight up FCC-violating RF garbage.

Could you explain more about what the Powerline interference are? #explainitlikeImfive

Turns your entire house into an antenna that radiates across useful frequencies. Like whispering between two people while a tornado siren is going off 100 feet away.

"Unfortunately these devices tend to wipe out almost the entire HF spectrum for anyone listening nearby. As household powerline cables are not shielded for RF emissions they radiate in the HF spectrum quite heavily."

https://www.rtl-sdr.com/showing-the-hf-interference-problem-...

https://www.youtube.com/watch?v=6IW3FVhHR58

All digital gizmos basically radiate electromagnetic energy at more or less all frequencies all the time while they're on. But some gizmos are better behaved than others, and are rather quiet. Some are total trash, and they're just "shouting" loudly across a broad interval in the RF spectrum.

If there's something like that nearby, your receiver will drown in noise, and you'll be unable to pick up faint signals from distant transmitters.

I don't know much about Powerline, but typical offenders are plasma TVs, cheap computers, etc.

Think of every wire that connects your outlets together, generally these are pretty long. Powerline Ethernet turns those wires into antennas so you get things like this[1].

When you're talking about radio waves there's two power measurements PEP and ERP. PEP is roughly what wattage a radio is spec'd at. ERP is PEP * Antenna Gain, so your long runs of wire make them a high gain antenna.

To use a poor car analogy PEP = horsepower, ERP = 0-60mph. Powerline is a motorcycle, not a lot of HP but still stupid quick(loud).

What makes this even worse is that since your wires are different length is means the noise is pretty wide-band(every frequency) and so it's not something that can be easily filtered.

[1] https://youtu.be/6IW3FVhHR58?t=91

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