Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

QuadRF can spot drones and see WiFi through my wall

jeffgeerling.com

Post reply on HN
Print view View original

41–50 of 249 posts

Re: QuadRF can spot drones and see WiFi through my wall

#41

Post by mikeweiss »

mlfreeman wrote: post #34

The visualizer reminds me of my thermal camera. I have heard claims of devices (mostly TVs) supposedly coming with secret 5G cell uplinks built in [never heard a specific model mentioned though]. If there were more variants covering more commonly-used RF bands, people could walk around and literally check for once. (incidentally i'm sure three letter agencies have had this sort of tech in their bug-detecting toolkit…

Whos paying the telcos for those 5G connections and also has the FCC been degraded so much that they would allow for undeclared radios in consumer products?

Re: QuadRF can spot drones and see WiFi through my wall

#42

Post by throwaway85825 »

mikeweiss wrote: post #41
mlfreeman wrote: post #34

The visualizer reminds me of my thermal camera. I have heard claims of devices (mostly TVs) supposedly coming with secret 5G cell uplinks built in [never heard a specific model mentioned though]. If there were more variants covering more commonly-used RF bands, people could walk around and literally check for once. (incidentally i'm sure three letter agencies have had this sort of tech in their bug-detecting toolkit…

Whos paying the telcos for those 5G connections and also has the FCC been degraded so much that they would allow for undeclared radios in consumer products?

Secret 5G is not as common because there is a huge incentive to resell the free service. Maybe with eSIM it will be harder. Kindles uses to have a free data plan SIM.

Re: QuadRF can spot drones and see WiFi through my wall

#43

Post by Onawa »

ac29 wrote: post #38
random3 wrote: post #27

Earlier quoted context omitted.

Please elaborate. There are literary step-by-step videos on how to build these. E.g. https://www.youtube.com/watch?v=g3LT_b6K0Mc

Phased array radars are export controlled in the US. It doesnt mean its illegal to build or own, but it might be illegal to sell in some cases

I thought I remembered even seeing public Git repos with passive radar code that ended up getting shut down due to export controls?

Re: QuadRF can spot drones and see WiFi through my wall

#44

Post by lambda »

peteforde wrote: post #36
raziel2701 wrote: post #29

Earlier quoted context omitted.

I don't see any professionals turning to this for EMC/EMI testing, they already have all the test equipment for that job.

That's absolutely missing the point. EMC/EMI testing is expensive, time consuming and requires scheduling and experiment design. Being able to do local soft-run testing on-site to be sure that you eliminate the easy 90% of issues before you get to the lab would be a huge win.

I think that for a single device, this probably wouldn't help much over just having a more traditional signal analyzer, either benchtop or handheld. If you know what you're testing, just using a signal analyzer around it will give you a good first pass picture of emissions, and probably be much more informative and precise than this.

This seems more useful for finding unknown or hidden RF sources, for instance looking thorugh an entire building to find unknown RF sources, or maybe a whole complex assembly like a car or aircraft.

Re: QuadRF can spot drones and see WiFi through my wall

#45

Post by FuriouslyAdrift »

mikeweiss wrote: post #41
mlfreeman wrote: post #34

The visualizer reminds me of my thermal camera. I have heard claims of devices (mostly TVs) supposedly coming with secret 5G cell uplinks built in [never heard a specific model mentioned though]. If there were more variants covering more commonly-used RF bands, people could walk around and literally check for once. (incidentally i'm sure three letter agencies have had this sort of tech in their bug-detecting toolkit…

Whos paying the telcos for those 5G connections and also has the FCC been degraded so much that they would allow for undeclared radios in consumer products?

More likely 4G LTE MTM (https://www.verizon.com/business/products/internet-of-things...). It's dirt cheap and paid for by the vendor of the device it is in (usually) in the name of 'telemetry'.

I've seen so many random industrial devices and parts come into our plant that have their own cellular it's wild.

Re: QuadRF can spot drones and see WiFi through my wall

#46

Post by lambda »

varispeed wrote: post #39
raziel2701 wrote: post #29

Earlier quoted context omitted.

I don't see any professionals turning to this for EMC/EMI testing, they already have all the test equipment for that job.

How about "non-professionals"? It could be useful to check device before sending for pre-compliance / compliance checks and save money - that would avoid very expensive iterations.

But there are already benchtop or handheld signal analyzer for that purpose.

This seems more like a tool for checking across entire large assemblies like an entire building, car, aircraft, etc, for unknown sources. If you have an individual discrete device that you're already testing, just using traditional instrumentation seems reasonable, but on a large, complex assembly, I can see it being useful. Also useful for things like detecting if a particular antenna is working without actually going up there to measure near it; if you have a MIMO setup with multiple antennas, this might make it easier to check if all of them are working correctly when mounted in inconvenient areas.

Re: QuadRF can spot drones and see WiFi through my wall

#47

Post by lambda »

Onawa wrote: post #43
ac29 wrote: post #38

Earlier quoted context omitted.

Phased array radars are export controlled in the US. It doesnt mean its illegal to build or own, but it might be illegal to sell in some cases

I thought I remembered even seeing public Git repos with passive radar code that ended up getting shut down due to export controls?

Yeah, Kraken SDR removed some functionality due to these concerns, if I remember correctly.

Odd, because export controls don't generally apply to published material (like open source software), but maybe they were worried that because they were also selling the hardware they could have issues due to the combo being export controlled.

Ah, found discussion of what exactly it was they pulled, it was the passive radar code: https://www.reddit.com/r/RTLSDR/comments/yu9rei/krakenrf_pul...

And indeed, they confirmed that they believe the open source software should be OK, but they had concerns because they also sell the compatible hardware: https://nitter.net/rtlsdrblog/status/1591657740229046274

Re: QuadRF can spot drones and see WiFi through my wall

#48

Post by piinbinary »

One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from.

This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)

Re: QuadRF can spot drones and see WiFi through my wall

#50

Post by flutas »

piinbinary wrote: post #48

One day I want to build something like this, except for sound. It would be great to get a heading and distance for where a sound is coming from. This could be both for small scale things (e.g. which part of this is squeaking?) or large scale (e.g. is that booming noise coming from the construction a few blocks away?)

Not sure if you've heard of them, but they're starting to come to market with this exact thing aside from distance detection and more on the "which part is squeaking" side.

https://www.youtube.com/watch?v=l8-5lSVCR2w

Post reply on HN