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

A Beginner's Two-Component Crystal-Style Wi-Fi Detector

siliconjunction.wordpress.com

Post reply on HN
Print view View original

31–40 of 45 posts

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#31

Post by b00ty4breakfast »

zoklet-enjoyer wrote: post #29
wowczarek wrote: post #21

Remember those little LED keychains for your "mobile phone" that would magically light up when taking/making calls and sending/receiving texts?

I don't remember that, but I do remember my speakers buzzing just before a call or text came through.

they still do that, but I think that this is RFI from the processor rather than a deliberate rf transmission

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#33

Post by zoklet-enjoyer »

b00ty4breakfast wrote: post #31
zoklet-enjoyer wrote: post #29

Earlier quoted context omitted.

I don't remember that, but I do remember my speakers buzzing just before a call or text came through.

they still do that, but I think that this is RFI from the processor rather than a deliberate rf transmission

I haven't heard it in years, since around the time of the song your username references

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#34

Post by cluckindan »

didntknowyou wrote: post #18

curious, so if you build a "wall" of these, it would use up the wiress energy in the air so will absorb the excess waves around you?

An array of these would also allow you to better discover individual sources in a room with lots of devices.

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#36

Post by jeffbee »

jqpabc123 wrote: post #2

Can this be used to detect radiation escaping a microwave oven? A friend of mine has a microwave that noticeably degrades his wifi when it is in use.

Microwaves degrade everyone's 2.4 GHz ISM band radios. Wi-Fi occupies the ISM band because it's a garbage band that was already wrecked by this type of equipment. There isn't a solution to this; the safe leakage from a microwave oven is millions of times more powerful than wifi field strength. 5 or 6GHz band avoids the problem.

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#37

Post by jeffbee »

zxexz wrote: post #3
jqpabc123 wrote: post #2

Can this be used to detect radiation escaping a microwave oven? A friend of mine has a microwave that noticeably degrades his wifi when it is in use.

Sounds like he’s in need of a new microwave. Not tongue-in-cheek; sounds like there’s something up with the shielding, and if it’s not visible, how will you know if it gets worse? Edit: I see no reason this wouldn’t work, however?

There is not substantial variance from one microwave to the next. They are all made by one outfit, then dressed up in different superficial brands and priced randomly. The emissions of a microwave oven are regulated by the FDA, not the FCC.

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#38

Post by pwg »

jqpabc123 wrote: post #2

Can this be used to detect radiation escaping a microwave oven? A friend of mine has a microwave that noticeably degrades his wifi when it is in use.

From the fine article, second paragraph:

"you can build a tiny “crystal detector” that responds to 2.4 GHz Wi-Fi, Bluetooth, and even microwave oven leakage"

Re: A Beginner's Two-Component Crystal-Style Wi-Fi Detector

#39

Post by georgefrowny »

jeffbee wrote: post #36
jqpabc123 wrote: post #2

Can this be used to detect radiation escaping a microwave oven? A friend of mine has a microwave that noticeably degrades his wifi when it is in use.

Microwaves degrade everyone's 2.4 GHz ISM band radios. Wi-Fi occupies the ISM band because it's a garbage band that was already wrecked by this type of equipment. There isn't a solution to this; the safe leakage from a microwave oven is millions of times more powerful than wifi field strength. 5 or 6GHz band avoids the problem.

There is a solution. Spread-spectrum methods for digging out signals from deep in the noise floor. It's just maths, but the amount of noise you can reject that way is really nuts.
Post reply on HN