News for hackers. Stuff that matters.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by immad on Thursday February 15, 2018 @08:33PM (#16389266)
Instead of shutting it down couldn't he put the miner in a faraday cage?
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by TuringNYC on Thursday February 15, 2018 @09:24PM (#16389431)
That would seriously crimp the profit margins, and probably make heat dissipation more difficult.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by flashman on Thursday February 15, 2018 @09:45PM (#16389498)
The notice[1] says it was operating in the 700 MHz band. The wavelength for this band is 42.9cm. A few sources I found (StackExchange, Anandtech) say a Faraday cage is effective with a mesh 1/20th the wavelength.

Surrounding the device with metal containing 2.1cm (0.85in) holes would probably work and only require minor modifications to support heat dissipation.

Side note, now everyone knows Victor Rosario in Brooklyn probably has a bunch of cryptocurrency...

[1] https://transition.fcc.gov/Daily_Releases/Daily_Business/201...

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by krallja on Thursday February 15, 2018 @10:07PM (#16389556)
> Victor Rosario in Brooklyn probably has a bunch of cryptocurrency...

At 1155 GH/s, he has probably mined upwards of several dozen dollars worth of cryptocurrency this month. And an extra hundred dollars on his power bill, assuming it’s not included in his rent.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by kerkeslager on Thursday February 15, 2018 @11:38PM (#16389910)
Brooklyn apartments this time of year are often poorly heated. If you're paying for the electricity to run a space heater, it might as well produce bitcoins.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by quickthrower2 on Friday February 16, 2018 @12:20AM (#16390061)
Heat pumps are more efficient. A miner makes an inefficient heater.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by Klathmon on Friday February 16, 2018 @12:30AM (#16390115)
And heat pumps are more expensive to buy and impossible for a tenant to install themselves in an apartment they rent from, which is why people use small portable and cheap resistive heaters.

And in that case, a miner is just as efficent if not more efficient since it's making the user some money (maybe).

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by quickthrower2 on Sunday February 18, 2018 @05:47PM (#16409289)
First thing I found on Amazon US

https://www.amazon.com/Honeywell-MM14CHCS-Portable-Condition...

Portable heat pump + air con. I've had something like this before, typically comes with something to slot/seal up into a gap from leaving the window open. Can be moved between rentals.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by kerkeslager on Monday February 19, 2018 @12:26AM (#16410945)
Efficient in what units? Heat pumps are more efficient in BTUs/kWh, but I doubt you've done the pricing to say they're more efficient in BTUs/dollar, because that's fairly complicated.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by quickthrower2 on Monday February 19, 2018 @12:33AM (#16410973)
Sure, lets say $500 for a heat pump, $50 for a heater. Then what 'yield' are you getting on the $450. Let's say heat pump is 2x as efficient (should be understimate). Let's say that you run 2kw normal heater for 1 hr / day winter only for 3 months. That's 180kwh. @12c that's $21.6. So you save $10 a year. A 2.2% yield tax fee. So admittedly not great.

OTOH a mining rig, well who knows that IS complicated. You might lose money, or spend a lot of time tweaking but break even.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by TD-Linux on Thursday February 15, 2018 @11:56PM (#16389980)
Strangely, the Antminer comes in a metal case with holes smaller than that. Maybe it wasn't grounded or something? Or it was radiated through the external power supply wires?

EDIT: mixed them up, Spoondoolies ones had a nice mesh but the Antminer ones don't behind the fans. That 1" of plastic must be enough to let a significant amount through (or the power supply wires still)

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by MithrilTuxedo on Thursday February 15, 2018 @10:15PM (#16389585)
Profit margins?

You dissipate the heat into the faraday cage. There's been a patent for this: https://patents.google.com/patent/US5901040

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by s0rce on Thursday February 15, 2018 @09:37PM (#16389470)
A metal mesh shouldn't compromise heat dissipation or forced air cooling.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by taneq on Thursday February 15, 2018 @10:01PM (#16389545)
You could literally just wrap it in chicken wire...
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by jeremyt on Thursday February 15, 2018 @09:12PM (#16389387)
Cages only block external em, they don't block internal em from getting out.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by NateyJay on Thursday February 15, 2018 @09:15PM (#16389398)
Yes they do. A Faraday cage is equally good at blocking radio waves going out as coming in. They don't protect against conducted emissions though - along a power cable for example - so they're not a complete solution.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by sterlind on Friday February 16, 2018 @03:46AM (#16390870)
Perhaps the radiation wasn't mostly coming from the Antminer box itself - each 700Mhz clock the rig draws current, the transformer propagates it back to the wall, and the power lines in the flat become a big antenna.

Powerline Ethernet has this problem, but it uses only a 25MHz carrier wave, so it only bothers hams.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by tgb on Thursday February 15, 2018 @11:21PM (#16389840)
While people are pointing out your mistake, it's worth bringing up the fact you were certainly thinking of: when it comes to static electric fields, a Faraday cage complete protects the interior from external charges but does nothing to shield the interior from the external charges. However, we are considering non-static electric fields and in particular ones at high frequencies.

However, I think the fact that the Faraday cage is not symmetric when it comes to static electric fields is very interesting. Ask yourself this: how does the cage know what "inside" versus "outside" means? You know the old joke where a mathematician has to enclose the greatest area with a given fence and so she takes the fence and wraps it around herself and declares "I am outside the fence." Well, why can't I declare myself to be inside the Faraday cage and suddenly get the benefits of its shielding?

You might say that the difference is that the outside has the "boundary" of the universe and that makes it distinct from the inside. [1] But we don't yet know that the universe isn't finite and wrapped up on itself spatially, so if that were the difference, then isn't a Faraday cage experimental evidence in favor of the universe not being finite? I think therein lies the answer: if we wanted to actually use this as an experiment, we would have to place a charge outside of the Faraday cage and wait for sufficiently long time that the electric field is effectively static. However, for our experiment to work, we would have to wait so long that the electric field becomes static on the scale of the entire universe. And so no, the Faraday cage is not an experiment we can practically perform to measure the shape of the universe and the difference is the obvious one: the exterior is the larger one and is simply just "big enough" that we can't ever wait for the EM fields to settle down in the exterior like we can on the interior.

[1] Mathematically, this come in as the fact that the Poincare lemma https://en.wikipedia.org/wiki/Closed_and_exact_differential_... requires a "contractible" domain. The exterior of the cage is not contractible, so we are not guaranteed to be able to use the integral forms of Maxwell's equations over the exterior of the cage. However, the interior is contractible.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by ofcourseianal on Friday February 16, 2018 @02:14AM (#16390533)
“Faraday cage complete protects the interior from external charges but does nothing to shield the interior from the external charges”

What are you on about?

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by tgb on Friday February 16, 2018 @08:21AM (#16392113)
Basic electrostatics.

>So for all intents and purposes, the cage generates the same DC electric field that it would generate if it were simply affected by the charge placed inside.

https://en.m.wikipedia.org/wiki/Faraday_cage

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by tzs on Friday February 16, 2018 @03:20PM (#16395732)
I think what he means when he asked what you are on about is what is the difference between "protects" and "shields"?

You said:

> Faraday cage complete protects the interior from external charges but does nothing to shield the interior from the external charges

So you are saying that the interior IS protected from but IS NOT shielded from the exterior charges. Most people would expect "protected from" and "shielded from" to mean the same thing. Hence the confusion.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by tgb on Tuesday February 20, 2018 @10:23AM (#16420977)
Yeah I think I swapped "exterior" with "interior" there oops!!
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by ofcourseianal on Thursday February 15, 2018 @09:16PM (#16389399)
https://en.m.wikipedia.org/wiki/Faraday_cage

“Faraday cages are also used to enclose devices that produce RFI, such as radio transmitters, to prevent their radio waves from interfering with other nearby equipment.”

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by bdonlan on Thursday February 15, 2018 @09:17PM (#16389405)
Sure they do, that's how microwaves avoid heating people standing nearby. However, getting the power in without letting the RFI escape the power connections is the tricky bit.
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by AstralStorm on Friday February 16, 2018 @03:54AM (#16390909)
Not too tricky, the right transformer or ferrite coil with active PFC is good enough. Of course that would increase the bill.

The fault is on FCC side for approving borderline power supplies.

Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by hatsunearu on Thursday February 15, 2018 @09:42PM (#16389485)
A lot of EM phenomena is symmetric, and this one's not an exception
Re:Brooklyn Bitcoin Mine Causes Static for T-Mobile Users by jsjohnst on Thursday February 15, 2018 @11:19PM (#16389833)
So explain how you can stand next to your microwave then? Did you think the size of the holes in the metal mesh of the window was consistent across all microwaves by coincidence?