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Hardware Hacking

Ask Slashdot: How Do You Build Your Own Vacuum Tubes? 271

Could you beat wireless headphones by creating your own DIY home audio system? Two weeks ago one Slashdot commenter argued, "to have good audio that is truly yours and something to be proud of, you need to make your own vacuum tube amplifier and then use it to power real electrostatic headphones over a wire." And now long-time Slashdot reader mallyn is stepping up to the challenge: I want to try to make my own vacuum tubes. Is there anyone here who has tried DIY vacuum tubes (or valves, to you Europeans)? I need help getting started -- how to put together the vacuum plumbing system; how to make a glass lathe; what metals to use for the elements (grid, plate, etc). If this is not the correct forum, can anyone please gently shove me into the correct direction? It needs to be online as my physical location (Bellingham, Washington) is too far away from the university labs where this type of work is likely to be done.
Slashdot's covered the "tubes vs. transistors" debate before, but has anyone actually tried to homebrew their own? Leave your best answers in the comments. How do you build your own vacuum tubes?

Comment Re:Ignorant fools (Score 1) 190

That's a nice, happy, clean cow out in pasture too in the article. The exact opposite of what people are actually eating. It's a muddy, grassless horror show out there, and I can't imagine how it would look with a thousand sickly cows wearing festering, manure-soaked backpacks permanently attached to their bodies.

It probably looks like this. Nature is violent and gross. Ever hear of cookie cutter sharks? They're basically vicious little living hole saws, and they chew gaping holes into the flesh of pretty much anything they can get their mouth on. Oh, and then there's the mantis shrimp, which literally smashes its prey to death. I'll close with some appropriate song lyrics from The Lorax:

Well there's a principle of nature (principle of nature)
That almost every creature knows.
Called survival of the fittest (survival of the fittest)
And check it this is how it goes.
The animal that wins gotta scratch and fight and claw and bite and punch.
And the animal that doesn't, well the animal that doesn't winds up someone else's lu-lu-lu-lu-lunch (munch, munch, munch, munch, munch)

Comment Ugh, the vegan preaching... (Score 2) 190

I'm blowing my chance at moderating this story, just so I can say this: There's not a damn thing you can say or scientific study you can point to that will make me stop eating meat. Even if it meant becoming a "second amendment person" (thanks, Trump) and hunting animals, I would. I could watch a PETA "Meat is Murder" propaganda video while chomping down on a burger and it wouldn't faze me in the least. Like religion and most republican policies, my decision to eat meat isn't based on reason or logic. It's based on a deep carnal desire to devour animal flesh, compounded with my belief that it's also delicious.

If you truly were satisfied with your lifestyle choice, you wouldn't feel the need to seek validation by attempting to convince others to come to the same conclusion.

Now if you'll excuse me, I have to go put a "I'm with Her" sticker on my economy car, and then order some meaty Tuscan pasta on my iPhone from Pizza Hut.

Comment Cricket (Score 1) 196

I've been using the same $35/mo plan with Cricket since back when they were AIO. Unlimited talk, unlimited text and 2.5GB high speed data (plus throttled-back-to-the-stone-age unlimited). T-Mobile has nothing that can touch it, coverage (Cricket uses AT&T's towers) or price-wise.

Also, it seems Cricket is also beating T-Mobile's unlimited pricing if all you want is a single line. They're offering unlimited data for $65/mo, with autopay. Yay for competition.


Florida Regulators OK Plan To Increase Toxins In Water (washingtontimes.com) 182

An anonymous reader quotes a report from Washington Times: Despite the objection of environmental groups, state environmental regulators voted Tuesday to approve new standards that will increase the amount of cancer-causing toxins allowed in Florida's rivers and streams under a plan the state says will protect more Floridians than current standards. The Environmental Regulation Commission voted 3-2 to approve a proposal that would increase the number of regulated chemicals from 54 to 92 allowed in rivers, streams and other sources of drinking water, news media outlets reported. The Miami Herald reports that under the proposal, acceptable levels of toxins will be increased for more than two dozen known carcinogens and decreased for 13 currently regulated chemicals. State officials back the plan because it places new rules on 39 other chemicals that are not currently regulated. The standards still must be reviewed by the U.S. Environmental Protection Agency, but the Scott administration came under withering criticism for pushing the proposal at this time. That's because there are two vacancies on the commission, including one for a commissioner who is supposed to represent the environmental community.

Qualcomm's New Snapdragon 821 Is 10 Percent Faster Than the 820 (theverge.com) 30

An anonymous reader shares a report on The Verge: Qualcomm has announced a new flagship mobile processor called the Snapdragon 821. The 821 is a slight update to the Snapdragon 820 that debuted in smartphones earlier this year and promises modest performance gains. The 820 has been found in virtually every high-end Android smartphone this year, including Samsung's Galaxy S7 and S7 Edge, the HTC 10, the LG G5, the OnePlus 3, and the Xiaomi Mi5. In our experience, we've found it to be quite a capable chip, with great performance and efficient power utilization. It's a far cry from last year's Snapdragon 810, which was plagued with performance and thermal issues. Qualcomm says the Snapdragon 821 builds upon the 820's features, but provides a 10 percent performance increase. Its quad-core CPU runs at 2.4GHz.AnandTech has more details.

Hacker Finds Bug to Edit or Delete Any Medium Post (vice.com) 39

Joseph Cox, reporting for Motherboard: Medium has become the go-to home for extended blog posts from researchers, CEOs, and even the President of the United States. Now, one hacker has found a way to edit or delete any post on the publishing platform. "I tried to think of different possibilities or testing cases on how can I delete a story of any user. And fortunately, I found a severe bug," Philippines-based freelance penetration test and bug bounty hunter Allan Jay Dumanhug told Motherboard in an email. The trick, Dumanhug explained in a blog post published at the end of last month, centres around Medium's "Publications" feature. Users can create their own publications -- perhaps a page dedicated to infosec news, for example -- and then request to add other users' posts to it. Each post on Medium is given its own unique, 12-character identifier code. The person who authored the post has to approve that request, otherwise their story doesn't go anywhere. But Dumanhug found that while adding his own story to his own publication, he could intercept the HTTP request and simply change the identifier to that of another post.

Researchers Criticize New DAO Ethereum VC Fund (softpedia.com) 39

Three cryptocurrency experts published a scientific paper Friday detailing seven attacks that could influence how the Decentralized Autonomous Organization (DAO) allocates its Ether funds. An anonymous Slashdot reader writes, "Coincidentally or not, they released their work with one day before funding for the DAO closed, and not surprisingly, Ether's price went down, devaluing the DAO from $150 million to $132 million."

From Softpedia: DAO is a crowdfunded project that works on the Ethereum network, a new crypto-currency network that deals with crypto-currency named Ether, which many experts say is better than Bitcoin's blockchain... Investors can submit funding proposals, on which the DAO users vote by submitting some of their tokens and a YES/NO vote. In the end, based on the tokens and YES/NO votes, the DAO's computer program decides on the outcome.
Softpedia reports that the paper released Friday also suggests a series of mitigations to a design they say will "incentivize investors to behave strategically; that is, at odds with truthful voting on their preferences."

Doubts Raised About Cellphone Cancer Study (vox.com) 100

Vox is strongly criticizing coverage of a supposed link between cellphones and cancer suggested by a new study, calling it "a breathtaking example of irresponsible science hype." An anonymous reader writes: A professor and research monitoring administrator at an American medical school reported that to get their results, the researchers "exposed pregnant rats to whole body CDMA- and GSM-modulated radiofrequency radiation, for 9 hours a day, 7 days a week," and the results were seen only with CDMA (but not GSM-modulated) radiofrequency. "[F]alse positives are very likely. The cancer difference was only seen in females, not males. The incidence of brain cancer in the exposed groups was well within the historical range. There's no clear dose response..."
An emeritus professor of applied statistics at the Open University in Britain also called the study "statistically underpowered..." according to Vox. "Not enough animals were used to allow the researchers to have a good chance of detecting a risk from radiofrequency radiation of the size one might plausibly expect."

Lab-Grown Meat Is In Your Future, and It May Be Healthier Than the Real Stuff (smh.com.au) 274

An anonymous reader shares an article on The Sydney Morning Herald:Scientists and businesses working full steam to produce lab-created meat claim it will be healthier than conventional meat and more environmentally friendly. But how much can they improve on old-school pork or beef? In August 2013, a team of Dutch scientists showed off their lab-grown burger (cost: $435,000) and even provided a taste test. Two months ago, the American company Memphis Meats fried the first-ever lab meatball (cost: $23,700 per pound). Those who have tasted these items say they barely differ from the real deal. The Dutch and the Americans claim that within a few years lab-produced meats will start appearing in supermarkets and restaurants. And these are not the only teams working on cultured meat (as they prefer to call it). Another company, Modern Meadow, promises that lab-grown "steak chips" -- something between a potato chip and beef jerky -- will hit the stores in the near future, too.

Samsung Galaxy S7's Moisture Warning Prevents Charging When Wet (hothardware.com) 74

MojoKid writes: The Samsung Galaxy S7 and S7 Edge don't officially launch for a few more days, but some carriers appear to have shipped pre-orders early and some phones are already in consumers' hands. One early Galaxy S7 Edge owner appears to have tested his phones' water-resistance already and uncovered another new feature in the process. The user submerged his Galaxy S7 Edge in water and snapped a photo, then about four hours later plugged the phone into its fast charger and a warning popped-up on screen that stated, "Moisture detected in charging port", and the phone wouldn't charge. The user dried the phone and let it sit for a while, and it eventually started to charge again, but it wouldn't quick charge any longer. Frustrated, the user RMA'd the phone and plans to send it back to T-Mobile. The Galaxy S7 is IP68 rated, which means it is sealed against dust and can handle continuous submersion in up to 1 meter of water. However, the water detection feature that's apparently built into the Galaxy S7 is a good idea. Though the devices are IP68 rated, a few drops of water in the charging port could easily cause a short when the phone is plugged in.

Comment Good luck with all those pogo pins (Score 1) 139

If you actually use this phone in the real world, it will be glitching like an old school Nintendo game when dust, dirt and corrosion get between the contacts of all the "modular" components.

Honestly, every time I've ever purchased a newer mobile device, the old one seemed to have become equally deficient across all its specs - RAM, flash storage, screen size/quality, and camera resolution/quality. I've never once thought "Gee, it's awesome to be rocking Ice Cream Sandwich, a 480x800 3.7" display, 512MB RAM, a 1GHz single core CPU, and 8GB of flash, but man - this 8MP camera sure is killin' me!"

Sure, repairability is a nice feature, but it's not difficult to replace the display assembly on a modern iPhone (I've done it myself, and it takes less than 5 minutes if you've got the proper tools). You're likely looking at an entire replacement phone anyway if you've killed the motherboard (example: water damage), or smashed the housing up too badly (fell in a blender, 50' drop, etc.)

Spec wise, this seems similar to the unlocked Blu phones Best Buy sells. If you're not making a "flagship killer", you're caught in a very competitive race to the bottom. I get that this is supposed to be better for the Earth or conflict regions where rare earths are mined, but there's got to be a way to ease your conscience without such pathetic hardware specs.

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The test of intelligent tinkering is to save all the parts. -- Aldo Leopold