Dan's Data letters #134
Publication date: 1-Dec-2004.Last modified 03-Dec-2011.
Godzillaptop
I am in the market for a new laptop. Having perhaps more dollars than sense, I keep enviously eyeing some of the impressive systems put together by people like Alienware and IBuyPower (Extreme Editions of the P4 3.2/3.4GHZ chips in a laptop? SATA?! RAID 0?!?!)
I normally give thanks for living in Australia rather than in the US, but the Yanks crap all over us for high spec laptops.
Is there anyone in Australia offering anything like these crazy systems? I can't consider a system without local support as the opportunity cost to my business of having to freight it overseas for a service is too high.
Joe
Answer:
Not many of the big names in portable computers actually make their own hardware, so you won't be surprised
to learn that smaller outfits like these are also actually in the business of rebadging products from OEM manufacturers.
This isn't to say that they're rip-off artists, mind you; they may specify some higher grade components for their rebranded machines than the OEM manufacturer usually includes, and then there's warranty support and software and so on. But it's usually possible to buy pretty much the exact same thing for less, if you're willing to forego the cosmetic extras.
See, for instance, the Alienware Area-51m 7700, a monster 17 inch gaming laptop with all the loony options you mention.
It is, unless I'm very much mistaken, a Sager NP 9860 with a decorated lid.
The Alienware-to-Sager price difference for top-spec units isn't huge, but people who buy the Sager version can pay about the same and get Bluetooth and a TV tuner built in, which Alienware don't offer. Fiddle about with the specs and you can usually find a way to save a reasonable amount.
The problem, as you say, is finding the darn things in Australia. Fortunately it's not actually that hard, once you resign yourself to the fact that nobody ever seems to sell the big "white box" laptop brands under those same brands here.
For instance, here the little Sager/Alienware melonpicker is again, now branded "ITC".
Note that I'm not recommending that reseller in particular; I've no idea whether they're any good or not.
Regarding P4EE processors in laptops; yes, if you're troubled by an uncomfortably fat wallet, those are indeed a great way to reduce the pain. Given the trivial performance advantage of the top-spec P4s, even rabid enthusiasts can usually find it in their hearts to make do with a non-EE version, and maybe even a humble 3GHz.
These are all, of course, desktop chips, which means these laptops run hot and usually have miserable battery life (giant 17-inch screens don't help). Don't expect a whole lot more than an hour of untethered run time, and that's from a new battery.
(Changing the battery in some of these machines, by the way, requires the use of a screwdriver. They really don't expect you to be using the battery as anything but a UPS for emergencies.)
"Desktop replacement" super-laptops have always been this way, though; they're just much cheaper today than they used to be. Top-end laptops used to be a $AU10,000 proposition; now machines with far better specs are $AU4000 or so - or five grand, once you stack on all of the options. All of these laptops have crap battery life, but personally, I think that's a very good tradeoff, for the large contingent of laptop users who don't actually do very much untethered computing.
A few manufacturers have even toyed with making desktop replacement machines that don't have an internal battery at all - it's an external plug-in option. I don't think anybody's ever made one of those things that worked really well, though.
If there's a point to using SATA in laptops at the moment, though, I cannot see it. The abovementioned Sager/Alienware/whatever machine has PATA as well, and PATA laptop drives are much cheaper. Maybe I'm missing something.
The RAID option could be useful for some people too, but the dual drive bays with a couple of un-RAIDed drives in them are more useful; the ability to cram 160Gb (about 150Gb formatted) of disk space into a portable computer with no external storage could be very handy indeed, for all your portable-entertainment-centre needs.
Of course, if a laptop's just going to be sitting beside your hotel bed playing movies, it's not a huge extra imposition to buy a cheap 200Gb desktop drive and put it in an external USB enclosure. But that won't impress your mates as much.
The Plugpack That Stole Christmas
We've got a Christmas tree that we bought on clearance right after Christmas last year. Unfortunately in the intervening year, the power transformer no longer functions. I live in the States and it's a simple step down transformer to drop it from 120V to 12V AC. There is a VERY simple rectifier circuit in the base (one diode, one cap). I've used a multimeter to confirm that there appears to be NO voltage coming out the secondary side of the transformer. So unless you know a way to fix it, I'm in the market for a good power transformer. Something like this. Only problem is, that's out of stock.
The current draw is 4700mA, so it's a pretty hefty piece. If I don't find something soon, I'm gonna be in trouble with the SO. She wants this tree working.
Grey
Answer:
High power 12-volt-AC power supplies are surprisingly easy to find. They're used to power low voltage garden lights, halogen downlights and so on.
A transformer with a 60-watt rating will probably handle this load perfectly well. A 100W-rated one will do it easily. Neither should cost you a whole lot, though they probably won't come pre-wired; you'll have to screw on a two-wire mains cable and the output wires yourself. Mummify the thing in vinyl tape afterwards (or use pretty heat-shrink or paint-on insulation, but tape is traditional, dammit) and you're done.
Downlight transformers should have thermal protection, overload protection, isolated output, the works; this makes them a much safer proposition than a plain E-core lump. Mind you, there are some cheap downlight transformers that don't offer any of these features, which makes them illegal in many of the countries in which they're sold.
Given what you say about the simplicity of the circuit - which is to be expected for mere holiday-light products - the tree will probably also be perfectly happy with 12VDC, provided you get the polarity right. Many simple devices with AC power adapters will run from DC; they only come with an AC wall wart because that kind is cheaper.
High-current 12VDC power supplies are quite easy to find; they're sold so people can run things like automotive CB radios in their homes. Heck, your tree lights would probably run from a dirt cheap car battery charger. But I'd go for a halogen downlight transformer, myself.
Lining up
I have two spirit levels, each with a built-in laser. One of them has a sliding lens which switches it from a dot to a line, the other does not. The line lens is pretty impressive, giving a reasonably bright and solid line that can be seen on two faces of a wall (around corners, in marketing-speak). I assume it's turning the laser beam into a flat fan shape.
My question is, how exactly is it doing this, and where can I find another or these lenses to add to my other spirit level?
Mat
Answer:
The thing you're looking for is called a "line optic" or "line lens", but I don't think you're likely to find one
that you can just stick on your old level and get decent results.
On the plus side, you can just shine a regular collimated laser beam into a line lens and get a line out of it; this isn't some special optic that has to replace the collimation lens on the end of the laser. On the minus side, though, alignment is important here, and you may find it impossible to line up an add-on lens well enough even for ordinary small-scale carpentry.
For this reason, add-on line lenses for small lasers don't really exist. They exist for systems that're made to take them already, like this speaker alignment system, but standalone line lenses are usually chunky expensive things made for use on optics benches.
You might be able to jury-rig a setup that works by affixing a small line optic to the existing level, but I think your time could be spent better elsewhere.
A.K.A. "high-spec audiophile mastic"
I recent got a pair of speakers and some Atacama Nexus stands.
The stands have a flat top and the speakers have a flat bottom.
What is the best way to attach the speakers so they won't fall off?
Lucian
Answer:
Blu-Tack.
Not big blobs of the stuff; just a few thin discs should keep the speakers in place, and also decouple them a bit from the stands. People who live in countries were Blu-Tack is only sold in hi-fi stores (instead of every supermarket...) may substitute whatever sticky putty stuff people use locally to attach posters to walls.
There's disagreement in hi-fi nutcase circles about whether it's best to decouple speakers from the listening room as much as possible, or couple them tightly to the floor. It's not generally great to give speakers a strong mechanical connection to the floor - by, for instance, screwing them to their stands and then screwing the stands to the floor - because vibrations transferred to the floor that way will turn it into a resonator that probably won't do much for your stereo illusion, unless the floor's concrete or something.
The problem with decoupling the speakers, in contrast, is that if they're not firmly connected to a big solid object then Newtonian physics will cause the speaker cabinets to move backwards when the bass driver cones move forwards, and vice versa, thereby blurring the output of the smaller drivers, slightly reducing cone excursion, and so on.
In the real world, the lightness of woofer cones and the heaviness of all half-decent speaker cabinets mean that the effects of even drastically decoupling your speakers - hanging them by wires from the ceiling, for instance - are very probably going to be undetectable in a blinded test.
Blu-Tack provides a happy medium between the two approaches, anyway; it's like stickier Silly Putty, and resists sudden movements much more than slow ones, so it partially couples the speakers to the stands, preventing them from falling off or buzzing while also absorbing some of the vibration that'd otherwise pass to the stands.
Gun smuggling redux
With all the gear you get from Backyard Artillery, have you imported any proper pukka BB guns and/or Airsoft guns into Australia? If so, how'd they go when they went through Customs?
I'd only be looking at buying one (plus a bag of pellets but I might order that separately).
Jamie
Answer:
No, I haven't. And if I had, I wouldn't tell you.
BB guns and pellet guns are legal in Australia if you've got a license; Airsoft guns are, de facto, not. If Customs open your package and find something obviously illegal - as a BB gun will be in Australia, if you don't have the right paperwork, which I take it you don't - then they will not necessarily stop at confiscating it. You may be looking at a day in court, possibly followed by a large fine.
If they don't see it, of course, then they won't bust you. But if the contents label on the package is honest, they're likely to notice.
The level of prohibition of Airsoft guns in Australia is mildly ridiculous, given how safe they are. Even if you get shot right in the eye at quite close range with a stock Airsoft gun, you'll probably be OK - in the long run. Over the subsequent few days you won't be happy, and you may manage to suffer permanent damage, especially if you're shot with a high-powered Airsoft gun. But, y'know, the same applies to people who've been poked in the eye with a finger. It's only because most Airsoft guns look so real that Australian police actually care about them at all.
Proper BB guns can easily deliver ten times the muzzle energy of an Airsoft gun. You're usually talking only about half a joule for an Airsoft gun, but five-joule BB guns are common, and there are plenty of spring guns that manage 10 to 15 joules. That's more than enough to pop an eyeball or cause some other thoroughly hospital-worthy injury; in rather unlikely cases, 10 joules spread over the small impact patch of a .177-calibre air-rifle pellet can even kill someone.
So there's more sense behind the Australian laws about air guns. Un-macho though they sound, they really are dangerous weapons. Though they're still, of course, not in the same class as any firearm.
The generally-regarded-as-almost-harmless .25 ACP pocket-pistol cartridge, for comparison, has about 87 joules of muzzle energy. That can be matched by some very high-end modern air rifles, and considerably exceeded by the huge hunting and battlefield air guns of the flintlock era. But nothing in the consumer air-gun marketplace comes close to even this tiny firearm cartridge.
The humble .22 Long cartridge manages at least ninety joules. .22 Long Rifle, the most popular cartridge in the world, approaches 200 joules.
I talk about the purely theoretical importation of non-realistic Airsoft guns here.
Still waiting for Learjet4Free.com
Please tell me Driving 4 Dollars is for real!
I was hyped until the ever-popular "stock images" squeezed through my poor dial-up connection, then I had an epiphany. DAN WOULD KNOW!
Rigs
Answer:
"Free car" schemes are, if not outright scams, a very poor bet. One of my favourite sites
talked about them a while ago.
Not every "cool thing for free" scheme is a swindle, but the more valuable the thing and the less you have to do to get it, the less likely it is to be on the level.
Sorry.
These, you could import
I'm trying to locate a toy I had in the 1950's. It was a pistol which had a roll of paper as ammunition - not caps - no gunpowder. When you fired it, it broke the paper and made a fairly loud noise. Great!
Have any info?
Paul
Answer:
You're thinking of a "Paper Popper" or "Paper Buster"; the most popular ones were sold under the Nu-Matic brand, but
other companies made them as well (Daisy, for instance).
See some examples here, here, here and here. They were also available as cannons!
Ugly but working examples can often be had cheaply, though original ammo may be ridiculously expensive. It wouldn't exactly be rocket surgery to make your own ammo rolls, of course.
