Dan's Data letters #21
Publication date: 14-Jan-2003.Last modified 03-Dec-2011.
Tank power
I'm a Swedish Tamiyaholic and I really appreciate your excellent reviews about the tanks.
I just surfed in today and found the Pershing review, I´ve seen the other stuff before `bout the Sherman and the smaller ones.
I've got a few questions about the Tamiya tanks.
Why does the Tiger I use 2 Ni-Cd packs and the other tanks in the series only use one? Can I put in two packs in the Pershing or either King Tiger?
Whats the reason for the difference? Different MF-modules or T-modules?
I'm planning to get one of these things as soon as possible, I've been wanting one since I was about ten years old. But I want to buy the right tank.
Which is better in your opinion - the Tiger I, the new King Tiger or the Pershing?
Can I put a more powerful battery in one of these? For example a small gel-cell battery?
Fredrik
Answer:
Why two batteries in the Tiger I and not in the others? Probably because
they had room for two in the Tiger. I don't think the light-and-sound
Tiger model's electronics draw any more power than the other tanks', so
it's not necessary that it have two batteries; it could have one
and a Y-adapter to power its two electronics modules, like the others. But
it doesn't hurt to get more run time. And it lets Tamiya sell more
batteries, I guess.
I doubt you'd be able to fit two packs into any of the other tanks. I don't think you can make enough room for them. Certainly not in the Pershing. The _non_-light-and-sound tanks - the ones with a drive system, but no turret movement or gun noises - have a lot more room inside them.
Which one's better? Depends which tank turns your crank the most. Electronically and mechanically they're all pretty even, I think. None have steel tracks; they're all steel-pinned, with plastic treads.
Any 7.2 volt battery should be fine to run these tanks, but I don't think a six volt lead acid battery would cut it, and you're unlikely to have enough space in the chassis to install a much higher capacity battery than a standard stick pack. You'll get good run time from a 3Ah NiMH stick pack, though, and that'll fit fine.
sdrawkcaB
Can you briefly explain as to why stereo audio is reversed (as in, the left channel is coming from the right speaker) when I use my headphones that're plugged into the audio out of my speakers? The same thing also happens when I use the front audio port of my newly bought case - that is, of course, connected to the sound card. What's the easiest way around it, as at the moment I am just wearing my headphones backwards, which is a bit awkward as I have those Sony Street Style ones.
Michael
Answer:
Assuming your sound card driver software doesn't have a "reverse stereo"
button, something would appear to be wired backwards.
If everything was backwards all the time, then I'd suspect a software problem, but if headphones are backwards compared with speakers (and if you haven't just put your speakers on the wrong sides of the monitor...), then something's probably physically crossed over inside the speakers. This is not exactly unheard-of. The backwards-ness of the front audio ports plugged directly into the sound card output, though, suggests either that the front port is also wired backwards - which would be an odd coincidence, but not an incredible one - or that you've plugged the front port in backwards. If the front port connects via a loopback cable to the sound card's back-panel 1/8th-inch sockets then you can't plug it in backwards, but if it uses a symmetrical four-pin plug that can be plugged into a motherboard or sound card header either way around, then reversing the plug should solve the problem.
So this might be a PEBCAK sort of problem. But let's assume that some wires genuinely are crossed over.
You can deal with problems like this by resoldering stuff inside the speakers, but you can also just make a left/right-switching adapter for the headphones and/or front port. Assuming you don't want to solder one up, you can do it with two 1/8th-inch-plug to twin-RCA-plug adapters, two RCA cable joiners (female sockets at both ends), and one 1/8th-inch cable joiner (female socket at both ends). Plug one adapter cable into the speaker output, attach an RCA joiner to each of its plugs, plug the RCA plugs of the other adapter cable into the joiners (with right going to left and left going to right; this is what swaps the sides), then attach the 1/8th inch joiner to the 1/8th inch plug on the end of the second adapter cable. Plug the headphones into the joiner.
All this isn't terribly elegant, but it's not too hideous or stunningly expensive, and it'll give you a few more metres of headphone cable, in case you need it.
Vanishing D60?
Very much enjoyed your EOS-D60 review. So much in fact I went to buy one from Dirt Cheap Cameras, who tell me that Canon have discontinued the model. Feeling rather saddened by their information I held on the phone for just under 30 minutes for Canon support. They, after some hold-music time, advised they were not taking any further orders. No more info available.
Do you have information? Dirt Cheap Cameras said a D80 or D90 is on the way? Or is it just Australia that's in short supply of the D60?
Did you consider buying a D60 from the US?
Antony
Answer:
As I write this, Canon worldwide have not discontinued the D60. But
Canon Australia (and Canon Canada, apparently) are, as you say, apparently
not bringing any more in. Which amounts to the same thing if you want to
buy one locally. There's been some
independent
confirmation of this now.
Canon sold all of the D60s they could get into Australia, early on (I had to wait a while to get mine), but that was because they weren't actually bringing many in. There aren't that many people here who want to drop thousands of bucks on a digicam.
Now, although there hasn't been any official announcement yet, there does seem to be an EOS-D120 (or 80, or 90, or something) on the way, which'll occupy the D60's place in the Canon lineup.
[Update: They announced it on the 27th of February, 2003; it's the EOS-10D. A bit better than the D60, and significantly cheaper.]
If Canon Australia are still displaying the same level of caution, they would appear to be willing to throw away some late sales in return for knowing they won't be stuck with unsellable stock of an old model when the 80/90/120/whatever turns up. Hence, no more imports.
At the moment, of course, the only Canon alternative to the EOS-D60 is the EOS-1DS, which is in all respects a better camera, but which has an Australian list price of $AU16499 (list price in the States is $US7999). I don't know about you, but I can think of something better to do with that extra eleven thousand Aussie dollars over the D60's price.
Buying a D60 from the USA is not a terrible idea. It's only a nightmare if you want warranty support, or if you want to use TV output and get an NTSC camera that won't work with PAL TVs (I've never used any digicam's TV output to do anything more than verify that it worked, and teh D60 has switchable PAL/NTSC output anyway). You may save a bit of money by buying from the States, especially if Australian Customs fails to notice your package and so you don't get slugged for 10% GST. And there are plenty of reputable dealers to choose from in the States (Hint: If the price is way below Dirt Cheap Cameras', who really do have good pricing and who are well ahead of every other Aussie dealer I've found, then you are not looking at a reputable dealer, and you are probably going to get screwed. This is not a paid announcement; despite my best efforts, I have failed to scam anything of substance from Dirt Cheap Cameras).
Adorama are an example of a decent Internet-dealing camera joint; as I write this, they still have D60s. I haven't bought cameras from Adorama, but I've bought lenses.
They know who you are
I have a question about Optus cable Internet access.
I recently got hit with the 3Gb cap. Now I want to know - HOW does Optus monitor how much I download? I thought it was the computer name on the network - but changing that did nothing. So I thought it might be the network card, so I hooked up the cable modem to my laptop, and still no change.
I figure it's the cable modem itself. How does Optus configure the cable modem to my Optus account? I don't understand, because when they installed it, they just plugged in the modem and didn't install any software to get the Internet going.
Someone who signs himself "Russell Coight"
Answer:
Optus authenticate by cable modem
MAC address.
Back when they were all @Home-y, they used a
hostname, but
now it's just MAC address.
If someone sneaked into your house and swapped your cable modem for his, and if he was on the same node as you (each node covers a quite large slice of a city), your accounts would be swapped as far as Optus was concerned, I think. It might even work if he was from a different node; I don't know.
Optus could notice that suddenly "you" were getting mail from "his" e-mail account and other passworded services, and vice versa, but apart from that you'd look the same.
Fan placement
I'm building a water-cooling rig and have picked up a rather large heater core (grill is 7"x6"x2.5"). I'm placing two 92MM Panaflo L1A fans on an acrylic surround I'm building for it. My question is: How far away from the fins should the fans be for optimum effect? I'd like to know before I spend all that time gluing acrylic making a spiffy shroud.
I've Googled for literally hours and come up with some anecdotal tales that getting the fan up off the fins makes it quieter (the fan blades evidently make noise when they are very close to the fins) and cool better (allowing air to flow in front of the dead spot in front of the fan hub) but nowhere have I found a guide that will tell me how far away to place them.
David
Answer:
Getting a hard answer for this is really tricky; I'll be quite happy if
I never have to build a
hot-wire anemometer as long as I live.
There are some basic rules that apply, though.
First: Axial fans for computers (the regular rotating-blades kind that suck air from one side and blow it out the other) have high free-air flow statistics, but low static pressure capacity. This means that anything that presents a substantial obstacle to air flow - like tight-packed fins on a heat sink or radiator - will greatly reduce flow, no matter where the fan is. Get fan placement on a radiator wrong and airflow will be very, very bad. Get fan placement right, and airflow will be merely very bad, compared with the free-air rating.
Second: If the fan placement is such that the blades are whizzing away right next to the fins, there'll be severe turbulence problems, which will further reduce the air flow. As you say, this also makes noise; if the fan's far enough away from the fins that it's not making a fan-flat-on-a-table kind of noise (a centimetre or two should be fine) then the turbulence situation is also likely to be about as good as it's going to get, without extra guiding vanes and similar fripperies. Some super-powered fans, like Delta's "Focused Flow" models, have such vanes after the impeller; most don't. Building them yourself isn't worth the effort.
Third: Pretty much any water cooling rig will have far better performance than it needs for the load it's under, even if you're using it to cool a seriously overclocked CPU, a graphics card, and a couple of hard drives.
So it's OK that computer fans can't push air through fins very well; just mount them so that they don't make a racket, and you're done.
If your design could accommodate a single 120mm fan instead of the two 92mm ones, then you'd get better results. Larger fans can spin slower for the same airflow and thus make less noise, and they're also more efficient, all things being equal.
