Note: I’m not kyle. I’m just hosting his pic.

In case anyone gets any smart ideas, as Ive heard his adventures have pissed some RFDers off.

Want to increase convenience at the potential expense of security? Don’t we all. Well here’s how to authenticate without passwords*, and make aliases for your hosts while you’re at it.

First of all let me get that * out of the way. While it is possible to set up ssh logins with no password at all using this method, I recommend using a password when creating your key pait. This will give one master password shared between all logins that only needs to be entered once per session.

First of all you need to create a public/private key pair. I’ll assume you haven’t already done this.

user@machine:~$ ssh-keygen -t dsa -f ~/.ssh/id_dsa

It will prompt for a password. You should use one here, and use this key pair for several hosts. This would give the same password across all of the hosts. Or, you can just leave it blank. If you do that, then if anyone gets your private key file, they can access all of the servers that have your public key file. So especially if you leave the password blank, protect your private file!
You should now have 2 files in .ssh/. One will be your private key (id_dsa) and the other will have a .pub extension.

Now,
user@machine:~$ scp ~/.ssh/id_dsa.pub user@remote_host:.ssh/

Then log into the remote host,
user@machine:~$ ssh anotheruser@remote_host

And move the key into the authorized_keys file
anotheruser@remote_host:~$ cd .ssh
anotheruser@remote_host:~/.ssh$ cat id_dsa.pub >> authorized_keys2


And set the file permissions, if the file didn’t already exist.
anotheruser@remote_host:~/.ssh$ chmod 640 authorized_keys2

and delete the .pub file
anotheruser@remote_host:~/.ssh$ rm id_dsa.pub

You can now log out of the remote host. Try logging in again, it should just ask for the master password. For subsequent logins, no password should be needed.

Now, how about setting up an alias for the host name, and having SSH remember your login name? On the local system open the ~/.ssh/config file. Create it if necessary. Simply set up the aliases like this:

Host mybox
User anotheruser # remote login, if different
Hostname mybox.somedomain.com

Host anotherbox
Hostname anotherbox.anotherdomain.org


Once this is all set up, you should be able to ssh mybox, and the system will automatically select user name ‘myname’ and use the DSA key pair instead of a password.

So, youre sitting there listening to music and all of a sudden your amp clicks out, the power light goes red, and theres no music. ‘Shit. Its broken’, you think. Power off/on? Same thing.. Once it cools down, it powers up, but it clicks out again after 10 or 15 minutes of use.

Well if you found me by the google because precisely this happened to you, you’re in luck. I just repaired mine for the wonderful sum of 63 cents. Anyway, let’s move on.

To perform this fix you need to be somewhat comfortable with a soldering iron, and be willing to take your amp apart. If you aren’t very good with an iron, you’ll want to read through some how-to pages elsewhere until you’re comfortable with replacing capacitors on a printed circuit board.

My C370 ripped apart on my workbench

So it turns out the problem with the design is that NAD decided to put a hot-running diode right beside (touching!) some electrolytic capacitors. This dries out the caps, which changes their values. When their values change, the protection circuit goes all wonkey.

The protection circuit

First of all, locate the protection circuit pictured above. As you can see from the picture, mine had some obvious heat problems. Nothing looks broken per se, but it looks nicely toasted, especially on the right side and top. To get it working again, I’d reccomend replacing the three topmost capacitors. Their values are 4.7uF, 47uF and 10uF all rated at 50V. I wouldn’t get anything larger than 50V as I’m not sure if it would fit. For those who are interested, here is the schematic for the protection circuit:

NAD C370 Protection Circuit Schematic

With those three caps replaced, the amp should work fine. But in a couple years, those caps will die too. I found a great solution on a forum: move the diode to the other side of the board. Watch the polarity!

Diode on the back of the board

Now apply power, hope there aren’t any sparks, and enjoy the music!

This weekend I rigged up a jacob’s ladder from an old microwave oven transformer. Due to the low voltage (~2kV) it won’t self start. You can see me starting it with a paperclip on the end of a paint stirring stick. Although the voltage is a bit low, these transformers can put out huge current, so the arc is great once it starts.

Playing around with it earlier, I got arcs as long as 10″ from it. Now the search is on for another MOT or perhaps an old neon sign transformer.

I just put up a website for the Ryerson Hobby Electronics Club.

Not much point, really.  Just linking it so the googlebot checks it out.

Thanks to my local freecycle list, I just got myself a new oscilloscope.

The Tektronix 585A, from what I’ve read, represents the peak of tube oscilloscope technology. It was originally designed to be a 100Mhz scope, but the plugins never realized this figure. The plugins are interchangeable units that provide vertical amplifiers and all the necessary controls for one to four channels. You can quickly swap between them to change the sensitivity/rise time/etc of the scope. You can see 2 extra plugins on the cart beneath the scope.Surprisingly enough, this 37 year old behemoth fired right up, and has given me little trouble so far. It seems to be more or less calibrated, and has only some minor dust in the controls.

80 tubes of glory!

(click image for full size)

This unit came with four plugins, the cart and a camera attachment, which I’ll detail later, as well as full instruction manuals for everything. Tektronix makes wonderful manuals that not only cover operation, but troubleshooting, repair, calibration, and full schematics for everything. I’m confident there is enough information in the manuals for me to keep it running indefinitely.

If anyone wants more information on the scope, or details from the manuals or anything like that, feel free to contact me. In my googling I’ve noticed that people are still using and repairing these, but many are short on manuals and such.

I’ll post more details on the set-up later.

edit: I didn’t post those details.  Feel free to contact me if you want some info. mod@ this domain. (thats pithed.org).  There hopefully the spambots can’t read that.

Just came across this excellent list of keyboard shortcuts for linux. Definitly worth a look.
linkage

Well, after playing with water cooling off and on for a couple years, I’ve finally gotten sick of it. I had a system that worked well for a while, but then my pump died. Good pumps are expensive, and the cooling system just seemed to be a sink for money. I decided to switch to air. I searched google for the best of the best of heatpiped heatsinks. I found most reviews rate the thermalright ultra 120 as one of the best. I noticed it would allow me to use my own 120mm fan, which I already had for my radiator, so I bought it. First off, this thing is BIG. Really big. Just look at it.

I didn’t think to take a pic of it, so I lifted this one from www.overclockersonline.net.

Either way, this beast looks impressive. So impressive in fact that I thought it might have similar performance to my water system. The sink is half the size of my radiator, and its directly connected to the cpu. Sounds like a good plan.

My dreams started getting crushed when I went to install this piece. According to the instructions it just bolted to the standard backplate that comes w/ ones motherboard. It definitly didn’t. The bolts supplied were far too short. In the end I had to use the backplate and nuts from my waterblock to get it installed. The stock Thermalright hardware also only allows for a top-to-bottom layout on 939 boards. I was under the impression I could have a front-to-back layout, so it would blow the hot air right out the back of the case. Overall not very impressed.

I finally managed to get the door on my case to shut (I had some clearance issues), and started doing some testing. The result? Absolutely terrible performance. I don’t know if water jaded me, or if this thing is just a POS. I get ~40c idle, and ~50c load on an A64 4000+ 939 San Diego core. Maybe I mounted it wrong? I remounted the sink 4 times trying both arctic silver 5 and the supplied compound, cleaning with alcohol in between. I still haven’t managed to get the temps down. I guess air cooling just isn’t that impressive.

I just received a letter from one Domain Registry of Canada, informing me that my domain was soon to expire (its renewed now. no stealing for you, bitches). This letter looked very much like a bill, and offered to extend my domain registration for a while. The problem? I use dreamhost. A quick skim through the document is enough to see that it is not in fact a bill, but I must wonder how many people fall for this scam. It seems like others have been recieving these as well.

Maybe I’m an idiot to have thought this was a bill for even a short moment, but with the outrageous rates that this company charges, I’m sure they’re making a killing from the few responses they do get.

Bastards.

Like really really horrible.

No, worse than that. You wont even believe. Just listen to this nonsense.

Him: Write down one cent. How would you write one cent?
Floor Manager: 0.01
Him: How do you write half a cent
Floor Manager: uhh that would be… point… 0, 0, 5 of a cent… i dont know if thats right.. I’m not a mathematician.

…I’m speechless.

edit: Listen! -> Verizon vs Math round 2 - Peter’s battle.