brainwagon

Yesterday, I wrote about soldering together my bliplace kit. Today, I thought I’d have a peek at the code and the schematic. Here’s the schematic: Not much there, but a couple of interesting things. The microphone is an electret, which needs some power to be functional (supplied through the 10K RU resistor). To me, the […]

Drew, KO4MA, didn’t let a little thing like the missing antenna on ARISSAT-1 keep him down. He aimed his antennas at the satellite, and recorded the following: What’s goin on here? Drew has a pretty good antenna setup, which includes an M2 CP42 for the uplink. That provides about 16.8db of gain. Since the ARISSAT-1 […]

I was in the mood to melt some solder, but didn’t really have a lot of time and/or brainpower last night, so I turned to my box of little electronics kits that seems to have been growing over the last few years. I located a small plastic bag which contained tanjent’s “bliplace”, a tiny kit […]

Okay folks, I’m sorry, I promised that I’d try to stay up late enough to record some of the first passes of ARISSAT-1, but physical need for sleep outpaced my natural enthusiasm and curiosity, and the first good pass found me sound asleep. Through some perverse quirk of fate, all the best passes of the […]

First, the good news: ARISSAT-1 is floating free in space. I urge hams to listen for its 2m downlink on 145.950 to see if you can hear it. There is also a CW beacon on 145.919 and a special BPSK-1000 telemetry downlink on 145.920. Now, the bad news. It appears that the UHF antenna was […]

While looking up some references on amateur nuclear fusion (don’t ask!) I found that Raymond Jimenez had written a cute 40 page book on his own experiments with a Farnsworth Fusor. You can apparently order a dead tree version from Lulu for $12.50, but it’s also available as a free download. Raymond Jimenez’s Storefront – […]

I was shown some truly horrifying code that reported to decode a quadrature shaft encoder. It was just mind bogglingly stupifying that someone would go to that much work to write something so utterly horrible. Here’s the way that I think of them. A quadrature shaft encoder looks like a 2-bit Gray code counter. Instead […]

I subscribe to the Sixty Symbols YouTube channel which is produced by the University of Nottingham, and today, I noticed they had a new video on a subject near and dear to many a physicists heart: Guinness. If you think that beer is beneath the interest of physics, you should surf on over to Amazon.com […]

I’m interested in low cost computing. Like the kind of computing that costs what a Blu Ray disk costs. For a while, that’s been something like the Arduino, which has a 16Mhz 8 bit processor. But the Raspberry Pi is something else: a proposed computer which plugs into an HDMI port for display, uses USB […]

Ham Nation is a relatively new weekly podcast that is brought to us through the power of the TWIT network, Leo Laporte’s mighty podcast empire. Fellow blogger KE9V had some comments on it, some of which I agree with, and some of which I do not. Of Dits and Bits | KE9V’s Ham Radio Blog. […]

Over on the #savagecircuits IRC channel on irc.afternet.org, Atdiy was trying to decipher the mysteries of a mainstay of analog circuit design: the RC filter such as the one pictured on the right (diagram cribbed from Wikipedia) It dawned on me that (newbie as I am) I didn’t really have a clear understanding of them […]

I think I saw this a couple of years ago, but Doug Conroy seems to have made some progress on his implementation of a PDP-10 on an FPGA. It now can apparently boot ITS. I’m more interested in the prospect of running TOPS-10 so I can relive my early days, but booting ITS is pretty […]

I am a long time reader of Hack A Day. It’s a great website, and often details projects that I find interesting well before they are picked up on other sites. It also tends to drive significant amounts of traffic to sites mentioned, so it’s good publicity for many interesting objects. But lately, their comment […]

My tweets this morning included a link to a story by Scientific American editor Anna Kuchment, entitled “How to raise a science fair champ”. How to raise a science fair champ | Scientific American Blog Network On the one hand, it’s a mildly interesting look at some talented kids who have risen to the top […]

Digikey runs a Monday Mash puzzle every week on Monday. Last week, I entered and won! Huzzah! Here’s the video of me unboxing my prizes. Thanks to Roy Eltham from the #savagecircuits IRC channel for urging me to enter, and condolences for him not winning.