Archive for month: November, 2009

Recommendations for a little LTSpice design project?

November 28, 2009 | Amateur Radio | By: Mark VandeWettering

Well, one of the advantages of getting a new Windows 7 laptop is that I now have a much nicer environment for running LTSpice. Does anyone have any ideas of a good, simple project that I could do to help me learn the ropes of LTSpice, and which I could also build for real to […]

A couple of days of WSPR 2.0

November 27, 2009 | Amateur Radio | By: Mark VandeWettering

Left my FT-817 beaconing for the last 48 hours or so, mostly on 40m, and got some interesting DX, including someone I think I never reached before, KG6DX in Guam. Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az  2009-11-27 07:32   VK3AMW   7.040092   -19   0   QF22ir   5   K6HX   CM87ux   12668   59   2009-11-27 07:08  […]

New Google Voice Number

November 27, 2009 | General | By: Mark VandeWettering

Courtesy of Zeid, I finally got an invite to use Google Voice. I’ll write more about this when I figure more about it, but at a minimum, it gives you a real phone number (amazingly, for free) which anyone can call and leave voice mail. You can configure it to ring a different phone (say, […]

FreeBSD 8.0 is released…

November 26, 2009 | Operating Systems | By: Mark VandeWettering

I’ve been a long time fan of FreeBSD, going all the way back to the days (and used regular BSD going back even further). Today, I still have a server which runs FreeBSD, as well as another desktop which is running Ubuntu. Which one I prefer is not really something I choose to argue […]

Back on WSPR today…

November 26, 2009 | Amateur Radio | By: Mark VandeWettering

Well, I finally dug up all the cables I needed and hooked up my little HP netbook to my radio again, and got it going with the new WSPR 2.0 software. As of this moment, I’m beaconing out at 5w on the traditional 30m watering hole, and getting pretty good domestic spots. I might try […]

SO-67 Audio…

November 22, 2009 | Amateur Radio, Amateur Satellite | By: Mark VandeWettering

John, K8YSE recorded a North American pass of SO-67 (the new South African ham satellite) and posted the audio on his website. It appears the audio quality is actually pretty good. I’ll have to be trying it out fairly soon. SO-67_22Nov2009_141052z.mp3

A simple, naive implementation of a MasterMind solver

November 22, 2009 | Games and Diversions | By: Mark VandeWettering

Okay, I woke up this morning, and decided to code up a version of a MasterMind solver. About fifteen minutes later, I had this tremendously slow implementation, which nevertheless seems to solve patterns very pretty quickly (averaged just 4.71 guesses in the short run of 100 trials that I just ran. It’s tremendously slow though, […]

Investigations into the Master Mind Board Game

November 21, 2009 | Games and Diversions | By: Mark VandeWettering

Over at the Programming Praxis blog, the task of the day is to write a program to solve the game Mastermind. Mastermind is actually a fairly interesting game mathematically speaking, and has a fairly rich set of mathematics behind it, and yet it’s actually small enough to analyze easily using modern computing power. I might […]

Orion Nebula

November 21, 2009 | Astronomy | By: Mark VandeWettering

IMG001221st November, 2009 Dan Lyke of flutterby drew my attention to the astrometry pool on Flickr. If you upload an astrophotograph to this group, a process comes by later and tries to identify the stars in your image, and adds annotations and labels to it. Very nifty. Check it out. Try clicking the image above, […]

Creating an Anaglyph from a Stereograph

November 20, 2009 | 3D | By: Mark VandeWettering

Back in 2005, I wrote a little blog post about creating stereo images with the GIMP along with a screencast. Little did I know that a couple of years later, I’d end up learning far more about stereo imaging when I became the stereo rendering lead for Toy Story and Toy Story 2. This post […]

Handmade Cigar Box Instruments – Ukuleles – Banjos – Guitars

November 20, 2009 | Music | By: Mark VandeWettering

It’s been a while since I posted a link to anything related to home made musical instruments, so when I ran across this page this morning, I thought of my friend Tom and his love of quirky instruments, and decided to pass it along. Papa’s Boxes sells both kits and completed ukuleles and banjos made […]

Homemade Thin-Film Transistor Experiments

November 18, 2009 | Amateur Radio, electronics | By: Mark VandeWettering

Another link to some interesting experiments on building your own thin-film transistors. And a Quarter Gets You Coffee » Homemade Thin-Film Transistor Experiments Addendum: Of course any mention of building your own transistors would be remiss if it didn’t mention hacker-savant Jeri Ellsworth. She did an amazing job fabricating her own semiconductor devices, and in […]


November 17, 2009 | Amateur Radio | By: Mark VandeWettering

While listening to the “This Week In Amateur Radio” podcast this morning, I heard reference to a new record setting non-line-of-sight one way contact that took place over optical wavelengths. A sucessful transmission over a distance of 288 kilometers was achieved by using an LED based transmitter. The report (PDF) provides many interesting details, such […]

Mandelbulb formula…

November 16, 2009 | Computer Graphics | By: Mark VandeWettering

Without further explanation, here’s Daniel White’s “Mandelbulb” formula. (x, y, z)n = rn (cos(n θ) cos(n φ), sin(n θ) cos(n φ), -sin(n φ)) r = sqrt(x2 + y2 + z2) θ = atan2(y, x) φ = atan2(z, sqrt(x2+y2))

Another try at an Arduino Based Morse Beacon

November 14, 2009 | Amateur Radio | By: Mark VandeWettering

Back in 2008, I blogged about a stupid program I wrote to implement a Morse Beacon on the Arduino. I couldn’t find that code, and it was stupid anyway, so I went ahead and implemented a new version, with an added improvement: it doesn’t hardcode dots and dashes, it has a built in table. Right […]