Archive for month: October, 2009

Movie Review: This Is It (2009)

October 30, 2009 | Movie Review | By: Mark VandeWettering

Tonight’s movie screening at work was Michael Jackson’s This is It, essentially a concert movie starring the recently deceased King of Pop, Michael Jackson as he prepared for his first tour in a decade. Unfortunately the preparations for this tour were for naught when he died (under somewhat mysterious circumstances) on June 25th, 2009. Jackson […]

Hacking with Style: TrueType VT220 Font

October 30, 2009 | Link of the Day | By: Mark VandeWettering

I’m mostly resistant to nostalgia when it comes to computing. Let’s face it, the iPhone has way more impressive capabilities than the desktop machines I was using just a few years ago. But occasionally I do want to take a step back and revisit those heady days of yesteryear, when I would sit in a […]

From the Brainwagon Archive: Silly Arduino Project #1: A Trivial Beacon

October 30, 2009 | General | By: Mark VandeWettering

One year ago tody, I tinkered together a very simple program and keying circuit to use my Arduino to send out a simple Morse Code beacon message. brainwagon » Blog Archive » Silly Arduino Project #1: A Trivial Beacon It seems like complete overkill to me to use a $30 microcontroller to do this task […]

WSPR Organ – Computerless WSPR TX

October 30, 2009 | Amateur Radio | By: Mark VandeWettering

I mentioned G3ZJO’s “WSPR Organ” idea a couple of days ago: he has a much better write up of its success on his own blog. Check it out: WSPR Organ – Computerless WSPR TX – Radio – HF to Microwaves I think the idea of calling this “computerless” is a teensy bit misleading: he does […]

Audio processing for amateur radio voice communications…

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

This is just a brief note to myself to archive, well, what amounts to a single command that processes an audio file, but to stand as a placeholder for an interesting topic that I know virtually nothing about. 🙂 Here’s the basic idea: Amateur radio SSB communications are limited to narrow bandwidths (around 2.7khz is […]

Some interesting new (to me) radio techniques…

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

The Knightsqrss mailing list still intrigues me, although my own qrss beacon has been off the air for a while (I’m trying to get around to homebrewing its replacement, but have been distracted by other facets of life for a while). Recently, Eddie G3ZJO offered this rather interesting circuit which I scratched my head about […]

Link to K7QO’s Lab Notebook

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

I missed out on last night’s Echolink QRP confab (Sundays, at 6:00PM Pacific time) but I did notice that Henry had posted a summary of topics and links (thanks again Henry) and included a link to Chuck Adam’s lab notebook. I’m just about to dash off to work, but it looks like it has lots […]

The principles underlying radio communication

October 25, 2009 | Amateur Radio | By: Mark VandeWettering

While digging around for some information on crystal radios on the Internet (since i seemed to have misplaced the book on the subject I was looking for) I encountered some references to a book which happened to have been digitized and made available on This book was published by the National Bureau of Standards, […]

Make an Instant-Charge Screwdriver | Popular Science

October 24, 2009 | Amateur Radio | By: Mark VandeWettering

Ben Tongue’s article on using a supercapacitor to hold energy harvested from an antenna tuned to strong local broadcast system got me thinking about supercapacitors again. Digging around uncovered a link to a DIY project (very simple) for creating your own electric screwdriver powered by supercaps. (I think they are a bit cavalier with the […]

AA1TJ — “El Silbo”, a voice powered radio (complete with QSOs!)

October 23, 2009 | Amateur Radio | By: Mark VandeWettering

I subscribe to the very interesting QRP-L mailing list, and recently read an article by Michael Rainey, AA1TJ about an interesting radio and set of QSOs that he conducted. Michael’s experiments are amazing and cool, but I think his latest effort takes the cake: he had a number of QSOs using a transmitter powered entirely […]

Zero Threshold MOSFETs…

October 23, 2009 | Amateur Radio | By: Mark VandeWettering

I don’t know why this percolated to the top of my consciousness today, but I thought I’d dump a link here so I can find it again. I recalled reading an article about the use of a particular special MOSFET device for use in crystal radios. It took me a tiny bit of time to […]

EtherGeist: Quick prototype printed circuit boards

October 22, 2009 | Amateur Radio | By: Mark VandeWettering

I was reviewing Stu’s articles on his “Ethergeist” blog again regarding his QRPp WSPR beacon, and was admiring his nice looking prototypes. I’ve goofed around with using tin snips to cut small pieces of copper clad and gluing them down to make solder pads, but Stu just uses a carbide tip scribing tool to cut […]

Using the 74HC240 in radio applications…

October 19, 2009 | General | By: Mark VandeWettering

There are a number of interesting radios based upon using things like hex inverters or octal drivers as both oscillator and amplifier. In digging around, I found the most common chip used in this application is the 74HC240. Here’s a link to a page which contains many interesting links: Testes com 74HC240 Another link to […]

DC40B, Day 4, and stupidity on my part…

October 19, 2009 | Amateur Radio | By: Mark VandeWettering

Well, over the weekend I completed the trial assembly of my DC40B. The voltages all measured out correct, but the oscillator seemed to not start reliably. It appears that the twin 47pf caps that provide crystal feedback may not be quite sufficient to reliably start the oscillator on power up. If I prod the base […]

No DC40B work tonight…

October 16, 2009 | Amateur Radio | By: Mark VandeWettering

Too tired, so instead I took the wife out for some Mexican food and a movie, and when I got back I relaxed a bit. I have the feeling in my tired state I would have just made mistakes. I did dust off my old Manhattan style constructed oscillator since AK6L was going down the […]