Babbage in motion

While I was in Seattle I had the opportunity to see one of the two Babbage Difference Engines in operations. I’d seen it before in the Computer History Museum, but never in operation.

A difference engine is an automatic mechanical calculator designed to tabulate polynomial functions. It is viewed as a pioneer computing device and was created by Charles Babbage. There is quite a complex and intriguing story about how it came to be invented and then how the device came into being at around the year 2000. I’ll not go into that here though.

The difference engine is fascinating to watch, especially the back side, which reminds me of DNA‘s double helix. I added a youtube video of it operating that has a good background narrative.

A Great Glass Blowing Experience in Dallas

For Christmas, I purchased a glassblowing workshop with a Groupon for my wife. This weekend we finally got around to going to the workshop by Aaron Tate at the Marrsart studio.

We were shocked by the range of objects they would let us make in the workshop. Sure, they had the typical glass paperweight but they also had vases, bowls, cups, ring holders… with quite a range of colors as well.

The support staff were very helpful and patient, explaining everything that was going on and why it was being done. IMG_20170319_173337789

Michelle made a ring holder and I made a glass paperweight (with little bubbles in it).

We both decided that next time we’re both going to make bowls, since you actually first create a big blub (yes, like a Christmas ornament) and then suck on the tube to pull into a bowl shape.


That’s a picture of Michelle pulling the glass to twist the colors into it.


This is a picture of me turning the colored glass in the furnace that will be in the center of the paperweight. I had to get it up to temperature, so we can work with it more.

Last weekend was the Dallas FIRST Regional

Last weekend was the Dallas FRC regional. There are videos of the competition available on-line. This year’s competition was steampunk based.


I’ve been coordinating judging for the FIRST Robotics competition in Dallas for about 8 years now, so naturally there are a significant number of retired EDS and a few Raytheon folks involved.

FRC allows students to start from a standard kit of parts and some state of the art tools (received at the kickoff in January) to build a robot attempting to meet specified objectives. This video is an overview of this year’s challenge – FIRST Steamworks

The goal of FIRST is to encourage the understanding and passion around STEM. It has a proven track record of results that is hard to argue with. 

I was also drafted to judge the Jr. FIRST Lego League competition on Saturday morning. That competition is targeted at grade school students. At least in the Dallas area this competition was sponsored by Raytheon, among others.


QSO Morse practice app for Android

Over the Thanksgiving break I sat down an wrote a small application for Android to help individuals brush up on their Morse code. There are many apps already out there to teach Morse code but this one is aimed improving your ability to receive the interactions you’re likely to encounter over the air.

It is called QSOSender3, since it is the third iteration I’ve worked on. It generates QSOs based on the speed you’d like to receive. For 5-10 WPM, the simulated QSOs are fairly short but a realistic representation of what you’d likely see on the air. For 10-15, the QSOs are slightly longer and for 15 WPM and higher (see the picture below) they can become quite involved.

I used a grammar based generator to create the simulated QSO, so they can be very different from one to the next. In fact for the highest speed (longest), it is incredibly unlikely that any to generated QSOs will be the same. Have fun… here is a representative screenshot:


#amateurradio #hamradio

Circuits – shocking, it’s starting to come together.

Now that I have a battery, I need to wire it all together. I plan on using a circuit like:


I’ve had a very busy weekend that kept me away from working on my portable design much. I was able to stop by HRO and Frys and get the rest of the parts I needed.

My next entry will dig into selecting a case to haul this gear around and some quick and dirty mounting of the circuit shown. I’ll likely build something out of wood and 3D printed parts initially and think about a more permanent solution if that attempt doesn’t turn out to be good enough.

Not sure when that will happen, since next weekend will be keep me even busier then the last. Hopefully, I’ll have it all done by the end of the month and I can take it with me to the Belton hamfest.

Next step in my quest to be portable – the antenna

The antenna is easily the second most important component of a portable station and unfortunately it is also the area that is most easy to compromise on. I wanted to have one that would support multiple bands and yet still be small and flexible enough to carry with me and set up in minutes (by myself).

There are a number of types of antennas that may fit that bill:

  • A long wire – They are low cost and easily to transport but they require an antenna tuner, lots of room. They are not all that easy to set up, since you’d need to be in location with tall structures or trees and some way to get the wire into the air.
  • A multiband wire antenna (like a G5RV) – These have some of the same issues as the long wire although they shouldn’t require an antenna tuner.
  • Mobile antennas – Little verticals are easy to switch out. Carrying around the various antenna resonators to support the bands would be a bit unwieldy. Verticals can be set up quickly but the costs can quickly add up if you want to work on multiple bands. Small verticals like this are always a compromise on performance as well. An alternative is a screwdriver antenna that adjusts to support multiple bands.
  • Buddipole – I’ve known a number of hams over the years who have purchase these. They are not cheap but they do work on everything from 40M up through 2M with the default configuration. They are light (9.5 lbs.) and easy to carry. If you get the deluxe package, you get a tripod to mount the antenna on and pretty much everything you need. The antenna can be set up in minutes and it seems like the ideal solution for my needs.

I am sure there are others that I’ve missed but those are the alternatives I investigated.

I eventually ended up getting the Buddipole and hope to put it through its paces on the September VHF contest this weekend – more on that later.


Just to round out this post about antennas I’ll add: I heard the other day about two antennas getting married. The wedding was nothing to call home about, but the reception was amazing.