Featured Engineer

Interview with David L. Jones

David L. Jones

David L. Jones- World's Preeminent Engineering Video Blogger

How did you get into electronics/ engineering and when did you start?

The YouTube video telling the story is here.

Very similar to many others in the industry around my time, I started by taking stuff apart and trying to figure out how they worked. And then I got a Tandy/Radio Shack 50-in-1 Electronics Kit when I was about six or seven, and I never looked back.

What are your favorite hardware tools that you use?

The new 3000 series Infiniivision scope is pretty darn nice. Having 1,000,000 waveform updates per second is just phenomenal.

I’ve had the same Phillips screwdriver for about 30 years. It just seems to fit everything. The funny thing is I keep losing it, but it always seems to show up again, like Indiana Jones’s hat. I must be connected to it in some way.

I’m one of those engineers that simply MUST have a REAL calculator within reach at all times. None of this phone or Windows calculator rubbish. There is just something special about hardware dedicated to and designed for a specific task.

I still have a soft spot for my first Multimeter—an analog Micronta 18 range job I bought with my saved pocket money when I was, well, I don’t really remember, way before 10. I do like to dust it off occasionally and make some measurements for old time’s sake.

What are your favorite software tools that you use?

The Web is now the ultimate software tool. The information revolution has completely and permanently changed the landscape of electronics design. If I could have only one software tool it would be a web browser.

What is the hardest/trickiest bug you have ever fixed?

The next one most likely.

One rather nasty one though was on a third party TMS320 DSP based data logger that ran a Forth based OS written in some German compiler I didn’t understand. We’d get a data glitch about once or twice a week, so setting up to trigger off the event or debug it was completely hit and miss, and no doubt took a while.

The design was spread over five boards in a cube-shaped arrangement, so the ground system was rather nasty. It turned out to be a bizarre combination of some FPGA timing combined with some marginal signal integrity and a silicon bug rolled into one, and throw in an air-conditioning on/off switch thing that ensured the bug mostly only showed up at night. I couldn’t even explain it if I tried.

What is on your bookshelf?
  • Art of Electronics
  • The 20th Anniversary edition of the collective works of Dilbert
  • TI and NatSemi analog and digital databooks I kept for old time’s sake, plus some really good app notebook collections.
  • And my own book, The Art of Internet Dating.

As much as I love paper, deep down I know that ebook readers are the future, and their time is now. I love my Kindle.

When did you decide to start your Video blog and how did that come about?

April 4th 2009. I was talking with someone about electronics blogs, and thought about starting one to complement my existing web page approach, but there were quite a lot of electronics text blogs out there, so I didn’t see much point in it. And text blogs seemed rather boring, as you never got to really know the person behind it. At best you’d get a fuzzy photo of them on the About page. It all seemed very impersonal.

I saw a few unrelated video blogs around and I liked the idea, and then realized no one had done an electronics video blog. I was nervous at the idea, and had no idea what to do, but decided to just dust off an old 320×240 webcam and record whatever came into my head just for fun.

I didn’t like the result, but I knew enough not to try and perfect things, because then it will never get off the ground. You have to start somewhere, so I just swallowed my pride and uploaded the video to my personal YouTube account and posted it to the aus.electronics Usenet group. To my surprise, most people liked it and subscribed, and I instantly had 50 or so people waiting for another episode. I thought the novelty would wear off, and the audience would peak pretty quick, as I didn’t think many would want to watch a weekly video show with some guy just talking off-the-cuff about electronics. But I didn’t count on the popularity of YouTube as a search engine, and continuous non-stop growth in viewer numbers which I still have to this day. Encouragement came in droves, so the enthusiasm to keep it up was there, so I just kept on pumping out content on a regular basis. People seemed to love having a personality in front of the camera instead of just a voice over as was common on many other electronics YouTube videos.

I originally just called it the Electronics Engineering Video Blog, and I asked for name suggestions in the first episode because I didn’t like the name. But everyone else thought different, and EEVblog just eventually stuck. It wasn’t long before the show got its own YouTube channel, domain name, Wordpress blog, iTunes podcast, and forum, almost exactly as you see it today. I’ve tried to change as little as possible in terms of content and appearance over all that time. The rest, as they say, is history.

How did the Amp Hour come about?

Before the video blog idea I actually thought it would be a good idea to do an electronics radio show, I don’t remember why. But I had far from a radio voice, and I figured no one would want to listen to me yap on, so I dropped the idea, and the enthusiasm morphed into the video blog. Some time after the success of the video blog the thought popped into my head again that some people might prefer a radio version of the show to listen to while at work, in the car, in the lab, out walking, or other times when video isn’t really convenient. I figured a radio show wouldn’t work with just one person like video did, so I started thinking of a co-hosted show.

Not long after, I noticed a post on Reddit from someone asking for audio tutorials on Electronics. Chris Gammell (a fellow text blogger) took this idea on board and produced one, as he had a music background and had the gear. I thought it was okay; Chris sounded good, and of course he was keen, which is the main requirement for something like this. It helped that he sounded very straight-laced and was a Yank, so I thought an Aussie/Yanky combo could work, with a good contrast between personalities. So I drafted an email to Chris but sat on it for a few weeks because I didn’t know if I had the time to devote to two shows at once. But eventually we talked and he liked the idea.

Just like the video blog, I thought the best thing to do was “just do it,” so we grabbed some mics, called on Skype and hit record for an hour. The upload went onto our respective sites, and it took off from there. It started out as the as yet unnamed Dave Jones & Chris Gammell show, and paralleled the development of the video blog almost precisely, except that we started out with an existing audience base this time. It turns out there is a nice niche for such a radio show, and we now have a loyal following.

Do you have any tricks up your sleeve (a special way to analyze circuits or a special process you use to make something)?
  • After you’ve finished your prototype or project, a good way to test it for EMI robustness is to put a transmitting GSM mobile phone all over the board to try and find susceptible points. It’s amazing what you can discover.
  • Always remember that Ground ain’t Ground. When a circuit starts acting strange, point your finger at the ground system—guilty until proven innocent.
  • At work, be creative with names when ordering stuff and you can order almost anything. That fun looking remote control fart machine in the catalog is easily ordered as an “audio transducer.”
  • And always remember the golden rule of troubleshooting: Thou shall test voltages. In fact, one of the biggest mistakes you can make when troubleshooting is to assume something. Never do that. Measure it or test it, or Murphy will get you every time.
What has been your favorite project?

It’s hard to pick a favorite; my current or next project in my mind is always the favorite. But one memorable one is the Australian Navy Barra Sonobuoy that was used for finding a lost round the world sailor. The system was used well outside its noise performance envelope, and they were barely able to detect sounds of him on his boat—or what they thought was him at the time; it could have been some mating shrimp 100 kilometers away or something. I had laid out the front end board which dictated it’s noise performance, so I couldn’t help but think that if I hadn’t taken care on that layout to lower the noise floor beyond the spec, he might never have been found. Sometimes it does pay to “gild the lily” beyond the design spec.

Do you have any note-worthy engineering experiences, such as blowing up things or getting shocked?

When I was a kid our TV broke down and I naturally decided to take a look at it. I knew all about live chassis TVs, but had a major brain fart that day and decided it was okay to wiggle the inside RF antenna connector coax shield with the TV on. Oops, it blew me across the room ripping my hand in the process. I’ve hated high voltage stuff ever since. I once measured the shock and vibration response of feminine hygiene products. They were actually considered for use to shock dampen an ultra stable crystal oscillator module. By the way, don’t bother rushing out to buy them; their transfer characteristic is terrible, second only to cotton wool. The wings are marketing hype, they don’t help. I could not understand why accounts looked at me strange when I handed in an expense claim for said products.

What are you currently working on?

About half a dozen different projects, which is quite normal for me, and why I never finish most of them. I don’t have the required attention span, and I never seem to learn my lesson. I don’t really like telling people about my projects because I feel rather embarrassed when I never finish them. One of them does involve a quadcopter though.

What challenges do you foresee in our industry?

I’d like to come up with something profound and visionary to say here, but I don’t really see any need to look out for and overcome “challenges” that are here or may be coming in the industry. The more things change the more they stay the same. At the end of the day, you have to design and produce stuff with all the myriad of hurdles that have always gone along with doing that. Nothing new there. Head down, bum up.

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