To celebrate my 10,842 subscriber milestone. I thought I’d interview a YouTube legend in the electrical engineering industry. In the first part of this interview, we discuss his early days in electronics.
Part 1: The early days
In the first part of this interview, we discuss his early days in electronics.
- Pulling things apart.
- Dave’s never-ending project list, aka “finishing projects”.
- Trying to squash the impossible bug.
- Solving bizarre electronics faults.
- Dave’s Golden Rules.
- Why he is so scared of high voltages.
So here I am in sunny Cuba, where I've been told that Dave Jones from EEVblog comes to visit often. Now he's supposed to be here. So let's go and have a talk to him. What? You can't find him. What do you mean you can't find him? Well, we have the right date, don't we? And the right place, I mean. Hey, is that him behind the windsurfer. Nah. I've got a great idea. Why don't we call him? Has anyone thought of that? I mean, how about Skype. That always works, doesn't it? Look, let's just call him.
Yeah, good idea.
On in three, two ...
G'day, Dave. How you going, mate?
I was under the assumption that you were on holidays this week and you're at Cuba, your favorite beach, is that right? So I've just come down here looking for you, but I can't actually see you.
I've got to be there somewhere. Am I hiding behind the surf ski over there?
Oh, that one over there?
Whatever they're called. That's me. I'm hanging out right behind you.
From what I can see, you're actually in an office so you can't actually be there.
I think you've been caught out, mate.
Ah, this is all green screen. I'm actually at the beach.
Since you're there and since I'm here, how about we just do an interview, eh?
Let's do it. Can I put some real headphones on because these things are a heap of shit?
That's heaps better. I look stupid, though, so I thought I'd use these little daggy things.
Yeah. Well, look.
I hate wearing them and the audio quality's awful. And Skype sucks. So we gave up, we used to call it the amp hour on Skype, and we just gave up very quickly. It was horrendous.
Pulling things apart
So going back to how everything started with you, there's been a sort of a history with electronics enthusiasts to be pulling apart stuff and always be sort of interested in seeing how things work. How did it all start with you? Did it start like that?
Absolutely. Pretty much before I can actually remember the first time, like four or five years old or something, I was, yeah, I was taking stuff apart, taking the TV apart, taking apart the radio, taking apart, this is before we had any real gadgets which we take for granted these days. There were TVs and radios and other things. Maybe a little electronic toy. I'd get an electronic toy for Christmas. First thing I'd do is take it apart. That's how it started. My parents got pretty sick of it.
They thought, no, we've got to stop him taking everything apart. So they got me the Tandy 50 in one kit, if you remember those. Tandy / Radio Shack, you know the ones with the spring terminals?
Yeah, yeah. It was a wooden box with all the spring terminals on top. And you had individual resistors, capacitors and transistors and a light bulb. I don't think the first kit had an LED in it.
And also I think they had that integrated circuit, didn't it.
They had the integrated circuit. It was a SIP package, it was a single in line package, and I thought that was the most advanced thing I'd ever seen in my life. And they had the internal diagram if I remember properly. And it had like four transistors in it. It was like just a little transistor array that you could hook up and-
Those are the days, weren't they? I can remember that.
Ah, that was great.
And losing those ... The spring terminals would just suddenly sort of flick out sometimes and-
I don't think I ever had one flick out.
No, mine were pretty good. Yeah, I've still got my 200 in one kit. I don't have my original 50 in one kit. I'm not sure what happened to that-
Yeah, probably scavanged for parts.
Still got the 200 in one. I plan to do a video where my little boy, Sagen. Yeah, we're going to do a video of us just using my original 200 in one kit.
Fantastic. Look forward to that.
That's a lot of years ago. Their service still works. Not much can go wrong with the parts on it.
So what were some of the things that you made in the early days?
Test gear, a lot of it was test gear because that was what was in the electronics magazines, Electronics Australia. That was the main one. And to buy your own test gear back in the day it was expensive, so you built your own, and that was one of the most popular projects in the magazines was build your own test gear, mostly test gear. The fact that you didn't have other projects to use your test gear on didn't matter much, it was just-
You made some test gear. So later on your career, what are some of the projects that you really got a kick out of it?
Sadly speaking, my professional career was pretty boring. Yeah, I was like a regular Joe Bloggs engineer in a big ... Mostly large companies working on projects that they just get canned. Like I could be working on a project for two years and it'd just get canned. It'd never make it to market. Most of them didn't. So it was either that or I was working on test gear for production and stuff like that. So there wasn't a product, it was customized bits of gear that you'd make five of for actually testing your widget in production and stuff like that.
So yeah, it's a very uneventful career.
Dave’s never-ending project list, aka “finishing projects”
Outside your professional career what about some of the stuff that you've made?
Oh, once again I got sidetracked back in the teens, early twenties and stuff like that. I got sidetracked from electronics into the PC world. That's when PCs were becoming a big thing, and I got into programming and doing that sort of stuff and games and got distracted into the programming side of things for a lot of years there. But projects, once again I didn't finish a lot of them. I started a lot of them. And I'd have notebooks with all the designs and stuff like that. A few of them I got published in the magazines. I think I had half a dozen projects published in the magazines over the years. Six or seven projects and occasionally they'd make it out, but a lot of the time I just liked dabbling on stuff.
I wasn't a very good finisher-
.. of projects. I'd just get sidetracked on something else and I'd just get interested-
Yeah, it seems to be a trait with electronics enthusiats, doesn't it? Not to finish things.
It is, and it carries over today as well. I'll start a series, a design series or something and I won't finish it and it pisses off a lot of people. I don't know. I just lose interest fairly easily.
Trying to squash the impossible bug
So looking back at your professional career and also sort of your non-professional career, what's the one of the hardest sort of fault or hardest sort of bug that you had to crack?
One of them. It's actually in the screenshot, you know my hand shot? You actually see the product that I'm talking about here. It was an ocean bottom seismic recorder thing. It was designed by this company in Germany. It was all a bit ... It was all written in German and everything and the source code was in Forth. If you remember the Forth. And it was on a TMS 320 processor, DSP processor.
And anyway I went to Germany to learn more about it and bring the technology back so that we could engineer it ourselves and maintain it because we were buying it. Anyway, and it was a complex six sided board cube arrangement so all the boards and all the grounds interacted. We used to have this fault ... It was a long term data logger and occasionally there'd be reports it was getting out of sync or skipping pulses. And it happened after 10 days of recording, and trying to debug something that only fails intermittently after 10 days is next to impossible. I spent like three months or something working on that and it turned out to be a convoluted arrangement of the grounds and stuff like that combined with some firmware issues. And it was nasty.
Solving bizarre electronics faults
Yeah, some of those long term issues are probably the hardest to solve, aren't they?
Yeah, really typical. If you've got a fault that's just there and it's failing all the time, it's easy. You can fix it.
Back in the early days when I was fixing photocopiers, there's one problem that would only happen between a certain time of day and the scanner head would go whack against the side of the carriage-
The end stop thing.
Yeah, and what I suddenly discovered was that, oh, between 10:30 and 11:00am the sun was up in the sky. It was shining down on the photo resistor on the-
Oh, it was actually the photo resistor. I was going to say, was it like an uncovered silicon diode something, one of those-
Well, the test bed was actually sitting in the window and it was just between that time of day it'd just fail. Every other time it was fine.
Nice. I've seen problems like that where you'd have one of those glass diodes and they're photo sensitive. And exposed semiconductors can be a problem. EPROMs without their window cover back in the day. And that problem I was telling you about with the cube thing, trying to solve that, I thought I had it. I thought, ah-ha. It turned on like 11:00 every night. Like I was able to capture it 11:00 every night. What's causing it? Oh, the lights in the hallway were automatically switching off at that time and the air con's switching off and everything. And it was a combination of my test gear, so all the test leads hanging off it. You can see in the photo. It's like there's logic analyzer leads hanging off and there's everything, and, yeah, we'll get an impulse from the air con and the light switching off at 11:00 at night. So I'd come in next morning and it's triggered. I captured it, and nah.
Dave’s Golden Rules
So thinking about failures and testing and all these sort of problems that do occur, what's some of the golden rules that you should always observe?
Thou shall test voltages is the first one, is the first rule of troubleshooting. And then don't assume anything because Murphy will get you every time. If you assume, oh, it can't possibly be that. Like don't worry about testing that. It can't be that. It will be that. Murphy will ensure it's that. So you've got to ... Yeah. Assumptions are the mother of all screw ups. Just if even if you think it's not related in any way, it can be. I've encountered so many issues that in a convoluted way they were involved and if I measured that it would have led me down the right path and I would have found it.
Why he is so scared of high voltages
So have you had any disasters or sort of personal injuries with electronics?
Yeah. I've been electrocuted by several kilovolts so-
And also mains power across the heart.
Oh, I remember when I was a kid, I don't know how old I was. Probably eight or nine or something, 10 maybe. And our TV was on the blink. You know the antenna connection? Old CRT TV.
I know where this is going.
And so I went and opened it up. And I could see that the antenna connector on the back looked loose inside the set. So I touched that and it threw me across the room. Lucky live chassis TV. And I knew. I knew about live chassis TVs because I'd been reading the servicemen column in Electronics Australia magazine. I knew this but I just in my enthusiastic ... Like I had forgotten all about ... And I just assumed that our TV wasn't live chassis-
.. in my subconscious and, no, it was. So there was 240 volt mains on the coax leading up the antenna connector on the back and, yeah, that tore my hand open because I maybe grabbed it or something. And that scared the ... So from that day on, high voltage scares the shit out of me. Anything over 12 volts DC ...
Back in my day when I was fixing photocopiers, there's a lot of corona wires, you know, the lot of high voltage-
Live corona wires, yeah.
So, yeah, I can remember getting electrocuted. A nice big sort of arc, was probably about an inch long.
How much energy is there in those power supplies which power those corona wires? Is there a lot of energy behind it or is it just high voltage?
No, just very high. It's a very low current, but high voltage.
Yep. Okay. So it probably couldn't kill you.
Give you a good zap.
Yeah, and it burnt a nice little crater in my skin and my fingers, so I was just sitting there going, 'Oh, hello.'
Check out other videos in this series…