DATE: May 7, 2013
TITLE: Hoodied HP Hijinks
PRESENTERS: Chris Gammell, Chris Gammell’s Analog Life
Dave Jones, EEVBlog
GUEST: Bob Davidson, Ambient Sensors
SOURCE FILE: http://traffic.libsyn.com/theamphour/TheAmpHour-144-HoodiedHPHijinks.mp3
FILE ARCHIVE: https://theamphour.com/the-amp-hour-144-hoodied-hp-hijinks/
INTRODUCTION: Welcome to The Amp Hour, I’m Dave Jones from the EEVBlog. And I’m Chris Gammell of Chris Gammell’s Analog Life. And this is Bob Davidson of the Ambient Sensors.
Dave: Hey, Bob, thanks for joining us.
Dave: Is it Bob or Robert? It’s Bob, right?
Bob: I go by Bob, yeah.
Dave: Yeah, everyone does, right? All Roberts do, don’t they?
Bob: Well, I’m…
Dave: Especially here in Australia.
Bob: If I hear Robert, I think I’m in trouble.
Dave: Robert J. Davidson, come here immediately.
Bob: Yeah, exactly. Yeah, exactly.
Dave: Very, yeah, Bob is like, the stereotypical name…
Chris: I hear he’s your uncle, Dave.
Dave: He’s my uncle, yeah. Bob’s my uncle here in Australia. Bob literally is my uncle. I do have an [inaudible 00:01:12], that’s how Australian I am, yeah.
Chris: That’s good, nice.
Dave: So tell us about yourself, Bob.
Bob: Okay, well…
Dave: Tell us your life story.
Bob: Oh gosh!
Chris: [Anger! 00:01:23]
Dave: Putting you on the spot.
Bob: How long do you have?
Dave: Well my parents met at a…
Bob: Yeah, exactly!
Chris: I was just a glitter in my father’s eye.
Bob: Well I…
Dave: Well start, sorry, start out where you’re working at the moment and what you do, and then go back on how you got started in electronics because everyone wants to know that.
Bob: Sure. Okay, well, I have a small consulting and product development company here called Ambient Sensors, it’s in Boise, Idaho, and do custom electronic design for all sorts of people. One of the projects that we’ve been working on recently is a hit detector for football that measures how hard football players get hit and then alerts them if they should be checked, which…
Dave: Checked? What do you mean? Like a profession?
Bob: It measures the probability of a concussion and it alerts them if there’s a 50% chance of a concussion.
Dave: Oh, right, I got you. I thought you were talking about the ball; now, you’re talking about the…
Bob: No, no, no.
Dave: Right. Body sensors!
Bob: It measures how hard they get hit in the head. I was working with the people at the injury biomechanics lab at Wayne State University and another group up in Ottawa called Biokinetics and they built this tester for measuring…
Dave: Banging heads!
Bob: Yeah, exactly!
Dave: What a great rig to build.
Bob: Yeah. Well they got it by studying videos of guys banging heads and so the thing has realistic velocities and forces. To give you a feel for what it’s like, it’s really violent. If Dave put a football helmet on and then let Chris take a baseball bat…
Chris: Can we hook this up because this…
Dave: Which he’s been dreaming of doing for years.
Chris: Yeah, I was going to say, is this a possibility?
Bob: No, it’s really awesome. The pro players are getting peak G-forces of 120Gs over…
Dave: Holy crap!
Bob: … impulses that are about 15 milliseconds wide.
Dave: Well yeah, that’s not many Gs. If you drop something on a hard surface of a bench, you can get thousands of Gs, right there. I mean G is just deceleration at given distance.
Bob: Right, so then when it’s connected to a head rigidly so [inaudible 00:03:32] then… that’s how you have to calculate the energy and the impulse and it gets pretty substantial.
Dave: Yeah, which is just basically the area under the curve is the energy of the impulse.
Bob: Exactly! Yeah. There is something called the head injury criteria that actually uses that. It’s an experimental curve that was developed, actually, originally for the automobile crash business then it’s been extended into this.
Dave: So this is like a standard curve, is it, a standard impact curve?
Dave: Yeah, that’s recognized by the insurance industry in an auto crash. So this thing has a little three-axis analog device, this accelerometer and NXP microcontroller that does all the management of that.
Dave: How do you find those MEMS accelerometers because I’ve never used those for shock and vibration testing? I’ve always used a real “accelerometer” from ICP or from Brüel & Kjaer or someone like that.
Bob: Right. You mean in terms of how close they agree?
Dave: Like its response, its linearity, its calibration, all that sort of stuff. Are those things any good?
Bob: They’re awesome! Actually, I’ve been doing testing here with what we call a drop tester, which has a laboratory-grade accelerometer…
Dave: They’re the ones I’ve used, yeah, the lab-grade ones, and they come with cal certificate and a response curve and the whole, you know.
Bob: Oh yeah and fancy amplifiers and labVIEW and all the rest of it. Then we drop it onto a pad that has a certain durometer that gives the kind of impulse that we want. I get very good fits to the data, like 0.998 for a goodness of fit and things like that when I’ve plotted one against the other, so actually it’s very good.
Dave: Awesome! Okay. I didn’t think they were that good. I thought they’re okay for getting a tilt on your mobile phone, but I’ve always wondered how good they are for actually, you know, linear calibration.
Bob: These go up to 200Gs, so although they’re similar technology, they’re not the same as what’s in the mobile phone. The use case before this one for these accelerometers is setting off air bags in cars, and that grade of accelerometer is pretty reliable of course and so.
Dave: It’d have to be, yeah, expensive.
Bob: Good one to use.
Dave: So all you pussies wearing helmets in your sports over there because we don’t wear helmets here in our football.
Bob: Right, exactly.
Chris: Look how that turned out!
Dave: Is it just in the helmet or does it [show them 00:06:52] on the body and stuff like that?
Bob: In this case, it goes in the chin cub. The part that holds the helmet on to the… they wear them very tight and it’s very rigid. The overall combination of chin cub, helmet and skull forms a pretty rigid body, so we do a lot of correlation work. One of the things we have to take into account is the angle of the hit and so we can compensate for…
Dave: I was going to say, can you determine the angle of the hit?
Bob: Yeah I can. Because of the initial acceleration, I can work it out.
Dave: Oh right, yeah.
Chris: Do you actually beam it over to the sidelines or something or is it data logging so that once they are hit, they just pull it off and see?
Bob: The other side of this is that we wanted to make one that was affordable at the high school level because that group of players is probably the least observed and most vulnerable.
Chris: The most career ahead of them, hopefully.
Bob: Hopefully! The system that I’ve been building only stores the data locally and uses a USB connector to download it. We looked at wireless and that could be an option later but the wireless is just not reliable enough. What we do right now is we, at least for the low cost stuff over an area the size of a football field with all the other interference and things around them, so what we do is we have a very bright LED and when the player gets hit, where there’s a 50% chance of a concussion based on that curve I mentioned earlier, it flashes bright red and they’re supposed to go off and get checked to see if they actually did suffer a concussion.
Chris: At least change the helmet out.
Dave: I can see this becoming like a crowd thing. Like if it pulses bright red, the crown erupt, whoah, hit him again!
Bob: One of the worries actually is that people start trying to…
Chris: Right. Dave’s [inaudible 00:09:19] [badge 00:09:20].
Dave: Yeah, they would hurt each other more, right, if they see…
Bob: Like in the carnival where you hit the hammer down and the thing starts ringing.
Dave: Oh boy!
Bob: I am actually on a national committee that’s setting standards for this because there will be, eventually, standards for how many hits… one of the issues is not so much the concussions, although those are bad enough, but there’s a whole spectrum of impacts below that level. They’re starting find accumulative damage and so they want to set, although the standards (00:10:00) haven’t been established yet, how many…
Dave: How many concussions you can sustain per game.
Dave: Which is crazy because if you ask any neurologist, they will say one concussion is too many. Do not even get one. Yeah, I guess well these sports have to exist, right?
Bob: The protocol now if you do get a concussion is you’re supposed to rest it for… you’re not even supposed to play video games or do anything, even think.
Bob: Well because they want to cut down the blood flow. It’s micro-tears in the brain tissue. Take up cross-country running or something.
Chris: Suddenly the average mass of a cross-country team goes up by a tenth of a football player.
Dave: So that’s what you’re currently working on with your own company, Ambient Sensors?
Bob: That’s one of them. I’m doing some weigh-scale work and other different things that come along.
Dave: Is this just a one-man band company – is this just you?
Bob: Actually I have myself and a couple of other people now. I didn’t really mean to have a company.
Dave: God damn it! I didn’t want to run a damn company!
Bob: I had done a start-up before and then I was working at the local university but with the cutbacks and things that job went away, so I just started this company to pay rent.
Dave: Oh okay, so you’re not currently working at the uni, you’re not a professor at the university?
Bob: No, I teach still for them. I just don’t get paid very much.
Dave: Right, okay.
Bob: Like this semester I’m teach engineering statistics.
Dave: Oh, yeah, right, fun stuff!
Bob: They don’t want to spoil the reputations of any of the other faculties on campus so they have me for…
Chris: The whipping boy of teachers now, right.
Dave: How does that work? You get paid less, so you’re, what, considered a temporary teacher is that what the…?
Bob: Well they call it adjunct faculty.
Dave: Ah right, okay.
Bob: Adjunct professor.
Dave: Ah right, adjunct, right. I’ve heard that term, I never really knew what it meant.
Bob: It means you don’t get paid very much. You don’t have tenure.
Dave: Right, okay.
Bob: I do it out of a community sense, and it also keeps me involved with the university and all that sort of stuff.
Chris: So this is University of Idaho?
Bob: It’s called Boise State University.
Chris: Oh Boise State, okay.
Dave: Why Idaho? Were you born and raised Idaho or did you move there for some reason?
Bob: Idaho is, like so many important things in your life, totally by accident.
Dave: Do tell.
Bob: In my first incarnation as a graduate student I was at Johns Hopkin working in X-Ray astronomy and we had an experiment that we flew on an air force satellite out of Vandenberg. I had gone to school as an undergraduate up at Washington State University and so I came out West for the satellite launch. I went up to visit my friends at Washington State, and actually Dave will relate to this, I was visiting with my friend and his kid needed to have his diaper changed. So while he was back changing the diaper the phone rings so he asked me to answer the phone. Well it was another friend of mine that was working down here. HP had just opened up a division, the disk memory division down here and they were looking for people to staff it up. The reason why it’s in Boise is because Hewlett & Packard used to like to ski quite a bit up in Sun Valley.
Dave: That’s right, yeah.
Bob: They even had a ranch up there. The guy who was the CEO at the time, John Young, was from Nampa, which is a small town close by. So there’s no other good explanation except that just pure accident.
Bob: Yeah. I did get in early days in the disk drive business, although disk drives back then were…
Dave: Manly disk drives they were; they were the maaaaan!
Bob: One of ours actually used a washing machine motor.
Bob: But we also could sell them for amazing amounts of money. We had a 400 Mb drive; I think it was about $25,000 piece of equipment back then. I graduated from college in ’77, my Bachelor’s degree.
Dave: That was before you were born, Chris.
Bob: Yeah, I know.
Bob: I had my first license as a Ham radio operator in 1967, when I was like 12…
Dave: Yes, awesome!
Dave: Okay that was before I was born.
Bob: That was the timeline. Just before that, it was the dinosaurs, right?
Dave: Right, yeah. And well according to some states in the US, yeah.
Bob: Exactly! So anyway – I forgot what I was talking…
Chris: You said you graduated in ’77 that was, I think, where you started.
Bob: So disk drives and microcontrollers and that kind of stuff were only available at big corporations, in computers basically. PCs came out in early ’80s. What amazes me at this point is how much access to technology there is. I just bought one of the new LPC-Link 2s, their new debugger and it’s, like, 20 bucks.
Dave: I know it’s crazy.
Chris: Versus [list 00:16:08] prices, right.
Bob: You can run Segger JTAG on it or the NXG, Red Probe and all this other stuff.
Dave: Well that’s the thing. People don’t realize, before about 1990 doing your own microcontroller stuff at home was practically unheard of.
Dave: You just couldn’t afford the tools.
Bob: It was impossible really.
Dave: Yeah, it was impossible.
Chris: Well I remember Jack Ganssle said he built his whole first business on doing an in-circuit emulator. They had this entire industry on its own.
Bob: Now the tools have just got so amazing too, the software tools to do the development. The same thing, okay – I feel so silly – when I first did PC boards at HP, we actually used tape and paper and then took a picture of it.
Dave: Yeah, been there done that. Chris hasn’t!
Chris: No, no.
Bob: Things like EAGLE are just amazing to me as well.
Chris: Yeah they had finger tips and everything, right, the CAD.
Bob: The other thing that’s been, I think, very exciting is the kind of things like Dave’s doing this video and other people, that there’s community around the Open Source and Jerry’s stuff. You can go out on the web now and learn so much if you want to. So being a autodidact is a much easier thing now than it used to be.
Chris: Yeah, let’s troop to the library. Knock on their doors, begging to sit in the library for a little while.
Bob: Well what’s amazing is also how willing people are to help. We were talking earlier about the Bluetooth low energy. I hadn’t done anything with Bluetooth low energy and I had a project come up that really needed it and started looking around. There’s this Jeff Rowberg I know at Open Source hardware site, and so I got in touch with him and he just turned out to be a ton of help in getting the Bluegiga BLE112 out and running. He even was able to provide EAGLE footprints. So just being able to do stuff these days is amazing. I think it’s the synergy of all the people working together that make it so interesting.
Dave: That used to happen before the communications’ revolution except you used to send letters or you’d call people up on the phone. I’d get letters in the mail; can you help me with this? So I’d spend all day writing a reply letter and lick a stamp and send it back and that’s how you communicated and shared information.
Bob: I’ve got some really funny ones. My dad saved some of mine from when I was a kid, writing off to these big companies asking for parts. I built a phase lock LUKE-based radio tele-type demodulator back in about 1970 and it was based on one of these brand new LM565s I think it was or 567. It replaced a refrigerator-sized piece of hardware at NASA, was one of the things they claimed at the time, which it probably did. I ordered one and the company thought I was some other big company or something, anyway it showed up on Christmas Eve by special delivery and all this stuff and I just wanted to work on it over the… and I built a board. We had – I forget why we had this – our school had (00:20:00) a, I think it was for exposing printing plates or something, UV lights…
Chris: Like a light box?
Bob: Yeah, light box, and so I was able to take it to school and spray on the resist and then expose it through a negative that I got made.
Dave: Those were the days.
Chris: [inaudible 00:20:17] look on the Internet, right?
Bob: Now I just send off Gerber files and the boards come back in a few days.
Dave: Exactly. [inaudible 00:20:26] of the world.
Bob: It is. It’s hard to decide where to divide your time too because you could do all these things still but it doesn’t seem worthwhile in some ways.
Dave: Tell us about it. It’s the bane of every engineer’s existence these days, isn’t it?
Dave: There’s just too much stuff to work on and just, you know, too much stuff cool stuff to play with and not enough time, I know.
Bob: I know.
Dave: It’s crazy.
Chris: I’ve just cut down on sleeping. Have you guys tried that?
Dave: I’m trying that but, you know, wife doesn’t get happy.
Bob: I’ve been reading a lot recently that you really should get eight hours of sleep to be creative.
Chris: Yeah, no, I do [inaudible 00:21:03].
Dave: Well, no, some of my best stuff has been done with my eyes practically shut.
Bob: Oh really?
Chris: That was under the gun probably too, right, Dave. It’s not like…
Dave: Of course, yeah, having that timeline, yeah, time…
Chris: I think that was more the key there.
Bob: Yeah. That’s one of my biggest motivators.
Chris: I just sit there like in a stupefied sleepless haze and I just click stuff at that point but I still want to be doing it.
Dave: So tell us about this start-up you did because we always love hearing start-up stories.
Bob: Well most of the start-up stuff you read, you know, the Facebook stuff is all business porn, pretty much. It was a fun project but it nearly ruined my financially.
Dave: Ooh, do tell; people love to hear these things.
Chris: You take the good, you take the bad.
Dave: Are you willing to lose all your money? Yeah.
Bob: You’ve got to be willing to do that. A start up should really be looked at as business hypothesis that you’re going to test out and you should be dispassionate about it. At the point where you’ve proven that it’s not, you should stop at some point. You know those inspirational posters that businesses like to put up?
Chris: Like with the cat hanging on by its…
Dave: Yeah, yeah, yeah.
Bob: The one with the ship anybody can sail on. The one I always liked was winners never quit and quitters never win. Anyway, never mind, I forget how that went.
Dave: yeah, I know.
Chris: Sounds like the posters worked.
Bob: Yeah. I learned a lot from it, I have to say that. I learned a lot. The idea was consumer product and getting traction and the resources you need to do a consumer product is really difficult.
Dave: That’s tough, yeah.
Bob: This is back in 2001/2002… you can also be too early into things.
Dave: Like pre-kick starter.
Bob: Yeah, pre-kick starter. So we had, essentially, a media center PC that was controllable through a wireless pad, but it was one of those early Windows CE pads and it was pretty awesome. We tried to differentiate it from just a big remote control by some of the things it could do. One of the things it could do is really simplify working with media that was on the Internet. One of the other things it could do though was display video from security cameras. The idea was that maybe you’d be watching the movie but then the doorbell would ring and you decided you needed to answer the door or something like that, or if you had a swimming pool and you wanted to monitor it. The security part of it is what got traction so we pivoted at one point, when we weren’t really making many sales on the entertainment side, into security and then sold the company to a small publicly traded company up in Canada. Then the guys that bought it tried to cram down all the early investors, including all the people that invested with me and my own self, and it got… they actually succeeded in pulling a lot of the capital out and having the stock… because I thought when we sold it to a publicly traded company that that would provide liquidity for the investors, which is what you’re always looking for.
Dave: Yeah, yeah, of course.
Bob: As part of the sale there was a period of time where they couldn’t sell and in that time they…
Dave: Ah, they stripped it.
Bob: Yeah, they did.
Bob: Anyway we had to get lawyers and it was a mess.
Dave: Ahh, yeah, right.
Chris: It was not fun anymore.
Bob: No. Well I learned a lot.
Dave: That’s what everyone says, yeah.
Bob: It wasn’t one of these deals where you work for 18 months and sell it for $1 billion to Facebook.
Dave: That’s never happened.
Bob: Well, Instagram.
Chris: Yeah, right.
Dave: Well, yeah, exactly. Out of how many start-ups, millions, there’s a dozen success stories. Nobody ever talks about the failures; that’s the problem. No, not failures but the non-success stories.
Bob: If you look at it as a hypothesis, then either a positive or a negative outcome is a good outcome because you’ve driven it to a resolution. The problem is if you get so enamored with your product that you don’t quit when you really should.
Dave: Right, yes.
Bob: It was a close failure.
Dave: Missed it by that much.
Bob: One of the other things I learned was to do something, or to have at least some way to have an income early on. This other product we worked for a year on it before we started trying to sell any. It’s better to do something, even when you’re first starting out that doesn’t have such… unless you have somebody with really deep pockets to back it. So the current company right now, I have some projects in the background that are sort of longer term. What I’m doing right now is more product development for other people. The problem with that is it doesn’t scale very well because you’ve either got to charge more…
Chris: Only so many hours to sell the data.
Bob: Or work longer.
Dave: You’re basically selling your hourly rate; you’re charging your hourly rate and you’re a gun for hire.
Dave: So there’s no big pay off at the end. You just get continuous employment and you can eat. Congratulations!
Bob: The way we’re using it is doing some product development on the side and to try to be strategic about the projects that we take on. For example, this Bluetooth low energy project gets us involved and learning a technology so that learning becomes an asset of the company.
Dave: Right, smart.
Chris: It is smart.
Bob: Hopefully it turns out…
Dave: You’re interested in this low energy stuff, Chris.
Chris: I am, yeah. You guys are using the 2540 chips.
Bob: Bluegiga is the company in Finland. What they’ve done is put some nice… well they sell these modules first of all, which are FCC-approved so you don’t have to put your equipment through the…
Chris: That’s awesome; that’s the reason to do them.
Bob: Then they also have provided a CAPI that you can compile if you have an external microcontroller with your code.
Chris: What’s it talk over? Does it just talk over some serial…?
Bob: Through the UR on the CC2540. They also have something called Bluegiga Script, which allows the module to actually… because it has an 8051 control in it, so the module itself, you can actually hook sensors directly to the module and run Bluegiga Script on it and not really have to hook up an external MC-02, so it can be a standalone.
Dave: Very nice!
Chris: That’s kinda cool.
Bob: Yeah. The other thing about Bluetooth low energy, it’s really Bluetooth in name only because it’s really the very lowest levels, like the physical layer that are Bluetooth.
Chris: Yeah, the stack on top is different, right?
Bob: It’s very different. And it’s designed for sending bursts of structured data, so if you have a thermometer or something. And it has a different way of hooking up. So if you have a sensor hooked to your Bluegiga module and then it advertises that I’ve got temperature data, so anybody that walks in the room with the application can say, oh that can attach to it.
Dave: Right. So it’s like in Windows, it’s a generic USB microphone or something. It just tells us that it…
Chris: It’s a nerd!
Bob: Yeah. There’s a thing called a general attributes’ file and packet that’s part of the advertising that tells everybody what it can do, whereas with traditional Bluetooth, you have to send a PIN back and forth and all this.
Chris: Yeah, it’s like a handshake at that point, right? [inaudible 00:30:23] traditional.
Bob: Yeah. It’s really designed for sensors and the Bluegiga script is a pretty cool way to program it because you just need XML Editor and then they provide an application that works with the TICC debugger, the same one that TI supplies when you work directly with their TCC2540. You don’t have to install IAR and all that expense associated with that to program it then.
Chris: Yeah. I see a lot of interest in that kind of stuff. I see a lot of projects online switching over to Bluetooth, finally. If you think about it too, if you think about Android devices or even iPhone devices too, there aren’t that many ways to get into the phone and that’s the de facto gateway these days, aside from going through the web.
Bob: I was reading an interesting article yesterday though about what this is doing to Apple’s ecosystem because they used to require that you joined this Mi-Fi or MFi, MEFi…
Chris: Yeah, having that Apple chip on a wire device, right, that does the translation.
Bob: Yeah. If you were designing hardware for Apple, you had to use the 32-pin connector that they’ve got that’s special and nobody else uses.
Bob: Now with the Bluetooth you can bypass all that, so yeah, that’s a good thing.
Bob: Bluetooth low energy’s on some of the Android devices, it’s on some of the Samsung Galaxy devices.
Chris: Yeah, on the HT-21, I think. I’ve been shopping for those. I was telling these guys before the show that I’m starting to shop for Google [iOS 00:32:13] stuff because that has Bluetooth low energy but it’s hard to find [inaudible 00:32:19] phones.
Dave: So you have to ask a specific phone with low energy support? Is it a different chip set the phone or is there just one chip set that handles low energy mode?
Bob: I guess they probably have to have a dual-mode chip but that’s pretty common. I guess that’s the main thing, but then otherwise it’s just software.
Chris: Yeah, and that’s the key thing.
Dave: A regular Bluetooth phone can’t talk to a Bluetooth low energy device?
Bob: No, no.
Dave: Okay. I’d need a new phone then.
Bob: Yeah. But I think it’s going to become more common. You turn phones over every couple of years anyway.
Chris: Yeah, right. I’m just a cheap ass.
Dave: Yeah, same here. I just keep cursing my phone. Instead of buying a new one, I just curse it every day.
Bob: I’ve got my Ericsson block phone.
Chris: There you go. It’s good for paper weighting and stuff like that.
Dave: Ah, love it!
Bob: Anyway [they have 00:33:21] good stuff.
Chris: What’s with the older stuff? You sent a picture out the other day on Twitter because you’re very active on Twitter, which is great and that’s…
Bob: I like to choose Acquiba.
Chris: Yeah. You sent a picture of you in a hoodie and said I was wearing hoodies before Zuckerberg was even born.
Bob: That’s true. That’s true.
Chris: What is in this picture?
Bob: Okay. What that is, is a system for measuring how the recording heads fly over the disk and it’s a Heterodyne Interferometry system. I take the single frequency laser, 632 nanometers, and split it and then frequency shift it with these things called acousto-optic modulators. Those signal generators up in the corner of the rack, those are just to drive the acousto-optic modulators at certain frequencies. What happens is when you recombine the light, you create an optical beat note and the phase shift of the beat note, which you can bring that beat note down into the 2 megahertz range if you want, or even down into hertz. In fact, you can actually slow in down just like you listen to a beat note between two tones and needs to bring the tones closer in frequency and you get that wow, wow, wow thing, you can see this all in the optics. What it does, it lets me then measure the phase by just measuring the phase of the 2 megahertz optical beat note, so I could get with the phase detector that I had, which had a tenth of a degree resolution, I could measure the [LAN 00:35:10] to over 3,600. In other words, 632 nanometers divided by 3,600, so I was getting like a tenth of a nanometer resolution in position.
Bob: With a 500 kilohertz bandwidth, and what I would do is eliminate the whole head and disk around it and…
Chris: So this is the actual head of the arm?
Bob: The recording head. In magnetic recording, the head’s actually flying over the disk, but if the head separation changes it modulates the amplitude and affects the air rate and other things.
Chris: So it’s just a bleed over channels and stuff then or…?
Bob: Well you can have that if things get really bad, but just back then we were trying to have [raw bed 00:36:00] air rates in the neighborhood of, it seems like 10 to the minus 8 or something like that. Then we’d boost it with ECC up into the 10 to the 10th.
Dave: You’re just doing this in the lab. Usually these hard drives are vacuum sealed to keep out dust and crap.
Bob: Yeah, well it was fairly clean conditions.
Dave: Fairly clean as in you would smoke outside instead of inside [laughs].
Bob: Actually it’s funny but back then they did allow people to smoke inside. You notice the disk diameter there is about 14 inches.
Dave: Yeah, yeah, it’s huge.
Bob: The flying height at the time seemed really small but we were flying at like 19 millionth of an inch above the disk surface.
Dave: Ahh, you’d drive a truck under that.
Chris: You can have an earthquake and it wouldn’t touch, right.
Bob: Yeah. What we were trying to do was design the mechanical structure that held the head out there so that it wouldn’t flap in the wind. Disk drives, they get pretty warm, especially if you can get some of those 15,000 rpm drives, they get pretty hot. Most of that heat is just the air friction.
Dave: Really, right.
Bob: Very little of it’s actually the electronic heat, or the electronic heat that we think about.
Dave: Yeah. Yeah.
Bob: Designing the mechanical structure inside to deal with all that was a pretty good challenge. The disk drives were a lot of fun to work on because they had all these server systems and mechanical challenges and magnetic challenges and electronic and you know…
Dave: This is a great photo. You’ve got to see it folks. We’ll definitely post this as your feature photo for the… or would you prefer your Twitter photo. This one’s awesome.
Bob: No that one’s fine.
Dave: Excellent beard by the way!
Bob: Oh, thanks.
Dave: So is this an anti-vibration laser table?
Bob: It’s just a giant piece of granite.
Dave: That works too.
Bob: It was 4′ x 6′ x 1′ thick.
Dave: That works as well, yeah.
Bob: Then the disk is actually on an air-bearing spindle. So the spindle’s very low vibration, very low run out.
Chris: What timeframe was this, this was 1980s, 1970s?
Bob: No it was about 1981.
Chris: ’81 okay.
Dave: What model HP scope are you using there?
Bob: Those are 1740s.
Dave: Right. There are no evil Techtronic scopes in the building?
Bob: No. It was pretty funny when people would want to get something like that. For some things they had to because that was the capability we didn’t have.
Dave: What’s this purchase order for this Techtronic’s scope? Heads will roll.
Bob: Well actually it wasn’t so much that there was… HP was an awesome place to work when I started there. Very different than the company it is now. It was 82 different divisions and each one you had a product, and each division was run as a small company. Disk Memory division was one of the largest ones, it had 300 people in it, but most divisions were 50 to 100 people and they had all the functions of a small company. The advantage of that was that they were really close to their customers. The disadvantage is that HP, looked at from 30,000 feet, the way the CEOs and MBAs look at it, it looked like a real fragmented place but it really wasn’t. Yeah, 1981 (00:40:00) very, very different times.
Dave: And Hewleys were all the rage?
Bob: Yeah. What I was going to say is Agilent now was part of HP then. The reason they broke up the company was, again an MBA thing, they broke up the company because their stock on computers had higher multipliers than the stock on the instruments. So people thought if they broke it up, then the half that was computers could run at a higher multiplier in the stock market than the instruments.
Dave: That old short-term gain chestnut.
Bob: It was, exactly.
Chris: It worked for a little while, right.
Dave: I’m sure it worked a treat.
Bob: It never worked very well at all. Every time they did a merger, two plus two equaled one and a half. It never even made it to four, much less five or six. They always convinced people that it was a good idea. A long way around but what I was going to say is, so we got these instruments for a transfer-at-cost they called it. So basically we got the instruments for paying the bill of materials on it.
Chris: Not any of the labor?
Chris: Oh wow, that’s pretty good.
Dave: Yeah, it’s awesome.
Bob: So we’d trade disk drives for oscilloscopes.
Chris: Back-alley deals.
Bob: Disk drivers were worth a lot. So we had a lot of nice instruments. Hewlett and Packard would actually come around. I’ve got this old HP signal generator that was based on Bill Hewlett’s Masters work at Stanford University but…
Chris: Oh 200, right?
Bob: Yeah. I got him to autograph it. They were just around at the time looking at… and I got him to… but they were the sort of people that you could just walk up to and talk to. One of the nice things that HP did for me was they sent me back to graduate school so I got my PhD back at Carnegie Mellon while working for Hewlett Packard.
Chris: Wow, that’s awesome!
Bob: So I was one of the better paid graduate students.
Chris: You were being paid?
Bob: Yeah because the deal was they paid all my tuition books plus I had 75% of my salary while I was going to school.
Chris: Oh, my God that’s awesome!
Bob: I know. They would never do that these days.
Chris: Yeah, these days, I don’t think you’d find any company that does that.
Bob: Yeah, so I wrote Hewlett a nice thank you note after it was all over, and he wrote back and it’s just the kind of people they were.
Chris: That’s really cool.
Bob: Whereas I was in a meeting with, I think this is fair to tell, they can’t fire me anymore.
Dave: Yeah, please, do tell.
Bob: I was in a meeting where they had all the senior engineers; it was a HP internal technical conference.
Dave: Ah, so there were Hewleys as far as the eye could see.
Bob: Yeah, exactly. Actually the HP guys were more like the old Ham radio operators.
Chris: Yeah, suit and tie, skinnies on.
Bob: No, it was always a jeans and t-shirt kind of place.
Chris: Oh good.
Bob: You never saw a tie around there, and if you did, people would make fun of you. This is when Carly first came in and so if it was Hewlett & Packard because I’d been to these kind of meetings before, they would come and have breakfast – they would always have a breakfast buffet beforehand in the morning – and they’d come sit at the table and talk and find out what was going on. The way HP changed when Carly came in was, we were sitting there having breakfast and then over the PA system it says now introducing the CEO of Hewlett Packard, Carly Fiorina, and she walks out on stage with spotlights and her sycophants in the audience. Then as soon as she was done, she took a few questions from some of the shills in the audience and then she said well I got to go and walked off and never talked to an engineer. So HP in the days when I was rigging there and the apex of it – I also worked down at HP Labs in Palo Alto – was a great engineering company to work for. There are still parts of it that are good but it’s just not the same as it was. So they used to be really out buying for the engineers.
Chris: I wonder if that kind of thing is even possible these days.
Bob: There are companies…
Dave: I’m sure it is. I think it is. It’s just got to have the right attitude.
Bob: Yeah, I think so. Actually Seagate is a little bit like that, at least the part of it that I’ve been to.
Dave: It’s very common in software companies like Altium who I used to work for, that was a dream job. There was no management, no adult supervision, no meetings, no nothing; it was just do whatever you want. It was just, you know.
Bob: Actually what they used to say is work smarter not harder. And it was management by objective. They really took that seriously. So if you agreed to do something and however you could get it done, they didn’t…
Dave: Done, then that’s it exactly.
Bob: They didn’t try to tell you how to do it.
Chris: That’s good.
Dave: So if any of our listeners out there work at a company like that, please tell us. We may even have you on the show to talk about it.
Chris: Jerry did, I thought.
Dave: Well, yeah, tell they have her the arse, year, which you might hear about shortly.
Bob: I’m really curious to hear about that.
Chris: You said management by objective, which is the like the Bill and Dave thing, right, that’s what their big thing was.
Chris: You actually had another management consultant, and I’m sure Dave’ll start droning now that I’m bringing it up, but you had someone sit in with you that’s pretty famous as well.
Bob: Yeah, you’re talking about Clayton Christensen, who’s famous in the business management circles for his book, The Innovator’s Dilemma, which actually is a serious…
Dave: [mock sigh], sorry!
Bob: Well actually I saw it happen because what he did… I hosted him at here because he did his PhD work on studying the disk drive business and the things that he described in there I could really relate to because the things that he describes in that book really did happen in the disk drive world. Yeah, he was out when he was a PhD student and I just hosted him around because he was collecting information on disk drive companies at the time.
Chris: Yeah. That was one of the big examples and then I think he talked about backhoe companies was another big one.
Bob: Yeah, well in disk drives, they have these companies that come in and people ignore them. If it was disk drives, it was Conner. We were building these big high margin 14″ discs and Conner came in with a 5″ disk that was kind of a toy that went into PCs and the performance wasn’t any good. Nobody thought it was… another thing that used to happen back in those days were people tried to protect their hardware by having proprietary interfaces and HP tried to ride that for as long as they could but the PC…
Chris: SCSI cables came along.
Bob: Suddenly changed it, yeah.
Dave: Yeah, the standards came in.
Bob: The companies like Conner got better and became Seagate and a…
Chris: Oh is that what started Seagate, I didn’t know that.
Bob: I don’t know the exact pedigree but it’s all entangled in…
Chris: [inaudible 00:47:53].
Dave: Yeah, it’s a very incestuous web, the hard drive industry.
Bob: Yeah, it is.
Chris: You got out though.
Bob: Yeah, well I did. HP decided they couldn’t make it anymore in disk drives, and whether they could or they couldn’t is debatable, but they got out of that business.
Dave: By selling it? Was there anything to sell off in the end or had they just been totally trumped. They folded.
Bob: No, they just totally walked away from it. There was some technology. They tried to capture some of the technology but if you don’t capture the people with… giving somebody a stack of gLab notebooks doesn’t really do a lot of good.
Chris: Here, fix this.
Bob: The big companies do a lot of patenting. But the patent business for them is not so much about the IP in the patents as just the overall throw weight of who has how many patents. So the disk drive business… it’s funny because they sent me to school and within less than a year of coming back from school, they shut down the division. So I got involved in a tape project actually called, Linear Tape Open, which was a new standard that got established, and HP was one of the companies that helped to establish that.
Dave: Tape, as in magnetic tape?
Bob: Yeah, magnetic tape, which is still used quite a bit in archive. If you think about the hierarchy of archive, you have fast drives and then slower drives and then still eventually when you get back far enough, you get onto tape because the volume density, information storage density, of tape is hard to beat. You can’t underestimate the transfer rate of a station wagon loaded with tape.
Chris: The next step up from sneakernet (00:50:00) is [wagonnet 00:50:].
Dave: It’s the sheer surface area, right because I assume you can’t get the same density on tape as you can on hard drive just due to the physical geometries and stuff.
Bob: You can do pretty good but not quite as good.
Dave: Not quite as good but the fact is, it’s very thin tape and you can roll hundreds of thousand meters on one little spool.
Bob: Yeah. The software that manages these storage systems is pretty amazing because they can work out and figure out which data’s not being used very much and move it further down the hierarchy until eventually it winds up on tape, where… stuff that you never. And it’s all handled transparently.
Chris: This is like cloud software you’re talking about, like high level storage.
Bob: Big data center software, yeah.
Chris: Huh! Is that like the…
Bob: Well I have a friend who makes these big disk arrays now for HP and they can store a petabyte and I said oh you’re working on pedophiles.
Bob: They can store a petabyte of data now; it’s not a big deal. That’s not uncommon.
Chris: Man, that’s a lot of data!
Bob: Well, there’s a lot of things making data these days.
Chris: That’s true, yeah.
Bob: Yeah, the FBI’s got to store all the phone messages they’re…
Dave: And every video that I produce, yeah…
Dave: So they can declare me a terrorist.
Bob: Exactly. Just throw random words into your video like plutonium or something.
Dave: Yeah, yeah, White House and President, exactly, that’s how to send out red flag. Awesome! Yeah, that’s my goal.
Bob: NASA, each of those probes generates a lot of data too. I don’t know there’s a lot of places to store data, Facebook, that’s kind of embarrassing. I remember when I started out and I was at HP Labs and we were on the early ARPAnet, I just felt insulted that they’re starting to let commercial operations onto the ARPAnet.
Chris: This is ours. Bob, would you write the first folio, like get these people out of here.
Bob: Back on the old UUCP groups. Well it just seemed like it was, yeah, it was commercializing something that was pure.
Chris: There goes the neighborhood.
Bob: Yeah, we didn’t lock our doors back then and now I’ve got firewalls and antivirus and everything else. I totally missed the whole web thing. I just thought that was a fad.
Dave: Oh really!
Chris: Oops! These things happen, you know. You’ll get it next time.
Bob: How can you make money on that. Facebook, that’s a dumb idea.
Chris: It is kind of dumb.
Dave: There’s a lot of dumb people out there. That’s the sheer weight of dumb people.
Bob: I don’t know how they make money on Twitter but I guess they do.
Chris: I don’t think they do yet.
Dave: No, I don’t think it’s a profit-making enterprise.
Bob: You know what’s amazing to me about Twitter is it’s like a cocktail party that never stops. I get on there and [Cuba’s 00:53:36] and Tokyo and micro-builders over in Paris and Chris’s on, VK2ZAY and all those people. So there’s always something interesting. In fact I have to shut it off when I want to get any work done.
Dave: Is your Twitter name, is that your Ham call sign?
Bob: Yeah, it’s my Ham call sign.
Chris: I was actually talking to people… because I just got my radio finally and I’ve been trying to find the repeaters around here. So I was asking about that because I got it all cued up to the right frequency and everything, and I was just sitting there waiting, waiting, waiting, waiting and I go, what the hell’s going on here. Someone says well, you know, there’s Twitter, there’s just tons of other ways to communicate whereas before repeaters were it.
Dave: Chris just jumped on the bandwagon…
Chris: I just got to the party.
Dave: … and realized he’s the only one left.
Bob: It is pretty quiet I have to say…
Dave: Hello, anybody out there?
Bob: … compared to what I remember.
Bob: Cell phones, now out here in Idaho it serves as a real public service because there’s lots of places where cell phones don’t get.
Chris: Yeah, right but just the repeater network before, it seems like that’s what it used to be. I see a lot of call signs on Twitter, which is great because people are making these longer contacts and I think it’s actually…
Chris: No, no I didn’t mean like that. I didn’t mean like that, although it is pretty funny. I meant they try for the harder stuff with their actual antennas and stuff. That’s what I really meant. Hey, this radio thing’s easy.
Bob: They get on Twitter and set up their radio contacts.
Chris: Yeah, right.
Dave: Well technically if you’re using a notebook you’re on wireless, right?
Dave: Unless I ping somebody in Germany.
Bob: That’s raised an interesting issue though because when I started out I had lots of help and I built a lot of electronics when I was a kid. It was made out of tubes but it was still electronics. The maker movement and all this stuff that’s being going on with the tools and things is a good thing but there’s been a period where people weren’t building a lot of hardware it seems like.
Dave: Yeah, the ’90s as a… to early 2000 was a…
Chris: A dead zone.
Dave: … a dead zone, yeah, it was.
Chris: Everybody was getting excited about computers. Bob, it’s your fault, you’ve made all these disk drives.
Dave: That was the problem back in the ’90s. That’s all people cared about was computers. Electronics as a hobby had almost vanished. It was really quite dicey there for a while. I thought the whole thing would actually vanish.
Bob: It seems to be coming back.
Dave: Well, you know, wouldn’t vanish but like all the magazines would die and then nobody would care about it on the Internet, but now, whoah, holy crap!
Bob: It’s a big change.
Dave: Love it!
Chris: It’ll be interesting to see at Hamvention too just to see if… I don’t know if they have any idea if there will be less people than old videos showed and everything…
Dave: No, there’ll just be lots of old grey beards standing around tweeting each other.
Chris: Yeah, right.
Bob: Chris mentioned it looked like Woodstock and I said, oh boy! I don’t know.
Chris: Don’t want to see naked Ham people around, no?
Bob: No, not the ones I’ve seen.
Bob: I did notice at our local Hamvention a few weeks ago, which I went to because they still stay in touch, that there was a bunch of younger people there. That’s probably a good sign.
Chris: Yeah, and Tony who we’ve had on the show before talked about microwave stuff. I think he sent me a link showing the ARRL membership is up a lot more than it used to be too.
Bob: Yeah. I like what Tony’s doing with making the microwave stuff available to people. I’m real tempted to jump into that.
Chris: Yeah. I’m just getting started on the “low frequency” stuff. High frequency for me used to be like 20 kilohertz and now it’s moving up a little bit.
Bob: That’s another interesting thing I think because high frequency digital circuitry used to be, I don’t know, 50 megahertz.
Dave: 10, 20, megahertz, yeah. You had 50, whoah, hold onto your hats folks.
Bob: And the radios now that are up in the 5 gigahertz and 10 gigahertz range that are all solid state digital things.
Chris: Crazy, like silicon, germanium, indium whatever’s in there, yttrium.
Dave: I never thought of kids building their own PCs with 4 gigahertz processors, it’s just ridiculous.
Bob: I was giving Acquiba a hard time because I just built one of those recently and I said I was going to put Linux on it so I could use VI and Arch and [GRUP 00:58:54] and stuff like that.
Chris: Yeah, well I don’t think you’ll be alone in that.
Bob: But at 3 gigahertz.
Chris: Oh right, yeah.
Bob: Actually what is amazing about PCs also now is that you can throw these virtual machines on and you can have Linux and all this stuff all in one box running at the same time.
Chris: Yeah. That’s great for troubleshooting. I’ve worked with some people too that they’ll throw an emulator on a virtual machine. It’s not quite as fast, and then you have to jiggle with the play through, the pass through, of like USB or whatever you’re debugging with. You can actually have entire ecosystems of like your compiler and everything else in a virtual machine and then you boot it back up and you have that exact same system. So that’s a nice little trick you can do too.
Bob: Yeah, I do that. Sometimes vendors will send you, I’ve got a Analog Devices A to D convertor and they sent along a little, well it’s really something based on LabVIEW and it really wanted to run in XP, (01:00:00) so I just set up an XP virtual machine and put it in there. It didn’t collide with my other LabVIEW. Yeah, so it’s a great thing.
Chris: That’s pretty cool.
Dave: Please can we not talk about PCs anymore?
Chris: Yeah, consumer world. It’s still tools we use though, right. I mean it’s not like electronics is getting away from [inaudible 01:00:21]
Dave: Yeah, but that’s it; they’re just pens really.
Chris: Yeah, right. No, the thing about it is…
Bob: Well I have one on my bench but it has a bunch of debuggers and…
Chris: LT splice.
Bob: Another things that amazing is these Saleae logic analyzers that you can hook onto your PC now and do a pretty decent job of analysis with that…
Chris: Yeah, versus the old huge Agilent or HP boxes.
Bob: Yeah, or having to buy of these expensive, although you can’t really call them expensive anymore, but one of these more expensive scopes. I’ve got a Rigol scope here, the 1052, but I’m tempted to go to the new 2200…
Dave: The new 2000, yeah, very nice.
Bob: I watched your YouTube on that.
Dave: Yeah, the comparison video of those two, yeah. It’s amazing how far we’ve come in four years.
Bob: The other thing is just awesome, and I bought it even though I really didn’t have a use for it right now, which was the Rigol 815 spectrum analyzer, which for $1,500 and it comes with a tracking generator and…
Dave: Amazing bang per buck, yeah.
Bob: Well, I don’t know, a year ago, you’d probably have to spend $12,000 to get that.
Dave: Yeah, yeah, I know. Yeah, several years ago, the average person could not afford a spectrum analyzer. If you were lucky you got a second hand old boat anchor one off eBay, but apart from that, yeah.
Bob: This is a pretty decent one.
Dave: Yeah, it’s not too bad. It’s not going to do leading edge stuff but it’s…
Bob: But neither am I. [laughs]
Dave: Exactly because it’s phase noise is not [inaudible 01:02:07].
Bob: I’m not trying to build a cell tower here.
Dave: No, exactly. That’s right.
Chris: Can it do 6 gig? What’s the frequency?
Bob: 1.6, yeah.
Dave: No it’s only 1.5.
Bob: Yeah, 1.5. It’s good for your camera.
Chris: Yeah, very good.
Bob: Looking at the Spectrum period in my handie-talkie.
Chris: Yeah. No, that’s pretty cool. You do some Open Source hardware stuff too, is that some of the energy harvesting stuff you’ve done or what was that?
Bob: Yeah, that was one project, just trying to give back in a small way because I’ve learned so much. It’s possible to be a EE and not actually do circuits, by the way. What I did mostly for HP was model magnetic materials and do computer models of actuators and disk drives and things, and I worked for some really interesting people and that was a lot of fun but it wasn’t designing circuits or biasing transistors and stuff like that. I’m really attracted, I guess because of my personality, to the self-learning that goes on, and so watching Dave’s videos on how to do PCBs now because I found out that nobody tapes them so I had to learn.
Dave: What, you use computers for that? What?
Bob: So I had to learn a whole bunch of new skills. One of the things about openness and about Open Source hardware that I found is that you get back more than you could ever give out. So I’ve been doing this little energy harvesting thing, which is more personal interest. I’m interested in wireless sensor networks and we have one over here in a grape vineyard where we monitor the grapes and that’s a whole other story. But the energy harvesting interests me because you’ve got to be able to power the sensors out in the field, so I built this little open source project. I’ve got emails from people all over the world about it that are just interested in it and tried to help, out some of them. A lot of college students that are trying to do senior projects on energy harvesting, but I try to help them as much as I can. I went to the Open Source Summit and that’s a great thing, if for no other reason than I got to hang out with Acquiba and Kevin Townsend and Jon, the engineer, and all those people back in New York.
Chris: I’m hoping to go that one again this year. I went to the first one but didn’t…
Bob: Yeah, go to the one this fall because I think everybody that I was with said they wanted to come back this coming fall because they had such a good time.
Chris: It’s in Boston this year too.
Bob: Oh is it?
Bob: I didn’t know that.
Chris: Yeah, I was surprised actually because it used to be in New York, the past three years, has been in New York at the Hall of Science, which is where Maker Faire is, or at Light Beam, which is where it was the last time, right.
Bob: IBEAM, yeah.
Chris: IBEAM, sorry, yeah.
Bob: Same thing.
Chris: The people who are putting it together, they’re up in Boston so they’re moving it up, like two or three weeks and then it’s going to Boston.
Bob: Okay. Well that’s fine. Boston’s a lot of fun too.
Chris: Yeah, it’s a great town.
Bob: The only thing I don’t like about Boston is going to the Museum of Computers because the stuff all looks brand new to me. What’s this doing in a museum, it’s still perfectly good?
Chris: So is this like the gift shop or…
Dave: Where’s the museum?
Bob: Actually one of the computers that I worked on, the companies that made them don’t even exist, like Data General and DAC and all that.
Dave: Oh yeah. I notice you’ve got an HP multimeter on your bench there, one of the hand-held. You don’t see too many of them around anymore.
Bob: Yeah. I don’t think they make those. I just bought a brand new Fluke 289, the true IMS voltmeter.
Chris: Oh yeah, that’s cool.
Dave: With the shit battery life, yeah.
Bob: I go to Costco.
Dave: Go to Costco [laughs].
Chris: I bet you could use some energy harvesting.
Bob: I have a microcurrent here for the energy harvesting, the EEBlog microcurrent.
Bob: I got it from Adafruit.
Chris: There you go!
Bob: Actually it’s a great thing because one of the big problems with the energy harvesting and wireless sensor nodes is being able to figure out how your software’s affecting the current drain.
Dave: Drain, yeah, exactly.
Bob: As you noted, and I guess that’s why you make it, it’s really hard to measure microamps.
Dave: Nanoamps. Well the story behind that is I originally made it because I wanted to overcome the burden voltage in the multimeter. It wasn’t necessarily because I wanted to measure nanoamps. I found the burden voltage annoying so I wanted to take that out of the equation. I thought when I was designing it, I thought I can throw in a nanoamp range, yeah, that might come in handy one day. That’s what most people seem to buy it for these days, is the fact that it can measure nanoamps. I didn’t think that would be a target market five years ago, when I designed it.
Bob: No I think it’s perfect for that. Speaking of multimeters, my dad was Ham radio operator and that’s partly how I got into it.
Chris: That’s awesome!
Bob: He had one of the Simpson meters [inaudible 01:08:12]
Dave: The 260 probably.
Bob: My dad and I would butt heads quite a bit because I would use the tools and not put them back and he would come and want something and couldn’t find the tools and it was always… but he always wanted me to work with him on stuff too, so I guess it wasn’t such a bad thing. I used to burn out that meter every once in a while because it’s tube days and it’s 300 volts and you’d have it on the arms and stick it across your 100 volts and burn out. Then he’d have to go replace the resistors in the thing.
Dave: They weren’t very forgiving.
Chris: No diodes built in.
Chris: No mercury valves or whatever it would be the [inaudible 01:08:59] diodes.
Dave: You usually wouldn’t burn out the meter movement because I think the meter movement had diode protection across it. I’m not sure about the Simpson 260 but most meters had, yeah, back-to-back diodes across the meter, so you wouldn’t blow that out. But as you said, you’d blow out important resistors.
Bob: The dividing resistors and so you’d wind them with… well he worked out at Hanford, which is an atomic plant up in Washington State, so he had access to some laboratory gear, so we’d wind new resistors to put in the front end of…
Dave: That’s awesome!
Chris: That’s really cool!
Bob: Yeah, my first radios had mercury vapor rectifiers in them and the old OA2s which had a nice argon glow to them. There were lots of smells and sensation and my first radio had a crystal oscillator driving a 6L6 [final 01:09:59]. It was (01:10:00)cathode keyed, so when you’d un-key the thing, it would come up to 300 volts, and if your fingers slipped off, you’d get the shock of your life.
Chris: Oh my God!
Bob: But it’s stuff you’d never get away with today but it was amazing.
Chris: Yeah, yeah, yeah.
Dave: Yeah, yeah.
Bob: I remember once this old railroad guy gave me boxes of batteries because they would replace the lamps with new batteries and they were those 6 volt…
Chris: The wet cells?
Bob: Yeah, well they were not wet, they were just… I can’t described them but they’re bigger than D cells but they were…
Dave: They were lantern.
Dave: Well we used to call them lantern batteries.
Chris: Even with the spring terminal on top and everything like the 12 volt?
Bob: Yeah. They were 6 volts I think.
Dave: Yeah, yeah.
Bob: So I had like 50 of them, so I thought well let’s just…
Chris: Yeah, of course, that’s why I [can be serious 01:11:00].
Bob: That made a really scary power supply.
Chris: For trying to get induction in this, yeah.
Dave: Well you could do the same thing with 9 volt batteries today; you don’t even need to wire them up. They just clip back to back and you can get 1,000 of them and put them in series and you can arc shit over. It’s really, you know, it’s really dangerous.
Bob: Actually I was replacing all the batteries at a summer camp that we were helping out at and sticking them in my pocket as I went along one day. I also had my keys in that pocket and all of a sudden my pocket started getting a little hot.
Dave: Oh no! My leg is melting.
Bob: Yeah, those 9 volt batteries.
Dave: And just before that, you used to ride a dinosaur to school.
Bob: That’s right.
Bob: Actually, it’s amazing what people used do to, though. My first radios were all World War II surplus but they weren’t that old at that point because the war was only like 15 years…
Chris: 22 years.
Bob: Korean War surplus.
Chris: Oh, there you go, yeah, nice.
Dave: Chris, you’ve heard of the Korean war, I’m surprised.
Chris: Yes, I had some relatives serve in it. And also I’ve seen M*A*S*H.
Bob: That’s about what I know about it.
Dave: Well they don’t call it the forgotten war for nothing.
Bob: You know there’s another thing that’s kind of interesting is when I was a Ham radio operator in my teen years, I joined this thing called Military Affiliate Radio Service. So we actually handled traffic and phone patches for soldiers that were over in Vietnam at the time.
Bob: And that was how people were able to talk to their families back then. It was very sporadic because you know how hard it is to talk on HF compared to Vietnam anyhow and so we…
Chris: You have to go for the right [inaudible 01:13:05].
Bob: Yeah. So we would pass messages and sometimes do phone patches for people which would be very brief, just because the conditions wouldn’t support it for too long. But now in Iraq or Afghanistan they just have cell phones.
Bob: Skype and talk, so that’s another major way how things have changed because that was the state of the art.
Chris: Yeah, that’s pretty cool.
Bob: One of the things that the Ham radio did lead to was I got my commercial radio telephone license and then I worked on two-way radios when I was in high school, and that was a really good job for a high school kid.
Dave: What actually repairing them or…?
Bob: Yeah. Well my very first job when I was 15, I was working in a TV shop when they used to actually repair TVs, you know, check the tubes and do all that stuff. It was a two-way radio business, so I worked for the local Motorola company and they installed radios for the public utilities and people that… and phone patches, even mobile radio, you used to have to call into an operator and then they’d patch you into the telephone network. It was crazy when you think about it.
Chris: Yeah, I mean that’s just hanging out there then, right; it’s not like it’s like a private phone call at that point.
Bob: Yeah, well there’s that too.
Chris: Yeah, you’re basing it on the fact that people own radios.
Dave: I can remember listening into people’s mobile phone conversations, back when we had the analog network. It was on 700 megahertz or something and I’d tune in with my scanner and you know it was boring as bird shit, you know, “I’ll be home at 7.00.” “What do you want for dinner, honey?”
Chris: Yeah, yeah, exactly.
Bob: This new phone it’s so cool. Yeah, it’s way different now.
Chris: You’re teaching now too though, you said statistics but you have some other stuff. like your research that you’ve done there and other stuff you’ve taught there. What was the… what was the one I saw in there? It was… crud! I lost it. What are some of the courses you taught? Oh here we go, finite element method. Is that like actual magnetic finite element analysis-type stuff?
Bob: Yeah and antennae stuff.
Chris: Oh antennae stuff, okay. I [inaudible 01:15:39] a class for transformers and he did some finite element stuff.
Bob: Yeah. When I started working in that, I started working with this group at McGill up in Montreal and Pete Sylvester and these guys, and they adapted that method from what civil engineers used to do but we used to use it to design electric machines like the actuators and disk drives. The actuator has a certain forced response to the current going through the coil but that becomes a game block in the server loop, so you want to map out how that varies with the angle and we could model that with the finite elements because we could get an accurate model of the magnetic fields.
Dave: It’s a very common technique for all sorts of things, very wide ranging.
Chris: FEA even?
Bob: Well yeah because you’re solving the differential equations and [espinements 01:16:43] have the same equations, have the same solution so you know I initially started out using a thermal model, which was just solving [inaudible 01:15:50] equation but it was for heat flow but you could change the names of things and then it became for magnetic materials.
Chris: That’s awesome!
Bob: But then there’s some special things that Maxwell’s equations do that thermal things don’t do that you had to take into account. So we developed our own programs for doing that. And actually you talk about the disk drive business being incestuous, but the finite element world is really… like the guy that started Ansys and HFSS and all that, [Salton Sendez 01:17:31] was a graduate student of Pete Sylvester who is a guy that I was working with at McGill. Yes, so I taught some courses in that because it’s a neat way to… you know, there’s only about three or four problems that you can actually solve in electromagnetics by hand, then you have to go over to computer methods. But that came along with digital computers too in the rise of PCs and the power of what you can do with those. And there’s a lot of interest in mixed physics models now. So you have eddy current heating and that couples into a thermal model so you can model the actual…
Chris: It’s like holistic now almost. It’s like current creates heat, affects current back and forth kind of thing.
Bob: Yeah, yeah, they do actually.
Bob: In the magnetic world, that’s sure the case.
Chris: Just because the materials change or what?
Bob: The materials have changed. Most things have magnetic properties that are dependent on temperature. In fact what they do in disk drives now, they’ve gone over to real heroics in disk drives because there is something called the super power magnetic limit, which has to do with if you keep making the bits smaller and smaller, you get to a point where just thermal energy can cause them to flip on their own.
Dave: Yeah, nasty business.
Bob: The way they used to prevent that is increase the coercivity or the resistance to change of flipping. The problem with that is then you have to increase the fields that come out of the recording head and you reach a point where you really can’t push it any further. So what they’re doing now in the current generation of disk drives, is they use a laser to temporarily suppress the coercivity by heating the material. Then you write on it and then turn off the laser and it cools quickly and sort of freezes in the magnetic pattern.
Chris: Wow! Just hearing about this stuff, I mean I’m very impressed with all this stuff, but it’s just like…
Bob: It’s like a house of cards.
Chris: It’s amazing, there’s so much energy spent on this, not even energy, but just so much brain power to just keep squeezing more data on there. I know that it’s an economic driver thing but, man, (01:20:00) it’s so cool.
Bob: You know, you can buy little terabyte drives at Costco now for…
Chris: Yeah, right.
Bob: That’s the result of it.
Chris: Right. Right. Then we put Jersey Shore, we store digital editions of Jersey Shore. That’s the ultimate thing that my brain goes to or Facebook.
Bob: Actually, the story of the increase in the aerial density, they call it the bits per square inch in disk drives is pretty amazing because it’s gone up at a very consistent rate over the years. There’s just like orders of magnitude every few years.
Chris: Yeah. Is there Davidson Law or… who got named after that one?
Bob: Oh the super power magnetic limit?
Bob: I don’t know, it’s just called the… we’re not as clever. We’ll have the marketing guys working with us so we’ll just call it the super power magnetic limit.
Chris: That’s catchy!
Bob: They said if HP sold sushi, they would call it cold dead fish.
Bob: Somebody else came up with the name sushi to make it sound good. That’s the problem with HP. The neat thing about HP is it was selling to other engineers so we knew our audience.
Dave: Yeah, exactly. That’s the difference.
Chris: It doesn’t matter if the test equipment’s all four-digit numbers, you just assign your own value in your head of, it’s something awesome.
Bob: Internally, we used to talk about the next bench phenomenon. You would see what the engineers needed on the next bench and then develop a tool…
Dave: Look on the next bench and then… yeah.
Bob: … to support that.
Chris: That’s crazy.
Dave: I think our time’s almost up.
Chris: Yeah, I think so too, but I think we could probably keep going for what another what, three hours, four hours.
Dave: As usual.
Bob: I’ve got more Woodchuck here, I’ thinking about going all evening.
Dave: I have to ask what this Woodchuck thing was, I have no idea before the show.
Bob: Hard cider from Vermont.
Chris: Delicious, delicious cider.
Bob: Yeah. It’s got a Woodchuck on the front of it.
Dave: I don’t think you can buy cider here.
Bob: You need to have apples.
Dave: Well you probably can but you don’t hear of anyone drinking cider here.
Bob: Do you have apples?
Bob: Then they probably have cider. They may make apple juice and they probably get cider eventually.
Chris: Yeah, exactly.
Dave: Well, yeah, you can buy apple juice, yeah.
Chris: Some parent leave it in the sippy cup too long and then they think well we should keep doing this.
Bob: Just leave it under the sink there for a while.
Chris: There you go.
Dave: All right. Okay.
Bob: Don’t put it back in the fridge and…
Chris: Bob, thanks so much for being on the show.
Chris: We’d love to have you back on some time and hear more about what you’re doing.
Dave: Where can we find you? Where can we follow you? People want to see more Hoodie HP photos.
Bob: Well those are kept in the archive but…
Dave: Well bring them out, I’d love to see these.
Bob: I’m WA7IUT on Twitter, that’s my Ham radio call sign. Then www.ambientsensors.com.
Chris: Lots of good projects and blog posts and stuff on there. You said you were getting back into…
Bob: I’m getting back into doing that, yeah.
Dave: Awesome! Thanks, Bob.
Chris: We’ll see everyone next week.
Dave: Catch you later, Bob.
Bob: Okay. Take care.
[…] For those interested, there is now a transcript available of Episode 144 […]