Central Oregon Retired EE

[Bob Mcree]

Greetings friends, and thanks to Doug for what I'm sure has been a mountain of work handling all our new requests for membership in this great forum. I helped build some of the first MRI machines back in the late 70's-80's at UCSF and eventually moved on to private companies building MRI systems, then on to help design and build test equipment for most of the big companies making the first flat panels, working for a small family-operated company in Silicon Valley.

I am semi-retired on a disability pension but still active. I am interested in all science and engineering, including electric bikes and metrology in general. Most of my experience is in hardware design and machine language programming; I have several PIC development systems. I am a bit of a nut about computers; I also have my own CRAY3. It is a prototype and hangs on the wall over my flat screen.

I worked as an engineer without a degree; from a job repairing TV's in high school to one building prototypes in the basement of UCSF to an eventual position as a design engineer and then engineering management positions in several companies.

I am in the high desert 125 miles southeast of Portland. I see a couple of other Oregon members; maybe this spring we can get together.

I am looking forward to becoming a member of this community.

[Doug Coulter]

Good to have you, Bob. Like you, at some point people realized I was good and ignored the fact I didn't have the right paper to be "an engineer", since I was better at it than many who do hold the paper. Results count! Out of the roughly 1000 requests, I'm letting in about 50 new members total - I've got around 40 to go, it takes time turnining the board settings on and off, logging in and out as "admin" so I can pretend to be a new user registering, then back to admin to validate it, and so forth.
Fast crowd here...that's deliberate. Most people are getting the "try this other site" owned by a friend, for noobs email. If they "graduate" over there - well then they can come here.

For some reason, I tend to have more respect for guys who've done hands-on troubleshooting of the mistakes made by other engineers. It makes you better, you know what not to do, and once you start designing things, you know that someday, someone's going to have to fix them, so it makes you a better engineer to have been a tech. Just my opinion. Could be a bit of bias since that's the path I took myself.

[Bob Mcree]

Thanks again Doug, I am looking forward to working together. I have been playing around lately with spectrometers made from a webcam and a piece of a DVD-r. It started with a CERN design and software from publiclaboratory.org. they have kits for sale but all it takes is the camera, a piece of 1200 lines per mm grating, and a slit, to use their online software for data acquisition and analysis. there is stand alone software in java they need help with, and anyone is welcome to contribute through github. their site is all about sharing scientific and environmental information. the results are pretty impressive. anyone interested should check it out.

[Doug Coulter]

That sounds really cool! I've long been known to simply pick up a CD and use it for a "back of envelope grade" spectrograph, kind of like the teacher version for grade school teachers. I'd think BW camera would be best, and getting a sensitivity curve vs wavelength important, but that should be real do-able.

Even holding something like that in the hand is enough to demonstrate, for example, the differences in the spectra of various light sources, like CCFLs, halogens, LED lighting, TIG welding, sparks, and so on...takes a little practice, but it's not overwhelmingly hard. I just never took it past that point.

A real-life application for things vacuum around here would be to use it with a discharge tube in the foreline of a high vacuum pump as a "poor man's mass spec" since most of the gasses have fairly different spectra - water's a lot different from air, helium, argon and so on - so it's potentially a leak detector as well, once the high vacuum pump has increased the pressure enough to get a visible discharge in the line between it and the forepump. And if the leak is "that bad" a discharge in the main tank serves...

[Bob Mcree]

The spectrometer design uses a color webcam simply because they are everywhere. I agree eliminating the Bayer filters and the quartet of sensors for each pixel would simplify things greatly. The camera software is open source, and there is a stand-alone java version I never used that may or may not work. The general way to use the software is to log in to spectralworkbench.org using google chrome, which permits the site software to assume control of the webcam for interactive spectrometer operation and data storage. Separate webcam software can be used to adjust integration time, etc. They have a version that works on a cell phone in addition to the $40 benchtop spectrometer kit. I slapped in an adjustable camera mount and a better webcam for 400nm-1100nm range with better than 1 nm resolution using a 200u slit.

This cheap spectrometer should work well as a helium leak detector. I have done a lot of "sniffing" around the seams of supercon magnets, squirting a bit of helium around and listening for the scream of the mass spec as the diffusion pump behind it pulled in the helium. There are several strong He lines in the middle of the optical spectrum that should be easy to detect when properly excited.

The Fabry-Perot interferometer formed between the array and the inside of the cover glass is evident when observing any broad band source, like my Photo Research 2856K black body source which shows "ripples" in the black body curve that we know are not real. There is some question whether the simple pixel-by-pixel scaling correction I have seen work well on spectrometers with line detectors would work as well on the webcam, but it would be worth a try.

I know you didn't want to start long threads here, so I'll find the appropriate place for discussion of spectrometers. I have some interest in working on a PIC based spectrometer/photoradiometer using a design something like the Ocean Optics units I have worked with in the past. Some of these UV-VIS-NIR spectrometers used cheap fax machine sensors.

Thanks again for sharing what you are doing, Doug.

[David McKee]

Hello Bob!

Impressive resume! And you and Doug are right, that piece of paper is expensive, but hardly worth anything. At best it might get your foot in the door of your first job, but by that time you probably should already be in the room so to speak... I got the paper, and my first job was secured because I showed the guy I interviewed with a computer controlled matrix switch for guitar effects I built - he could care less where I went to school.

BTW - would that be a Fender Jazz Bass in your avatar?

[Doug Coulter]

I skipped out of high school due to amazing SAT scores to start college as a HS sophomore, then skipped out of college as I was offered a 6 fig job - in '71. I don't even have a diploma of any kind! If you can do the stuff, the paper doesn't mean crap to a real businessman, nor does your color or sex in nearly all cases I've witnessed. My old company, C-Lab, got our first big customer based on the fact that yes, we'd done the first truly viable digital nonlinear audio editing system from the ground up (and it would do 38 CD quality channels on a 486 - with efx, and in real time full duplex)...
Came about in a weird way. I designed and built all this hardware and software while unemployed for something to do - it'd been a long time dream and it was getting close to possible at a time the best thing on the market was an 8 bit half-duplex system from creative labs. (and CD burners were scsi only and cost over $2k) I happened to be able to live without any real income, so I designed the board (Ti DSP, far more powerful than a 486), the windows drivers, the application, and the DSP software to run in the TI machine. Ti got to know me because of the questions I asked about some pretty serious detail (and even eventually used my input on the tms320-c30 series), and when asked by the guy who was to become our main customer who knew this stuff, told them about me.

It was a great interview. I just brought in the system and demo'd it. They (a big telecom/paging/pbx manuf) were appropriately amazed that I could do what I could do - make an entire 3 min song in about the time it took to play each instrument once through, and easily correct any errors -

They asked me who did the drivers. Answer, I did. Then asked who wrote the app, well, I did. Then who designed the hardware, well, same answer. How long did it take? Something under 6 months. The next question was how much money I wanted.
And that was that - roughly 10 million gross in 3 years and I had to frantically find other talented guys to hire to handle it all.

But you must understand, I was born at the lucky end of the gene pool, and by then had been working on engineering since the dual triode was the hot new thing. I was an overnight success after only a few decades of practice...(raised by an engineer, so I got to start real early).

No one asked me for paper, ever. That's not how you get the good jobs. You know someone, or someone knows you. You completely bypass HR, which always wants paper certs that say you have 6 years of experience in something that has only existed for 4-5....jerks/idiots/CYA types. You meet another engineer, by chance or something, and he and his boss decide you're going to be on the team, and you shine on the HR BS after that. No good job has ever come to me via resume submission. Never.

[solar_dave]

Strangely enough my story is similar. I was a tool and die maker and was drafted to become a tool inspector. They had these new fangled computer controlled measuring machines From Carl Zeiss. None of the old guys wanted anything to do with it so I was elected. Now I was the defacto expert. They continued to buy these machines until all total they had 27 of them. I had to learn to program and then taught a fleet of CNC programmers how to get from point a to point b. I took a couple of courses at the local community college to learn the logic stuff. We then did a guerilla net work with RS232 connections to the machine to a HPUX central data collection computer.

This lead to a job at IBM that was supporting the selling their inspection software, the interview last 2 minutes and I was hired, no real resume.
Same with the eBay job, no resume just a 5 minute phone interview.

The only job I ever gave a resume to was the contract with the Navy in San Diego, and I don't think they even looked at it, it was you come highly recommended by such and such. A couple minutes on the phone was all it took. (best paying gig I ever had but it damn near killed me with the travel and hotel living in San Diego, another long story)