While cleaning up the hard drive a bit, I found a picture of the last PWB I designed for a product at work. This is an opamp circuit to add a little gain into a 190 MHz IF signal in a radar receiver.
Thursday, February 25, 2016
Since It's Engineers Week
A little engineering humor to start. Since I'm retired, I don't know if I'm technically an engineer (and thinking about minute technicalities like that probably says I am), and I sure don't want to get into one of those "engineering is what we do not who we are" vs. "engineers are born not made" discussions, so I'll pretend someone even cares and post the humor. Design News posted this picture:
I suppose that the way it's composed is to say the guy is the engineer and he doesn't like being hugged at all. On the other hand, it could be that she's the engineer, he's not, and that's his reaction for having to be that close to one of us.
While cleaning up the hard drive a bit, I found a picture of the last PWB I designed for a product at work. This is an opamp circuit to add a little gain into a 190 MHz IF signal in a radar receiver.
For the unfamiliar the green thing is the printed wiring board. The concentrated patch of shiny traces in the middle is the place where the opamp was mounted. The Altoids Smalls tin is about 2 1/4 x 1 1/2". The board is about half the width of a "Forever" postage stamp, and maybe 3/4 as long. Yeah, this is the size of parts we work on these days. Probably large parts by someone's standards. For those of you who understand: the smallest parts are 0402 not 0201.
While cleaning up the hard drive a bit, I found a picture of the last PWB I designed for a product at work. This is an opamp circuit to add a little gain into a 190 MHz IF signal in a radar receiver.
Gain?
ReplyDeleteNoise Figure?
Yes, it had some of those ;-)
DeleteIt has been six months, but IIRC, gain was set to about 1.4 dB and the NF was Don't Care because it's so far down the chain there's nothing it could do to screw us up.
What do you do when you find out you need 1.4 dB gain at the last minute? But maybe it's not 1.4; maybe it's 2 dB, or maybe it's 1. It was the easiest fix.
BTDT!
ReplyDelete190MHz is an interesting IF for a radar.
All the stuff I've worked with was the 'old standard' 70MHz.
If combat engineers count, Gust Front is currently part of the Baen Free Library. Those who have read it will be nodding knowingly; those who haven't need to know that it's the second book in a series. Fortunately, the first book (A Hymn before Battle) is also part of the Baen Free Library.
ReplyDeleteThese days, you could probably put the whole thing on an ASIC and be done with it ... not to mention saving real estate (which I won't mention)
ReplyDeleteI find the humorous attempt by "Design News" to be pretty damn sad. That's the best they can come up with? What an insult. It would seem to me more fitting to honor the endless creativity and energy that men and women put into solving problems, inventing, creating, improving all manner of people and things around the world, every day.
ReplyDeleteI'll just tip my hat to all those good people and say, "Thanks for all your hard work. Keep up the great job. America needs your skills more every day."
It was just a joke aimed at the stereotypical social awkwardness of engineers.
DeleteWe could do dozens. Scott Adams has based an entire career on them.
"The Nack"
Deletehttp://youtu.be/CmYDgncMhXw
Terry
Fla.
The perfect example. I still get a laugh out of that. "Can he lead a normal life?", "No. He'll be an engineer".
DeleteI always wondered what the Doctor was talking to my Mom about when I was little....
DeleteAll that packaging makes parts ... so-o-o ... big.
ReplyDeleteQ
Yeah, but when it's a last minute add-in "band-aid" you don't have much choice.....
ReplyDeleteI had the privilege of designing circuit boards for a few years.
ReplyDeleteSome were pretty large and we designed them in teams by each taking a separate section of the whole.
The smallest one I ever did was when someone screwed up the pinout for an ethernet port.
I had to make a daughterboard to fit on top that transposed the pinout to fit.
Instead of 12345678 it was 13578642.
Or something like that.
It's been a few years.
Now I work in a museum of control systems that were built in the late seventies.
Aching to get a shot at commisioning the new one.
I meant to reply to this yesterday, but that part about making a daughterboard to fit a transposed pinout brought back painful memories. The worst was something like a 210 pin connector for board to motherboard connection that the PC librarians had entered upside down. They read a bottom view as a top view (or vice versa - it was long ago). The worst part is that it had to be re-wired by hand - not enough time for a re-spin. Over Thanksgiving weekend, preparing for a big demo for customers, all those nasty things at once.
Delete