The home lab of Barrie Gilbert
Analog Devices fellow Barrie Gilbert sent an email out that had a PowerPoint of his home lab. I doubt our web server would let us host a PowerPoint, so I just broke it up into HTML text and the pictures. Barrie looks pretty well set up there in the Portland Oregon forest. I want to post it in this blog so I can point to it in a post about Barrie’s rant to Bob Pease years ago. Oh, those were the days, when I would try to make peace between Barrie and Bob. That other post, actually a couple, since it is at 3000 words already, will appear in my other blog, Anablog, in a day or two.
I hope to publish Jim Williams home lab next on this blog, along with a few friends’ labs and maybe even my own. All comments with a bullet are Barrie’s. So without further adieu here is Barrie Gilbert’s home lab.
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- This set of drawers beneath a couple of Western Electric relays and the ringer is full of tubes of special and nostalgic merit. They’re the ones I used to build my earliest radio sets and oscilloscopes. The open drawer is but a small sample. I love ‘em all, and tell ‘em so.
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Ho-ho! here’s a tester to their rescue;
plug ‘em in and first they’ll glow, then
purr like tiger cubs, as the minuscule
& indivisible electrons begin to flow.
After they’ve confessed their low
gee-em they’ll ask you, sweating:
“OKAY… So, where’s the Show?”
These ancient guys are ever fretting;
ever at the ready, just to glow & GO!
- (Note this old-timer is a Du Mont ’scope on the far right. I have about two dozen scopes around the place.)
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- Just by the door of the lab is this venerable Ballistic Galvanometer. I plan to illuminate its mirror with a small laser on the other side of the lab, and teach visiting kids about ‘charge’ the old-fashioned way. There’s a split-anode magnetron up on the shelf.
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- In this first section, panning anti-clockwise around the lab, is a Tek 576, a Fluke high-voltage supply (to 5kV) another Fluke supply (dual ±900V), an HP microwave signal generator and spectrum analyzer, a Fluke 931 RMS voltmeter and some Tek 7000-series plug-ins.
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- Still panning anti-clockwise around the lab, there is a nice old US Navy signal generator (tubes, of course), an HP RF Power Meter, an HP DMM, another HP spectrum analyser, and a Tek scope. I am working on the Khron-Hite LP/HP filter (in the front, open) whose power supply seems to have gone south.
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- Round we go. Another cluster of useful stuff. Three slide-rules visible in this corner (1,2,3).
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- The thinking station. ,Eight dozen javelin-sharp pencils. Gridded pad. My trusty ARISTO slide-rule. Genuine 18th-century eye-glasses. No computer…
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- Et cetera. A Tek 545 and a 575 Curve Tracer, more HP stuff more power supplies and an IC probing platform. Everything in this microlab works - including the dozen or so venerable slide rules!
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- Alicia’s ham shack - to use the vernacular. The main piece of radio equipment she uses is a Kenwood transceiver, but you can also see - toward the left of the desk - an ex-RAF R1155. This used to be my window on the world. There is also an old Tek Model 31 calculator, out of storage to show a visitor, with a view to donating it to a museum being developed for Tek oldies. The rest of the stuff stored on the shelves includes several old vacuum-tube voltmeters.
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- In all, there are seven keyboards and another sixteen rack-mounted synths, including a Moog Voyager (here, at this level in the rack), plus two of Ray Kurzweil K-2000’s, two Yamaha Motifs, and many other music toys. One floor up, there is a MIDI-ed Yamaha grand, plus a spare one in the master bedroom.
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- That’s a 10″ Revox recorder. It works beautifully, if tape is your thing (I still like it). There are several high-end cassette recorders, DATs, etc. The scores in the shelves are all of classical music, which I like to rearrange for synths.
Barrie could not resist the double-entendre of noting that was a Gilbert Mixer to the right of his chair. Barrie is well known for inventing the Gilbert cell signal mixer, an integrated transistor version of tube mixer circuits.
GaAsManWes commented:
It was interesting working with Barrie for a bit in the mid '70's at Tek. One thing that is an amazing accomplishment (at least to me, a physics/process type) is that Barrie designed an analogu(e) chipset for Tek 7K scopes that generated the numerical screen readout (yes all analog!) long before it became the norm with digital logic.
C fost commented:
electron by now you have gone back and noticed the soldering iron,You should have picked up Barries glases on the bench. Berrie you are the best how do you keep it so clean
William Ketel commented:
It is indeed a wonderful thing to see, and a marvelous collection of excellent equipment. But the one comment is correct, in that it does look much more like a museum than a functional workshop. But I am glad for Barrie Gilbert to have such a wonderful play-space. But I do not envy him, since having those toys would be a large responsibility.
attilaunno commented:
Some years ago I had the honour to meet Barrie Gilbert personally. Thus I have no surprise to see his lab look like this.
I must say a lab like this is the secret desire of any Electronic Engineer, exactly as I am !!!!
electron tube commented:
Where is the soldering iron ???
cathode_ray commented:
VVery impressive, indeed, but...no one looks to work in that place. That's a museum, not a lab.
SteveT commented:
I miss working with the great crew in Tek Labs and rubbing shoulders with insightful engineers that were more scientists than engineers (like Barrie Gilbert). Tek did a disservice to the whole electronics community when it broke down Tek Applied Research and Tek Labs.
Cliff Harris commented:
The VOM reminded me that one of my bosses gave me a Simpson 260 they were going to throw away. I always regretted that I forgot it when I left that company.
LostInSpace commented:
Well very nice indeed, but I saw a picture that brought back bad memories. On one side I saw the only Tek scope that I never liked - It's that little portable T922 (or some such number) - I worked about as poorly as any HP scope that I have ever used. OK, well except that 22 GHz HP Sampling scope I had once, boy that was a beauty! We parted when Agilent gave me the boot out the door.
Fred Olsen commented:
Well, it's "Du Mont" actually. Two words. I also commend Mr. Gilbert for his neatness. I tend more toward the Bob Pease school of workspace tidiness.
John P. commented:
This is a really beautiful lab, I like the wood and cabinets. Very neat, everything is organized. I used to work in Venable Hall, a chemistry/physics/marine science building, part of the University of North Carolina and would see similar looking cabinets and shelves. My bench is closer to Jim Williams bench in appearance. Great job, I have always admired Barrie Gilbert, a great engineer.
phillip m gallo commented:
What a great environment you've created.
Paul Rako commented:
@Chan Shaw WA6EWY
Thanks for pointing out the misspelling of Dumont scope as Dupont. I have changed it and it will appear whenever the chron-job pointer indexes to the linked-list priority scheduler to auto-scrub the underlying wordpress blog that then gets stripped of its formatting and transmogrified to what you see here. Seamless
Dan Williams commented:
The "Gilbert mixer to the right of the chair" was a joke kiddies. No need to get into a Picard vs Kirk moment. Barrie's work stands very well on its own merit.
Sheesh, engineers!
Chan Shaw WA6EWY commented:
Some spelling "fix" - that is a Dumont, not "Dupont" scope. Two here when not loaned out to elementary schools. Allan B. Dumont was mfg of some of the first scopes on the market. Later, TV receivers-
LarryJ commented:
Not to detract from Barrie's reputation as he definitely belongs in a category with Pease & Williams, but he was NOT the first engineer to think (or "invent") using solid state devices to implement vacuum tube mixer circuits. I quote from Dr. Long's web page at www(dot)analog-rf(dot)com(slash)mixer(dot)shtml#summary
In 1963 Jones of Burroughs Corp. patented a common mode feedback addition to the transistor version of the circuit to mitigate the poor performance. This circuit in integrated circuit form was market by Sylvania in 1964 as an ECL exclusive or gate. People today who get their history from journalists instead of reality call this topology the "Gilbert Cell Mixer."
{scroll WAY down the page to subheads "Jones" and "Gilbert"}
"Jones"
In 1963, Howard E. Jones of Honeywell, Inc. filed for a patent using the transistor emulation (using what the British called a long tail pair which was in turn a transistor equivalent of one stage of a vacuum tube operational amplifier) of the chopper/7360/FDM telemetry circuit as a phase detector. It also included common mode feed back to correct for the poor matching of discrete transistors. This was issued March 15, 1966 as US Patent 3 241 078. ... Sylvania marketed this circuit in integrated form in 1964 as an ECL exclusive or gate. I have seen ECL parts used in commercial products as mixers and amplifiers.
"Gilbert"
In 1968, Barrie Gilbert published a paper on a four quadrant analog multiplier which combined the circuit of the Jones patent along with predistortion circuitry to make a large signal four quadrant multiplier. The entire content of the paper was about accuracy of multiplier circuits used in analog computers. In 1974 a further paper was published showing how to reduce the multiplication errors even further. It was the integrated nature of the circuitry that made the transistors match which made the circuit accurate. No reference was made to radio mixers in either paper. The circuit (of) The Jones patent was referenced.
Gilbert cites the Jones patent in his first paper. He, like tens of thousands of engineers in the previous 15 years, had independently conceived of using bipolar transistors in the topology that had previously used vacuum tubes. Also cited were two papers that used the topology in radio circuits and a master's thesis. There was a discussion on commercially available versions using discrete transistors needing temperature control ovens to reduce errors.
Not referenced is the following paper:
A simple d.c. to 10 Mc/s analogue multiplier ,R R A Morton 1966 J. Sci. Instrum. 43 165-168
with the following abstract:
R R A Morton Electrical Engineering Department, Monash University, Clayton, Victoria, Australia Abstract. A transistor analogue multiplier having a frequency response of 0 to 10 Mc/s with a maximum attenuation of 1 dB on either input and an accuracy to 1%, and which operates over four quadrants, has been developed. The multiplier inputs have a range of ±3 V and the outputs, ±2 V; residual noise (which determines the minimum useful output) is 3 mV r.m.s. Temperature stabilization over 20 to 50°C is achieved by using two matched transistor pairs and adding two thermistors to the circuit. The multiplier and a detailed analysis of the errors arising in it are described. Print publication: Issue 3 (March 1966) Received 14 September 1965
This web page has a great deal more information on mixers and their history for those who are interested.
theazz commented:
I think I have seen every one of those scopes tossed in the dumpster over the last 25 years.
long live the 80's
JTsantes commented:
Very cool!
Mr Fabulous commented:
The beer, where's the beer?
mlloyd commented:
geez, with all those toys, when does barrie get any work done?
:-)
G. Jorgensen commented:
Very impressive collection! But... no vintage electric guitars or amps???
This would not work for me..
