Resistors: Color code training for electronics technicians and repairers

chuckroast · Jan 7, 2024

Sirius Glass said:
Correct, to understand the measured value in situ one would need to derive the Thévenin equivalent circuit.

Thévenin's theorem - Wikipedia

en.wikipedia.org

Oh... I have such fond memories of cranking out Thévenin circuit analysis. Later on, I would come to understand that it's only really meaningful for DC steady state analysis. Anything with transients or with AC/RF running through the circuit was an entirely different kettle of fish ... and where all the fun was.

WWWWAAAY OT: Anyone else ever have the fun of doing Smith Chart analysis for transmission line and antenna impedance matching analysis?

Sirius Glass · Jan 7, 2024

chuckroast said:
Oh... I have such fond memories of cranking out Thévenin circuit analysis. Later on, I would come to understand that it's only really meaningful for DC steady state analysis. Anything with transients or with AC/RF running through the circuit was an entirely different kettle of fish ... and where all the fun was.

WWWWAAAY OT: Anyone else ever have the fun of doing Smith Chart analysis for transmission line and antenna impedance matching analysis?

Smith Charts: BTDT

r_a_feldman · Jan 7, 2024

Color Codes

xkcd.com

cmacd123 · Jan 7, 2024

chuckroast said:
I learned the inappropriate one first as well There are many other, more
sanitized ones here

List of electronic color code mnemonics - Wikipedia

en.wikipedia.org

I rember our High school electronics teacher prompting one of the lighting crew folks to tell us the one in Reference 11, 1nd 12 on that page. He also had an official one, but tha was the one that stuck.

eli griggs · Jan 7, 2024

Andreas Thaler said:
Has anyone an idea where to find information regarding cockpit electronics of those days?

Countless discrete electronic components and cables must be installed behind the instruments.

Fascinating!

Were there computers in fighter planes in the 1960s?

Not in the A.F. but in the Army, '76 - '79 with an artillery unit, still using fire control first used in 1950's FADAC Computers, which was a "digital" computer, working out final trajectory of artillery, and, I'd bet they were also used bombers, large and small, etc.

My unit was a Nuclear capable TOW 155mm and 8" SP artillery unit.

Early scientific pocket calculators were used by some officers and senior NCO's to back check FADAC results but, Officially, the FADAC WAS the machine that gave the final answer.

chuckroast · Jan 7, 2024

Sirius Glass said:
Smith Charts: BTDT

I think I still have a circular slide rule for calculating Smith Chart problems made by Amphenol floating around in the archives around here somewhere.

Andreas Thaler · Jan 8, 2024

eli griggs said:
Not in the A.F. but in the Army, '76 - '79 with an artillery unit, still using fire control first used in 1950's FADAC Computers, which was a "digital" computer, working out final trajectory of artillery, and, I'd bet they were also used bombers, large and small, etc.

My unit was a Nuclear capable TOW 155mm and 8" SP artillery unit.

Early scientific pocket calculators were used by some officers and senior NCO's to back check FADAC results but, Officially, the FADAC WAS the machine that gave the final answer.

Interesting in this context about the Boeing B-29, 1945:

… the B-29 had another element designed to enhance the capabilities of the human crew — a computerized central fire control system. With today’s modern, fly-by-wire warplanes, a centrally controlled, computer-corrected, remotely operated gun turret may not sound impressive, but in World War II it was revolutionary.

Defending the Superbomber: The B-29’s Central Fire Control System

Aeronautics curator Christophere Moore explores one important advancement on the B-29 Superfortress: its central fire control system.

airandspace.si.edu

jimgalli · Jan 8, 2024

Were there computers in fighter planes in the 1960s?

Only if you had your slide rule in your pocket.

Alan Edward Klein · Jan 8, 2024

koraks said:
That's a perfectly fine method if its mechanically feasible.

Back then, most circuits were discrete components, transistors, caps, resistors, etc. Plus they were on removable plug-in circuit cards. So it was easy to unsolder one lead from the back of the card after removing the card from the rack.

Jonathan-sv · Jan 12, 2024

Alan Edward Klein said:
When I was in the USAF in the 1960 learning electronics, we learned this to remember the color code number equivalents.

Bad Beer Rots Our Young Guts But Vodka Goes Well
There was a dirty one as well, but I don't think it's appropriate to post here

Numerically the value (0-9) of a resistor via the color-coded bands:
Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (purple, 7), Gray (8), and White (9)

I learned

Bachelor boys rush our young girls but veronica goes wild only for silver or gold.

JimC · Jan 12, 2024

I use one of these old resistor guides, I wish the large electronics distributors like Mouser and Digikey
would offer these guides again, mine is decades old and card board .

Resistors: Color code training for electronics technicians and repairers

Privacy & Transparency

Privacy & Transparency