Electronic – How Johnson measured Johnson-Nyquist noise

noise

How Mr. Johnson, the one after which Johnson–Nyquist noise was named measured/discovered this phenomena? Details about equipment and method are most welcome.

Best Answer

Here's Johnson's original 1928 paper. May give you some clue :-)

Note that there are two papers - one by Johnson and the immediately following one by Nyquist. Both are from Physical Review July 1928 with Johnson's paper immediately followed by Nyquist's. J's title is "Thermal agitation of electricity in conductors" and N's is "Thermal agitation of electric charge in conductors".

Johnson:

Nyquist:

Richmond.edu link below has a number of interesting papers.


Useful "modern" comment

http://www.claysturner.com/dsp/Johnson-Nyquist%20Noise.pdf

Related:

Various papers including Johnson's from above:

http://www.claysturner.com/dsp/Johnson-Nyquist%20Noise.pdf

http://kiwitobes.com/wiki/Thermal_noise.html

http://uk.ask.com/wiki/Johnson%E2%80%93Nyquist_noise

http://en.wikipedia.org/wiki/Talk%3AJohnson-Nyquist_noise

http://en.wikipedia.org/wiki/Johnson-Nyquist_noise

http://ocw.mit.edu/courses/physics/8-13-14-experimental-physics-i-ii-junior-lab-fall-2007-spring-2008/labs/lab13/