[Noisebridge-announce] Noisebridge Coherer Day, 2/2, 1pm

Johny Radio johnyradio at gmail.com
Thu Jan 23 00:27:43 UTC 2014

Announcing the first Monthly Noisebridge Coherer Day
Sunday, February 2nd, 1pm

aka Electronics Component Organizing Day
aka Noisebridge Resistor-Sorting Day

We will work on organizing the electronics component storage area. This 
is the area with capacitors, resistors, diodes, switches, connectors, 
etc (NOT the computer-ewaste section). We'll start by pulling everything 
out and cleaning. I expect this project will take more than one session, 
because there are a lot of components, and it's pretty bad in there! 
Hopefully, some peeps will help move it along on the in-between days.

(Donations for pizza gladly accepted, from any kind soul
Sunday, February 2nd, 1pm


In 1850 Pierre Guitard found that when dusty air was electrified, the 
particles of dust would tend to attach themselves together in the form 
of strings. In 1879, it was observed[4] that drops of water from a small 
fountain, when exposed to the influence of a charged piece of 
sealing-wax, would cohere into large drops. The coherer, invented around 
1890 by French scientist Édouard Branly, consists of a tube or capsule 
containing two electrodes spaced a small distance apart, with metal 
filings in the space between them. When a radio frequency signal is 
applied to the device, the initial high resistance of the filings 
reduces, allowing an electric current to flow through it. Coherers have 
difficulty discriminating between the impulsive signals of spark-gap 
transmitters, and other impulsive electrical noise:[7]
>"All was fish that came to the coherer net, and the recorder wrote down 
>dot and dash combinations quite impartially for legitimate signals, 
>static disturbances, a slipping trolley several blocks away, and even 
>the turning on and off of lights in the building. Translation of the 
>tape frequently required a brilliant imagination, similar to 
>interpreting drunk text-messages*."
>—Greenleaf Whittier Pickard

*ok, he didn't really say that about drunk text-messages.
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