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 Definition A type of radio detector, popular in the earliest days of radio development, beginning around 1890. [d] [e]
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A possible suggestion

I know nothing about this topic, but don't you think that for all the idiots like me the first paragraph should be somewhat rewritten? A quick suggestion is:

A coherer is a type of radio detector, popular in the earliest days of radio development, beginning around 1890. Coherers, in conjunction with spark-gap transmitters, were the first devices to make radio communication practical. Its defining characteristic is a "light-contact" segment, that is normally a poor electrical conductor, but which undergoes a sudden change in conductivity — usually a marked increase — in response to the increased voltage induced by a received radio signal.

This way, at least by the end of the second sentence, we have an idea of why this is an important concept.... Hayford Peirce 13:52, 12 June 2007 (CDT)

I have reorganized the opening sentences so the first section covers "what it is" and the second reviews "how it works". Please let me know if there are any other parts that need further work to make them understandable for a general audience.Thomas H. White 06:08, 17 June 2007 (CDT)


I have heard that Nikola Tesla was in fact the first to introduce both a rotating "coherer" and tuneable circuits; versions of both are incorporated into his patent for a robotic boat which I think well predates Marconi. I know the issue was in the past the subject of controversy; would it it worth mentioning here?

This is an area I will have to do some more research on. As far as I know Tesla's robotic boat was first demonstrated, and the patent applied for, in 1898, some years after Branley, Popoff, Lodge, Marconi and many others had successfully used coherer receivers for radio wave reception. Also, my understanding is that Tesla's U.S. remote control patent was eventually overturned in favor of one issued to Bradley A. Fiske, although I'm note sure what kind of receiver he used.Thomas H. White 09:17, 17 June 2007 (CDT)

Also, I am very glad to have someone with knowledge of early radio here! If your interest includes early (pre-WWII) televsion systems such as those of Baird and Farnsworth, I'd love to have your input into entries such as John Logie Baird and History of television -- your technical know-how would be a real asset. Russell Potter 16:49, 12 June 2007 (CDT)


Glad to see the circuit diagram and other improvements. Do you think this might be almost ready for nomination for Approval? Russell Potter 15:22, 17 June 2007 (CDT)

I hadn't seen your earlier comments about Tesla, so now I would like to review some articles available from the NC State Library, however two of them will require retrieving a volume from storage.Thomas H. White 16:50, 17 June 2007 (CDT)
OK, that sounds fine. It's fun to watch this entry grow and develop -- great stuff! Russell Potter 17:40, 17 June 2007 (CDT)