Post by thread:[EE] [PIC] A coherer based lightning detector proj

Hi, Since I've gotten so much help and insight from the piclist, I thought I would share a project I've been working on. It's a lightning detector that uses a coherer (a bit of old radio technology) as the detection element. Here is the address: http://roland.sw.edu/matthew/coherer/lightning_detector.html If that host doesn't resolve (as has happened when I've posted links to this server in the past) its IP address is 164.106.190.246. There isn't much to say that's already on the website, but if anyone has any comments I would welcome them. Take care, Matthew. -- "Adults who preach and moralize, especially with a cigarette between their fingers, a cocktail in their hands or three kinds of tranquilizers in the medicine closet, have very little credibility." - Margaret Mead (March 71 Harper's Bazaar)

At 04:43 PM 6/2/2005, Matthew Miller wrote: >Hi, > >Since I've gotten so much help and insight from the piclist, I thought I >would share a project I've been working on. It's a lightning detector that >uses a coherer (a bit of old radio technology) as the detection >element. Here is the address: OMG! I know what that is!! What's your Decoherer?

At 04:53 PM 6/2/2005, Dave VanHorn wrote: >At 04:43 PM 6/2/2005, Matthew Miller wrote: >>Hi, >> >>Since I've gotten so much help and insight from the piclist, I thought I >>would share a project I've been working on. It's a lightning detector that >>uses a coherer (a bit of old radio technology) as the detection >>element. Here is the address: > >OMG! I know what that is!! What's your Decoherer? Ah I see. I've seen doorbells used for this as well, the type with the hammer and gong. As it happens, I'm working on the desk with a Boltek unit at the moment. No lightning anywhere around, but my Theremin drives it nuts.

You seem to have glossed over the coherer itself. Looks homemade - what are you using to fill it? (You mention nickel filings as being used in some designs but don't say what you're using). Or is part of the purpose of the exercise to try different filling materials? Richard P On 03/06/05, Dave VanHorn <spam_OUTdvanhornTakeThisOuTdvanhorn.org> wrote: > At 04:43 PM 6/2/2005, Matthew Miller wrote: > >Hi, > > > >Since I've gotten so much help and insight from the piclist, I thought I > >would share a project I've been working on. It's a lightning detector that > >uses a coherer (a bit of old radio technology) as the detection > >element. Here is the address: > > OMG! I know what that is!! What's your Decoherer? > > -

Hi Dave, On Thu, Jun 02, 2005 at 05:00:37PM -0500, Dave VanHorn wrote: > >OMG! I know what that is!! What's your Decoherer? > > Ah I see. I've seen doorbells used for this as well, the type with > the hammer and gong. > > As it happens, I'm working on the desk with a Boltek unit at the moment. > No lightning anywhere around, but my Theremin drives it nuts. Wow! Do you have a photo of this Boltek coherer? I've just started researching these things and I find the history very interesting. I'm surprised by how sensitive some of the coherers I've made are. Right now, there are several appliances in my house that trigger the coherer when they turn on or off. Take care, Matthew. -- A good government is one "which shall restrain men from injuring one another, shall leave them otherwise free to regulate their own pursuits of industry and improvement, and shall not take from the mouth of labor the bread that it has earned." -- Thomas Jefferson (inaugural address)

At 09:38 PM 6/2/2005, Matthew Miller wrote: >Hi Dave, > >On Thu, Jun 02, 2005 at 05:00:37PM -0500, Dave VanHorn wrote: > > >OMG! I know what that is!! What's your Decoherer? > > > > Ah I see. I've seen doorbells used for this as well, the type with > > the hammer and gong. > > > > As it happens, I'm working on the desk with a Boltek unit at the moment. > > No lightning anywhere around, but my Theremin drives it nuts. > >Wow! Do you have a photo of this Boltek coherer? I've just started >researching these things and I find the history very interesting. It's not a coherer, actually the antenna is a proprietary "brick", about 2x2x3 inches. http://www.boltek.com

Hi Richard, On Fri, Jun 03, 2005 at 10:13:30AM +1200, Richard Prosser wrote: > You seem to have glossed over the coherer itself. Looks homemade - > what are you using to fill it? (You mention nickel filings as being > used in some designs but don't say what you're using). > Or is part of the purpose of the exercise to try different filling materials? There isn't an exercise (unless someone takes it upon themselves for there to be one), but if you follow the links, I have information about some of the materials I have used. At roland.sw.edu/matthew/coherer/coherer_tips.html I discuss some of my experiences. The coherer I'm currently using contains a 2:1 mixture of copper and U.S. Nickel filings. I wish I had a way to enclose the coherer components in a vacuum, but I don't have the glassware skills or any equipment. So far, my current coherer's sensitivity hasn't changed as greatly over time as pure copper coherers have. There seems to be a lot to investigate here. For me this has been a very pleasant diversion! Take care, Matthew. -- To be shaken out of the ruts of ordinary perception, to be shown for a few timeless hours the outer and inner world, not as they appear to an animal obsessed with survival or to a human being obsessed with words and notions, but as they are apprehended, directly and unconditionally, by Mind at Large -- this is an experience of inestimable value to everyone and especially to the intellectual. -- Aldous Huxley, "The Doors of Perception"

Hi Dave, On Thu, Jun 02, 2005 at 09:48:16PM -0500, Dave VanHorn wrote: > > It's not a coherer, actually the antenna is a proprietary "brick", > about 2x2x3 inches. > http://www.boltek.com Oh. Thanks for the link. My next project is a "real" lightning detector. A coherer, not sealed in a vacuum, becomes less sensitive with time. I'm planning to use a darlington type detector like what is mentioned here: http://homepage.mac.com/tbitson/weather/bslam/ I've read web sites and requested information from several companies, but I've not encountered boltek before. Another for my list. :) Matthew. -- "There are 100,000 total marijuana smokers in the US, and most are Negroes, Hispanics, Filipinos and entertainers. Their Satanic music, jazz and swing, result from marijuana usage. This marijuana causes white women to seek sexual relations with Negroes, entertainers and any others." -- Harry Anslinger, testifying to Congress, 1937

At 10:12 PM 6/2/2005, Matthew Miller wrote: >Hi Dave, > >On Thu, Jun 02, 2005 at 09:48:16PM -0500, Dave VanHorn wrote: > > > > It's not a coherer, actually the antenna is a proprietary "brick", > > about 2x2x3 inches. > > http://www.boltek.com > >Oh. Thanks for the link. My next project is a "real" lightning detector. A >coherer, not sealed in a vacuum, becomes less sensitive with time. I'm >planning to use a darlington type detector like what is mentioned here: >http://homepage.mac.com/tbitson/weather/bslam/ Not bad, surprisingly sensitive though you won't believe it till there's a storm in the area. (Never a good storm around when you need one!) The boltek gear gives you range and bearing, and can even tell C-C, C-G, and polarity. Pretty impressive, given the antenna is something you could put in a soda can.

Hi Dave, On Thu, Jun 02, 2005 at 10:24:44PM -0500, Dave VanHorn wrote: > At 10:12 PM 6/2/2005, Matthew Miller wrote: > > >http://homepage.mac.com/tbitson/weather/bslam/ > > Not bad, surprisingly sensitive though you won't believe it till > there's a storm in the area. > (Never a good storm around when you need one!) Yeah, so far, for every thunderstorm in this area I've not been home! :( > The boltek gear gives you range and bearing, and can even tell C-C, > C-G, and polarity. > Pretty impressive, given the antenna is something you could put in a soda > can. Your kidding?! I've not seen any products that do bearing and range; and from a single antenna? I'm definitely going to request some lit from this company. I wasn't aware that the cutting edge was far advanced. See what I learn posting to the piclist! :) Thanks, Matthew. -- "But I don't want to go among mad people," Alice remarked. "Oh, you can't help that," said the Cat: "we're all mad here. I'm mad. You're mad." -- Alice in Wonderland, Lewis Carroll