Re: [time-nuts] Loran, GPS, Lightning, Timing
Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Amen to that! It's also turned from reporting to preaching-political! I always wanted to build the amateur scientist stuff, but there were always the lines with arrows off the figure to power supply. Wonder if that's why I have hell boxes full of old power supplies:-) Probably a darned good thing I didn't build the x-ray tube! Don -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
QST lightning radar. But what a mess you get with google and every lightning and radar TV station in the US. Oh well if your replacing TVs every few years whats a few more opamps? Now how does a poor man build something for what started this whole thread? Time for me to hop off this thread. Regards Paul WB8TSL On Sat, Jun 28, 2014 at 2:37 AM, Don Latham d...@montana.com wrote: Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Amen to that! It's also turned from reporting to preaching-political! I always wanted to build the amateur scientist stuff, but there were always the lines with arrows off the figure to power supply. Wonder if that's why I have hell boxes full of old power supplies:-) Probably a darned good thing I didn't build the x-ray tube! Don -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
There is actually a lot of information on lightening observation. If you have access to a university library. Some public libraries have on-line databases you can search too. Google is not so good at this as most of the papers are in journals where you need a subscription, or more likely a library that has a subscription. I used to own a sail boat and took an interest in lightening and red a bunch about it a few years back. You can guess why. On a boat on the ocean you are very exposed, If a storm comes you can't simply get off the water so there you are living under a 65 foot aluminum pole which is the tallest conductor for miles and miles around. So what to do about it? I looked around and the most of the answers where coming from the University of Florida. They have some good How To publications if you want to survive direct hits (to cover the sailing example) and also theory but about detection, they have a lightening observatory there are there are papers describing the instruments. They observe the normal LF but also up in VHF and even x-ray detectors. Techniques are described for determining the types of strikes (polarity) and some time they cn see plrity reversals in cloudsand cloud to cloud discharges.Once you find a few survey papers they will have a long list of citations and you can hunt down those papers. A good search phrase is *Lightning Observatory in Gainesville * I think before anyone builds any detector it might help ask what data you want. Are you wanting to simply detect that lighting is nearby so you can disconnect equipment or do you want to characterize the lightening in some way?It turns out almost always you need to know the location and this means you need to make observations from sites that are some miles apart. What a good TN application. You need to have good time so you can combine the measurements. What I learned about the boat is that I needed a VERY good conducting path from the mast to the saltwater. This was made somewhat easy on my boat because I had a 7,000 pound lead keel in contact with water (except for some paint) and the mast was keel stepped. Give the current a nice easy straight line path and it will take it and not bother you. On Sat, Jun 28, 2014 at 6:52 AM, Brian Lloyd br...@lloyd.com wrote: On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Friday, June 27, 2014 22:47 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing C. L. Stong wrote The Amateur Scientist articles in Scientific American magazine for many years, throughout the 1940s - 1960s and later period. As a child, I read these avidly and built many of the things he described. I did not know he was a ham! All The Amateur Scientist articles are available on a CD. I particularly remember building a nuclear magnetic resonance spectrometer (well, a simple one) in the late 1950s from one of his articles. Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Larry W6FUB On 6/27/2014 9:34 PM, DaveH wrote: The only C.L. Stong (W2PFM - great call!!!) article that I could find at QST came up in an archive search: How to Cook a Ham from March 1947 A story about not having safety interlocks and getting zapped. http://p1k.arrl.org/pubs_archive/28044 You need to be an ARRL member to access the file. I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. Same for e-field. Dave KF7VNE ... -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I find that very puzzling. I was a subscriber to QST from some time in 1957 until into the 1960s. I didn't have a subscription to Scientific American so I couldn't have confused them. I suppose the article has been lost or somehow escaped being entered into the searchable database. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Brian Lloyd br...@lloyd.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, June 28, 2014 8:52 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Back on the topic of lightening, a destructive side of lightening can occur with between-cloud strikes. Beneath a cloud with a hefty charge on it there is a counter charge, a reflection, on the earths surface. This will have the same amount of charge but in inverse polarity. When the charge in the cloud jumps to another cloud, the counter charge has to move to beneath the new cloud. This involves currents of equal magnitude to lightening strikes moving in a similar time frame. Any water pipe or buried telephone or power cable may be obliged by a potential voltage similar to a lightening strike to carry part of this current. I saw a buried phone line that had been 3 feet underground converted to an open trench 100 yards long. Any conducting cable that cuts the transient magnetic field during one of these events may be a victim. Fibre optic would seem to be the answer for protection. cheers, Neville Michie ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Use a local solar cell and battery power supply. If it is self contained it should not attract lightning. Cheers, Neville Michie On 29/06/2014, at 1:13 PM, Hal Murray wrote: namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Batteries or PV system. Depending on what you want to run on the remote end, you might be able to find a used solar powered shed light and use the parts. Something like this for $20: http://www.harborfreight.com/solar-shed-light-95573.html If you find a unit whose batteries are failing, you can use the parts - check thrift stores and garage sales. Down side - you will have to replace it with every lightning strike. Up side - the parts are dirt cheap and readily available. You could also use a car battery and charge it every week or so - keep two in rotation for uninterrupted operation. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Saturday, June 28, 2014 20:14 To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Sat, Jun 28, 2014 at 10:13 PM, Hal Murray hmur...@megapathdsl.net wrote: namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? I recommend a kite, wet string, and a Leyden jar. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I have never seen an article using exotic special tubes. I understand that benefit but common tubes do a fine job. I still believe it was a QST article. Maybe 73 magazine. It was a long time ago. When I started using the 12AU7s again for the vlf pre-amp they were $1 or so 7 years ago. Now audiophiles have driven them into the silly range especially on the websites. I scrounged 4 at really good prices $2 recently. But the audiophiles were on the hunt as I noticed. Bottom line a tube frontend is easy to build for this application. Even if we want to make it seem hard. Its simply not the front end. Its the other parts of the solution that should be the focus. How to make a sub $$ solution. The European solution is several hundred Euros. Regards Paul WB8TSL On Thu, Jun 26, 2014 at 10:50 PM, Brian Lloyd br...@lloyd.com wrote: On Thu, Jun 26, 2014 at 9:08 PM, DaveH i...@blackmountainforge.com wrote: The tube was probably the FP-54 http://frank.pocnet.net/sheets/141/f/FP54.pdf No luck on finding the article - it is not in the Handbook of Projects for the Amateur Scientist by C.L. Stong http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf I thought it might be as I remember there was a project to detect sferics but this one used plain 12AU7s and 6AU6s When I was a kid this may have been my favorite book. I did build the MRS when I was 12. Sucker actually worked too! I was amazed. I have built several things from this and used many of the projects with modern electronics as projects for my students in middle school. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Let's see - lightning is basically a powerful spark. How about a home-made Marconi coherer? You don't have to go back in time to get one, and the audiophools haven't found a use for it. Bill Hawkins -Original Message- From: paul swed Sent: Friday, June 27, 2014 8:10 AM How to make a sub $$ solution. The European solution is several hundred Euros. Regards Paul WB8TSL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I think the QST article being referred to in this thread is one that I remember rather clearly. I kept the issue for a long time but it got away from me somewhere along the line. It was a lightening direction finder using a display much like a radar PPI. It used two crossed untuned loops and a vertical. All three signals were amplified using tubes and one of the loops was fed to the horizontal deflection plates of a CRT and the other loop's signal was fed to the vertical plates. The signal from the vertical was fed to the control grid of the CRT. The project was essentially an XY scope built from the ground up. He suggested figuring out the polarity of things by waiting for close lightening that was visible and correlating sightings with the display on the CRT. You wouldn't use a general purpose scope because the fair weather condition would burn a spot in the center of the screen. One more thing. He wound the loops in hula hoops he had cut open. I still have two hula hoops awaiting the project. The bandwidth of his amplifiers was low audio to about 100 kHz. I suspect that in today's radio environment some tuned traps would be necessary to notch out some of the strong signals in that frequency range. You now have all the information I have and I am sure I could build one if only I could find the time. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: paul swed paulsw...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 27, 2014 8:10 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing I have never seen an article using exotic special tubes. I understand that benefit but common tubes do a fine job. I still believe it was a QST article. Maybe 73 magazine. It was a long time ago. When I started using the 12AU7s again for the vlf pre-amp they were $1 or so 7 years ago. Now audiophiles have driven them into the silly range especially on the websites. I scrounged 4 at really good prices $2 recently. But the audiophiles were on the hunt as I noticed. Bottom line a tube frontend is easy to build for this application. Even if we want to make it seem hard. Its simply not the front end. Its the other parts of the solution that should be the focus. How to make a sub $$ solution. The European solution is several hundred Euros. Regards Paul WB8TSL On Thu, Jun 26, 2014 at 10:50 PM, Brian Lloyd br...@lloyd.com wrote: On Thu, Jun 26, 2014 at 9:08 PM, DaveH i...@blackmountainforge.com wrote: The tube was probably the FP-54 http://frank.pocnet.net/sheets/141/f/FP54.pdf No luck on finding the article - it is not in the Handbook of Projects for the Amateur Scientist by C.L. Stong http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf I thought it might be as I remember there was a project to detect sferics but this one used plain 12AU7s and 6AU6s When I was a kid this may have been my favorite book. I did build the MRS when I was 12. Sucker actually worked too! I was amazed. I have built several things from this and used many of the projects with modern electronics as projects for my students in middle school. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
You might be thinking of the file that David Byrne sent to the HP list last year on 9/7/13. It was an article by C. L. Stong and I think it was published in The Amateur Scientist in 1963. You should be able to find it in the HP list archives. Bob From: Max Robinson m...@maxsmusicplace.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 27, 2014 11:14 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing I think the QST article being referred to in this thread is one that I remember rather clearly. I kept the issue for a long time but it got away from me somewhere along the line. It was a lightening direction finder using a display much like a radar PPI. It used two crossed untuned loops and a vertical. All three signals were amplified using tubes and one of the loops was fed to the horizontal deflection plates of a CRT and the other loop's signal was fed to the vertical plates. The signal from the vertical was fed to the control grid of the CRT. The project was essentially an XY scope built from the ground up. He suggested figuring out the polarity of things by waiting for close lightening that was visible and correlating sightings with the display on the CRT. You wouldn't use a general purpose scope because the fair weather condition would burn a spot in the center of the screen. One more thing. He wound the loops in hula hoops he had cut open. I still have two hula hoops awaiting the project. The bandwidth of his amplifiers was low audio to about 100 kHz. I suspect that in today's radio environment some tuned traps would be necessary to notch out some of the strong signals in that frequency range. You now have all the information I have and I am sure I could build one if only I could find the time. Regards. Max. K 4 O DS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Fri, Jun 27, 2014 at 6:10 AM, paul swed paulsw...@gmail.com wrote: I have never seen an article using exotic special tubes. I understand that benefit but common tubes do a fine job. I still believe it was a QST article. Maybe 73 magazine. It was a long time ago. When I started using the 12AU7s again for the vlf pre-amp they were $1 or so 7 years ago. Maybe used tubes for $1. New ones where never that cheap, even in the tube era when they were common. The 12AU7 is a current production tube. You can buy a brand new one for under $10. Collectors have pushed the price of pristine vintage tubes up but the BIG market for tubes today is guitar amplifiers. Factories in Europe, Russia and China are making millions of new vacuum tubes. The tube cost less then the power supply you'd need to run it. I actually think a vacuum tube would be ideal for something that has to deal with lightening. Even if it gets fried, it's a cheap enough part in a socket that you can change it out in two minutes.Use a tube for the input end and fiber optic cable for the output and you'd be very safe during a storm. But the point of lightening monitoring is to share your data over a network and for that they need IDENTICAL receivers at each location. So even if you can build a superior LF amplifier it will not be so useful if you can't exchange data with others. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
It was QST and Max is right. I built it. There was a e-field antenna for amplitude and the crossed antennas the XY access. I guess the old brain has somethings correct. Now can I remember the tube line up. Heavens no. :-) The CRT was a little mil surplus 3p... But enough of that. Whats the chance of finding the article that would be a kick. Regards Paul WB8TSL On Fri, Jun 27, 2014 at 12:28 PM, Bob Stewart b...@evoria.net wrote: You might be thinking of the file that David Byrne sent to the HP list last year on 9/7/13. It was an article by C. L. Stong and I think it was published in The Amateur Scientist in 1963. You should be able to find it in the HP list archives. Bob From: Max Robinson m...@maxsmusicplace.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 27, 2014 11:14 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing I think the QST article being referred to in this thread is one that I remember rather clearly. I kept the issue for a long time but it got away from me somewhere along the line. It was a lightening direction finder using a display much like a radar PPI. It used two crossed untuned loops and a vertical. All three signals were amplified using tubes and one of the loops was fed to the horizontal deflection plates of a CRT and the other loop's signal was fed to the vertical plates. The signal from the vertical was fed to the control grid of the CRT. The project was essentially an XY scope built from the ground up. He suggested figuring out the polarity of things by waiting for close lightening that was visible and correlating sightings with the display on the CRT. You wouldn't use a general purpose scope because the fair weather condition would burn a spot in the center of the screen. One more thing. He wound the loops in hula hoops he had cut open. I still have two hula hoops awaiting the project. The bandwidth of his amplifiers was low audio to about 100 kHz. I suspect that in today's radio environment some tuned traps would be necessary to notch out some of the strong signals in that frequency range. You now have all the information I have and I am sure I could build one if only I could find the time. Regards. Max. K 4 O DS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
When currents are discharged into the earth (by lightning or power line faults), there is a phenomenon known as Ground Potential Rise. That is, as currents flow omni-directionally (earth is a giant resister, so current flows in many directions like a huge parallel circuit), the point nearest the discharge rises to a potential above ground, with levels decaying exponentially outward. Therefore, if all devices that require protection are bonded with low impedance cables (200mcm copper), the entire bonded community will at least remain at the same relative potential, even if elevated above ground. Many people use #6 solid copper for bonding, but that is only good for under 50 feet, then you should use serious cable like 200mcm. This is a tie-in to discussions concerning lightning strikes. Take for example a television station in Sarasota, FL that kept losing gear in lightning storms. The property was littered with parabolic satellite discs (6 to 10 footers), antennas, metal structures, etc. in a busy lightning season they replaced a lot of gear. Of course, anytime something tied to the phone lines got fried, they blamed us, so we went out and performed a ground survey (measured the value of ground rods or connections at every object). The results were that the telephone terminal was connected to the well casing, with a 2 Ohm ground measurement (fall of potential method). All other grounds were over 25 Ohmsseveral over 100 Ohms. We had them tie all objects, ground rods, etc together with 200mcm copper and they never again suffered equipment losses. Over many years, I could repeat this scenario in damage investigations..too many independent (unmeasured) grounds at a site. Just because you drive a ground rod does not mean you have a good ground (good meaning 25 Ohms or less, some sites require 5 Ohms or less). In my Florida days, it was pretty comment to see 100+ Ohm measurements on a single 8 foot ground rod. There are formulas for determining soil resistivity and the number/depth of rods to equal the required measure..I have those in a course book from a grounding class I took in the 1970's..it's about 5 inches thick! As someone else mentioned earlier, the Cone of Protection method is well documented in a book entitled Telecommunication Electrical Protection by ATT Press (1985). It has a blue cover so was called the blue book in industry circles. It also covers tent and other shapes for overhead protection schemes. It has much good info in protecting cables entering power substations and generating plants as well. Good read. Sorry for the long post.I'm a newbie so this may be info already covered. I'm on LinkedIn, give me a ping. Daniel B. Burch (TesCom Corp) Dallas, TX Sent from my iPad On Jun 25, 2014, at 10:55 PM, Alexander Pummer alex...@ieee.org wrote: Charley Wenzel made it very safe: here is http://www.techlib.com/electronics/lightning.html, I used cross-correlation to identify the right electrical noise Alex On 6/25/2014 8:22 PM, Brian Lloyd wrote: On Wed, Jun 25, 2014 at 4:42 PM, paul swed paulsw...@gmail.com wrote: I am currently using a 12AX7 as a ELF preamp and have for years. A note in the coldest part of winter preheat the tube low filament voltage. They tend to fracture. It sits 200 ft from the house as far away in the woods as possible. That said and back to the thread. At these frequencies tubes do work. The 12AX7 can be found on vlf.it and numbers of tubes will work. They run 12 V on the plate. They also stand up to nearby lightning very well. So Diddier now you have no excuse. I can't wait to implement your design on one of my stm boards. Not sure how to get this back on time-nuts topics Regards Try a 6DJ8 instead of the 12AX7. It has a higher GM and a LOT more bandwidth. What kind of risetime are we talking about for a lightning strike? And why not a loop antenna? That should provide plenty of signal but not destructive voltages. I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I am not too concerned about a direct hit as the antenna would be under the roof, and I have not had a direct hit to the house (yet) in 22 years but I am concerned about a close hit that could still generate hundreds of volts. I regularly (like every year or two, yes, it is getting old) replace TVs, networking gear and other various electronics even though I have surge protectors everywhere. Didier KO4BB On June 25, 2014 4:46:07 PM CDT, Chris Albertson albertson.ch...@gmail.com wrote: On Wed, Jun 25, 2014 at 1:24 PM, Didier Juges shali...@gmail.com wrote: One potential problem is that the preamps obviously must remain connected to the antennas when the storm gets close, while my ham radio gear is normally disconnected when not in use. I have had so much lightning damage over here (North West Florida) over the years that I am concerned about pissing off the Gods for good... It could be 100% safe if there were no wires leading back to the house. A battery powered receiver that connected back to the house over WiFi would be safe. Use a solar panel and a lead/acid battery for power. The only trouble is the added cost and a direct hit would still cost you a few hundred $$. Less risk is to expose only some minimum portion of the system to lightening then run fiber optic cable back to the house. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
The only C.L. Stong (W2PFM - great call!!!) article that I could find at QST came up in an archive search: How to Cook a Ham from March 1947 A story about not having safety interlocks and getting zapped. http://p1k.arrl.org/pubs_archive/28044 You need to be an ARRL member to access the file. I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. Same for e-field. Dave KF7VNE -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Friday, June 27, 2014 10:42 To: Bob Stewart; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing It was QST and Max is right. I built it. There was a e-field antenna for amplitude and the crossed antennas the XY access. I guess the old brain has somethings correct. Now can I remember the tube line up. Heavens no. :-) The CRT was a little mil surplus 3p... But enough of that. Whats the chance of finding the article that would be a kick. Regards Paul WB8TSL On Fri, Jun 27, 2014 at 12:28 PM, Bob Stewart b...@evoria.net wrote: You might be thinking of the file that David Byrne sent to the HP list last year on 9/7/13. It was an article by C. L. Stong and I think it was published in The Amateur Scientist in 1963. You should be able to find it in the HP list archives. Bob From: Max Robinson m...@maxsmusicplace.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, June 27, 2014 11:14 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing I think the QST article being referred to in this thread is one that I remember rather clearly. I kept the issue for a long time but it got away from me somewhere along the line. It was a lightening direction finder using a display much like a radar PPI. It used two crossed untuned loops and a vertical. All three signals were amplified using tubes and one of the loops was fed to the horizontal deflection plates of a CRT and the other loop's signal was fed to the vertical plates. The signal from the vertical was fed to the control grid of the CRT. The project was essentially an XY scope built from the ground up. He suggested figuring out the polarity of things by waiting for close lightening that was visible and correlating sightings with the display on the CRT. You wouldn't use a general purpose scope because the fair weather condition would burn a spot in the center of the screen. One more thing. He wound the loops in hula hoops he had cut open. I still have two hula hoops awaiting the project. The bandwidth of his amplifiers was low audio to about 100 kHz. I suspect that in today's radio environment some tuned traps would be necessary to notch out some of the strong signals in that frequency range. You now have all the information I have and I am sure I could build one if only I could find the time. Regards. Max. K 4 O DS. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
C. L. Stong wrote The Amateur Scientist articles in Scientific American magazine for many years, throughout the 1940s - 1960s and later period. As a child, I read these avidly and built many of the things he described. I did not know he was a ham! All The Amateur Scientist articles are available on a CD. I particularly remember building a nuclear magnetic resonance spectrometer (well, a simple one) in the late 1950s from one of his articles. Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Larry W6FUB On 6/27/2014 9:34 PM, DaveH wrote: The only C.L. Stong (W2PFM - great call!!!) article that I could find at QST came up in an archive search: How to Cook a Ham from March 1947 A story about not having safety interlocks and getting zapped. http://p1k.arrl.org/pubs_archive/28044 You need to be an ARRL member to access the file. I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. Same for e-field. Dave KF7VNE ... -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
How fast does the maltese cross turn? Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Neville Michie namic...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, June 25, 2014 10:46 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing Is anyone using a field mill? I have always been going to make one. It consists of a horizontal metal plane with a conducting button on the surface which is insulated from the ground plane. A metallic maltese cross driven by a motor alternately covers and uncovers the electrode exposing/not exposing it to the sky. The electrode button has capacitance to ground which drops its impedance, but across that impedance is an AC voltage proportional to the ambient static field. A typical field in fine weather is 300 Volts/metre so the signal is not trivial. You should be able to make a field mill that works continuously except when actually shorted by rain. This is not a very high impedance device, and should show many marvellous things as the clouds float over you. You can calibrate it with a metal plate, say 12 inches above it with 50 volts on it. That should produce a uniform field on the mill. cheers, Neville Michie I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Hi, the maltese cross is a chopper to interrupt the lines of electrostatic force. The cross could have a hundred legs, as long as it alternately blocks and unblocks exposure to the electric field. The cross spins in a horizontal plane, maybe half an inch above the sensor electrode which is flush or just above the ground plane. The idea is to get the output signal up to a frequency where the time constant of the sensing electrode can be quite short. If you can get it up to 400 Hz it only needs a 2.5mS time constant. Even then, since you can calibrate it you can have the signal below the time constant. A 12 legged cross spinning on a 4 pole motor gives a chopping frequency of 360 hertz, (in America), quite convenient for amplification and processing. If the motor is synchronous, or you put a sensor on the motor shaft you can run a phase sensitive detector and get polarity as well as magnitude. cheers, Neville Michie On 27/06/2014, at 1:59 AM, Max Robinson wrote: How fast does the maltese cross turn? Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Neville Michie namic...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, June 25, 2014 10:46 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing Is anyone using a field mill? I have always been going to make one. It consists of a horizontal metal plane with a conducting button on the surface which is insulated from the ground plane. A metallic maltese cross driven by a motor alternately covers and uncovers the electrode exposing/not exposing it to the sky. The electrode button has capacitance to ground which drops its impedance, but across that impedance is an AC voltage proportional to the ambient static field. A typical field in fine weather is 300 Volts/metre so the signal is not trivial. You should be able to make a field mill that works continuously except when actually shorted by rain. This is not a very high impedance device, and should show many marvellous things as the clouds float over you. You can calibrate it with a metal plate, say 12 inches above it with 50 volts on it. That should produce a uniform field on the mill. cheers, Neville Michie I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
The tube was probably the FP-54 http://frank.pocnet.net/sheets/141/f/FP54.pdf No luck on finding the article - it is not in the Handbook of Projects for the Amateur Scientist by C.L. Stong http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf I thought it might be as I remember there was a project to detect sferics but this one used plain 12AU7s and 6AU6s -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Wednesday, June 25, 2014 13:45 To: Discussion of precise time and frequency measurement; Didier Juges Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing In message 16957e54-f6d5-4c0a-9068-6f0c772d2...@email.android.com, Didier Jug es writes: I think it would be perfectly appropriate to design an LF amplifier with 12AU7s considering the high signal levels when the storm does get close. Somewhere, sometime, I saw an homebrew article for a lightning detector which was based on some obscure valve/tube that had grid on the top terminal. A wire from the grid electrode ran to a porcelain isolator and from there to the wire antenna, in order to get the highest possible imput impedance. I have no idea where I saw that article, but some HAM magazine or possibly Elector about 10-20 years back is a good guess. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Thu, Jun 26, 2014 at 9:08 PM, DaveH i...@blackmountainforge.com wrote: The tube was probably the FP-54 http://frank.pocnet.net/sheets/141/f/FP54.pdf No luck on finding the article - it is not in the Handbook of Projects for the Amateur Scientist by C.L. Stong http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf I thought it might be as I remember there was a project to detect sferics but this one used plain 12AU7s and 6AU6s When I was a kid this may have been my favorite book. I did build the MRS when I was 12. Sucker actually worked too! I was amazed. I have built several things from this and used many of the projects with modern electronics as projects for my students in middle school. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
This one is/was run by the Neveda Test Site. I don't know if NOAA took it over. When you get strikes, it give the lat/lon. http://www.sord.nv.doe.gov/Lightning.php?Location=SouthwestLtime=30 At the moment, all is quiet on the western front. However, I have to say that near real time website is more impressive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I have been watching the blitzortung system in the US for a few days now and really like the clean and simple display. Very nicely done. Also downloaded the information package. Oddly it does not use any 12AU7s in the design. Regards Paul WB8TSL On Wed, Jun 25, 2014 at 2:24 AM, nuts n...@lazygranch.com wrote: This one is/was run by the Neveda Test Site. I don't know if NOAA took it over. When you get strikes, it give the lat/lon. http://www.sord.nv.doe.gov/Lightning.php?Location=SouthwestLtime=30 At the moment, all is quiet on the western front. However, I have to say that near real time website is more impressive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Quite true. One of my other interests is the ionosphere and propagation. This of course has an effect on GPS and other time related receiving systems. In support of my monitoring and trying to measure such things I monitor on a more or less continuous basis CHU on 7850 KHz. This in itself may not seem that unusual except that I am about 20 miles from the CHU transmitters and I monitor this transmission with the idea of creating a dopplergram of it's signal. As we know, HF radio signals are reflected and refracted by the various layers of the ionosphere. In doing so the signal can exhibit apparent changes in frequency due to the continual movement of these refracting and reflecting layers. My advantage being so close to the transmitter is that I also receive the ground wave of these signals which are not reflected or refracted in any way. I have a receiver set up which feeds Spectrum lab running in a long integration mode and displaying a very narrow bandwidth of just over 3 and half Hz. I publish my dopplergrams to a dropbox web page here: https://www.dropbox.com/sh/9dakbbrrn2ju3hc/TIIKrDY-Iu usually stored by month these: https://www.dropbox.com/sh/9dakbbrrn2ju3hc/AAA7FLx2nZuEZzBayIqyMAUza/20140320 are for April 20 this year. The solid line more or less in the center of the image is the ground wave from the CHU transmitter on 7850 KHz, everything else is the Doppler shifted signal as it has been reflected and refracted by the various continuously moving layers of the ionosphere. You will note that sometimes there is more than one predominate Doppler shifted signal. Variations in the more or less solid line in the middle of the images is the result of drift in the local oscillator in my receiver. It is not currently locked to GPS. However, as Tom has suggested it makes a good thermometer as it is a relatively high stability oscillator but temperature variations in my lab show as minor changes in these images. I have in fact done a reasonable calibration and I can tell at glance the approximate temperature of my lab near this radio as well as when the furnace has started in the colder months or when the air conditioner starts in the warmer months. There is a group in Czech Republic doing something very similar: http://ok0eu.fud.cz/ They are using their own network of GPS disciplined transmitters on 80M and monitor their signals in a similar fashion. They describe their studies as also studying the effects of gravity waves. Along the lines of trying to measure and study the ionosphere using these dopplergrams, I have also toyed with the idea of trying to make my own passive sounder. There is a network of ionospheric sounders in the Canadian Arctic called CHAIN - Canadian High Arctic Ionospheric Network. They use GPS receivers to measure characteristics of the ionosphere such as total electron count (TEC) by monitoring phase scintillation of the GPS signals. They are using modified GPS's with high stability reference oscillators. I don't know yet if any of my GPS receivers would provide any useful data even with a high stability reference but the thought occurs that there might be another way indirect way. DGPS beacons transmit corrections for GPS users and something I stumbled across on another web site suggested that some of this data may be buried within the corrections provided by these DGPS beacons. And it so happens that I have a DGPS nearby which I can receive easily and reliably 24 hours a day but I just haven't got round to doing much more than brainstorming and trying to understand just what I need to do to connect the dots. For reference, this is the web site and blog posting were I stumbled across the idea of using DGPS correction data: http://goughlui.com/?p=1071 I have not been able to connect all the dots between all these subject but I am getting there. At least it is fun and educational trying. After all, it's the journey which is brings the greatest rewards, not the destination. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: June-24-14 3:35 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing I am seriously considering involved as I am a bit of a weather nut too. I suspect this is quite common. You don't have to get into precise time very deep before you realize that all your timing gear is just pile of environmental sensors in disguise. Before time-nuts began, the first timing guy I met was Doug Hogarth (www.niceties.com) and he was seriously into weather measurement. He later got into the world of ultra-precise weight (mass) measurement. So I guess time-nuts is just a subset of measurement nuts. A quartz oscillator makes a good thermometer and sometimes a hygrometer and barometer too. An OCXO is a sensitive anemometer (just ask anyone who uses a PWM
Re: [time-nuts] Loran, GPS, Lightning, Timing
I think it would be perfectly appropriate to design an LF amplifier with 12AU7s considering the high signal levels when the storm does get close. I have been thinking of building a system myself since I already have an STMicro Discovery board and several GPS receivers I could use. One potential problem is that the preamps obviously must remain connected to the antennas when the storm gets close, while my ham radio gear is normally disconnected when not in use. I have had so much lightning damage over here (North West Florida) over the years that I am concerned about pissing off the Gods for good... Didier KO4BB On June 25, 2014 1:54:19 PM CDT, paul swed paulsw...@gmail.com wrote: I have been watching the blitzortung system in the US for a few days now and really like the clean and simple display. Very nicely done. Also downloaded the information package. Oddly it does not use any 12AU7s in the design. Regards Paul WB8TSL On Wed, Jun 25, 2014 at 2:24 AM, nuts n...@lazygranch.com wrote: This one is/was run by the Neveda Test Site. I don't know if NOAA took it over. When you get strikes, it give the lat/lon. http://www.sord.nv.doe.gov/Lightning.php?Location=SouthwestLtime=30 At the moment, all is quiet on the western front. However, I have to say that near real time website is more impressive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I do other things. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
In message 16957e54-f6d5-4c0a-9068-6f0c772d2...@email.android.com, Didier Jug es writes: I think it would be perfectly appropriate to design an LF amplifier with 12AU7s considering the high signal levels when the storm does get close. Somewhere, sometime, I saw an homebrew article for a lightning detector which was based on some obscure valve/tube that had grid on the top terminal. A wire from the grid electrode ran to a porcelain isolator and from there to the wire antenna, in order to get the highest possible imput impedance. I have no idea where I saw that article, but some HAM magazine or possibly Elector about 10-20 years back is a good guess. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I am currently using a 12AX7 as a ELF preamp and have for years. A note in the coldest part of winter preheat the tube low filament voltage. They tend to fracture. It sits 200 ft from the house as far away in the woods as possible. That said and back to the thread. At these frequencies tubes do work. The 12AX7 can be found on vlf.it and numbers of tubes will work. They run 12 V on the plate. They also stand up to nearby lightning very well. So Diddier now you have no excuse. I can't wait to implement your design on one of my stm boards. Not sure how to get this back on time-nuts topics Regards Paul WB8TSL On Wed, Jun 25, 2014 at 4:44 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message 16957e54-f6d5-4c0a-9068-6f0c772d2...@email.android.com, Didier Jug es writes: I think it would be perfectly appropriate to design an LF amplifier with 12AU7s considering the high signal levels when the storm does get close. Somewhere, sometime, I saw an homebrew article for a lightning detector which was based on some obscure valve/tube that had grid on the top terminal. A wire from the grid electrode ran to a porcelain isolator and from there to the wire antenna, in order to get the highest possible imput impedance. I have no idea where I saw that article, but some HAM magazine or possibly Elector about 10-20 years back is a good guess. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Wed, Jun 25, 2014 at 1:24 PM, Didier Juges shali...@gmail.com wrote: One potential problem is that the preamps obviously must remain connected to the antennas when the storm gets close, while my ham radio gear is normally disconnected when not in use. I have had so much lightning damage over here (North West Florida) over the years that I am concerned about pissing off the Gods for good... It could be 100% safe if there were no wires leading back to the house. A battery powered receiver that connected back to the house over WiFi would be safe. Use a solar panel and a lead/acid battery for power. The only trouble is the added cost and a direct hit would still cost you a few hundred $$. Less risk is to expose only some minimum portion of the system to lightening then run fiber optic cable back to the house. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
The Boonton (later HP) model 260A Q meter used such a tube for a 100 megohm VTVM. The tube was specially made for Boonton as the 535-A. There are also references to the 1659/535-A. If you search for it, use Boonton 535-A to avoid the Tektronix 535 scope. The Q meter manual has a picture of it. Bill Hawkins -Original Message- From: Poul-Henning Kamp Sent: Wednesday, June 25, 2014 3:45 PM Somewhere, sometime, I saw an homebrew article for a lightning detector which was based on some obscure valve/tube that had grid on the top terminal. A wire from the grid electrode ran to a porcelain isolator and from there to the wire antenna, in order to get the highest possible imput impedance. I have no idea where I saw that article, but some HAM magazine or possibly Elector about 10-20 years back is a good guess. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
A couple of other things about dealing with lightning: There is a cone of protection starting at the highest grounded point around for about 100 feet. These were developed to protect explosives bunkers from direct hits. The angle of the cone (between a vertical line to the tip and the edge of the cone) is 30 to 45 degrees. Exceptions have been reported, of course. That should save you from most direct hits. Then you have to deal with the electric field that builds up from passing charged clouds. Some kind of high-value resistor in parallel with a small glass sealed spark gap from antenna to ground would help. It doesn't have to deal with a direct hit, just keep the grid from arcing in the tube. Some of the sealed spark gaps also contain inert gas. You don't want a triggered spark gap, just a surge suppressor. Old radios with octal sockets had tubes in the RF and IF amplifiers with grid caps, like the 6K7. Should be a lot more available than the Boonton 535-A. Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
On Wed, Jun 25, 2014 at 4:42 PM, paul swed paulsw...@gmail.com wrote: I am currently using a 12AX7 as a ELF preamp and have for years. A note in the coldest part of winter preheat the tube low filament voltage. They tend to fracture. It sits 200 ft from the house as far away in the woods as possible. That said and back to the thread. At these frequencies tubes do work. The 12AX7 can be found on vlf.it and numbers of tubes will work. They run 12 V on the plate. They also stand up to nearby lightning very well. So Diddier now you have no excuse. I can't wait to implement your design on one of my stm boards. Not sure how to get this back on time-nuts topics Regards Try a 6DJ8 instead of the 12AX7. It has a higher GM and a LOT more bandwidth. What kind of risetime are we talking about for a lightning strike? And why not a loop antenna? That should provide plenty of signal but not destructive voltages. I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
As I recall, the Boonton 535A isn't specially made at all, but rather a selected 2A6 triode/twin diode. The tube is selected for having an especially clean vacuum, and being capable of running with a really high grid leak resistor (100M). -Chuck Harris Bill Hawkins wrote: A couple of other things about dealing with lightning: There is a cone of protection starting at the highest grounded point around for about 100 feet. These were developed to protect explosives bunkers from direct hits. The angle of the cone (between a vertical line to the tip and the edge of the cone) is 30 to 45 degrees. Exceptions have been reported, of course. That should save you from most direct hits. Then you have to deal with the electric field that builds up from passing charged clouds. Some kind of high-value resistor in parallel with a small glass sealed spark gap from antenna to ground would help. It doesn't have to deal with a direct hit, just keep the grid from arcing in the tube. Some of the sealed spark gaps also contain inert gas. You don't want a triggered spark gap, just a surge suppressor. Old radios with octal sockets had tubes in the RF and IF amplifiers with grid caps, like the 6K7. Should be a lot more available than the Boonton 535-A. Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Charley Wenzel made it very safe: here is http://www.techlib.com/electronics/lightning.html, I used cross-correlation to identify the right electrical noise Alex On 6/25/2014 8:22 PM, Brian Lloyd wrote: On Wed, Jun 25, 2014 at 4:42 PM, paul swed paulsw...@gmail.com wrote: I am currently using a 12AX7 as a ELF preamp and have for years. A note in the coldest part of winter preheat the tube low filament voltage. They tend to fracture. It sits 200 ft from the house as far away in the woods as possible. That said and back to the thread. At these frequencies tubes do work. The 12AX7 can be found on vlf.it and numbers of tubes will work. They run 12 V on the plate. They also stand up to nearby lightning very well. So Diddier now you have no excuse. I can't wait to implement your design on one of my stm boards. Not sure how to get this back on time-nuts topics Regards Try a 6DJ8 instead of the 12AX7. It has a higher GM and a LOT more bandwidth. What kind of risetime are we talking about for a lightning strike? And why not a loop antenna? That should provide plenty of signal but not destructive voltages. I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Lightning risetimes are slow enough that back-to-back zener diode limiters can protect the input circuitry for a 1-meter probe. Nothing will stop a direct strike, even a 12ax7 :-). A series resistor on the input helps. Actually, a well-designed active probe antenna, even (shudder) one made by MFJ will be quite adequate for vlf-ulf phenomena. May have a lo-pass filter that needs attention. Measuring the earth/s fair-weather field, 100 v/m or so, or even a field under a thunderstorm, 5000v/m or higher, would require input impedance in excess of 10^15 ohm. Better is to raise a sharp point, say a sewing needle on a nice protected teflon or better kel-f insulator, and measure the small current of around 10 fA. Needs a small breeze to work right. Clean off the spider webs and wasp nests as needed. Better is to build a device called a field mill (q.v.) that essentially chops the field into an AC signal. Getting too far from time nuttery and into atmospheric electric nuttery :-) Don Brian Lloyd On Wed, Jun 25, 2014 at 4:42 PM, paul swed paulsw...@gmail.com wrote: I am currently using a 12AX7 as a ELF preamp and have for years. A note in the coldest part of winter preheat the tube low filament voltage. They tend to fracture. It sits 200 ft from the house as far away in the woods as possible. That said and back to the thread. At these frequencies tubes do work. The 12AX7 can be found on vlf.it and numbers of tubes will work. They run 12 V on the plate. They also stand up to nearby lightning very well. So Diddier now you have no excuse. I can't wait to implement your design on one of my stm boards. Not sure how to get this back on time-nuts topics Regards Try a 6DJ8 instead of the 12AX7. It has a higher GM and a LOT more bandwidth. What kind of risetime are we talking about for a lightning strike? And why not a loop antenna? That should provide plenty of signal but not destructive voltages. I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Is anyone using a field mill? I have always been going to make one. It consists of a horizontal metal plane with a conducting button on the surface which is insulated from the ground plane. A metallic maltese cross driven by a motor alternately covers and uncovers the electrode exposing/not exposing it to the sky. The electrode button has capacitance to ground which drops its impedance, but across that impedance is an AC voltage proportional to the ambient static field. A typical field in fine weather is 300 Volts/metre so the signal is not trivial. You should be able to make a field mill that works continuously except when actually shorted by rain. This is not a very high impedance device, and should show many marvellous things as the clouds float over you. You can calibrate it with a metal plate, say 12 inches above it with 50 volts on it. That should produce a uniform field on the mill. cheers, Neville Michie I know you are talking about measuring lightning strikes but if you get the impedance high enough, you can actually measure the earth's electric field. (It is about 200V/m if I recall properly.) Interestingly it is affected by the solar flux and solar wind. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Loran, GPS, Lightning, Timing
A friend pointed me to this site: US http://www.blitzortung.org/Webpages/index.php?lang=enpage_0=30 EU http://www.blitzortung.org/Webpages/index.php?lang=en This is a wonderful out-of-the-box project, with echoes of Loran-C and GPS triangulation. It's also a clever combination of home-brew receivers, UTC timestamping, the web, and global participation. You'll find technical details on the site; it makes good reading for any time nut. And adds new meaning to pulse per second... Two questions. 1) Is anyone on the list a participant in this effort? 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. Ok, getting accurate time and disciplining clocks with GPS or NTP or WWVB is too easy so why bother. But it would be interesting to use this raw data to set, calibrate, and discipline local clocks, as an redundant method, independent of existing broadcast TF sources. Some crunching on the data would at least determine what level of precision could be obtained with a, what shall we call it, CLDO (Coordinated Lightning Disciplined Oscillator). /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Indeed, very interesting. I stumbled across this the other day. After a preliminary read of one of their documents: A World-Wide Low-Cost Community-Based Time-of-Arrival Lightning Detection and Lightning Location Network Found here: http://www.blitzortung.org/Webpages/index.php?lang=enpage=3 I am seriously considering involved as I am a bit of a weather nut too. There are other similar projects too, this is one: http://lightningradar.net/ At the moment it seems there are only a handful of participating stations in North America. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak Sent: June-24-14 12:52 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Loran, GPS, Lightning, Timing A friend pointed me to this site: US http://www.blitzortung.org/Webpages/index.php?lang=enpage_0=30 EU http://www.blitzortung.org/Webpages/index.php?lang=en This is a wonderful out-of-the-box project, with echoes of Loran-C and GPS triangulation. It's also a clever combination of home-brew receivers, UTC timestamping, the web, and global participation. You'll find technical details on the site; it makes good reading for any time nut. And adds new meaning to pulse per second... Two questions. 1) Is anyone on the list a participant in this effort? 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. Ok, getting accurate time and disciplining clocks with GPS or NTP or WWVB is too easy so why bother. But it would be interesting to use this raw data to set, calibrate, and discipline local clocks, as an redundant method, independent of existing broadcast TF sources. Some crunching on the data would at least determine what level of precision could be obtained with a, what shall we call it, CLDO (Coordinated Lightning Disciplined Oscillator). /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. This electronic message, as well as any transmitted files included in the electronic message, may contain privileged or confidential information and is intended solely for the use of the individual(s) or entity to which it is addressed. If you have received this electronic message in error please notify the sender immediately and delete the electronic message. Any unauthorized copying, disclosure or distribution of the electronic message is strictly forbidden. NAV CANADA accepts no liability for any damage caused by any virus and/or other malicious code transmitted by this electronic communication. Le présent message électronique et tout fichier qui peut y être joint peuvent contenir des renseignements privilégiés ou confidentiels destinés à l’usage exclusif des personnes ou des organismes à qui ils s’adressent. Si vous avez reçu ce message électronique par erreur, veuillez en informer l’expéditeur immédiatement et supprimez le. Toute reproduction, divulgation ou distribution du présent message électronique est strictement interdite. NAV CANADA n’assume aucune responsabilité en cas de dommage causé par tout virus ou autre programme malveillant transmis par ce message électronique. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
In message 06013AA10880459380352E3FB29C4B5C@pc52, Tom Van Baak writes: 2) Can you imagine applying this entire process in reverse. That is, instead of using GPS to timetag lightning strikes, use lightning strikes to synchronize a global network of local clocks. The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! The next issue is that lightnings are seldom vertical, they can trivially wiggle many hundred meters sideways, so at absolute best your jitter is going to be no better than the microsecond domain, and probably much worse, increasing with distance. But there's a workaround: if you have the right kind of pregnant thundercloud overhead, a plain firework rocket trailing a thin grounded wire will, on your command, get you a lightning strike. Not only are these lightnings almost always entirely vertical, they are also particular sharp and potent (for that very reason). So if you live in the right kind of place, you *could* implement a daily clock synchronization service much more spectacular than a mere ball-drop. I belive the US electrical grid industry runs a joint research center somewhere in northern Florida, using this method to test lightning protection of the power grid components. I suspect they ignite their rockets using remote control. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! That's true for ultimate accuracy. But notice how each strike is seen by dozens of observers and each observer knows their (fixed) position and has their own local (approximate) clock. So it seems to me it's not unlike how GPS works: with enough samples, it should be possible to solve for latitude, longitude, and time of each strike. Like running GPS in 3D mode rather than position hold (zero D) mode. Now the accuracy is clearly not going to be at the nanosecond level. Maybe not even microsecond level, since as you mentioned, there are biases and jitter and who know what propagation variations. But over time, you should be able to converge on differential local clock measurements. What I'd like to see is the TDEV of this as a common view time transfer method. A couple of hops and we could compare UTC(PHK) with UTC(TVB), for example. Perhaps another side effect of their lightning project is that it could create dynamic propagation maps using the residuals in their massive database. When I first owned WWVB gear I thought I had accurate time. After I got GPS, I realized that my WWVB receivers now became accurate Colorado-to-Seattle weather stations. As they say, one man's error is another man's signal. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
as, ahem, one of the early experimenters of lightning detection, gotta tell ya, the return stroke risetime is on the order of 1 us. Also, the very beginning of the waveform, that is the first part of the spike, is connected with the beginning of the breakdown, hence the location on the ground. Subsequent parts of the waveform are due to higher portions of the channel. Also, there are two polarities of discharge, and the positive discharge gives a waveform that looks like a cloud discharge that does not strike ground at all. Those seriously interested should get hold of a copy of Lightning by Martin Uman; this is bby now old, but is available inexpensively and will get you started. The original detectors used wideband crossed loops to get direction and no time of arrival; well before GPS timing. I hadn't looked into the amateur network! Vaisala corp has the best USA net, otherwise there is one in Boston and TOA enterprisesin Florida. U of Washington has a network as well. Enjoy! I can tell you after 50 years of dinking with it, Lightning is fun if ya ain't too close. Don Tom Van Baak The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, nd we're back to sqare one! That's true for ultimate accuracy. But notice how each strike is seen by dozens of observers and each observer knows their (fixed) position and has their own local (approximate) clock. So it seems to me it's not unlike how GPS works: with enough samples, it should be possible to solve for latitude, longitude, and time of each strike. Like running GPS in 3D mode rather than position hold (zero D) mode. Now the accuracy is clearly not going to be at the nanosecond level. Maybe not even microsecond level, since as you mentioned, there are biases and jitter and who know what propagation variations. But over time, you should be able to converge on differential local clock measurements. What I'd like to see is the TDEV of this as a common view time transfer method. A couple of hops and we could compare UTC(PHK) with UTC(TVB), for example. Perhaps another side effect of their lightning project is that it could create dynamic propagation maps using the residuals in their massive database. When I first owned WWVB gear I thought I had accurate time. After I got GPS, I realized that my WWVB receivers now became accurate Colorado-to-Seattle weather stations. As they say, one man's error is another man's signal. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
I am seriously considering involved as I am a bit of a weather nut too. I suspect this is quite common. You don't have to get into precise time very deep before you realize that all your timing gear is just pile of environmental sensors in disguise. Before time-nuts began, the first timing guy I met was Doug Hogarth (www.niceties.com) and he was seriously into weather measurement. He later got into the world of ultra-precise weight (mass) measurement. So I guess time-nuts is just a subset of measurement nuts. A quartz oscillator makes a good thermometer and sometimes a hygrometer and barometer too. An OCXO is a sensitive anemometer (just ask anyone who uses a PWM fan for TBolt temperature control). Quartz also makes an excellent accelerometer, gravimeter, tiltmeter, or even seismometer. An OCXO with EFC is a good voltmeter. Atomic clocks are superb magnetometers. And as Einstein predicted, atomic clocks make good altimeters and speedometers too. So everything we play with is a sensor. It's no wonder we are preoccupied with environmental sensing. Maybe Time is just what's left over after you shield or attenuate or compensate for everything else. /tvb See also: Quartz Resonators vs Their Environment: Time Base or Sensor? http://dev.quartzdyne.com/pdfs/quartzresonators.pdf http://www.paroscientific.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Oh man does this bring back memories of 12au7s and loop antennas pre internet 1970 as I recall. A QST magazine article. I built it and it used a crt for readout. There wasn't really a way back then to share the data. But will say this is quite a nice setup. Regards Paul WB8TSL On Tue, Jun 24, 2014 at 3:35 PM, Tom Van Baak t...@leapsecond.com wrote: I am seriously considering involved as I am a bit of a weather nut too. I suspect this is quite common. You don't have to get into precise time very deep before you realize that all your timing gear is just pile of environmental sensors in disguise. Before time-nuts began, the first timing guy I met was Doug Hogarth (www.niceties.com) and he was seriously into weather measurement. He later got into the world of ultra-precise weight (mass) measurement. So I guess time-nuts is just a subset of measurement nuts. A quartz oscillator makes a good thermometer and sometimes a hygrometer and barometer too. An OCXO is a sensitive anemometer (just ask anyone who uses a PWM fan for TBolt temperature control). Quartz also makes an excellent accelerometer, gravimeter, tiltmeter, or even seismometer. An OCXO with EFC is a good voltmeter. Atomic clocks are superb magnetometers. And as Einstein predicted, atomic clocks make good altimeters and speedometers too. So everything we play with is a sensor. It's no wonder we are preoccupied with environmental sensing. Maybe Time is just what's left over after you shield or attenuate or compensate for everything else. /tvb See also: Quartz Resonators vs Their Environment: Time Base or Sensor? http://dev.quartzdyne.com/pdfs/quartzresonators.pdf http://www.paroscientific.com/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
