RE: [Repeater-Builder] Direct Strike Lightning Detector
Jess, Tape an empty aluminium drink can to the side of the single point earth strap (or to the leg of the tower). The magnetic field from the few thousand amps of strike current should flatten the drink can in microseconds! Mark vk3byy From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jesse Lloyd Sent: Thursday, 29 April 2010 10:56 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Direct Strike Lightning Detector We've followed the polyphasor book to the best that we can, using 3 copper strap everywhere, single point ground, etc, etc. I'm reasonably confident that if it does get hit we won't know. I'd just like something simple to indicate that all our efforts were worth it (so I can say to the boss we got hit and everything survived, told you so). From reading some specs and documentation on tower leg mounted strike counters I think the fuse idea might work. So far I haven't seen any that won't work's float by in the threat, so thats something I suppose. Jesse On Tue, Apr 27, 2010 at 8:44 PM, Gerald Pelnar wd0...@cox.netmailto:wd0...@cox.net wrote: Got tower? On a high spot? It gets hit!! If you can't tell, that's a good thing. Gerald Pelnar WD0FYF McPherson, Kansas - Original Message - From: Jesse Lloyd ve7...@gmail.commailto:ve7lyd%40gmail.com To: Repeater-Builder@yahoogroups.commailto:Repeater-Builder%40yahoogroups.com Sent: Tuesday, April 27, 2010 12:32 AM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse Yahoo! Groups Links
Re: [Repeater-Builder] Direct Strike Lightning Detector
We've followed the polyphasor book to the best that we can, using 3 copper strap everywhere, single point ground, etc, etc. I'm reasonably confident that if it does get hit we won't know. I'd just like something simple to indicate that all our efforts were worth it (so I can say to the boss we got hit and everything survived, told you so). From reading some specs and documentation on tower leg mounted strike counters I think the fuse idea might work. So far I haven't seen any that won't work's float by in the threat, so thats something I suppose. Jesse On Tue, Apr 27, 2010 at 8:44 PM, Gerald Pelnar wd0...@cox.net wrote: Got tower? On a high spot? It gets hit!! If you can't tell, that's a good thing. Gerald Pelnar WD0FYF McPherson, Kansas - Original Message - From: Jesse Lloyd ve7...@gmail.com ve7lyd%40gmail.com To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com Sent: Tuesday, April 27, 2010 12:32 AM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse Yahoo! Groups Links
Re: [Repeater-Builder] Direct Strike Lightning Detector
My Dad used to have a small tower for his TV antenna. One Christmas we strung Christmas lights up the thing and they got left there for a couple years. All the coloring wore off, leaving bare bulbs (the old outdoor size of years ago). The tower took a direct hit one summer. Every one of the bulbs ended up with a burned out filament and a large black spot on the inside of the glass. The antennas were fine, TV was fine, but the scanner (with antenna on the tower) didn't make it. Took all summer for the grass to start growing again under the tower. Chuck WB2EDV - Original Message - From: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Wednesday, April 28, 2010 8:55 PM Subject: Re: [Repeater-Builder] Direct Strike Lightning Detector We've followed the polyphasor book to the best that we can, using 3 copper strap everywhere, single point ground, etc, etc. I'm reasonably confident that if it does get hit we won't know. I'd just like something simple to indicate that all our efforts were worth it (so I can say to the boss we got hit and everything survived, told you so). From reading some specs and documentation on tower leg mounted strike counters I think the fuse idea might work. So far I haven't seen any that won't work's float by in the threat, so thats something I suppose. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
On Wed, 28 Apr 2010, Chuck Kelsey wrote: My Dad used to have a small tower for his TV antenna. One Christmas we strung Christmas lights up the thing and they got left there for a couple years. All the coloring wore off, leaving bare bulbs (the old outdoor size of years ago). The tower took a direct hit one summer. Every one of the bulbs ended up with a burned out filament and a large black spot on the inside of the glass. The antennas were fine, TV was fine, but the scanner (with antenna on the tower) didn't make it. Took all summer for the grass to start growing again under the tower. Chuck WB2EDV That makes me think a bit. If you take and run fluorescent lights all the way up the tower, connected together with short copper jumpers, once the ionization voltage is reached, they will form a large conduction channel to the termination point. It might potentially be a lower resistance than that of the tower, although your neighbors aren't going to like it when The Big Tower lights up because the voltage from ground to the top is enough to bias the lights into operation. If you don't bond it to the tower, you could have fun. If you do bond it, you'll know when the strike hits. On the other hand, if you do get a direct strike, your neighbors will be picking up pieces of glass for months. You will too. =) -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Direct Strike Lightning Detector
Sounds like you have done it by the book. I didn't help with your original request. Just wanted to assure you if it sticks up in the air, it has been hit. Gerald We've followed the polyphasor book to the best that we can, using 3 copper strap everywhere, single point ground, etc, etc. I'm reasonably confident that if it does get hit we won't know. I'd just like something simple to indicate that all our efforts were worth it (so I can say to the boss we got hit and everything survived, told you so). From reading some specs and documentation on tower leg mounted strike counters I think the fuse idea might work. So far I haven't seen any that won't work's float by in the threat, so thats something I suppose. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
On Mon, 26 Apr 2010, Jesse Lloyd wrote: I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with Direct hit? Sure, look for anything that has the magic smoke let out of it. In a direct hit, something is gonna go. -- Kris Kirby, KE4AHR Disinformation Analyst
Re: [Repeater-Builder] Direct Strike Lightning Detector
But Paul...Toronto is not near Lake Erie ! It's on Lake Ontario:-)) John VE3AMZ Waterloo, Ontario - Original Message - From: Paul Plack To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 27, 2010 1:54 AM Subject: Re: [Repeater-Builder] Direct Strike Lightning Detector Jesse, A radio engineer in Atlanta years ago told me a neat trick he said allows confirming a strike, and estimating the current it produced. It involves rexcording an audio tone on a piece of magnetic tape several feet long, sealing it in a weatherproof, non-conductive tube, and positioning it perpendicular to a tower leg. If lightning strikes, the magnetic flux produced around the conductor will vary proportionate to the current, and playing back the tape will reveal an erased portion which can be measured for its physical length. I have no idea how well that would actually work, or how to calculate the current based on how many inches of tape are erased. These days the only magnetic tape machines left in common use are old cassette decks, but it might be worth a piece of PVC pipe and some glue to try it. If you just want to know if it's hit, set up a vertical conductor some distance from the tower, but well within its cone of protection, connected through a fuse to an independent ground. If the tower gets smacked, you can bet some serious current will be induced in a 10-foot vertical wire. Years ago, an engineer for WBEN radio in Buffalo told me that on summer days when thunderstorms would hit the Toronto area across Lake Erie to the north, a hit on a radio tower up there would produce a spark across the ball gaps on the towers in Buffalo. That's 90 miles! 73, Paul, AE4KR - Original Message - From: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 11:32 PM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
Well sure...if you take the shortcut! ;^) I gotta remember not to post after 1am... - Original Message - From: John J. Riddell To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 27, 2010 3:52 AM Subject: Re: [Repeater-Builder] Direct Strike Lightning Detector But Paul...Toronto is not near Lake Erie ! It's on Lake Ontario:-)) John VE3AMZ Waterloo, Ontario
Re: [Repeater-Builder] Direct Strike Lightning Detector
Poly phase makes a unit that clamps on the leg of a tower and works very well. John - Original Message - From: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 27, 2010 1:32 AM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
Another old trick was to wire a flash bulb in shunt with about 20 feet of tower. W8AK In a message dated 4/27/2010 1:32:51 A.M. Eastern Daylight Time, ve7...@gmail.com writes: Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
Got tower? On a high spot? It gets hit!! If you can't tell, that's a good thing. Gerald Pelnar WD0FYF McPherson, Kansas - Original Message - From: Jesse Lloyd ve7...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 27, 2010 12:32 AM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse Yahoo! Groups Links
[Repeater-Builder] Direct Strike Lightning Detector
Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
Re: [Repeater-Builder] Direct Strike Lightning Detector
Jesse, A radio engineer in Atlanta years ago told me a neat trick he said allows confirming a strike, and estimating the current it produced. It involves rexcording an audio tone on a piece of magnetic tape several feet long, sealing it in a weatherproof, non-conductive tube, and positioning it perpendicular to a tower leg. If lightning strikes, the magnetic flux produced around the conductor will vary proportionate to the current, and playing back the tape will reveal an erased portion which can be measured for its physical length. I have no idea how well that would actually work, or how to calculate the current based on how many inches of tape are erased. These days the only magnetic tape machines left in common use are old cassette decks, but it might be worth a piece of PVC pipe and some glue to try it. If you just want to know if it's hit, set up a vertical conductor some distance from the tower, but well within its cone of protection, connected through a fuse to an independent ground. If the tower gets smacked, you can bet some serious current will be induced in a 10-foot vertical wire. Years ago, an engineer for WBEN radio in Buffalo told me that on summer days when thunderstorms would hit the Toronto area across Lake Erie to the north, a hit on a radio tower up there would produce a spark across the ball gaps on the towers in Buffalo. That's 90 miles! 73, Paul, AE4KR - Original Message - From: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2010 11:32 PM Subject: [Repeater-Builder] Direct Strike Lightning Detector Hey All, I am trying to think of a way to detect if a tower at one of our sites gets a direct hit. I was thinking of paralleling a ground strap with a 10mA amp glass fuse. Maybe make the two connections to the ground stap 2 ft apart and use a fuse holder for fuse testing and replacement. I suspect the fuse would blow if any significant current went down the ground strap (or would the whole thing melt? I suppose either way I'd know!). Ideas? I live in an area that doesn't see a lot of lightning, I'm curious if the tower gets hit. Jesse
