I was fishing today aboard a friends boat off Key West. We put up the vhf antenna in some rain and noticed something that threw us all for a loop. the antenna was buzzing.
Any idea what would cause that? We were expecting to get hit by lightening, based on the wierd noise.
For real, any ideas?
Dug
Antenna Noise
Moderators: CaptPatrick, mike ohlstein, Bruce
-
waggles02673
- Senior Member
- Posts: 73
- Joined: Jun 30th, '06, 06:10
- Location: Cape Cod
I bet you were in serious danger of being struck.
All lightning does is release the electrical potential that builds up between the earth and the clouds, that gets big because of water droplets rubbing around together, turning the cloud into a big floating capacitor that wants to release its energy. Just before the charge gets big enough to cause a lightning strike the air around the strike area gets ionized.
I've see some stuff on Discovery, Nova, or the like, where they figured out that cloud-to-ground (or to water) lightning actually begins with a small static charge that starts on the ground and works its was up to the clouds. When it finally gets there then zap, the big charge from the clould comes down along that path. My guess is your antenna buzzing was from one of those little feeder charges working its way up.
I know a guy that has been struck on the water three times. One time it actually blew a 6" hole through the bow of his boat while offshore. He was able to make it in by staying on plane (little open console) which kept the hole out of the water. He actually ran Sebastian Inlet and 10 miles of the innercoastal that way. He pulled up to a buddy's dock and as soon as he stopped, the boat immediately suck under his feet. I wouldn't have believed the story except he had pictures of the boat hull with a big melted hole in the fiberglass.
Lightning is a hot topic here amongst boaters in East Central Florida, also known as the lightning capital of the world...
All lightning does is release the electrical potential that builds up between the earth and the clouds, that gets big because of water droplets rubbing around together, turning the cloud into a big floating capacitor that wants to release its energy. Just before the charge gets big enough to cause a lightning strike the air around the strike area gets ionized.
I've see some stuff on Discovery, Nova, or the like, where they figured out that cloud-to-ground (or to water) lightning actually begins with a small static charge that starts on the ground and works its was up to the clouds. When it finally gets there then zap, the big charge from the clould comes down along that path. My guess is your antenna buzzing was from one of those little feeder charges working its way up.
I know a guy that has been struck on the water three times. One time it actually blew a 6" hole through the bow of his boat while offshore. He was able to make it in by staying on plane (little open console) which kept the hole out of the water. He actually ran Sebastian Inlet and 10 miles of the innercoastal that way. He pulled up to a buddy's dock and as soon as he stopped, the boat immediately suck under his feet. I wouldn't have believed the story except he had pictures of the boat hull with a big melted hole in the fiberglass.
Lightning is a hot topic here amongst boaters in East Central Florida, also known as the lightning capital of the world...
"Who," Galileo asked, "would dare assert that we know all there is to be known?"
-
Brewster Minton
- Senior Member
- Posts: 1795
- Joined: Jun 30th, '06, 07:44
- Location: Hampton Bays NY
- Contact:
That is what I thought. We high tailed it out of there pretty quickly.
My buddy had his boat on the top level of a rack in the Oceanside Marina and the rack collapsed on Wednesday afternoon loaded with boats. We drove into the yard yesterday and the rack looked like a pretzel. So far it has been a great adventure down here... but I like the weather!
His boat had some good solid chunks out of it, and some good scratches, but we splashed it anyway, and have had two great days on the water. Fishing is slow, but the flying fish are spectacular!
Looking forward to returning to Boston for the Noreaster on Monday!
Dug
My buddy had his boat on the top level of a rack in the Oceanside Marina and the rack collapsed on Wednesday afternoon loaded with boats. We drove into the yard yesterday and the rack looked like a pretzel. So far it has been a great adventure down here... but I like the weather!
His boat had some good solid chunks out of it, and some good scratches, but we splashed it anyway, and have had two great days on the water. Fishing is slow, but the flying fish are spectacular!
Looking forward to returning to Boston for the Noreaster on Monday!
Dug
-
mike ohlstein
- Site Admin
- Posts: 2394
- Joined: Jun 29th, '06, 11:39
- Location: So many things seem like no-brainers until you run into someone with no brain.
- Contact:
Would not be surprised if your flight was delayed a bit.
http://www.wunderground.com/blog/JeffMa ... amp=200704
they are predicting some coastal flooding
http://www.wunderground.com/blog/JeffMa ... amp=200704
they are predicting some coastal flooding
Nope, flying sunday, I hope. And I picked the best airline in the world for this! Jet Blue. Hmmm...
Just crossing my fingers at this point. But until then, we fish in the morning!
And I will worry about it when I have to, if I have to.
Until then, between boat racks collapsing, antenna's buzzing, flights being missed (another story...) and all, I don't care at this point. It is warm, sunny, and that does not suck.
As Jimmy sings, "Come Monday", but until then I don't have to be anywhere but where I am!
Life is good...
Dug
Just crossing my fingers at this point. But until then, we fish in the morning!
And I will worry about it when I have to, if I have to.
Until then, between boat racks collapsing, antenna's buzzing, flights being missed (another story...) and all, I don't care at this point. It is warm, sunny, and that does not suck.
As Jimmy sings, "Come Monday", but until then I don't have to be anywhere but where I am!
Life is good...
Dug
-
Dave Kosh R.I.P.
- Senior Member
- Posts: 162
- Joined: Jun 30th, '06, 00:10
- Location: Ft. Myers Beach, FL 33931
- Contact:
All the above comments where on the money. Ion build up was occurring which precedes a lightning strike. On my 25 B I would get that quite often offshore but luckily nothing ever happened. On my 31B I have the VHF and SSB antennas mounted on the Tuna tower and so far have never had that problem.
You may want to check some manufactures for more information like Lightning Elimination Associates (expensive but works) also Patriot Antenna Systems has some good links and also checkout Poly Phaser Lightning Protection systems. They are inexpensive and work well on all my satellite dish installations. They should make them for VHF as well. Best way for protection is to simply disconnect the VHF radio antenna when that occurs in absence of an ion discharge system. Sounds technical but the Poly Phaser ones are cheap and they do work. You must provide a direct ground for these at both radio and antenna end however. A more practical method would also be to use an antenna disconnect switch (all metal housing) . Also ground your VHF to the boats grounding system via a .005 uf capacitor per Icom's recommendation. This provides a good RF ground which will not allow noise to get to your radio from the engines and other mechanical noises you may have genset etc. Or simply ignore the above and "get out of Dodge" as fast as you can. Dave K
You may want to check some manufactures for more information like Lightning Elimination Associates (expensive but works) also Patriot Antenna Systems has some good links and also checkout Poly Phaser Lightning Protection systems. They are inexpensive and work well on all my satellite dish installations. They should make them for VHF as well. Best way for protection is to simply disconnect the VHF radio antenna when that occurs in absence of an ion discharge system. Sounds technical but the Poly Phaser ones are cheap and they do work. You must provide a direct ground for these at both radio and antenna end however. A more practical method would also be to use an antenna disconnect switch (all metal housing) . Also ground your VHF to the boats grounding system via a .005 uf capacitor per Icom's recommendation. This provides a good RF ground which will not allow noise to get to your radio from the engines and other mechanical noises you may have genset etc. Or simply ignore the above and "get out of Dodge" as fast as you can. Dave K
Keep Fishing...
Who is online
Users browsing this forum: Bing [Bot] and 469 guests