Just a reminder, bad weather today Sunday Jan 22

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Lawless

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To those with basic antennas and gear, get your radios unplugged and antenna cables disconnected and away from your equipment.

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Lawless;n67141 said:
To those with basic antennas and gear, get your radios unplugged and antenna cables disconnected and away from your equipment.

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I suffered a major lightning event about 15 years ago. Lightning entered via the twisted pair, on the utility pole in my yard, then got into the electrical system. I was here when it happened. A bright flash of blue, along with the sound of a bullwhip cracking.
 
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Did that last night...... All disconnected at the outside panel.
 
Does anyone have a switch on the feed line you can just open when you're not using your rig?
 
Yes. I can flip 2 switches and all rigs, and antennas go to ground. It's a good practice, however not a guarantee of protection.

Many coaxial antenna switches, switch the center conductor to ground.


With open feed lines one can use a knife switch.

 

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With lighting all bets are off when trying to open or prevent it with a switch. Granted it could save it but I have seen it jump 2-3 feet before as well.
 
Straight from the testing labs of the ARRL.

Lab Notes: Lightning Protection By Mike Tracy, KC1SX, Technical Information Services Coordinator


Q: Is there an easy way to disconnect my setup?

A: A quick, convenient way to disconnect your feed lines is through a feed-line switch. If you're using a coaxial feed line, you can use a manual, multiposition coax switch, a remote coax switch or an in-line coaxial relay. Although you could also simply disconnect your coax by hand, it's awkward and the connectors will become worn after repeated connecting and disconnecting. Some coax switches also contain lightning arrestors. For open wire or ladder line, you could install a knife switch or electrically operated remote 2-pole relay. Whichever method you choose, be sure to mount the switch on the outside of your entrance panel.
 
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Next thing you know some will be advising you to put your coax in a glass jar so you can make a grenade. The "SIMPLE" question was "Does anyone have a switch on the feed line you can just open when you're not using your rig?" . The Simple answer is "YES!". Also as stated with a direct hit you can run but you can't hide! I too can find pictures and stories of how lightning took obliterated various pieces of equipment. I Had a friend who had the ground wire "ONLY" connected to his radio. Lightning came out the outlet in the same room looking for a ground and found his radio ground right through the front of his radio. Only safe place to put a radio is probably in the box in a closet "MAYBE".

I run coax switches on all my radios, antennas, etc. It is not practical for me to disconnect everything at the radio or antenna. I have too many. Therefore, I use switches grounded as my best alternative. Also have radios, amps, tuner, etc grounded.

You can search the internet and copy and paste a thousand different answers. Experience is what is going to pay off more than anything. I only have 39 years of experience and still do not feel I am an authority by any means but know enough to be dangerous.

Once went to a meeting on grounding and had a gentleman very knowledgeable from the local power company. I have not seen this but he stated "SOME" insurance companies were even checking how your equipment was grouinded before they paid? True or false? I do not know and I worked for an insurance company doing just what he described.

Never heard of burying a section of coax underground? Not sure what purpose that would serve? Not saying it don't work but that I have not read the website you have pulled this from. Most of my answers will come from experience and not what I can find on a website unless I have to do research. And I've been wrong more than once! LOL
 
I have never heard of burying coaxial cable to assist in lightning protection. May be valid, may be another myth. I have no idea. I do know this. About 15 years ago, lightning stuck the utility pole in my back yard. Lightning entered my home through the phone lines. My phone lines were buried, and there was a nice trench through my yard, created by the lightning strike traveling through the lines. In my case, a buried line appeared to do nothing. I bet State Farm wished it would have worked. No photos, so I guess you'll have to take my word for it.
 
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Cape Fear;n68482 said:
Does anyone have a switch on the feed line you can just open when you're not using your rig?
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yes, grounded and outside disconnect - bone fide, blah blah - lightning is dangerous.
 
WK4R;n68754 said:
Never heard of burying a section of coax underground? Not sure what purpose that would serve? Not saying it don't work but that I have not read the website you have pulled this from. Most of my answers will come from experience and not what I can find on a website unless I have to do research. And I've been wrong more than once! LOL
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I briefly read over many sections of 'electrical code', as well as a quick search on the net. Zero mention of burying of coaxial cable as protective measure against a lightning strike. I would be interested in the source of this information, so I can further educate myself, on lightning protection. Taking in consideration of what I experienced first hand approx 15 years ago, I wish to take any countermeasures I can against this ever occurring again.
 
Thanks for the discussion guys. Jayne has offered to let me use his IC-718 to get on HF but I'm a little nervous about borrowing a $700 radio knowing it could get smacked. IF I go through with it I want to take every precaution so I'm studying now how to set up my shack.

The good news is that I have access to some grounding conductors through work, I may even be able to find some copper bus bars and flat strap if I dig deep enough. Dang thieves make that tough though.
 
Good electrical bonding is very important. Do not cut corners. Also, NEVER take what anyone says (including myself) as gospel. Do your own research using known reliable sources of information. However I will NEVER offer you advice, that I don't follow myself..
 
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Burying coax is a good practice. There is a thread by the guru on lightning I read about a month ago that was very enlightening.

A polyphaser on the feed is great but if you are home, best practice is disconnect and move the feed as far as possible from the coax coming into the equipment.
 
Lawless;n68959 said:
Burying coax is a good practice. There is a thread by the guru on lightning I read about a month ago that was very enlightening.

A polyphaser on the feed is great but if you are home, best practice is disconnect and move the feed as far as possible from the coax coming into the equipment.
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Lawless if you dig up that article please link, I'd like to read it.

Oh and get back to work, I'm waiting on the next chapter of your book ;)
 
Lawless;n68959 said:
Burying coax is a good practice. There is a thread by the guru on lightning I read about a month ago that was very enlightening.

A polyphaser on the feed is great but if you are home, best practice is disconnect and move the feed as far as possible from the coax coming into the equipment.
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Can you provide me a link to this guru? I'd like to read his findings. Thanks
 
308Prepper;n68965 said:
Can you provide me a link to this guru? I'd like to read his findings. Thanks
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I am looking for it now.

Had information that contradicted a lot of common sayings.
Guy was a licensed electrical contractor and engineer as well as wrote the actual grounding part of THE book that is used for national electrical codes.
 
Lawless;n68966 said:
I am looking for it now.

Had information that contradicted a lot of common sayings.
Guy was a licensed electrical contractor and engineer as well as wrote the actual grounding part of THE book that is used for national electrical codes.
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Great... I'd like to read his findings, and compare to several of well known sources. 73
 
What about the lightning protectors that go in-line with your coax? I've got one on my feed line out to the 30' vertical antenna / lightning rod in the back yard. I've lost IP cameras, switches, routers, DSL modems and solar controllers to lightning so far but have yet to blow up a radio. I'm probably due.
 
Searched the Internet for any well respected publications by author of that QRZ thread. Came up empty.
 
Jayne;n69013 said:
What about the lightning protectors that go in-line with your coax? I've got one on my feed line out to the 30' vertical antenna / lightning rod in the back yard. I've lost IP cameras, switches, routers, DSL modems and solar controllers to lightning so far but have yet to blow up a radio. I'm probably due.
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What do you have Jayne? The ones that use the replaceable "fuse" or the PolyPhaser type that reset all on there own?
 
Jp8819;n68624 said:
Granted it could save it but I have seen it jump 2-3 feet before as well.
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It's good to think about this a bit.

It jumped a mile or so to get from the cloud to the spot near the earth (or directly to your antenna) !


The closest I've come to a direct hit, is about 5 yrs ago. A bolt of lightning hit a tree in my woods about 50' from my tower and about 100' from my house. It did the normal work of turning tree moisture to steam and splitting a seam up the tree.

It also induced enough voltage in my antenna to

a: bypass enough energy around the polyphaser which is mounted at the base of my tower and connected via 4" wide copper strap to a ground field at the base of the tower (a poor ground field...5 8' copper plated rods spaced 10' apart and inter connected by #0 solid copper wire.

b: travel undergound 70' via coax which is run thru 4" PVC piping under the yard. It's underground to protect the coax from my fleet of vintage Cub Cadets in lawn duty rather than any specific protection.

c: Jump a 12" gap between the floating ends of the coax, carbonizing the wall of the plastic bottle that keeps the disconnected PL259 dry and discharged to ground via my patch panel, which has a ground rod connected to it via a 1" heavy solid copper bar and is in turn connected to the service entrance ground via #2 solid copper wire. (service entrance is at the opposite end of the house from ham station and antenna...naturally).

d) melt the edge of the PL 259 threaded ring as it exited on the way to my patch panel.


MY advice:

* Disconnect antennas when they're not in use
* Ground the inputs to your radios when not in use
* Don't trust any purchased inline devices to do much other than shunting some near miss energy to ground.

I still worry when thunderstorms rumble in and I have 50' of steel in the air.... :)
 
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It's interesting to look at commercial towers. I think the first thing they do (particularly the AM station types) is shunt as much energy as possible to ground thru an air gap. This is done via a pair of interlocking steel rings , or discharge balls like:






These giant things will shunt some power down to where the little polyphaser gas discharge or semiconductor shunts might be able to deal with steering the rest of the energy to ground before it reaches the antenna input jack on your radio.

Remember that your radio is capable of resolving microvolt (10^-6 ) level signals, whereas the lightning bolt may contain millions (10^+06) of volts of potential. Twelve orders of magnitude is a lot to deal with
 

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Lawless;n70500 said:
What do you have Jayne? The ones that use the replaceable "fuse" or the PolyPhaser type that reset all on there own?
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cheap fuse type, and the fuse isn't replaceable.
 
JohnFreeman;n70624 said:
. This is done via a pair of interlocking steel rings , or
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If you are talking about the below pictured interlocking rings, this is an Austin Isolation Transformer used to power the traffic lighting on an AM broadcast tower. It has nothing to do with lightning, rather lighting.

Sometimes you will see the lightning air gap balls on the same mount, but the two perform separate functions.

Of course, I could be wrong.

 

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^^ I learned something! I read that they do incorporate an air gap lightning discharge as well. (as does, I guess anything that runs up the tower). It was interesting to google the technology behind them. Thanks for the info. Those guys make some interesting products.
 
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