Dipole questions, cont'd

[gamegetter]

hopefully it will minimize the damage, by directing most of the strike into the ground

but true that I have still had damage to modems(on the phone line) and satellite receivers(on the dish) from nearby lightening strikes

 

[hookedon6]

And just a reminder, lightning can also get into the house/equipment from the ground side. No antenna connected and there's still the probability that there can be enough 'charge' entering by way of the grounds to do damage. Grounding or throwing that feed line out the window is not a sure way of preventing lightning damage.
- 'Doc

yep,... and if you have a beam on a rotor,. don't forget that cable either

 

[QROdx]

The biggest thing that you have to remember is that people are cheap, they don't want to spend money on things that they can't touch or play with... a ground system is one of these things.

A few posts have mentioned "proper" ground systems.
I have installed many proper ground systems and I know that it is beyond the budget of most people.

Soil resistance tests to determine layout of the halo.
Digging up almost the entire property and installing at minimum of 20 12' ground rods all interconnected and cadweld bonded to 4 gauge or larger stranded copper below grade.
Bonding every metallic piece of the structure, tower, equipment, coax and antennas as well as electrical system and even installing lightning rods and polyphasers.

I have been on properly grounded sites when lightning struck and it sounded like a bomb went off and none of the equipment even paused.
On the other hand, none of my personal equipment is grounded and I have taken direct hits while transmitting and had zero damage other than a few chips of brick falling in the fireplace from the chimney.

Most people will just connect a wire from their equipment and tie it into the existing service ground, a few will actually drive a rod and connect to that... even fewer will go to all the trouble of installing a proper ground system.

Do what you can afford or do nothing at all, either way the choice is yours.

 

[RADIOOMAN]

Your best lightning insurance is to have no antenna or radio gear. Tear down the house, dig a hole, and live underground.

Read the documents referred to in the other message thread. Properly bond your antenna and AC grounds together and there is very little reason for concern. The likelihood of a direct hit in reality is low. If you build the station properly the vast majority of any surge current can be diverted around the equipment, greatly reducing or eliminating any damage. Having to disconnect antenna lines and bring them outside is utter nonsense and for clueless people who don't know how to install things.

Nothing will protect you against all perils. What about if there is a flood, hurricane, tornado, or major snow or ice storm? You have to deal with hazards regardless.

Yeah but, we know that is nonsense.?!?!?!?

What if you live in an apartment and you can't mess with the electrical wiring.
If you use the mains ground as your preferred path of discharge then what happens when lightning only strikes the ground or something conductive sticking up from the ground (like maybe a tree) and then raises the soil potential and subsequently the mains ground is raised in potential to a dangerous level and the the energy is still going to go through the radio equipment to an alternate path.
I think you are failing to understand the all of the requirements and expense necessary to install a good lightning protection grounding system.
Since the ground is not a real good conductor it has associated resistance and trying to rely on it to absorb all of the energy without an associated voltage drop is nonsense.
A lightning protection system is not just as simple as "bonding everything to the mains ground."
You have to consider that sometimes the energy from the lightning discharge comes from the mains and sometimes it comes from the ground side and sometimes it comes in through the coax or telephone wires.
A sophisticated lightning protection system monitors all of these and then makes a decision as to where to direct the unwanted energy; And sometimes the ground is not the best choice, sometimes the mains voltage is lower than the ground voltage when lightning strikes something nearby.
So, once again, the cheapest and simplest and most effective way to protect your house and your equipment is to unhook the coax and put it outside and unplug from the wall.

Geeez, are we done with this yet!?!?!

 

[Captain Kilowatt]

Yeah but, we know that is nonsense.?!?!?!?

What if you live in an apartment and you can't mess with the electrical wiring.
If you use the mains ground as your preferred path of discharge then what happens when lightning only strikes the ground or something conductive sticking up from the ground (like maybe a tree) and then raises the soil potential and subsequently the mains ground is raised in potential to a dangerous level and the the energy is still going to go through the radio equipment to an alternate path.
I think you are failing to understand the all of the requirements and expense necessary to install a good lightning protection grounding system.
Since the ground is not a real good conductor it has associated resistance and trying to rely on it to absorb all of the energy without an associated voltage drop is nonsense.
A lightning protection system is not just as simple as "bonding everything to the mains ground."
You have to consider that sometimes the energy from the lightning discharge comes from the mains and sometimes it comes from the ground side and sometimes it comes in through the coax or telephone wires.
A sophisticated lightning protection system monitors all of these and then makes a decision as to where to direct the unwanted energy; And sometimes the ground is not the best choice, sometimes the mains voltage is lower than the ground voltage when lightning strikes something nearby.
So, once again, the cheapest and simplest and most effective way to protect your house and your equipment is to unhook the coax and put it outside and unplug from the wall.

Geeez, are we done with this yet!?!?!

I believe VO1KS said that bonding everything is of the utmost importance but not the only thing. Thge entire idea is that all grounds which are bonded will rise and fall in potential the same amount regardless of what that potential voltage is and you will not have current flowing through grounds and equipment. That combined with an alternate path for it via ground rods is the best thing to do.

As for VO1KS not understanding I just have to chuckle. I know him personally and can tell you that he works at the bottom of a 600 foot tower ( is that right Warren somewhere around that) on a hilltop that supports all kinds of broadcast equipment both radio and television and it all remains on the air when it gets hit. Not if, but WHEN. He is a commercial broadcast engineer as I used to be until about 7 years ago. He does know his stuff.

Yes it can be argued that throwing the cable out the window will work and in some cases it is all one can do, however there are cases where the cable can be left connected to the gear and have nothing damaged after a hit. It involves a bit of work and minimal expense to do it right but you first have to understand what is right and what is generally accepted as being right. There is a considerable difference.

 

[RADIOOMAN]

I believe VO1KS said that bonding everything is of the utmost importance but not the only thing. Thge entire idea is that all grounds which are bonded will rise and fall in potential the same amount regardless of what that potential voltage is and you will not have current flowing through grounds and equipment. That combined with an alternate path for it via ground rods is the best thing to do.

As for VO1KS not understanding I just have to chuckle. I know him personally and can tell you that he works at the bottom of a 600 foot tower ( is that right Warren somewhere around that) on a hilltop that supports all kinds of broadcast equipment both radio and television and it all remains on the air when it gets hit. Not if, but WHEN. He is a commercial broadcast engineer as I used to be until about 7 years ago. He does know his stuff.

Yes it can be argued that throwing the cable out the window will work and in some cases it is all one can do, however there are cases where the cable can be left connected to the gear and have nothing damaged after a hit. It involves a bit of work and minimal expense to do it right but you first have to understand what is right and what is generally accepted as being right. There is a considerable difference.

Ok then, so that's how it's gonna be.
Et tu, Brute.
When I offer someone advice that helps them with their situation that is simple and cheap and effective then someone decides to use that to denigrate me, well then, you see, this is what you get.

When I tell someone that they can disconnect the coax and put it outside and disconnect the equipment from the wall and any other associated wiring attached to the equipment and someone indicates in an open forum that that "is nonsense", well then I feel denigrated.
You receive that you give.

You have qualified yourself and the offending party.
My self: 1) Licensed Indiana Consumer Repair Technician since 1972
2) Amateur Extra
3) GROL (frn 004170486)
I was a field technician for AT&T for the microwave tower linking system.
I worked with many aspects of a microwave tower installation and its associated equipment.
I have some experience with communications towers and the systems used to protect them and their equipment from lightning discharge.
Additionally I have experience with the system concept and equipment designed for the protection of electronical/electrical equipment at a rock quarry. (earth grounds are essentially useless when you are on top of a rock )

 

[Captain Kilowatt]

With that kind of experience you should in fact realize that it is entirely possible to remain connected and survive a strike unscathed. As I said it IS possible to do the same thing by disconnecting the cables. I never disagreed with that however I do contend that it is not necessary IF you install a proper ground. Many stations are not in a situation where they can easily do so. I myself have three runs of LDF-4 running underground into the houise. Noty ver practical to disconnect that. Same thing for the rotator control and antenna switch control cables. You can't just simply disconnect them and toss them out the window. I am far from being alone in this regard. So many people are of the understanding that the ONLY way to avoid damage is to disconnect and throw it out the window and this is simply just not true. In many cases like apartment living or rental properties that may be the most practical solution. Upon that I agree however it is not difficult to install a proper ground if you have total control over your own property.

As for the uselessness of earth grounds on a rock I admit it is difficult. I had an FM station sitting on a mountaintop with between 6 and 16 inches of overburden and then rock. The guy anchors were drilled to accept rock bolts. Ground plates were installed by a backhoe and drilling as well as radials to carry the current. In a rocky situation radials help even if just on the ground as long as they are in contact with it or just under the surface. I know of one AM station where the radials were run on the surface of the granite which was everywhere. It took hits to one or another of the two towers and remained on the air many times.

Yeah it is nonsense to disconnect and throw for most of the situations but it may be the only way for some. I myself have never thrown the cables out the window or whatever as I have made "other arrangements" for the lightning. It's been 35 years and so far so good.

 

[RADIOOMAN]

With that kind of experience you should in fact realize that it is entirely possible to remain connected and survive a strike unscathed. As I said it IS possible to do the same thing by disconnecting the cables. I never disagreed with that however I do contend that it is not necessary IF you install a proper ground. Many stations are not in a situation where they can easily do so. I myself have three runs of LDF-4 running underground into the houise. Noty ver practical to disconnect that. Same thing for the rotator control and antenna switch control cables. You can't just simply disconnect them and toss them out the window. I am far from being alone in this regard. So many people are of the understanding that the ONLY way to avoid damage is to disconnect and throw it out the window and this is simply just not true. In many cases like apartment living or rental properties that may be the most practical solution. Upon that I agree however it is not difficult to install a proper ground if you have total control over your own property.

As for the uselessness of earth grounds on a rock I admit it is difficult. I had an FM station sitting on a mountaintop with between 6 and 16 inches of overburden and then rock. The guy anchors were drilled to accept rock bolts. Ground plates were installed by a backhoe and drilling as well as radials to carry the current. In a rocky situation radials help even if just on the ground as long as they are in contact with it or just under the surface. I know of one AM station where the radials were run on the surface of the granite which was everywhere. It took hits to one or another of the two towers and remained on the air many times.

Yeah it is nonsense to disconnect and throw for most of the situations but it may be the only way for some. I myself have never thrown the cables out the window or whatever as I have made "other arrangements" for the lightning. It's been 35 years and so far so good.

I agree with some of your first paragraph, however, my original posting in this matter was for the benefit of the thread starter, Ironguts; And it was and is very useful for his pupose.
I had not intended it to applicable to all, just to Ironguts.

 

[QROdx]

the old wives tale, or should I say "the grumpy old CB'ers tale" around here has always been to just unplug the coax from the back of your gear and put the connector in a glass jar.
Their theory , i guess, was that glass is an insulator and that if lightning does come in on the coax that it will just run around inside the jar until it gets bored or dies.

I guess it was about 15 years ago that this was theory was tested by a lightning strike directly to a set of stacked moonrakers.
People here are scared when a cloud comes up so this guy had already had the pl259 disconnected from his amp and placed inside a glass mayo jar.
It seems that lightning doesn't get bored when it reaches the jar LOL it didn't even notice the jar... charred up his table and looked for the closest thing that it could find to get to earth which was the wall plug behind his gear, which his gear was still plugged into.
so even though the coax was disconnected but still inside the house, he lost his gear and was still finding tiny pieces of glass for several weeks after.
Just something this topic reminded me of.....

 

[HomerBB]

 

[RADIOOMAN]

"THAT'S RIGHT!"

 

[QROdx]

LOL according to the allstate insurance commercial
"They can't put anything that isn't true on the internet"
"Where did you hear that?"
"On the internet!"

Since nothing on the internet is wrong then I need to start pushing my coax wax again....

 

[Lil'Yeshua]

10/11 Meter Ground Plane Antenna - YouTube

 

[RADIOOMAN]

LOL according to the allstate insurance commercial
"They can't put anything that isn't true on the internet"
"Where did you hear that?"
"On the internet!"

Since nothing on the internet is wrong then I need to start pushing my coax wax again....

I am glad you posted this.
Maybe you know where I can get me some of that "SKIP WAX" for my antenna I been hearin' some guys talk about.

 

[QROdx]

LOL
never seen the skip wax but people laughed at the coaxwax label i printed up and stuck on the table at kennehoochee hamfest near atlanta years back.
Thought seriously about buying some cheap car wax and putting the labels on and see if it would actually sell

Maybe I can make some lightning-b-gone wax ????