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 Post subject: setting up a 100' antenna
PostPosted: Aug Sat 08, 2020 4:30 am 
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Joined: May Wed 27, 2009 5:24 pm
Posts: 240
Location: n9842 n birch rd, tomahawk, wisconsin, 54487
I'm going to setup a 100' single wire antenna in a clearing of the woods in north central Wisconsin. It will service my small collection of 6 and 32 volt farm radios and several crystal sets. It will be equipped with all the usual insulators and a healthy 8' grounding rod by the house. My silly question is this. Why is the rod always by the house? Wouldn't it be best to have it on the other end to draw the lightning away from the house? Or a rod on each end? Or is that like wearing a belt AND suspenders?


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sat 08, 2020 5:08 am 
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Joined: Jun Sat 15, 2019 7:43 pm
Posts: 939
Any of your ground rods have to be bonded (connected) to the house ground rod per code. The more ground rods you have, the better RF ground you will have. I use #6 copper to bond the ground rods.

DM


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sat 08, 2020 6:13 pm 
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Joined: Feb Wed 12, 2014 4:25 pm
Posts: 153
Location: Southeast Kans. - KA0HCP
There are multiple types/purposes for ground rods. What type/purpose is yours?
1. Lightning/surge protection of antenna
2. Electrical Safety ground of radio
3. RF ground as second half of antenna

Realize that technical understanding of ground rods uses and best practices has changed since the beginning of radio when "Every radio needs a ground and an antenna is a wire and a ground rod".

-Lightning/surge protection requires grounding outside, nearest the antenna house entrance, with the ground rod 'bonded" to the house service ground rod. Some sort of surge device must me placed in the antenna feedline.

-Electrical Safety; Before the 1970's most radios had no fuses and no ground connection to the house service ground. The best practice is to add three wire modern connection to your radio with an isolation transformer. Otherwise you will need to connect to a ground rod, immediately outside the window, with the rod bonded to the house service ground.

-Antenna: Soil is a terrible conductor of radio frequency. No radio requires connect to soil ground. Copper wire is over 1,000 times more conductive than the best soil. Shorter, more efficient antenna can be made by using a dipole, vertical ground plane or other modern design. A single wire, with soil grounding via rod, is still effective, but is inefficient and requires much more space, a ground rod bonded to the house service rod for safety, as well as surge device for lightning protection. Copper wires (radials) connected to the antenna ground rod and laid on the ground will noticeably improve reception.

Bottom line: connections to any ground rod, of whatever purpose should be kept to the minimum length necessary. A ground rod is a poorer choice as an RF conductor over other methods, but is a satisfactory, and venerable tradition.

Have fun, b.


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sat 08, 2020 11:10 pm 
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Joined: May Sat 30, 2015 11:49 pm
Posts: 1379
Location: Keystone Heights, FL, USA 32656
What is the ground rod going to be connected to? Surely not the other end of the wire antenna.

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Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Mon 10, 2020 12:14 am 
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Joined: May Wed 27, 2009 5:24 pm
Posts: 240
Location: n9842 n birch rd, tomahawk, wisconsin, 54487
Just to make it clear what the antenna is to service - 6 and 32 volt 1930s battery radios and crystal set radios. No household AC voltages at all. All battery. I plan on using a 8' copper plated ground rod driven just outside the house foundation and a lightning arrester connected between the two. Then a wire from the antenna terminal into the house to the radio. Is this sufficient. Am I missing something?
This is my first outdoor antennae as for 30 years I had a great 150 ft indoor one in my 32' square house on a large hill before we retired to our cabin in the woods with a metal roof. Thank you for your patience.


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Mon 10, 2020 2:23 am 
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Joined: Jun Wed 14, 2006 11:49 pm
Posts: 7141
Location: Leo, IN or Zellwood, FL
37oldsguy wrote:
Just to make it clear what the antenna is to service - 6 and 32 volt 1930s battery radios and crystal set radios. No household AC voltages at all. All battery. I plan on using a 8' copper plated ground rod driven just outside the house foundation and a lightning arrester connected between the two. Then a wire from the antenna terminal into the house to the radio. Is this sufficient. Am I missing something?
This is my first outdoor antennae as for 30 years I had a great 150 ft indoor one in my 32' square house on a large hill before we retired to our cabin in the woods with a metal roof. Thank you for your patience.


you have it correct. Ground Rod plus arrestor and you should run another wire from your ground rod to the electric utility ground rod according NEC. The only thing else you can do is make that 100 foot wire into a much longer wire if you have the real estate. 1000 feet would be really nice. Battery Radios? Turn off the main breaker to your house and eliminated all your In House Noise Makers. Your Battery Radios should hear very well.
John k9uwa

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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Mon 10, 2020 4:29 am 
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Joined: May Sat 30, 2015 11:49 pm
Posts: 1379
Location: Keystone Heights, FL, USA 32656
I thought the original question was, why not put the ground rod at the far end of the antenna?.

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Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sun 16, 2020 1:27 pm 
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Joined: Aug Mon 18, 2008 3:17 pm
Posts: 1169
Location: Dallas Tx.
If you are worried about lightning strikes to the gnd rod add a copper float ball on top of it.


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sun 16, 2020 6:49 pm 
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Joined: Jun Wed 14, 2006 11:49 pm
Posts: 7141
Location: Leo, IN or Zellwood, FL
37oldsguy wrote:
My silly question is this. Why is the rod always by the house? Wouldn't it be best to have it on the other end to draw the lightning away from the house? Or a rod on each end?


Ground Rods serve TWO purposes. #1 Grounding for "Human Protection and Lightning Protection for buildings and equipment" And #2 Grounding provides "The OTHER HALF of an ANTENNA system" In many cases #1 and #2 are interactive and can effect BOTH at the same time.

NEC "National Electrical Code" says: ONE AND ONLY ONE GROUND OR GROUND SYSTEM. That means that ALL GROUND RODS MUST BE CONNECTED TO EACH OTHER BY PROPER SIZED CONDUCTORS... AKA WIRES.

First lets look at #2 above. The Other Half of your Antenna. A real dipole antenna is two equal lengths of wire and it will have a two wire feedline. Be it Coax or Twinlead or wider spaced pair of wires. That forms a balanced antenna. So therefore the only use for a ground for this type antenna is the #1 Human Equipment protection ground. No need for a RF ground for that type of antenna. Our Long Wires be them 20 feet or 1000 feet in length are Unbalanced Antennas. Meaning that they will work better if they have a proper RF ... other half of the antenna equal RF ground including ground rods. Dirt itself provides a lousy RF ground. Therefore many times we will use a radial setup of many grounded wires running from the feedpoint outward sometimes in specific directions to form the other half of the Long Wire Antenna. This of course will involve having at least one ground rod at the feedpoint of the In the Air portion of this Unbalanced antenna. That rod of course also has to have by NEC code a connection to all the other utility ground rods. Then the radial plus ground rod form the other half of the unbalanced antenna.

That is the easy part. ... Now for the #1 Ground System. For "Most Homes" A simple ground rod at the electrical Utility entrance to the home provides a reasonable ground system. If you have phone lines to your house a second rod. Second rod needs a wire connection back to Rod #1 the Electrical Utility rod. If you have Cable TV/Internet then perhaps a 3rd rod and again a wire from it to rod #1 Utility ground rod. The Cable TV/Internet or a Dish in your backyard or the old Phone Lines will also have a protection device called a lightning protector that takes care of the not directly grounded side of the coax or twisted pair or whatever other wires are there. If you put in a ground rod for your long wire antenna then that rod also needs a wire connection back to Utility Ground Rod. Your House is still NOT protected from a lightning strike that comes in on the power lines. You can still get a hellava charge if the pole behind your house gets a direct hit by lightning. You don't yet have a Protection Device between the two HOTS and the Neutral Ground wire for power to your house. Yes most likely the lightning will jump the short distance inside your breaker box between the two Hot wires and the grounded wire back to the ground rod. Better if you have what is called a "Whole House Protector" that provides a path from the two HOTS to the Neutral/Ground rod. Those devices will provide a path from Hot to Ground if the VOLTAGE exceeds 175 volts per leg or 300 volts or so from both hots to ground. Be that simple RELAYS that literally throw a DEAD SHORT on the incoming THREE WIRES. I have just such a system on this house. More on that later. The same is true of the lightning arrestor protection devices on the cable TV or Dish lines. Whatever the normal voltage is on those lines the protector will be set for some voltage above that number to throw the temporarily dead short on that line until the surge is past and gone. This takes Milliseconds to happen.

Lightning always seeks the quickest best path from air to ground. Yes I know the opposite direction... ignoring that part... Lightning strike into a 100 acre bean field. Totally flat ground and conductivity of the ground isn't any different one part of the field to another so Lightning hits ground and scorches a bunch of beans. But if the Farmer is riding his large metal tractor in the vicinity then the Tractor is a better path to ground so Tractor and Farmer are TOASTED. Or a Golfer on a Golf Course is hiding out from the rain under a WOODEN TREE Tree is technically a somewhat of an insulator but to the lightning it is still better looking that just plain old grass and dirt. So Golfer and the tree are TOASTED. Better the golfer should have laid down out in a slightly low spot on the grass and the tree would have been the only thing damaged.

So now the house that isn't your "Normal House" House with TOWERS. TALL METAL OBJECTS. These will attract ala better grounds than trees or plain old dirt. My backyard has three towers. The tops of them are at 88 feet, 130 feet and 185 feet. Also many trees that are up to around 70 feet in height. The Towers have 5 Rotors that turn antennas Each of those rotors has from 8 to 12 wires that control them. There are about 35 antennas hanging on those towers. There are about a dozen relay switch boxes on the towers that allow selection of the different antennas. Each of those relay boxes will have 6 wires from the box to the house. There are more pieces of coax cable coming from the antennas to the house than I care to count. All of this is on a two acre lot along with the house. In other words. I AM THE LIGHTNING ROD for the whole neighborhood. The tallest tower provides the easiest path for lightning from sky to ground. Therefore MOST of the direct hits are to the tallest of the three towers. A Direct HIT on that tower is about the equal of an AERIAL BOMB going off about 10 feet from your head as to sound level. And about the same as to the flash bulb effect of lighting up the area that one would expect if you were only 10 feet away from an AERIAL BOMB same like you see many of for the 4th of July Fireworks displays. Except instead of being hundreds of feet up in the air it is within 50 feet of the house. That tower has had many many many direct hits. The last time I looked at the Hit Counter it said 400 or so. Hit counter has been there since 1989. Neighbors think that our whole house blew up any time the tower gets direct hit. Nothing is ever disconnected. None of it is usually even turned OFF. Almost Zero Damage has ever happened. Will explain ALMOST later.

The Ground System. A big THANK YOU TO "POLYPHASER CORPORATION" and there equipment and their techs who helped design the Ground System that I have on this house. First you have the Cone Of Protection that is about 1/3rd the height of the tallest tower. 185 x 0.33 = 56 feet. The second tower at 130 feet has taken direct hits a couple times. It is only 70 feet away from the tall one. But most of the hits were to the tall tower. Ground System Design. First a triangle between the three towers. This is 3/8" inside diameter copper tubing. that connects the three towers. Next is the Radial Ground . From each of the towers extending outward from the triangle is again 3/8" ID copper tubing that is at least 56 feet in length A total of 8 equally spaced radials from the towers. 7 of the 8 radials have an 8 foot ground rod each 16 feet along that run of copper tubing. The 8th radial run toward the house has no ground rods along its path to the "Ground Window" which is at the house. The Ground Window in my case is a plate of aluminum that is 1/2" thick and about 2 feet by 6 feet. It is supported by two 8 foot ground rods. And then in my case we have what is called the "Perimeter Ground" around the building. In my case it is only on two sides of the house. It connects ALL utility cable tv phone and electrical entry to the house. Again an 8 foot ground rod each 16 feet along that path of ground rods. From the ground window into the house is a 2 inch wide copper strap that connects ALL of the Ham Station pieces of equipment has a direct short wire from every box to this copper strap. That forms the entire ground system.
At the ground window you find all sorts of protectors most are Polyphaser devices and some are simple MOV's. All have a specific limit whereby they themselves short together ground to whatever the other wires are with set voltages above all expected correct voltage limitations.

When a direct hit on the tower happens... the entire house goes totally BLACK... remember we just shorted out the 240 volt electric to the whole house. And the backyard lights up like a very over sized flash bulb and the BOOM could be heard probably for close to a mile away from the house. In an instant it is all over.. the lights come back on ... the computers reboot as does the modem router and some of the radios if they happen to have been left turned on when the event took place.

OK now a little bit about the "ALMOST NO DAMAGE" About 15 years or so ago I switched from a plain old telephone line over to an internet based VOIP Phone system. I disconnected the entire house of course has phone outlets in every room of the house. Some of the larger rooms have two phone outlets. I disconnected this wiring from the Phone Company box outside the house. Now the connection from all that house wiring is through a little interface to one of the computers and from there into internet. OOPS. Setting here one day and I hear a little SNAP from under the desk inside one of the computers. This was what I would call the "Capacitor Effect" A whole lot of small wire throughout the house that picked up some voltage differential between that bunch of wiring and the sensitive low voltage stuff inside the computer. The "Cure" for that so it never happens again is a PHONE protector whereby at the computer connection to this mess of whole house wire is a protection device that really is a GOOD power strip plus PHONE protection. So now the line from computer to this mess of house wire goes first through that protection gadget. No more Problems with that part. The only other thing that ever happened is remember that "Whole House" protector on the incoming 240 volt AC line to the house that throws relays a dead short on the 240 line? Well one day after a hit on the tall tower Jean says to me that box next to the main breaker box is smoking. I told her it wasn't old enough to smoke ... she didn't see the humor in that remark at all. I clipped the three wires off that box and called Polyphaser on the phone. I told the nice lady what had happened she only asked me one question... "Was anything else in the house damaged? " I answered NO all was protected and still working. She checked her inventory and said yes she had several of those identical units on the shelf. I said Thank You can I get one over nite since we are in the midst of our springtime thunderstorm period? And yes the next morning it arrived and I installed it.

One additional comment for those who think they can just disconnect their antenna during lightning storms. I local ham friend who has a little 50 foot tower and antennas yes he has adequate grounding system on the house. He had in his Ham Radio room a metal 4 drawer filing cabinet that was about 10 feet from his ham station equipment. On top of that filing cabinet was a small TV set. It wasn't plugged into the wall and no antenna connected to it. After a hit on his tower that TV set wouldn't work He did the Degaussing routine and yes the TV set did come back to life. That would have been again the capacitor effect that caused that problem. So if you disconnect the antenna you better also ground that antenna to the ground rod right next to the house and that ground rod better have a suitable wire connecting it to the other ground rods around your house.

probably the above is more than you ask for about lightning and grounding.
John k9uwa

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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sun 16, 2020 11:45 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 5913
Location: Beautiful Downtown Burbank CA
k9uwa wrote:
probably the above is more than you ask for about lightning and grounding.
John k9uwa

But a good read none the less.


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Sat 29, 2020 12:22 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1037
Location: St. Louis, MO, USA
This brings up another point. Are all houses required to have a ground rod? I had the power company out to investigate interference. And he said I don’t have a house wiring ground. He didn’t say I had to have one but now I wonder.

Dennis


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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Mon 31, 2020 5:03 am 
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Location: near ST Louis Mo 62002
They used to let you get by with with gounding to you water line , but with all the plastic pipes that is a big no no nowadays .Also if your water line into the house is galvanised pipe the joints will corroid and become a high resistance over time .I would definitely add one if it was my house .

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 Post subject: Re: setting up a 100' antenna
PostPosted: Aug Mon 31, 2020 7:07 pm 
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Joined: Jun Wed 14, 2006 11:49 pm
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Location: Leo, IN or Zellwood, FL
Dennis Banker wrote:
This brings up another point. Are all houses required to have a ground rod? I had the power company out to investigate interference. And he said I don’t have a house wiring ground. He didn’t say I had to have one but now I wonder.

Dennis


I would have said "Then you better put one in for me" Maybe in MO but never in Indiana or most states. And this from the NEC that is NATIONAL ELECTRICAL CODE.

What NEC code section applies to grounding procedures?
As Section 250.4(A)(1) explains, electrical systems connect to ground to limit voltage imposed from lightning strikes, line surges, high-voltage crossovers and to stabilize voltage-to-ground under normal operation. Then equipment is connected to the system to limit voltage-to-ground at the equipment.

This "earth ground" is a very important part of your electrical system to ensure electrical safety. According to the National Electrical Code, or NEC, a ground system should have a grounding resistance of 25 ohms or less. Achieving this may require more than one ground rod. Nov 10, 2019

As to the mention of 25 ohm ground system. Us Hams who depend on grounding rods for lightning protection as well as RF ground requirements strife for a FIVE ( 5 ) ohm ground system.

I don't see how that guy could have walked away from your house without placing an order for someone to come out and install a ground rod.

John k9uwa

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 Post subject: Re: setting up a 100' antenna
PostPosted: Sep Tue 01, 2020 2:16 am 
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Joined: Aug Mon 18, 2008 3:17 pm
Posts: 1169
Location: Dallas Tx.
The electrical code does not require upgrading old systems unless rewiring is done.
The electrical codes apply to AC electrical equipment. Ham antennas and such. Stand alone xtal set systems do not have to be tied to home ground systems and work better usually when they are not.


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