Where to connect ground to antenna
- Slvbeard
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Where to connect ground to antenna
I have a roll of Radio Shack aluminum grounding wire that I want to connect to a grounding rod directly under where I mounted my Shakespeare Big Stick antenna. The previous home owner must have had a TV antenna on the roof in the same location, and left the ground rod. I figured I could just use it.
The antenna is on 2 10' masts mounted to the side of the house with 2 wall brackets. My question is, should I connect the ground wire to the bottom of the antenna mast, to the wall brackets, or somewhere else?
The antenna is on 2 10' masts mounted to the side of the house with 2 wall brackets. My question is, should I connect the ground wire to the bottom of the antenna mast, to the wall brackets, or somewhere else?
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i would put it on the mount too. its funny the arrl antenna books dont say where to attach it either ! but the do say : the best for grounding is solid copper strap (expensive) the next best is copper braid. solid wire is good for lightning protection, but no good for rf ground. the radio signal tries to travel back up the solid wire. even worse with aluminum as it does not conduct as well. home depot sells 7 strand copper ground wire, uninsulated, for about 60 cents a foot. thats about the minimum i would go with. vertical antennas depend on the ground for efficiency, a better connection to ground will make it more efficient, so get the best you can. also, solder/braise connector lugs on it, copper reacts with other metals and if not soldered will corrode and ruin the connection.i know you already have wire and stuff, but this is how it should be done for the best results. i remember rolling my eyes when i bought $86 of solid copper strap ,but everytime i key up, there is security i did it by the book. try to come as close as u can. 209
2zero9 workin this top secret station in massachusetts.
i agree 100 percent with Punkin Head and 209 but would just like to add another good reason to ground directly to the antenna mounting bracket is its not uncommon for mast/poles to have some sort of coating on then for weathering protection and some are actually painted . the coatings can at least impede grounding and at worst prevent grounding . also where the section join can develop corrosion over time that can also impede/prevent a ground from making a ground . one other thing , i wouldn't just trust that left behind ground rod . it most likely isn't deep enough . a proper ground rod needs to be solid coppper and 5 feet into the ground . if you really want to use it id suggest at least having someone fairly strong (you or someone else) using gloves just simply trying to pull it up , really give it a good try . if you can do that it isnt deep enough to start with and the ground , if any, would be minimal .
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Grounding wire resonate like an antenna at 27MHz if its just 9' long. quarter wave.KI4MSJ wrote:Try to keep it short. If it is 1 wave length long, 36' it will want to resonate like an antenna. I have mounted to the bottom of the mast but, I was roof mounted and only had a 5' mast. Good luck
The reasons for grounding a base-station antenna:
1) safety from lightning strikes. single point grounding is the best protection. use polyphaser if your in a lightning area.
2) static buildup. ground reduces static buildup that raises your noise floor on receive.
If you have stray RF around your radio, then you have some coax or antenna issues.
If you have TVI, then you're sending harmonics, or neighbors have unshielded electronics.
Grounding is not the right answer for those two.
Unlimited power permitted on CH1 to CH27 as per FCC CFR 47 part 18: 18.305(a) and 18.301
Here's the deal guy. For years and years us older radio folks going way back have put the 8' c*pper rod into the ground and attached a solid c*pper ground wire that is not insulated and made specifically for grounding at the base of the pipe or tower and left it go at that. That is the ground. Rf is an electrical make up if you will and it all grounds out. Lightning is powerful and a direct hit is not going to be good. that's why you un plug your coax in a storm just in case. the pipe is on or in the ground as is a tower. add the ground rod and wire. shortest grounds are the best grounds. drive that puppy in the ground next to your pipe/tower attach the solid ground wire and you're done.
You just don't see grounds running a mast from the antenna to ground and all this other fancy fantasy world crap. I think too many times people forget that "white noise" is almost always present in the air waves that you're listening on. you can add 500 pounds of c*pper wire to an antenna you can only ground away so much noise. Keep it simple.
My tower is 3 feet deep in concrete with added ground rod and wire and I can talk and here just as good as anyone. it's a hobby and for fun. i'm not trying to sound like i am scolding you but i read everywhere on here and sometimes it sounds like people have c*pper gold mines just in an antenna set up for grounding only.
You just don't see grounds running a mast from the antenna to ground and all this other fancy fantasy world crap. I think too many times people forget that "white noise" is almost always present in the air waves that you're listening on. you can add 500 pounds of c*pper wire to an antenna you can only ground away so much noise. Keep it simple.
My tower is 3 feet deep in concrete with added ground rod and wire and I can talk and here just as good as anyone. it's a hobby and for fun. i'm not trying to sound like i am scolding you but i read everywhere on here and sometimes it sounds like people have c*pper gold mines just in an antenna set up for grounding only.
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way to go watchman.. i do not think it will be a problem. if people want to think all this crazy grounding stuff isnt needed, thats cool. me personally, i will go by the arrl suggestions. if a plain old wire was good enough, why do they have all that info on grounding in the books including descriptions of conductors used for ground. as far as reradiating rf if it is a certain length, in the books that applies to the ground going from the station to ground, not the antenna ground. the station ground must not be over 1/4 wavelength of the stations operating frequency or it will reradiate. if the antenna ground reradiated, there would be no towers over 1/4 wavelength tall. if ya dont have the 25$ for the arrl antenna book, or handbook, stop in at barnes and noble bookstore and read the grounding stuff/station setup ect in the index for 20 minutes. i think they are in the technology section. look up counterpoise ground too if u are above the first floor. 209
2zero9 workin this top secret station in massachusetts.