Grounding a beam

[RoadRunner]

I just put up a moonraker4 and was wondering whats the best way to ground it also if grounding it and the radio may help cut down on the noise

 

[DuckKilla]

I use welding lead with a large copper eyelet mounted to the center boom clamp and run it down to the top of the tower where I have #6 copper ground wire running down to the ground rods below.It is a good idea to solder all connections.
I use at least three 8 ft ground rods in a triangle around the base of the tower spaced about 4 ft from the tower.At the top leave a loop in the welding lead as you do with the coax to allow for rotor movement.Depending on your soil it is sometimes a good idea to use a post hole digger and dig down three to four feet and then drive in your ground rod and a T post driver works good for this.After you have driven it in fill in the whole with about a foot of rock salt and the rest oh the hole with dirt.Then water it and add more dirt.
Hope this helps.73

 

[frmboybuck]

Do as duckkilla said but forget the ground wire running to the beam. Grounding the tower will be suffucient. The beam is already grounded to the tower. Also your rock salt idea is snake oil......Does nothing but cause corrosion and quite possilbe make your ground connection worse in time. Just drive those 8' ground rods in the ground and be done with it........

 

[DuckKilla]

I wont get into a pissing match but you NEED to run the ground wire from the boom.A rotor doesnt make a good ground.
The whole idea is to give the lightning a better path than your coax.Which is a better conductor?
1 Magnesium
2 Aluminum
3 Copper

So what is the best path.Copper from the boom to the earth.

As for the rock salt.It isnt snake oil.It works.Anything that makes the soil more conductive is a good thing.I dont use it here as my soil is good enough without it and I am sitting on top of iron ore deposits.
73s

 

[DXman]

Do as duckkilla said but forget the ground wire running to the beam. Grounding the tower will be suffucient.

frmboybuck,
Just grounding the tower "may not be suffucient", especially if he may have "thrust bearing" mounted on the tower. Some times you may not a good ground thru a bearing or the rotor.
I do "bypass" my rotor with a ground wire on my tower and I also run a #4 bare copper wire from the top of tower all the way down the tower to the ground. Then the 3 rods tied together off the 3 legs.
Once a tower gets several years on it and it may begin to rust,so one may not be getting a good ground just through the tower. Such as mine, which is 29 years old now and getting to look like a rust bucket.

DXman

 

[RoadWarrior]

I have seen long runs of copper wire burn up from
direct lightning strikes. Better use a real heavy wire if
making a long run from your antenna.
All the connections where each tower section goes
together should be free of paint. Should be clean
inside and outside and use penetrox or another like
product on the connections points.
Each leg of the tower should be grounded to there
own ground-rod in the shape of a Triange. Ground-rods
should be about 6ft apart.
All the ground-rods should be tied together.
Our electric code in our area also requires these ground-rods
to be tied in with the electric ground-rods for the electric box of the house. Electric box/cable/phones creating a single
point ground system. Radio is grounded to a outside ground-rod. This rod is also tied in with your tower/antenna grounds. Should be no longer than a 7-8ft run of heavy wire for 11
meters. Each town or city,state has different codes and requirements. If you want to further protect your coax
and radio, add a polyphaser to the coaxial line outside
near a ground-rod. Otherwise your coax should be unplugged
and electric plug pulled out during lightning storms.
Some people place the coax connector in a heavy glass
jar during thunderstorms. Whether that works or not, can't
tell ya.

 

[frmboybuck]

Point taken on the rotor not being a good conductor. I would bypass the rotor with some 1/0 welding cable and go from there.....No need for the long wire. If you do it right you should never have to worry about the connections deteriorating. Sloder all connections and use dielectric grease. That tower will carry way more current than that 6awg wire running down the tower... Better listen to Roadwarrior. He has hit the nail on the head

 

[redwing21]

grounding

u can either buy a polyfaser from a ham catalog (price depend about power handling) and install it line with the coax someplace out side with 2 pl-259 and run a ground strap to it for the ground rods. Or, if u are on a budget u can do the same by just exposing about a inch of the braided wire in the coax .Wrap some ground strap over the braid or the coax .make it tight and soilderit in place and got to home depoand buy some of that rubber 3m weather reistant tape wrap i over the exposed area a few time to get a good seal then cove it with regulare electric tape . I have done this on many antenna systems and i hav eneve had any interferenc problems or rf leakage

just my 2 cents worth

 

[RoadRunner]

Thanks guys for the info so its best to run more than one ground rod from it as for soil i know its mostly clay in that area i guess thats why they call it clay township

 

[RoadWarrior]

http://www.hamuniverse.com/grounding.html

 

[freecell]

"I have seen long runs of copper wire burn up from direct lightning strikes. Better use a real heavy wire if making a long run from your antenna."

you better use the tower. apparently some of you have no clue as to the nature of the circumstances surrounding the amount of energy that can be contained in a direct strike. currents in excess of 200 KA at temperatures of 50,000 degrees fahrenheit travelling at up to 1/3 the speed of light at bridge potentials of several hundred millions of volts are hardly going to be deterred by a piece of copper welding cable. the stuff melts at just under 2,000°F and you can forget soldered connections for lightning ground protection as the melting point of most solder is in the region of 370°F. low resistance metal-to-metal and exothermic cad welded connections are the only ones that stand a chance of providing any protection during a direct strike.

more reading on the subject........
http://www.harvardrepeater.org/news/lightning.html

 

[RoadWarrior]

Good article FREECELL!