Base Antenna Grounding

[RoadWarrior]

A 8ft ground-rod spaced 1ft apart from another rod is useless
for lightning protection. The second rod needs spaced 8-16ft from the first rod to be effective.

 

[Marconi]

It sounds to me like you may be installing the ground rods in the basement and going thru the walls. Why not just do it outside of the basement window in the ground beside and below the antenna up on the chimney and then run a ground wire or Cu' tubing in thru the wall and attach it to your stations grounding bulkhead that is insulated from the building also and for sure is not attached to the slab.

If you read the info on PP site you should look at a subject called single point grounding. Lightning has many access point to enter your home and if you radio you are exposed to all of these points particularly since you have your antenna attached to your home. There are also issues concerning slabs with rebar and wire mesh in them that also needs to be attached to your single point grounding system. There is lots to read there.

Lightning struck and unattached antenna with coax on it I had in a pine tree. The coax was wrapped around the tree and tied off about 3' above the ground. The pulse went out the end of the coax and into the ground digging a trench about 12" deep and 4' long towards my water supply pipe from the meter at the street. It got into the electrical ground side of stuff in the house using this path since code in those days did not restrict grounding to plumbing, and we had no three wire grounded AC circuits in the old part of the house. It was mess. Blew out all the windows because the current reached the non-conductive air again at the tip of the coax going to the ground below and it made a big bang fight then outside the front of the house. It was very loud because of the sonic boom and because the current down the tree and the coax was not controlled at that point as it entered the earth. It broke sheetrock all along the front of the house too. It also killed the pine which was worth about $3500 in those days. I had a eye witness across the street that heard and saw the ball lightning as it were comming down our street and then go up into the top of my pine tree to hit the antenna. I guess everthing including the coax is still flying.

After this experience I have never since attached an antenna to the house, garage, or any other building here. It is just too dangerous and these days may well void your insurance if you have a weather related claim.

 

[RoadWarrior]

Somewhere i missed about having the ground-rod in the cellar.
Not good if you do. The idea is to carry as much lightning energy away from your house as you can. Which means
spendings lots of money on a complete lightning system.
1 or 2 rods is not nearly enough to disperse that much energy
into the ground. Read up on Lightning and do searchs for antenna lightning protection

 

[Captain Kilowatt]

Am not concerned about the weight of the Astroplane on the chimney mount, it's only 4 lbs. Just want to do the best I can to stay safe.

The weight is not the issue with the chimney mount.The leverage provided by a 20 foot mast in the wind is HUGE. :shock: Also the constant vibration due to even a slight wind blowing can and will cause cracks to form over time. :?

 

[SmackDown]

Grounding

The ground rod is outside the bldg. A 10' rod with only 8" exposed. When I said that several concrete slabs would need to be removed I was merely commenting on the advice given that I should use a " radial ground ". Because of height limitation I can't drive a 10' rod inside the basement, and from what I've been reading it's not wise to run ground wire through the wall. I do like the idea of driving another ground rod at least 10' apart from the first one then electrically connecting them together. And the wind loading of the AP is only 1.88 sq. ft. I dunno, maybe I can use a shorter mast.
3's and 8's and enjoy your Easter holidays.

 

[RoadWarrior]

Info on lightning protection:

http://www.polyphaser.com/ppc_TD1016.aspx

 

[Marconi]

Smackdown, radial ground systems are nice and probably work just as well or better, but they take up a lot of room and the lead to the feed probably should be near the center if symmerety has anything to do with its effectivness. This tends to make the ground lead very long and that may be counter productive.

 

[SmackDown]

I appreciate the " 5 " Marconi. Road Warrior I checked out the PP article but it slants towards towers while I'm using a chimney mount. Earlier I also said I'd use 20' of mast but now instead of 20' of mast I'll use 10'. I'll get 1/0 cable as my ground wire.