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Aluminum ground system

S

secondchoice

A friend of mine works for a contractor that buries AC power cable. He says the power company will sell the overhead wire for "scrap" price to anyone who will haul it off.

A lot North GA has acidic soil which loves to eat copper. There are a couple of AM sites where the ground system is just green copper "rust". It takes 60 to 80 years for aluminum cans to "decompose" on the road side which IMHO is longer than AM will last with the current set of rules. There is an opertunity for storage on the site and everything will be dug up away.

Would the FCC have an issue with aluminum instead of copper for a ground system? The "above ground" system is too much of target for criminals to steal.
 
Buried aluminum power cables, at least in household applications such as going from a home to a detached garage or workshop shed, have a greater tendency to corrode (it turns into a white paste) compared with copper should the insulation be damaged by burrowing animals or biodegraded.

What I am not sure about is whether the ground radials need to be bare versus just taking induced currents through waterproof insulation.
 
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secondchoice said:
Would the FCC have an issue with aluminum instead of copper for a ground system? The "above ground" system is too much of target for criminals to steal.
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I've been told that KCMO (710) in Kansas City has such a ground system, installed after numerous copper thefts.
 
secondchoice said:
Would the FCC have an issue with aluminum instead of copper for a ground system? The "above ground" system is too much of target for criminals to steal.
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Far from an expert on AM counterpoise systems, but I'd think the only question from FCC staff would be about meeting minimum efficiency, if your station is required to meet that rule. I believe Class C stations are exempt.
 
Here in Florida copper is not good for a counterpoise. Your right it disintegrates to a copper powder. However, Aluminum has a tendency to mash like modeling clay over time so the issue becomes is there a good connection at the point it is connected to the ground system at the tower. A connection of different kinds of metals should always be regularly checked.
 
PTBoardOp93 said:
Far from an expert on AM counterpoise systems, but I'd think the only question from FCC staff would be about meeting minimum efficiency, if your station is required to meet that rule. I believe Class C stations are exempt.
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My first job was at WJMO 1490 in Cleveland Heights, Ohio, in 1959. The station was founded as WSRS, and located on the second floor of a Chevy dealer. The ground was a counterpoise about 12 feet above the roof, soldered to a ring of copper on the 4 edges of the roof. The area was about 150' by 200', and there were a full 120 radials in the system.

No way it met minimum efficiency for the other classes of AMs.

It worked well with the 250 watts as a suburban Cleveland only station. But when it became WJMO, it served the Black community which was definitely not in Cleveland Heights. So they moved as far towards Cleveland as they could while still putting the required signal over the COL. They built a full buried radial system and welded some of the radials to the underside of New York Central rails that went by the eastern side of the site.

When the then Class IV's got 1 kw daytime, they even did well on the near West Side of Cleveland.
 
davideduardo said:
My first job was at WJMO 1490 in Cleveland Heights, Ohio, in 1959. The station was founded as WSRS, and located on the second floor of a Chevy dealer. The ground was a counterpoise about 12 feet above the roof, soldered to a ring of copper on the 4 edges of the roof. The area was about 150' by 200', and there were a full 120 radials in the system.

No way it met minimum efficiency for the other classes of AMs.

It worked well with the 250 watts as a suburban Cleveland only station. But when it became WJMO, it served the Black community which was definitely not in Cleveland Heights. So they moved as far towards Cleveland as they could while still putting the required signal over the COL. They built a full buried radial system and welded some of the radials to the underside of New York Central rails that went by the eastern side of the site.

When the then Class IV's got 1 kw daytime, they even did well on the near West Side of Cleveland.
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I remember visiting the site when it was atop that building. It definitely improved when they got the ground system into the ground and closer to the city proper. The kilowatt night power helped cover the interference too.
 
I wonder if a shunt feed system wrapped around one of six legs of really tall water tower work for a class D?

There are miles of steel pipe heading to town. I am pretty sure you would have to be on the leg "facing" town because the other legs would be a "passive blocker".
 


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