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stylzmovement
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Joined: 11 Oct 2003
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Post grounding Reply with quote
how do you ground a comet cfm95sl antenna, the conditions are
1) Location of the antenna is on top of a building 3 floors high
2) the building has cold water pipes in the basement.
3) their are no open area to drive a ground rod into the soil or ground ( every thing is paved with cement.
4) the has a-lot of people living there

i will like to use three groung stakes but will like to know how to do it with these conditions
Sat Oct 11, 2003 9:33 pm View user's profile Send private message
stylzmovement
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Joined: 11 Oct 2003
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there are so many users of comet , can someone give me som answers.
Tue Oct 14, 2003 9:40 pm View user's profile Send private message
Bill O. Rights
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Post Reply with quote
Wow, tough one! Couple of questions.
1)where do you plan to mount antenna?
Not unusual to find a ground of some type on top of buildings
2)do you have a three prong ground in ac/wall outlet?

3)If you try to ground to cold water pipes, you must make sure that there are no pvc or plastic pipes in the line to mess up ground.

Good luck

Bill O. Rights
Sat Oct 25, 2003 9:29 am
stylzmovement
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Post Reply with quote
1)antenna will be mounted on a building tower.
2)i will attatch the antenna to a 2 inch pipe then that pipe is 10 feet long , i will clamp that to the air vent which runs down between the building floors to the ground this is also connected to the cold water pipe.
2)i have 3 prong plug , that my transmitter is connected to.
Sun Oct 26, 2003 7:34 pm View user's profile Send private message
Fleetinglimpse
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Post WHY AND HOW TO Reply with quote
LIGHTNING PROTECTION

New Myths & Old Realities As They Apply To Your Home And Your Station

by Bob McGraw - K4TAX
©2003



First some general comments about lightning. Lightning is a capricious, random and unpredictable event. Its' physical characteristics include current levels sometimes in excess of 400 kA, temperatures to 50,000 degrees F., and speeds approaching one third the speed of light. Globally, some 2000 on-going thunderstorms cause about 100 lightning strikes to earth each second. USA insurance company information shows one homeowner's damage claim for every 57 lightning strikes. Data about commercial, government, and industrial lightning-caused losses is not available. Annually in the USA lightning causes more than 26,000 fires with damage to property (NLSI estimates) in excess of $5-6 billion.

The phenomenology of lightning strikes to earth, as presently understood, follows an approximate behavior:

1. The downward Leaders from a thundercloud pulse towards earth seeking out active electrical ground targets.

2. Ground-based objects (fences, trees, blades of grass, corners of buildings, people, lightning rods, etc., etc.) emit varying degrees of electric activity during this event. Upward Streamers are launched from some of these objects. A few tens of meters off the ground, a "collection zone" is established according to the intensified local electrical field.

3. Some Leader(s) likely will connect with some Streamer(s). Then, the "switch" is closed and the current flows. We see lightning.

Lightning effects can be direct and/or indirect. Direct effects are from resistive (ohmic) heating, arcing and burning. Indirect effects are more probable. They include capacitive, inductive and magnetic behavior. Lightning "prevention" or "protection" (in an absolute sense) is impossible. A diminution of its consequences, together with incremental safety improvements, can be obtained by the use of a holistic or systematic hazard mitigation approach, described below in generic terms.

As previously stated, lightning has its own agenda; it is entirely capricious, random, and unpredictable. Man's attempts to fit lightning into a convenient box, with Codes and Standards to describe its behavior, are a best guess. The system of conventional lightning rods as commonly employed does represent the best method for providing a preferred pathway to ground. One very important aspect of ham radio antennas is the fact that they present themselves as being no different than lightning rods and therefore should be installed in the same manner and according to the standards used for lightning rod systems. Antennas are no different than any other air terminal.

Second, lightning safety for group or large scale outdoor events is very difficult - maybe impossible - to accomplish. Injuries at a June 1998 rock concert at RFK stadium in Baltimore are a good example. Some 35,000 people were there. Lightning rods were there. Still, some 13 people were badly injured by incoming lightning. In July 1998 in Las Vegas NV, five firefighters were injured when lightning struck their fire truck. At a soccer match in the Republic of the Congo (October 1998), 11 members of the team were killed by lightning.

Third, the myths about lightning persist:

LIGHTNING NEVER STRIKES TWICE - (It hits the Empire State Building about 25 times a year.)

RUBBER TIRES WILL INSULATE ME FROM LIGHTNING - (It has traveled miles through spacea few inches of rubber mean nothing at all.)
Tue Oct 28, 2003 10:24 am View user's profile Send private message
Fleetinglimpse
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Joined: 26 Oct 2003
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Post INFO PACKET..READ AND GET SOME IDEAS Reply with quote
stylzmovement wrote:
1)antenna will be mounted on a building tower.
2)i will attatch the antenna to a 2 inch pipe then that pipe is 10 feet long , i will clamp that to the air vent which runs down between the building floors to the ground this is also connected to the cold water pipe.
2)i have 3 prong plug , that my transmitter is connected to.


Hey Stylz-Movements..How is the heat in California doing these days?Have you had a chance to to chat with AHHNOLD The Gubanator as yet?

Klik on the following URL and you should find answers to point you in the right direction.

http://www.signalengineering.com/ultimate/earth_ground.html

Hope that helps..Will address that topic in detail when i do a Comet Rewind
Thu Oct 30, 2003 6:22 pm View user's profile Send private message
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