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eHam Forums => Station Building => Topic started by: KC2PTA on January 11, 2008, 06:00:41 PM



Title: grounding bar
Post by: KC2PTA on January 11, 2008, 06:00:41 PM
Ok, my station is ungrounded, and i run it all the time, i thought id make a ground inside the shack, so, will 1"X1" square tubing work for a ground bar? Or do I HAVE TO HAVE copper ground bar?


Title: grounding bar
Post by: K9KJM on January 11, 2008, 11:49:20 PM
First question is WHY do you want to ground it at all?

RF ground? Safety Ground? Lightning Ground???

For any balanced type antennas, An RF ground is not really needed.
If your house has the 3rd prong grounded outlets, That is all the safety ground you need.
(Most of the little blurbs you see about "grounding" are still holdovers from the 1940's or 50's before the widespread use of grounded power outlets.)
AND a lot has been learned about proper protection from lightning since then........

For a good lightning ground, It is a huge discussion and fairly complex to properly protect a station.
About the easiest way to start is to drive some ground rods outdoors, Twice the distance apart as the depth, Use heavy copper wire to join them, Run flat copper strap to the house where the coax enters and mount coax switches on that flat copper. Just switch the coax to ground when the antennas are not in use.
Be sure to bond the antenna or tower mast to your ground system, And also bond all grounds together. (Power, telco, Catv, etc.)  
Note that I said that is just a start.......
The best way to protect equipment if you do not have a really good system is to also completly disconnect the radio during a storm. But be SURE that you have the coax grounded, As with the before mentioned coax switch to put the antennas to ground!

Simply "disconnecting" any coax and just leaving it lay, Or putting it in a glass jar as some do is pretty foolhardy and dangerous!

For some good info on lightning protection see this site:  http://members.cox.net/pc-usa/station/ground0.htm


Title: grounding bar
Post by: KC2PTA on January 12, 2008, 09:26:44 AM
Ok, here is what i have been told by oter hams.

 ALL radio and inshack equipment must be grounded by using an "in shack" grounding bar. MUST run copper strap or braid from chasis of equipment to a bar in shack, and then to a grounding bar, or bars out side.


Title: grounding bar
Post by: KC2PTA on January 12, 2008, 09:46:16 AM
Not the most efficient.  To ground your cable     cut/peel outer insulation  shield, and carefully wrap copper- foil Use 5/8" Rod only                  connecting to ground.

this is what i was told exactly.


Title: grounding bar
Post by: KB9CRY on January 12, 2008, 10:44:00 AM
How many times are you going to ask the same question but in a slightly different way?  Check out the answers on the Elmers forum. Hope that answers it?  Come back to one of the forums for followup if needed.


Title: grounding bar
Post by: K9KJM on January 12, 2008, 11:25:35 PM
Quote: "Not the most efficient. To ground your cable cut/peel outer insulation shield, and carefully wrap copper- foil Use 5/8" Rod only connecting to ground.

this is what i was told exactly."

Very poor idea. Whoever told you that clearly knows very little about proper lightning protection grounding.

And I agree with CRY.

 


Title: grounding bar
Post by: AB3CX on January 14, 2008, 10:43:20 AM
Yes, you need a common ground at the shack equipment. Use a bar or pipe, makes no difference. Connect every piece of equipment (amp, transceiver, computer, tuner, etc) by a separate piece of braided shield to the common ground bus. Then, run a wire from the ground bus to a ground rod, keeping the run as short as possible. Connect that ground rod to the ground rod for your main electrical panel, using heavy conductor. Now you have eliminated any ground loops, and got the start of a good RF ground. In the future, as you add any other ground rods, connect them to the ground rods you started with. This will provide you with surge protection in case of a nearby lightening strike


Title: grounding bar
Post by: NJ2H on February 21, 2008, 08:54:16 AM
AB3CX has the right advice. Just try to keep the braid between the bar and the ground rod as short as you can.