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Author Topic: Apartment antenna setup  (Read 4917 times)

Posts: 6


« on: February 18, 2002, 03:19:45 AM »

I finally have permissions to go ahead with my plans to mount an antenna in a flower pot filled with cement and place it on my 3rd floor balcony at the apartments where I live. My only concern is that of lighting damaging my apartment building/occupants.

I have a magnet mount scanner antenna on the square tube railing of my balcony, and a copper J mounted in the flower pot. The scanner antenna has the coax attached at the factory, and is attached at the other end to a Uniden BC780XLT base/mobile scanner. This scanner has a grounded wall outlet AC/DC transformer, and other than that is not grounded. The J antenna will be connected to a Kenwood TH-G71A VHF/UHF handheld.

Most of the plans I've found for the J didn't mention where to attach a ground to it, but I assume I should attach the ground wire to the shield side of the coax connector mounted on it? As for the scanner antenna, should I cut the wire and install an inline connector and then ground the shield of that? Also, should I attach the ground to a random point of the chasis of my scanner, or does this not matter from a lighting point of view? I've read a lot about how all station equipment should be grounded, but I haven't heard much about how to go about grounding when using a handheld connected to an outside antenna. Should I just ground the shield of the coax adapter than I use to connect the antenna to the top of the radio?

Now, here comes the tricky part. The nearest cold water pipe is on the complete other side of my appartment, so it would require a rather long wire run. Alternativly, I could connect it to the cover plate screw of the electric outlet that's mounted right under the balcony window that I will be running my antenna wires through. Will this ground be  reasonably sufficient to ward off lightning, and if not, will running the wire to the water pipe be much better? It seems to me, the shorter the ground wire inside my apartment, the less lightning will be in here in the unfortunate case that my antenna does get hit.

Thanks for any and all replies,
John (KD5RBB)

Posts: 21757

« Reply #1 on: February 18, 2002, 12:55:02 PM »

Most effective thing you can do, which is also easy to implement and very low in cost:

Disconnect your antennas and toss the feedlines and connectors outside when you're not using the rigs and antennas.  Then, plug them back in when you are.  Don't leave the equipment connected when you're not home.

You should NEVER, NEVER, NEVER have a "lightning" ground inside your home, or even close by.  A "lightning" ground should be independent of any other grounding, very low impedance, and both outside, and as far as possible from, your living quarters.

If this cannot be achieved, do not use any other method.  Neither your scanner antenna nor your J-pole require any sort of ground to function properly.  To drain "static discharge" from distant lighting, any old ground will do, including sticking a 10 penny nail in the ground with some wire attached to it, and an alligator clip attachment to your antenna's ground point.  There's no current in this static, it's just voltage at very low energy levels.  

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