[Towertalk] Lightning Protection - Conclusion (for me, anyway)

[EUGENE SMAR]

TT:

     Sorry for rolling a grenade under the tent and walking away!  I haven't
responded to any of the postings on this subject for a few days, even though
I think I started the discussion on soldered ground connections.

     I think many questions you-all might have about how I have arranged the
grounding system at my QTH might best be answered by some photos or
drawings.  Unfortunately I am not very ept at web page making yet so please
bear with me as I try to learn these new-fangled computer gizmos.

     Sorry for any confusion I may have caused, but I hope I can clarify my
installation with some photos and captions this summer.

73 de
Gene Smar  AD3F
-----Original Message-----
From: Tom Rauch <w8ji@contesting.com>
To: towertalk@contesting.com <towertalk@contesting.com>; EUGENE SMAR
<SPELUNK.SUENO@prodigy.net>
Date: Wednesday, May 15, 2002 10:11 PM
Subject: Re: [Towertalk] Lightning Protection - Conclusion (for me, anyway)


>> bought advising this connection.  But as I described, I already have
>> the three coax shields grounded just before they hit the suppressors
>> out at the tower. (I'd rather keep the lightning in my back yard away
>> from the house than conduct it closer to the shack before it's shunted
>> by the suppressors.)
>
>The best place for the suppressor, if you feel them necessary, is at
>the house end of things....not at the tower. Keep in mind what the
>suppressor does, it simply ties the center to the shield when voltage
>reaches nearly 1000 volts.
>
>Placing the suppressors at the tower leaves the possibility of
>lightning ingress into the center conductor from any sort of poor
>shield connection in the system, and damage in the house.
>
>At the tower bottom, you need good shield grounding. You should also
>bury the cables for some distance and keep them at ground level up to
>the house, where the cable ground should be common to the service
>entrance ground for your house with a very short excellent conductor.
>If you can't do that, then everything in your room should be grounded
>to the feedlines at one point, and then ALL cables (telco, power,
>control, and RF) should leave that point to your equipment.
>
>If you do that you can have your center-to-shield lightning
>suppression in the house, where it belongs. Then if you have ANY poor
>shield connection outside the suppressor will limit voltages to a
>thousand volts or so from the shield to center conductor. Of course
>the BEST practice by far is to disconnect the coaxial cables and
>power line connections TOTALLY by pulling the plugs and ALL
>connections to the outside world.
>
>Keep this in mind....**any lightning suppression device that will let
>a kilowatt or two out will let much more than that back in to the
>station**. Even a few volts can be devastating to the receiver.
>
>The very best thing, short of unscrewing the cables at the bulkhead
>entrance point and tossing them in the yard and unplugging everything
>in your station from telephone and power lines would be to use a
>switch that opens the cables to the radios and grounds the center
>conductors on the antenna side of things.
>
>But again, the key to everything is wiring layout, good connections
>and grounding at some point BEFORE the building is entered, and
>avoiding loops through gear. That's actually about all I do here, and
>my towers can take direct hits without any damage to any gear.73, Tom
>W8JI
>W8JI@contesting.com
>