Brian (and TT):
The address and phone number for the Mil Hdbk are:
Commanding Officer
Naval Publications and Forms Center
5801 Tabor Ave.
Phila., PA 19120
The phone number in the HDBK, 215-697-3321, rings with no answer. So
you might have to call around via Directory Assistance for another listing
in the Pubs and Forms Center before you can get a human to fill the order
over the phone (as I did earlier this year but I didn't save the number that
worked).
73 de
Gene Smar AD3F
-----Original Message-----
From: Eric Gustafson <n7cl@mmsi.com>
To: towertalk@contesting.com <towertalk@contesting.com>;
brian_smithson@vds.com <brian_smithson@vds.com>
To: <towertalk@contesting.com>
Date: Monday, October 11, 1999 11:59 AM
Subject: Re: [TowerTalk] newbie, Installing a 80' crank up
>
>
>Hi Brian,
>
>I don't think you are asking for trouble per se. But you are
>asking for a requirement that you exercise somewhat more care in
>the design of the ground system.
>
>Only you know what the value and vulnerability of the stuff in
>and around the barn is likely to be. If it is an abandoned
>facility which is unlikely to have animals or personnel in or
>near it during a storm, that is one set of circumstances. If it
>is an active dairy operation which is likely to have people and
>livestock working in the vicinity and valuable production
>equipment in operation, that is another.
>
>The "rule of thumb is ok if no lightning protection effort can be
>tolerated. But it doesn't mean that a tower cannot be safely
>located adjacent to a tall conductive antenna structure.
>
>Buildings located next to towers are routinely lightning
>protected to the degree that the radio station inside the
>building can and does operate right through a direct hit on the
>antenna structure without any damage to the building, equipment,
>or personnel in the vicinity or even any interruption in service.
>There is an FM transmitter south of town here (Tucson, AZ) that
>gets hit an average of twice a day during our monsoon season.
>Probably, the safest possible place in the entire valley for a
>person to be during a summer thunderstorm here is inside that
>transmitter building. It is all a matter of how much attention
>is paid to the lightning protection system requirements.
>
>Start with the PolyPhaser book "Grounds for Lightning and EMP
>Protection". And get a (free) copy of MIL-HDBK-419A Vols. I and
>II. This is by far the best reference on this subject I have
>ever seen. It has both the theoretical basis and practical
>instruction relating to lightning protection. Do some reading.
>Don't stop until you understand the concept of "step potential"
>and how to control its magnitude. Then decide on where you want
>your tower based on the ground system effort required for your
>situation and what you are willing or financially able to do.
>
>73, Eric N7CL
>
>
>
>>From: "Brian Smithson" <brian_smithson@vds.com>
To: <towertalk@contesting.com>
>>Date: Mon, 11 Oct 1999 09:54:34 -0400
>>
>>Uh oh,
>>
>>> Regarding tower placement, the rule of thumb is a minimum of
>>> 50 feet away from the nearest person or structure. A tower
>>> will tend to attract lightning, so you don't want to attract
>>> it right near your home
>>
>>I've marked out a spot for the base of my 2nd Trylon
>>self-supporting to be close to a barn in our backyard. The barn
>>is >300' from the house, but the tower will (was going to) be
>>less than 10' from the barn. I'm planning a pretty extensive
>>ground system - am I still asking for trouble?
>>
>>-Brian n8wrl
>
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