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   WIN95      Chat about Windows 95, 98, ME systems      13,597 messages   

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   Message 12,102 of 13,597   
   Mike Luther to Ed Vance   
   Re: UPS units and Lightni   
   22 Jun 15 10:31:42   
   
   Nice to chat again Ed ..   
      
   Good question!   
      
    EV> While reading this I wondered if Your home has Lightning Rods too?   
      
    EV> My home doesn't.   
      
    EV> The house I rented before moving here had a metal roof and Lightning   
    EV> Rods on it.   
    EV> That's why I thought to ask You about this.   
      
    EV> 73 de W9ODR   
      
   In my case there is more than one 'family' home site.  Neither has Lightning   
   Rods on the building.  Both have multiple antenna 'poles' that go a good way   
   up above the highest part of the building.  The one I am writing this from in   
   the City of College Station, Texas that has been here since it was built in   
   1947 just as a house for sale and Dad bought it when I was eight years old.    
   In this neighborhood the power lines, telephone lines, cable TV lines, and   
   heavy wood pole support for them are all above the height of the single story   
   homes like ours.  As well, many of the trees are WAY above even two story   
   homes.  With metal antenna 'pole' or 'tower' support, that puts a very small   
   risk of any DIRECT strike on the building.  Thus no Rods on it,   
      
   However, protection on it is much more detailed than normal utility rules we   
   see in cities.  At the point where any metal based power line, telephone line   
   or cable connection comes down from the utiliy pole lines in the easement, the   
   really needed lightning strike protection needs to be added to the standard   
   metal ground rod where the meter is mounted.  At ground level you take about   
   ten qauge bare copper wire and cut it into about eight foot or so chunks.  You   
   then put each one like radial spokes on a wheel about two inches below the   
   ground and connect them all to the normal metal ground rod of the power   
   company.  Reason; lightning is a radio wave which does *NOT* travel on the   
   inside of the metal!  It travels on the SURFACE and is hunting massively for   
   the GROUND SURFACE where it is a hit or of focus.  Then as well, if your   
   telephone or cable lines are attached above the ground at the same point on   
   the building and they have a ground protection unit there, it too will route a   
   strike surge of any kind,direct or otherwise, to your radial dispense on the   
   surface of the GROUND where it wants to go.  Be careful if the telephone or   
   data metal lines are at a different point than the power line entry on the   
   building.  If so you need to create a MATCHING direct to ground radial   
   dispense point if the company has put in a one ground rod like the power   
   company uses and make your own direct down system if as many of them do to   
   carry the protection unit ground even MANY feet away to the power company   
   standard ground rod site.   
      
   Next point for your antenna pole or tower units on your property, *OR* if you   
   have, say, a TV or FM antenna isolated on your roof or so!  You need to make   
   *SURE* that it goes directly down to the ground to a radial set to spread the   
   strike on to the surface of the ground.   
      
   Obviously as a ham radio operator, you could have an antenna tower or pole   
   away from the building.  AHA!  If this is a vertical you should *NOT* use it   
   as an insulated antenna element that is fed at ground level!  The safe way to   
   create say 66 foot 80 meter vertical elements is to use a totally ground metal   
   element and SHUNT feed it from a ground level coax power line that is   
   protected at the bottom with a lightning protector to carry the hit surge to   
   the 'normal' radial near surface ground plane wires or metal flat plate you   
   use!  Then BURY the coaxial cable feed line back to the house where you use a   
   radial ground dispense point just where it touches the building on the way   
   into your place.   
      
   The main difference between most smaller city house sites and the country   
   places is that there you almost always have a number of different vectors for   
   your antenna locations.  As well it is WAY a long way to any other property   
   owner's site.  In this case what you need to do is to make, say. a ten guage   
   wire ring at ground level all the way around your house at the bottom of the   
   building.  You make a number of individual eight or ten foot two inch lower   
   radial lines connected to this ring to dispense the hit onto the ground from   
   this ring.You focus a few more at any point where you have a rising coax   
   connection or a ground line coming down from, say, a window where you have a   
   normat protection fix from any feed line attached to an upper point on the   
   structure.   
      
   Yes, Lightning Rods are good for you in rural sites.  As well as for metal   
   roof conduction for the surge to ground route.  But the KEY issue for any   
   rural house or building is that even a strike a good way away to a tree or any   
   other site creates a HUGE radio wave that roars away from the hit even if it   
   is cloud to cloud!  That is an EMP pulse that ANY wiring in your building   
   collects that as it is a RADIO WAVE traveling on the SURFACE of even your   
   internal power or phone lines or antenna wires an can totally burn up any   
   electronic device tied to an affected line!  It is especially damaging to ANY   
   unit that has a none pig-iron transformer for a power supply!  Which was the   
   focus of my previous message here..,   
      
   BTW, if you need an elevated 40 or 80 meter vertical array, you can put the   
   bottom of it about eight feet above ground with a wire ground plane there,    
   You can feed it with coaxial line connected SHUNT fed work for each element   
   of, say, a four tower array.  Then you can carry the coax feed line about the   
   eight feet above ground to your house,  Where you use the same ground   
   protection method before it goes into the building.   
      
   As noted I've never had any damage from the strikes since about 1974 when I   
   really protected the places this way.   
      
      
   Mike Luther as W5WQN at 1:117/100   
      
   ---   
    * Origin: BV HUB CLL(979)696-3600 (1:117/100)   

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