Just a sample of the Echomail archive
Cooperative anarchy at its finest, still active today. Darkrealms is the Zone 1 Hub.
|    WIN95    |    Chat about Windows 95, 98, ME systems    |    13,597 messages    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
|    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)    |
[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]
(c) 1994, bbs@darkrealms.ca