WX7G wrote: ..."does anyone run simulations or calculations on lightning strikes. A common direct stike is 100 kA with a risetime of 8 us, correct? If so, using an inductance of 200 nH/ft, the voltag
I would get that one wrong. There is no need to bond those rods together. It serves no purpose other than to waste wire. The reason is that the potential coming from the tower will be the same on ea
Jim is correct. A well designed lightning ground will also make an excellent RF ground for a vertical antenna. If it will not serve as an RF ground then it is not an adequate lightning ground either
Hi Don, Lightning peaks around 1 MHz but extends well into VHF. A 160 meter ground system will take care of the bulk of it. In some types of soils placing ground rods on the radials has shown some i
I would assume you could contact the VEC folks building the question pools. And, of course, my original comment was that the 2005 NEC (the latest.. it comes out every 3 years) doesn't say anything (a
Excellent.. so it's not the NEC, but rather TIA-222. That's a pretty significant difference in most locations. Most cities, etc. require compliance with NEC but not to TIA-222 (at least for non-comme
The literature shows several folks doing a NEC model with a frequency sweep, so they can determine a coupling model (vs frequency). Then, they take the lightning current waveform (which is well known
Author: "Robert G. Strickland" <rcrgs@verizon.net>
Date: Fri, 05 Jan 2007 04:07:49 +0000
[I apologize if this is a dupe] Being more of a beginner than an expert, and following this thread - and others - leaves me with questions "sort of" unanswered. Modeling lightning strike wave forms a
..."The book "grounds for lightning protection" from polyphaser has those examples and formulas in it. They tell you how to estimate how much voltage will appear in different parts of the system. You
Author: "K8RI on TowerTalk" <K8RI-on-TowerTalk@tm.net>
Date: Fri, 5 Jan 2007 00:25:13 -0500
Big versus little is quite relevant as all strikes may be big, but some are a *LOT* bigger than others. My tower takes a number of hits every year. I rarely disconnect anything in the house and have
Actually the trend over the last several years has been the adoption of the International Building Code as the state building code, enforced statewide, in most states. See: <http://www.iccsafe.org/go
Even though a search through the archives will reveal the same information, many times over the past number of years (at mulitple times per each year), I'll state my understanding of the good practic
Don't forget these tied to your SPG 6. Gas 7. Water 8. Telephone 9. Cable TV Cheers, Steve K7LXC TOWER TECH _______________________________________________ __________________________________________
One clarification the the below statements. The "single point ground" often gets misused in these discussions. A single point ground is NOT a place or spot in the earth but it is a point of common co
I agree with the above statement but in my personal case I have SO many cables a massively large single panel is not doable. So I have four Hoffman enclosures which are mounted next to each other an
In my case, (building a new house) the radio cables will enter below grade on the other end of the building from the shack. The main 220V supply to the house will be close to the shack. I intend to h
"International" Building Code? Is that something like the Baseball "World" Series? -- 73 from Ian GM3SEK _______________________________________________ ______________________________________________
Not ideal. The BEST, by far, is for all cables -- power, antennas, CATV, telco to enter at the same point so that the ground connections between them can be as short as possible. Remember that the MO
You betcha... go to the ICC website, and you see a map of the US, only. To find something that applies world wide, you need something like "Miss Universe".. (Haven't seen a contestant from the Moon o
I think all you guys have the concept down correctly, but this term "single point ground" has always been a major point of confusion. It is a terrible misnomer. I actually refuse to use it. Instead I