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Od: "Mike O'Connor" <os2-wireless_users@2rosenthals.com> Glava
Izvorno E-sporo?ilo
Zadeva: Re: [OS2Wireless] Wireless router (mainly OFF TOPIC)
Datum: Fri, 26 Mar 2010 15:03:26 +1000
Za: OS/2 Wireless Users Mailing List <os2-wireless_users@2rosenthals.com>

Hi t'other Mike,

Thank you very much for your input - it should probably be re-broadcast over a selection of OS/2-eCS lists/groups for promulgation!
That was a very clear and superb explanation. I worked all my adult life - 1958 - 1995 (when I had to resign for medical reasons) in Aviation Meteorology, tracking (on WX Radar 1.5 degree beamwidth elevated 1.5 degrees above horizontal, at 3 rpm, also scanning vertically to determine the freezing level and cloud bases and tops (up to 84,000 ft in Darwin, in the Northern Territory, the world's record highest) in a blacked out windowless room with heavy black rubber curtains to exclude any incident light) and forecasting Thunderstorms and associated Terminal Area Extreme Turbulence was a major component of my duties with the Australian Bureau of Meteorology, as Shift Supervisor and Briefing Officer for both International airlines and Domestic too at major airports like Sydney/ Brisbane/ Darwin/ Cairns/ Townsville and on Military bases here in Australia.

Naturally I'm always monitoring Severe Weather events here from www.bom.gov.au (equivalent of the NOOA/NWS (is it still called that these days?), and whenever storms get within 20 km of here, and heading this way (only have 4 Doppler Radars in the whole of Australia, to date -- first was between the NSW/Queensland border and Brisbane, a couple of years ago, followed by adelaide in S.Australia, then Melbourne, and recently Sydney), I shut all systems down, and pull all plugs (except the refrigerator) and the landline phone cables - my sole home landline phone is a transportable 5.8GHz Panasonic - base-station is next to my bed, plus the ADSL2 line from the Central Splitter to the Gateway "modem". Then I wait until all activity has passed before hooking up the Gateway "modem" and powering up the T43 - to check the Radar/ Satellite photos to confirm before re-plugging and switching everything else!

The weather I experienced here in April 2006 was not forecast BTW!

Once again many thanks for the knowledgeable input. I learned a lot from that!

Mike Luther wrote:
** Reply to note from "OS/2 Wireless Users Mailing List"   <os2-wireless_users@2rosenthals.com> Thu, 25 Mar 2010 21:48:16 -0400  Serious professional advice from a NARTE certified Master Telecommunications   Engineer since 1985 here about lightning.      
Wow! That's all I can think to say about such a massive lightening strike and the negative results. No, that's not true. I think you just convinced me to do two things:    1] Buy a UPS regardless of the physical size of the unit and find room for it no matter what! 2] Get myself some renter's insurance, regardless of the monthly or yearly premium!    
Smart decision.  But the folks here need to know some real radio facts about   lightning to make a proper decision on protection.  As a commercial broadcast   engineer since even the late 1950's and even Chief Engineer for the Texas Aggie   WTAW radio station back then paying my way through A&M, I offer some serious   information.    Lightning is *NOT* electricity as most people think about that.  It is, for   fact, a very intense radio wave issue!  As such, it does *NOT* travel through a   wire or metal object!  It actually travels on the SURFACE of it.  Further, since   it is a radio wave and it oscillates, it also focuses on some frequency during   the actual strike, which CHANGES as the strike takes place in those thousandths    of a second!  Frequency means that, as to the stroke going through the   atmosphere or down the surface of a tree, wire; whatever, it has a wavelength   just like a broadcast station transmitter output or TV station.  Radio waves are   curious, in that for each QUARTER wavelength we see a MAXIMUM current for   MINIMUM voltage, then a reversal to a MAXIMUM voltage for a MINIMUM current a   quarter wave down the path from there.      The air gap voltage required in the atmosphere for an arc to proceed through it   is perhaps 35,000 or so volts per inch.  Think about that.  How many million   volts per bolt?  Yes, the air is burned into a conduction path, the SURFACE of   which is conducting the lightning.  But wait!  Remember, a million volts at one   end of the quarter wave point and maybe a thousand amperes current?  Then a   quarter wave later a million amperes and then a thousand volts?  Interesting.   The absolute 'intent' of a lightning bolt which travels between a cloud and   ground, because it MUST travel on the SURFACE of the conductor, is to actually   spread itself out across the SURFACE of the earth at that end of the path.  Well   fine, if as part of the strike conduction path, the surface travel down to the   earth terminates in such a way that on the SURFACE of whatever conductor, that   surface is actually touching and bonded to the surface of the earth.  But in the   case of the horrid hit described earlier here, if the metal surface of the   conductor carries it down into a hollow shaft below the surface of the earth,   and thence down the surface of the metal wires to other houses, apartments;   whatever, the only path toward the surface of the earth will be as described.    Through MASSIVE damage sites inside the building(s)!    As well, because the strike is a huge magnetic pulse issue, a strike also   radiates that same Electro Magnetic Pulse (EMP) out away from it.  Thus even   though the strike hits your neighbor's house, the pulse lights up EVERY wire in   it's path, at the speed of light, as the energy radiates away from the hit as   well.  Interesting.    OK, how do we REALLY protect against lightning?   Answers.   That NEMA ground rod at your power meter entrance to the building is there   generically for this reason as well as bonding the power line ground wire to   ground from your electric service.  But the real problem is that this NEMA   ground rod is driven INTO the ground!  Which does *NOT* do much good for the   radio wave lighting strike which is traveling trying to reach the SURFACE of the   earth.  If you really want to use this to protect your home, apartment or   whatever, the proper way to do this is to fan out a little wire radial group in   a circle around that NEMA ground rod, about six or eight feet long for each   wire.  Like the spokes on a wagon wheel.  Which go down only a small inch or so   at GROUND level from the NEMA rod.  What that does is to properly shift the   lightning bolt to the SURFACE of the ground as it roars down the ground wire to   that NEMA ground rod.  You do the same thing for the bottoms of TV antenna   poles, metal flag poles, the wire that carries lighting arrester spikes at the   top of the buidling to the ground.  Further, you NEVER pass antenna wires directly into the attic or through the   window into the place  - unless - you have a proper lightning arrestor plasma   device which lets the shock arc through it from the SURFACE of the wire that   goes into the building to a good heavy flat sheet copper strip with a wide   surface to the ground.  And then out along the surface like the NEMA rod deal.    A round wire has little surface, right?  The proper lightning ground is the flat   surface of a copper strip, even though it is rather thin.   Plus the proper place to put the lightning protection on the power, phone lines,   TV cable system and so on is at this common place near your power meter and so   on.  That to divert the bolt AWAY from the bulding.  You really want it all to   be protected together from a common decent protection set of devices.  Even to a   for real master protection set of devices on your meter, and NOT these deals you   buy to 'protect' your stuff in the house.  Yes, the do OK for noise.  But not   for lightning.  About the only thing they are good for is the insurance you may   get with them too.  Scowl.   Now we go inside.  But before we do please note.  OK, so the average quarter   wavelength of the huge bolt is at 1 Megahertz, 1000 Khz on your AM radio dial.    But the bolt also can and does have an average quarter wavelength of only say   EIGHT feet as well with frequencies way up in the TV channel area at points in   it's split second of lifespan.  Ouch.  Which are still traveling over the   OUTSIDE of all the wires going through your building if you let it in too.    AHA!  Now you know why in many strikes that penetrate a building, you'll see   your TV blown to bits on one part of the same power circuit that doesn't fry   your guitar amp eight feet away.  Hmmmmmm.   More important, there is a HUGE   issue here very few people know and understand about so-called surge protector   plug boxes you get to 'protect' your computer; guitar amp -- and so on.  These   protector devices, at least virtually all of them, work by letting a pulse of   over a couple hundred volts arc across a path to the GROUND neutral, the big   round rod on a three prong power plug.  Well so what?  Remember that because   lightning is a radio wave, just because it shunts the surge to that green wire   ground connection, where is that, in terms of quarter wave spacing, for the hot   spots on the lighting bolt as that happens?    Surprise!  Ground, in this case, may not even be back toward the electric panel   and the NEMA rod.  Instead, it may be actually going down the SURFACE of that   same green wire INTO your computer, your guitar amplifier, your TV set!  Now   watch what else ABSOLUTELY happens to virtually all modern electronic gear.    Years ago we gave up metal transformer power supplies for such things.  All of   the conversion from 120 volts or 240 volt of AC (Alternating Current) down the   power lines to the DC (Direct Current) for the equipment, is done through what   is now switching power supplies.  But that is a DISASTER for a voltage spike   which comes IN on the green ground wire, seeking out the phone line ground,   perhaps, or .. worse .. your PRINTER!  Because your laser printer draws a high   power amount you can't pay for UPS coverage.  So you plug it in to the power   plug and then connect it with a metal ground wire to your computer which is on   your UPS.  Get the idea?    What happens is that the lightning strike, even only a hundred volts maybe by   the time it gets here, raises the GROUND foils of your computer above the GROUND   level for a SURFACE radio wave for the difference of 120 volts AC to 12 volts DC   and...  Surprise!  If it is a 300 volt pulse, your ground foils are 30 volts   above ground and POOF your whole computer, guitar amp, TV set, stereo is blown   to bits.  It is not at all unusual for even a strike on your neighbor's place to   surge your power lines up to 600 volts or so.  Not at all.  Bottom line.  The ONLY way to use a UPS to protect anything is to make SURE that   your UPS uses a METAL TRANSFORMER to isolate the house from whatever you are   trying to protect.  Why?   Because the lightning bolt cannot pass through the   metal pig iron between the primary coil and the secondary coil wires in it.    Thus that really DOES ISOLATE your equipment from the pulse.  But ONLY if you   protect ALL of the devices on the output side.  And do *NOT* run your printer   elsewhere and then connect it to your computer.  Or use any kind of phone line   or cable modem connection metal wire to another ground possible source to the   protected device.  Without thinking carefully how it is absolutely protected to   keep the pulse out of the building and shunted to ground properly.    There does happen to be a form of surge protector that does not have this   horrible pulse clamp effect.  But it is quite rare.  It uses an inductor choke   and capacitor to clamp the pulse to the HOUSE side of the power line service and   like the transformer style device, blocks the pulse from crawling on the surface   of the wire into your equipment.  It sure isn't sold in Walmart, Lowes, HEB or   any place like that folks.   Final notes here.  If you are using huge antenna farm stuff like I do as a   serious ham radio operator with towers all over the place at my site, you also   may be required to put a substantial metal wire circular ring around the house   which bonds the various sink ground spoke sites at several places going into the   building!  And, in fact, my site gets a direct hit on the average of at least   twice a year big time.  My towers are all grounded and radial spanned at the   bottoms for protection purposes.  As well the feed lines are all brought in   either at underground level, properly protected by plasma arc protectors there   at tower connections.  Or in the proper ground plate side panel entry points   that do properly connect to the ground.  I have had this careful protection   since about 1980 at the site.  And direct hit after direct hit, I have NEVER   since ever had a computer failure or radio or any failure, other than a couple   modem failures ever since properly protecting it.      But I do use all proper pig iron UPS stuff there.  Which in my case has been for   years the APC full professional sine wave output Smart UPS units.  As well all   the computer equipment on the site is also actually still pig iron linear power   supply relay rack stuff.  I use *NO* switching power supply stuff at all in any   rural heavy tower radio site locations, like we also never do at broadcast   stations.  Which get hit a heck of a lot more with their 250-500 foot high   towers that are a lot higher than mine, chuckle.  And at WTAW's 1150KHz AM   frequency is a 256 foot quarter wave high tower.  Which we took about 60 hits a   year while I was Chief Engineer there paying my way through A&M.  And never once   lost anything from an antenna strike.   Sorry for all the words.  I am just trying to help here..     
Do you have any quick methods of how-to size up what power-level of UPS to buy? I know I can go to google.com and find the info but if you have some quick method off the top of your head it will save me the time of reading and figuring out for myself what I need. Not to mention the fact that also I trust your judgment more so than what I might find on the 'net.    
You have to totalize the wattage level use of the electronic equipment you wish   to protect.  Then you figure out how long the batteries of the UPS will crank   out that much wattage to keep things going.  Either so you can shut it down if   you are hit, or it will go on until the real chances are that decent power will   be restored.  At my ham radio site, when I am not there, the APC UPS with the   battery power level available to it, will keep the simple computer, phone line   access and low level VHF data service going for about 24 hours.  I've only once   since the 1980's ever not been able to get out there in more than 24 hours to   shut things down and police the things if I'm not there on site when bad things   happen to the power at this very rural location.   Not the same Mike.        
Thanks Mike, seriously! You've knocked some digital sense into this old brain-pan of mine, and for that I am grateful. I'd be sick if I lost even half of my gear!    Greg    
But with the best of my professional heart at work here to help not only you but   the otheres who might benefit from this.  --> Sleep well; OS2's still awake! ;)

Mike Luther
Mike O'Connor

Failed the exam for
MCSE - Minesweeper Consultant and Solitaire Expert
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