harnessing lightning, or not
in [Design]
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From: Paul Keinanen on 14 Jun 2010 16:06 On Mon, 14 Jun 2010 12:46:40 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Spehro Pefhany wrote: >> On Mon, 14 Jun 2010 11:43:55 -0700, Archimedes' Lever >> <OneBigLever(a)InfiniteSeries.Org> wrote: >> >>> On Mon, 14 Jun 2010 11:24:34 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> Archimedes' Lever wrote: >>>>> On Mon, 14 Jun 2010 13:56:25 -0400, Spehro Pefhany >>>>> <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >>>>> >>>>>> On Mon, 14 Jun 2010 03:04:03 -0400, "Michael A. Terrell" >>>>>> <mike.terrell(a)earthlink.net> wrote: >>>>>> >>>>>>> Joerg wrote: >>>>>>>> Michael A. Terrell wrote: >>>>>>>>> Joerg wrote: >>>>>>>>>> Michael A. Terrell wrote: >>>>>>>>>>> Joerg wrote: >>>>>>>>>>>> John Larkin wrote: >>>>>>>>>>>>> On 12 Jun 2010 07:16:54 -0700, Winfield Hill >>>>>>>>>>>>> <Winfield_member(a)newsguy.com> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> My Maxwell capacitors hard at work energy from harnessing lightning, see my post >>>>>>>>>>>>>> with photo, at the CR4 forum. >>>>>>>>>>>>>> >>>>>>>>>>>>>> http://cr4.globalspec.com/thread/55751/Lightning-Arrestor#comment579837 >>>>>>>>>>>>> You rate 3 "good" answers out of 14. That site has very high >>>>>>>>>>>>> standards! >>>>>>>>>>>>> >>>>>>>>>>>>> Why not use the lightning to heat water? The impedance match is >>>>>>>>>>>>> potentially better, and it's easy to store hot water. We could throw a >>>>>>>>>>>>> neighborhood hot-tub party after every strike, every 40 years or so. >>>>>>>>>>>>> >>>>>>>>>>>>> We don't get lightning here. I kind of miss it. >>>>>>>>>>>>> >>>>>>>>>>>> I don't miss it, seen to much electronics come to grief from it. Hey, >>>>>>>>>>>> why don't engineers at RF module manufacturers get it into their heads >>>>>>>>>>>> that the first part after the antenna jack has got to be an inductor to >>>>>>>>>>>> ground? Anything else will eventually go *PHUT*. >>>>>>>>>>> Yawn. >>>>>>>>>>> >>>>>>>>>> T'is what I did when I just encountered the umpteenth module where that >>>>>>>>>> was done wrong :-) >>>>>>>>> Yawn, as in: WHAT ABOUT ALL THE RF EQUIPMENT WITH A DC VOLTAGE AT THE >>>>>>>>> INPUT CONNECTOR? >>>>>>>>> >>>>>>>> Gear out in the field typically never has that. I've done a lot of RF >>>>>>>> designs and even more re-designs by now. The number of units that would >>>>>>>> be DC-fed or have to provide LNA power was zero. Fact is, units deployed >>>>>>>> in the south or on the island won't even live through the first year >>>>>>>> with a nice big inductor to ground. Lightning strike into some fence out >>>>>>>> there, voltage surge, somewhere above 100V the input cap decides it's >>>>>>>> had it ... *POP* ... preamp and final TX amp are goners. >>>>>>>> >>>>>>>> Of course, if you design sat-gear that's different. >>>>>>> If they won't survive, why are there hundreds of Dish and Direct >>>>>>> satellite companies around here? Or line powered TV preamps? >>>>>> Active antennas (powered through the signal coax) are quite common on >>>>>> aircraft navigation systems too, so splitters etc. have to be >>>>>> specified with some care. >>>>> >>>>> They are usually NOT exposed. ie under a sheath, nosecone, or dome. >>>> >>>> How's that going to help against lightning effects? >>> >>> An antenna under a dome or sheath will not be an attractor for >>> lightning like a raw, exposed stick would, so the strike will be upon the >>> craft, not the antenna. The only effect after that are the induced EM >>> effects, if any. >> >> Not much of a "stick" at L1, L2, or the frequencies used by the >> geostationary sats for WAAS, as well as sat data/voice (eg. Iridium). >> > >I've seen (and remedied) situations where 2"-3" sticks caused massive >field failures. Because the inductive path was lacking. For this reason a folded dipole is nice, since you can ground the midpoint of the upper (continuous) side. No extra inductors needed.
From: Joerg on 14 Jun 2010 16:35 Paul Keinanen wrote: > On Mon, 14 Jun 2010 12:46:40 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > >> Spehro Pefhany wrote: >>> On Mon, 14 Jun 2010 11:43:55 -0700, Archimedes' Lever >>> <OneBigLever(a)InfiniteSeries.Org> wrote: >>> >>>> On Mon, 14 Jun 2010 11:24:34 -0700, Joerg <invalid(a)invalid.invalid> >>>> wrote: >>>> >>>>> Archimedes' Lever wrote: >>>>>> On Mon, 14 Jun 2010 13:56:25 -0400, Spehro Pefhany >>>>>> <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >>>>>> >>>>>>> On Mon, 14 Jun 2010 03:04:03 -0400, "Michael A. Terrell" >>>>>>> <mike.terrell(a)earthlink.net> wrote: >>>>>>> >>>>>>>> Joerg wrote: >>>>>>>>> Michael A. Terrell wrote: >>>>>>>>>> Joerg wrote: >>>>>>>>>>> Michael A. Terrell wrote: >>>>>>>>>>>> Joerg wrote: >>>>>>>>>>>>> John Larkin wrote: >>>>>>>>>>>>>> On 12 Jun 2010 07:16:54 -0700, Winfield Hill >>>>>>>>>>>>>> <Winfield_member(a)newsguy.com> wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>>> My Maxwell capacitors hard at work energy from harnessing lightning, see my post >>>>>>>>>>>>>>> with photo, at the CR4 forum. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> http://cr4.globalspec.com/thread/55751/Lightning-Arrestor#comment579837 >>>>>>>>>>>>>> You rate 3 "good" answers out of 14. That site has very high >>>>>>>>>>>>>> standards! >>>>>>>>>>>>>> >>>>>>>>>>>>>> Why not use the lightning to heat water? The impedance match is >>>>>>>>>>>>>> potentially better, and it's easy to store hot water. We could throw a >>>>>>>>>>>>>> neighborhood hot-tub party after every strike, every 40 years or so. >>>>>>>>>>>>>> >>>>>>>>>>>>>> We don't get lightning here. I kind of miss it. >>>>>>>>>>>>>> >>>>>>>>>>>>> I don't miss it, seen to much electronics come to grief from it. Hey, >>>>>>>>>>>>> why don't engineers at RF module manufacturers get it into their heads >>>>>>>>>>>>> that the first part after the antenna jack has got to be an inductor to >>>>>>>>>>>>> ground? Anything else will eventually go *PHUT*. >>>>>>>>>>>> Yawn. >>>>>>>>>>>> >>>>>>>>>>> T'is what I did when I just encountered the umpteenth module where that >>>>>>>>>>> was done wrong :-) >>>>>>>>>> Yawn, as in: WHAT ABOUT ALL THE RF EQUIPMENT WITH A DC VOLTAGE AT THE >>>>>>>>>> INPUT CONNECTOR? >>>>>>>>>> >>>>>>>>> Gear out in the field typically never has that. I've done a lot of RF >>>>>>>>> designs and even more re-designs by now. The number of units that would >>>>>>>>> be DC-fed or have to provide LNA power was zero. Fact is, units deployed >>>>>>>>> in the south or on the island won't even live through the first year >>>>>>>>> with a nice big inductor to ground. Lightning strike into some fence out >>>>>>>>> there, voltage surge, somewhere above 100V the input cap decides it's >>>>>>>>> had it ... *POP* ... preamp and final TX amp are goners. >>>>>>>>> >>>>>>>>> Of course, if you design sat-gear that's different. >>>>>>>> If they won't survive, why are there hundreds of Dish and Direct >>>>>>>> satellite companies around here? Or line powered TV preamps? >>>>>>> Active antennas (powered through the signal coax) are quite common on >>>>>>> aircraft navigation systems too, so splitters etc. have to be >>>>>>> specified with some care. >>>>>> They are usually NOT exposed. ie under a sheath, nosecone, or dome. >>>>> How's that going to help against lightning effects? >>>> An antenna under a dome or sheath will not be an attractor for >>>> lightning like a raw, exposed stick would, so the strike will be upon the >>>> craft, not the antenna. The only effect after that are the induced EM >>>> effects, if any. >>> Not much of a "stick" at L1, L2, or the frequencies used by the >>> geostationary sats for WAAS, as well as sat data/voice (eg. Iridium). >>> >> I've seen (and remedied) situations where 2"-3" sticks caused massive >> field failures. Because the inductive path was lacking. > > For this reason a folded dipole is nice, since you can ground the > midpoint of the upper (continuous) side. No extra inductors needed. > I sure wish I could find a 900MHz antenna like that right now. But it must be under 4dBi for license reasons and must be a vertical stick because of space constraints. But, I guess, it'll be the usual. Fix the bugs the RF module mfgs let slip by :-( -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Archimedes' Lever on 14 Jun 2010 19:05 On Mon, 14 Jun 2010 12:44:45 -0700, Joerg <invalid(a)invalid.invalid> wrote: > >That's why I am surprised you don't understand why there needs to be an >inductor. Show me where I said that at all. You are confusing me with some other person you were arguing with.
From: Joerg on 14 Jun 2010 19:10 Archimedes' Lever wrote: > On Mon, 14 Jun 2010 12:44:45 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > >> That's why I am surprised you don't understand why there needs to be an >> inductor. > > Show me where I said that at all. > > You are confusing me with some other person you were arguing with. Show us how you deal with induced lightning load sans inductor. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: krw on 14 Jun 2010 19:25
On Mon, 14 Jun 2010 13:35:13 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Paul Keinanen wrote: >> On Mon, 14 Jun 2010 12:46:40 -0700, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Spehro Pefhany wrote: >>>> On Mon, 14 Jun 2010 11:43:55 -0700, Archimedes' Lever >>>> <OneBigLever(a)InfiniteSeries.Org> wrote: >>>> >>>>> On Mon, 14 Jun 2010 11:24:34 -0700, Joerg <invalid(a)invalid.invalid> >>>>> wrote: >>>>> >>>>>> Archimedes' Lever wrote: >>>>>>> On Mon, 14 Jun 2010 13:56:25 -0400, Spehro Pefhany >>>>>>> <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >>>>>>> >>>>>>>> On Mon, 14 Jun 2010 03:04:03 -0400, "Michael A. Terrell" >>>>>>>> <mike.terrell(a)earthlink.net> wrote: >>>>>>>> >>>>>>>>> Joerg wrote: >>>>>>>>>> Michael A. Terrell wrote: >>>>>>>>>>> Joerg wrote: >>>>>>>>>>>> Michael A. Terrell wrote: >>>>>>>>>>>>> Joerg wrote: >>>>>>>>>>>>>> John Larkin wrote: >>>>>>>>>>>>>>> On 12 Jun 2010 07:16:54 -0700, Winfield Hill >>>>>>>>>>>>>>> <Winfield_member(a)newsguy.com> wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> My Maxwell capacitors hard at work energy from harnessing lightning, see my post >>>>>>>>>>>>>>>> with photo, at the CR4 forum. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> http://cr4.globalspec.com/thread/55751/Lightning-Arrestor#comment579837 >>>>>>>>>>>>>>> You rate 3 "good" answers out of 14. That site has very high >>>>>>>>>>>>>>> standards! >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Why not use the lightning to heat water? The impedance match is >>>>>>>>>>>>>>> potentially better, and it's easy to store hot water. We could throw a >>>>>>>>>>>>>>> neighborhood hot-tub party after every strike, every 40 years or so. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> We don't get lightning here. I kind of miss it. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> I don't miss it, seen to much electronics come to grief from it. Hey, >>>>>>>>>>>>>> why don't engineers at RF module manufacturers get it into their heads >>>>>>>>>>>>>> that the first part after the antenna jack has got to be an inductor to >>>>>>>>>>>>>> ground? Anything else will eventually go *PHUT*. >>>>>>>>>>>>> Yawn. >>>>>>>>>>>>> >>>>>>>>>>>> T'is what I did when I just encountered the umpteenth module where that >>>>>>>>>>>> was done wrong :-) >>>>>>>>>>> Yawn, as in: WHAT ABOUT ALL THE RF EQUIPMENT WITH A DC VOLTAGE AT THE >>>>>>>>>>> INPUT CONNECTOR? >>>>>>>>>>> >>>>>>>>>> Gear out in the field typically never has that. I've done a lot of RF >>>>>>>>>> designs and even more re-designs by now. The number of units that would >>>>>>>>>> be DC-fed or have to provide LNA power was zero. Fact is, units deployed >>>>>>>>>> in the south or on the island won't even live through the first year >>>>>>>>>> with a nice big inductor to ground. Lightning strike into some fence out >>>>>>>>>> there, voltage surge, somewhere above 100V the input cap decides it's >>>>>>>>>> had it ... *POP* ... preamp and final TX amp are goners. >>>>>>>>>> >>>>>>>>>> Of course, if you design sat-gear that's different. >>>>>>>>> If they won't survive, why are there hundreds of Dish and Direct >>>>>>>>> satellite companies around here? Or line powered TV preamps? >>>>>>>> Active antennas (powered through the signal coax) are quite common on >>>>>>>> aircraft navigation systems too, so splitters etc. have to be >>>>>>>> specified with some care. >>>>>>> They are usually NOT exposed. ie under a sheath, nosecone, or dome. >>>>>> How's that going to help against lightning effects? >>>>> An antenna under a dome or sheath will not be an attractor for >>>>> lightning like a raw, exposed stick would, so the strike will be upon the >>>>> craft, not the antenna. The only effect after that are the induced EM >>>>> effects, if any. >>>> Not much of a "stick" at L1, L2, or the frequencies used by the >>>> geostationary sats for WAAS, as well as sat data/voice (eg. Iridium). >>>> >>> I've seen (and remedied) situations where 2"-3" sticks caused massive >>> field failures. Because the inductive path was lacking. >> >> For this reason a folded dipole is nice, since you can ground the >> midpoint of the upper (continuous) side. No extra inductors needed. >> > >I sure wish I could find a 900MHz antenna like that right now. But it >must be under 4dBi for license reasons and must be a vertical stick >because of space constraints. If you need a source for antennas send me a note. We have a couple of manufacturers who work pretty closely with us. One has come up with a solution for 900MHz that even fits where we need it. ;-) >But, I guess, it'll be the usual. Fix the bugs the RF module mfgs let >slip by :-( |