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Groups > sci.physics > #535788
| From | jimp@specsol.spam.sux.com |
|---|---|
| Newsgroups | sci.physics |
| Subject | Re: long antenna |
| Date | 2015-11-27 01:37 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <1ookic-uq4.ln1@mail.specsol.com> (permalink) |
| References | (7 earlier) <n377fg$5f6$1@speranza.aioe.org> <ru3kic-ul2.ln1@mail.specsol.com> <n37rf3$12p$1@speranza.aioe.org> <l69kic-a73.ln1@mail.specsol.com> <n389sn$8v6$1@speranza.aioe.org> |
gilber34 <fafa@invalid.com> wrote: > On 11/26/2015 3:12 PM, jimp@specsol.spam.sux.com wrote: >> gilber34 <fafa@invalid.com> wrote: >>> On 11/26/2015 1:42 PM, jimp@specsol.spam.sux.com wrote: >>>> gilber34 <fafa@invalid.com> wrote: >>>>> On 11/24/2015 4:58 PM, jimp@specsol.spam.sux.com wrote: >>>>>> gilber34 <fafa@invalid.com> wrote: >>>>>>> On 11/24/2015 2:04 PM, jimp@specsol.spam.sux.com wrote: >>>>>>>> RichD <r_delaney2001@yahoo.com> wrote: >>>>>>>>> On November 17, Timo wrote: >>>>>>>>>>> The idea that making an antenna longer makes it work better comes from >>>>>>>>>>> AM radios and car whips where the antenna is much much shorter than >>>>>>>>>>> wavelength and in that case making it longer often DOES make it work >>>>>>>>>>> better. >>>>>>>>>> >>>>>>>>>> It can help, even when the antenna is larger than the wavelength: >>>>>>>>>> https://en.wikipedia.org/wiki/Arecibo_Observatory >>>>>>>>> >>>>>>>>> Comparing dish vs. wire antenna, is apples vs. oranges. >>>>>>> >>>>>>>>>> But typically one wants to pay more attention to design than just >>>>>>>>>> "long extension wire". >>>>>>>>> >>>>>>>>> More dish area will collect more signal power, but >>>>>>>>> apparently this doesn't apply to a wire. >>>>>>>> >>>>>>>> A dish doesn't collect anything, it concentrates energy to a point. >>>>>>>> >>>>>>> >>>>>>> wrong again. >>>>>>> >>>>>>> a dish is a reflector which changes signal phase over an area, where it >>>>>>> adds in phase is called the focus. >>>>>> >>>>>> And the focal point is where the energy is concentrated. >>>>> >>>>> wrong, it is where the signals add in phase. >>>> >>>> What is the energy density in the region of the focus with no reflector? >>>> >>>> What is the energy density in the region of the focus with a reflector? >>> >>> you ask for energy density w/wo reflector. you can find that on google. >> >> Nope. It depends on the ERP of the transmitting station and the propagation >> characteristics between the two points. > > you over complicate it, no need for transmitting station foo foo or > probagation losses bla bla. > > Hint: What is energy density "ratio", w/wo reflector. (assume dipole if > you must) Yet again you show you haven't a clue what is going on. >> Normalize it for analysis, if you know what that means. >> >>> What size and type of reflector ? >> >> Any size and any type; pick one. > > again you forget frequency, > Frequency 60 Hz, reflector=dish, gain 20 DBi, > you calculate Dish size Yet again you show you haven't a clue what is going on. >>> what shape is the reflector required to have and why ? >> >> Any rational shape you desire. > > no! shape parabolic, go study equations, they are not hard, I cannot do > this for you. Yet again you show you haven't a clue what is going on. >> >>> in terms of signal travel time or phase ? >> > >> >>> Did you know you can make a flat C band "reflector" out of different >>> length beer cans ? All the cans do is reflect and change the phase do >>> to length. >> >> It is not a reflector, it is a horn. > > not a horn, again you eyes play tricks on you brain. > the reflector is made up of about 200 beer cans, attached together and > mostly flat, like a freznel lens. Cans are cut to length for the phase > change needed. but this is beyond your experience, sorry. Yet again you show you haven't a clue what is going on. >> FYI people have been making horn feeds from various cans for well over >> 60 years now. > > feed horns, not reflectors. I had a modified paint can feed horn tuned > to 1.4 to 1.6 GHz with a VSWR of 1.05 a long time ago. Yet again you show you haven't a clue what is going on. > >> >>>> https://en.wikipedia.org/wiki/Parabolic_antenna >>>> >>>> Again, get a copy of the ARRL handbook and read it. >>> >>> no need to. >> >> >> You didn't read the Wiki link either, did you, or you wouldn't have >> posted the babbling gibberish below. > > wiki worse than amatuer ARRL. Both are far better than you word salad babble. >>>> >>>>> you thinking magnifying lens as in optics, >>>>> like when you were burning ants on sidewalk >>>>> >>>>> it is not that way in RF or Microwave. >>>> >>>> Light, RF, and microwave are ALL electromagnetic radiation. > >>> the solutions are vastly different in the bands. Gamma? X-ray ? >>> Parabolic antennas are phase changers, from 700MHz to 40GHz. >>> does your parabolic work on gamma ? or 200GHz ? >> >> Babbling gibberish. >> >> Whether of not a parabolic antenna works or not is purely a function >> of it's size in wavelengths. > > wrong again, how do you make it work on Gamma rays ? or x-rays ? > or 60 Hz ? Yet again you show you haven't a clue what is going on. > try to be specific and provide answers, instead of the red herring > clue-less bone throwing > >> >> >> >>>>>>> "concentrate" is what they do to Orange Juice. >>>>>> >>>>>> concentrate verb > >>>>>> to bring or come together in a large number or amount in one particular >>>>>> area > >>>>>> Again, get a copy of the ARRL handbook and stop being so ignorant. >>>>> >>>>> you base you knowledge on an out of date, stale, amateurish, Amateur >>>>> Radio book >>>> >>>> Nope, but if YOU were to read the 2015 edition, you might lose some >>>> of your ignorance about the basics of RF, such as light and microwaves >>>> being different and what a reflector in an antenna system does. >>> >>> forget ARRL, that is kindagarden, >> >> Then you must be pre-school. >> >>> move to "Antennas" by Kraus immediatly, then read "Antennas for all >>> Applications" by Kraus, then read "Radio Astronomy" by Kraus >>> seems like some should be online, public domain stuff. >> >> I actually have a job and buy books. > > ok, you got Kraus in you libarary ? (any of them?) Did you mean to say, "do you have Kraus in your library?" If so, yes, and many others, but that doesn't fix your ignorance of RF. >> >>> and they have all the equations to design your own. >> >> I've been designing antennas that actually work for about about 50 >> years now. > > they are fun to design and make, I did a tribander for police car in UHF > and 800 MHz bands. but uW are more fun. Word salad babble. 800 MHz is UHF. > ever see the insides of the dome of the Omnitracs system ? clever design > there. (trucking industry, communicates and gets location from > stattilites, qualcomm in SD) Whoopdee fucking do; so you are tourist. You are also ignorant in regards to RF in general and antennas in particular. -- Jim Pennino
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long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-17 10:42 -0800
Re: long antenna Odd Bodkin <bodkinodd@gmail.com> - 2015-11-17 12:46 -0600
Re: long antenna Poutnik <poutnik4nntp@gmail.com> - 2015-11-17 20:10 +0100
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 20:28 +0000
Re: long antenna benj <nobody@gmail.com> - 2015-11-17 16:59 -0500
Re: long antenna Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-18 22:56 +0100
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 16:57 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-18 23:15 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-18 20:42 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 05:29 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-19 08:54 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-19 18:44 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-22 15:32 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 23:16 +0000
Re: long antenna HVAC <mr.hvac@gmail.com> - 2015-11-19 06:59 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-19 20:02 -0500
Re: long antenna benj <none@gmail.com> - 2015-11-19 01:36 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-17 13:28 -0600
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-17 14:04 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-17 22:35 +0000
Re: long antenna benj <nobody@gmail.com> - 2015-11-17 19:28 -0500
Re: long antenna Timo <timo@physics.uq.edu.au> - 2015-11-17 17:18 -0800
Re: long antenna RichD <r_delaney2001@yahoo.com> - 2015-11-24 11:39 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-24 15:12 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:21 -0600
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 10:05 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 20:05 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:39 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:46 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:55 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 20:04 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:33 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 22:58 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 09:11 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 19:42 +0000
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 11:57 -0800
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 14:52 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 21:12 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 18:58 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 01:37 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-26 23:45 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-27 01:01 -0600
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-26 23:31 -0800
Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:34 -0500
Re: long antenna "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2015-11-27 09:58 -0800
Re: long antenna benj <nobody@gmail.com> - 2015-11-27 11:46 -0500
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-28 16:42 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-28 22:58 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 07:46 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 19:01 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 14:12 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:43 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:41 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 00:15 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 20:23 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 06:21 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-30 15:22 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 20:48 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 17:16 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-30 23:52 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-30 19:59 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-12-01 02:16 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-30 19:20 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-27 18:53 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-25 00:08 -0500
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 06:13 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-18 16:25 -0800
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-19 16:08 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-20 00:40 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-20 15:51 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 00:34 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-21 14:37 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-21 19:32 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-22 14:50 +0000
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-22 11:27 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:44 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-22 19:40 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-23 14:13 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-23 13:00 -0500
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-24 13:40 -0500
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-25 13:44 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-23 18:47 +0000
Re: long antenna jmfbahciv <See.above@aol.com> - 2015-11-24 13:20 +0000
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 19:49 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-24 16:36 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-24 23:00 +0000
Re: long antenna gilber34 <fafa@invalid.com> - 2015-11-26 16:17 -0600
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-26 23:35 +0000
Re: long antenna benj <none@gmail.com> - 2015-11-20 20:58 -0500
Re: long antenna benj <none@gmail.com> - 2015-11-19 20:09 -0500
Re: long antenna "nuny@bid.nes" <Alien8752@gmail.com> - 2015-11-24 12:51 -0800
Re: long antenna benj <none@gmail.com> - 2015-11-25 00:01 -0500
Re: long antenna "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-11-25 15:36 -0800
Re: long antenna jimp@specsol.spam.sux.com - 2015-11-25 23:51 +0000
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