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Groups > sci.physics > #535711
| From | jimp@specsol.spam.sux.com |
|---|---|
| Newsgroups | sci.physics |
| Subject | Re: long antenna |
| Date | 2015-11-26 21:12 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <l69kic-a73.ln1@mail.specsol.com> (permalink) |
| References | (6 earlier) <n32ojo$jm0$1@speranza.aioe.org> <6l6fic-59f.ln1@mail.specsol.com> <n377fg$5f6$1@speranza.aioe.org> <ru3kic-ul2.ln1@mail.specsol.com> <n37rf3$12p$1@speranza.aioe.org> |
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. Normalize it for analysis, if you know what that means. > What size and type of reflector ? Any size and any type; pick one. > what shape is the reflector required to have and why ? Any rational shape you desire. > in terms of signal travel time or phase ? Gibberish. You haven't a clue. > 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. Again you haven't a clue. FYI people have been making horn feeds from various cans for well over 60 years now. >> https://en.wikipedia.org/wiki/Parabolic_antenna >> >> Again, get a copy of the ARRL handbook and read it. > > no need to. You have a desparate need to if you don't want to continue sounding like an idiot. You didn't read the Wiki link either, did you, or you wouldn't have posted the babbling gibberish below. >> >>> 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. Again you haven't a clue. >>>>> "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. > and they have all the equations to design your own. I've been designing antennas that actually work for about about 50 years now. > and you can realize and understand the reason why a parabolic antenna > "works" in RF and Microwave is by shifting phase in the right way over > an area. Babble. > > read "Microwave Scanning Antennas" while your at it. Worked on phase array radars decades ago. >> I recommend the ARRL Handbook because it is a very good source for >> learning the basics of RF, which you utterly lack, and the mathematics >> in it are no more complex than algebra. > > ARRL is kindergarten. I think you need complex number understanding to > help with phase. Then you are pre-school with no basic understanding. -- 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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