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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/COF3M2IMB2U5IVYN3LWGASX62UGITIIJ/", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/", "message_id": "[email protected]", "message_id_hash": "COF3M2IMB2U5IVYN3LWGASX62UGITIIJ", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/COF3M2IMB2U5IVYN3LWGASX62UGITIIJ/", "sender": { "address": "jf.va2ss (a) gmail.com", "mailman_id": "ab8ed96d641e4ccba1d42cc60b6e68cf", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/ab8ed96d641e4ccba1d42cc60b6e68cf/emails/" }, "sender_name": "Jean-François Ménard", "subject": "[amsat-bb] Re: Antenna project with 2 ELK antennas", "date": "2009-08-08T16:50:44Z", "parent": null, "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Le 8 août 2009 11:54, i8cvs<[email protected]> a écrit :\n> Hi Jean, VA2SS\n>\n> Since the ELK antenna is a log-periodic antenna covering a wide\n> band from 2 meters and 70 cm it is difficult to connect 2 ELK in\n> phase and gain 3 dB in 2 meters and 70 cm as well.\n>\n> Also it is difficult to connect 2 ELK with a phase offset of 90°\n> to get circular polarization in 2 meters and 70 cm\n>\n> I would prefere to put one ELK horizontal and the other one\n> vertical feeding each antenna with an individual coax line.\n>\n> Using a coax relay in the shack you can immediately switch\n> from the Horizontal to the Vertical polarization.\n>\n> About the distance between the antennas over the plastic boom\n> the distance is a function of the antenna gain and higher is the gain\n> (in order do not overlap the aperture area of each antenna) larger\n> must be the distance between booms\n>\n> Since the gain of the ELK in the lover 2 meters band is 6.6 dBd\n> over the dipole or 6.6 +2.14 = 8.7 dBi over the isotropic then the\n> aperture area wich is a circle perpendicular to the antenna boom\n> can be computed using the following formula:\n>\n> / 2\n> G x /\\\n> Aperture area= ----------\n> 4 x Pi\n>\n> Since G= 8.7 dBi = 7.41 in power ratio\n>\n> 2\n> 7.41 x 2\n> Aperture area= -------------- = 2.36 square meters\n> 4 x 3.14\n>\n> A circle with a geometrical area of 2.36 square meters\n> has a radius of\n>\n> \\ /--------------------\n> radius = \\ / 2.36 / 3.14 = 0.86 meters\n> \\/\n>\n> Hence the distance between the booms is 0.86 x2 = 1.72 meters\n>\n> In this condition both aperture areas are tangents but it is better\n> to overlap the areas a 10 % to prevent the generation of side lobes\n> so that a distance of 1.55 meters between the antenna booms\n> is recommended.\n>\n> I hope this helps\n>\n> 73\" de\n>\n> i8CVS Domenico\n>\n> ----- Original Message -----\n> From: \"Jean-François Ménard\" <[email protected]>\n> To: \"i8cvs\" <[email protected]>\n> Sent: Saturday, August 08, 2009 4:00 PM\n> Subject: Re: [amsat-bb] Antenna project with 2 ELK antennas\n>\n>\n> Hi,\n>\n> I do not know much about antenna... But I tought that could be better\n> for satellite this way... I did not do any search at this time about\n> this project... it is only an idea that I had.\n>\n> If you have any suggestion for such project using 2 Elk antenna....\n> please let me know.\n>\n> I don't want to spend much money at this moment... and I have only\n> these 2 antenna.\n>\nWow !!\n\nThanks !! This is the kind of answer that I really like.\nI will try this with the recommendation you gave me. I'm not familiar\nwith all those formulas regarding antenna, so a little help time to\ntime is really helpful.... I like to learn, so you won't repeat the\nsame thing twice.\n\nThank again.\n\nBest 73\n\nJ-F VA2SS\n\n> 73\n>\n>\n> 2009/8/8 i8cvs <[email protected]>:\n>> ----- Original Message -----\n>> From: \"Jean-François Ménard\" <[email protected]>\n>> To: \"AMSAT Mailing list\" <[email protected]>\n>> Sent: Thursday, August 06, 2009 10:44 PM\n>> Subject: [amsat-bb] Antenna project with 2 ELK antennas\n>>\n>> Hi,\n>>\n>> I have 2 ELK antennas here, and I would like to do an experiment with\n>> these two antennas. I would like to stack side by side, one vertical,\n>> and one horizontal.\n>>\n>> 73\n>>\n>> Jean-François Ménard\n>> VA2SS\n>>\n>> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n>> AMSAT www.amsat.org / Member #37102\n>> ARRL www.arrl.org\n>> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n>>\n>> Hi Jean, VA2SS\n>>\n>> Staking 2 ELK antennas side by side,one vertical,and one horizontal\n>> what type of polarization you plan to get ?\n>>\n>> 73\" de\n>>\n>> i8CVS Domenico\n>>\n>>\n>>\n>>\n>\n>\n>\n> --\n> Jean-François Ménard\n> VA2SS\n>\n> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n> AMSAT www.amsat.org / Member #37102\n> ARRL www.arrl.org\n> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n>\n>\n>\n>\n>\n>\n>\n>\n>\n\n\n\n-- \nJean-François Ménard\nVA2SS\n\n=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\nAMSAT www.amsat.org / Member #37102\nARRL www.arrl.org\n=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n\n", "attachments": [] }