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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/XKDUFBZ477WGLMT6CZZW5IFE3IR5ZAOR/", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/", "message_id": "[email protected]", "message_id_hash": "XKDUFBZ477WGLMT6CZZW5IFE3IR5ZAOR", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/XKDUFBZ477WGLMT6CZZW5IFE3IR5ZAOR/", "sender": { "address": "manxmat (a) hotmail.com", "mailman_id": "b0384b3644f1489da68eb3ae83fb2b85", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/b0384b3644f1489da68eb3ae83fb2b85/emails/" }, "sender_name": "Matty Cunningham", "subject": "[amsat-bb] Re: AMSAT-BB Digest, Vol 7, Issue 79", "date": "2012-02-16T22:55:12Z", "parent": null, "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Hi folks,\n\nRegarding the 10m balloon tracking:\n\nThere's some interesting vertical 'Moxon' antenna designs here:-\n\nhttp://www.moxonantennaproject.com/\n\nIf you can get hold of a fibreglass pole then it wouldn't be so difficult to \nbuild a vertical - possibly even use wood,\n\nThere's even a very handy 'Moxon Generator', link here:-\n\nhttp://www.moxonantennaproject.com/design.htm\n\nSome of the builders report great DX if used near sea level, however I guess \nthis wouldn't be so good for tracking balloons as they have a low radiation \nangle, you would probably get a better angle for the balloon if you were \naway from the sea.\n\nThe antennas have a good F/B ratio, but a wide beamwidth, so again this may \nmake it more difficult for 'accurate' direction finding, but I'm sure would \ngive a general idea of the direction.\n\nWhat could be awesome is a series of GPS locked SDR receivers at known \nlocations, on the RX frequency (with vertical antennas) - if you could pull \nall the data together from the different RX's, this might be able to get a \ngood fix on the balloon.\n\n\n\nRegards\n\nMatty\nMD0MAN\n\n\n\n\n-----Original Message----- \nFrom: [email protected]\nSent: Thursday, February 16, 2012 8:00 PM\nTo: [email protected]\nSubject: AMSAT-BB Digest, Vol 7, Issue 79\n\nSend AMSAT-BB mailing list submissions to\[email protected]\n\nTo subscribe or unsubscribe via the World Wide Web, visit\nhttp://amsat.org/mailman/listinfo/amsat-bb\nor, via email, send a message with subject or body 'help' to\[email protected]\n\nYou can reach the person managing the list at\[email protected]\n\nWhen replying, please edit your Subject line so it is more specific\nthan \"Re: Contents of AMSAT-BB digest...\"\n\n\nToday's Topics:\n\n 1. Dick Daniels (Martha)\n 2. Re: TransAtlantic Balloon on 28 MHz ? (Roger)\n 3. Re: TransAtlantic Balloon on 28 MHz ? (John Magliacane)\n 4. Re: TransAtlantic Balloon on 28 MHz ? (Bob Bruninga)\n\n\n----------------------------------------------------------------------\n\nMessage: 1\nDate: Thu, 16 Feb 2012 11:02:11 -0500\nFrom: Martha <[email protected]>\nTo: AMSAT BB <[email protected]>, Board of Directors <[email protected]>,\nAMSAT Officers <[email protected]>, Jan King\n<[email protected]>\nCc: [email protected], Mark Kanawati <[email protected]>, Tak\nOkamoto <[email protected]>\nSubject: [amsat-bb] Dick Daniels\nMessage-ID:\n<CAPk0USwORY5LmbSsyuLfZJeY8Cm=3nK1mntNcut+4Wv-Zvoo_A@mail.gmail.com>\nContent-Type: text/plain; charset=ISO-8859-1\n\nA memorial service will be held for Dick Daniels, W4PUJ on Saturday,\nFebruary 25th at 1:00PM . The location is the Little River Presbyterian\nChurch, 6025 Little Falls Rd, Arlington VA 22207. In lieu of flowers, the\nfamily suggests a contribution to: Capital Caring, 950 N Glebe Rd #500,\nArlington VA 22203. This is the organization that provided hospice care for\nDick.\n\n-- \n73- Martha\n\n\n------------------------------\n\nMessage: 2\nDate: Thu, 16 Feb 2012 11:39:48 -0500\nFrom: Roger <[email protected]>\nTo: [email protected]\nSubject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?\nMessage-ID: <[email protected]>\nContent-Type: text/plain; charset=ISO-8859-1; format=flowed\n\nCB uses vertical beams...the difficulty is that they have to have a non\nmetallic mounting pole extending into the beam or be end mounted (think\ntorque)\n\nWith enough planning I'm sure enough hams could chase something up and\nuse empty Stationmaster radomes, fiberglass poles or even schedule 80\npipe to get something up.\n\nRoger\nWA1KAT\n\nOn 2/16/2012 12:18 AM, Bob Bruninga wrote:\n> Do you have a 10 meter (28 MHz) vertically polarized beam?\n>\n> We are working on a 28 MHz transatlantic Balloon with a CW transmitter on \n> 10m using (of course) a vertical dipole.\n>\n> It will have no GPS, so tracking will be entirely by beam headings and \n> some signal-strength assessment.\n>\n> Just wondering if anyone has a vertical beam.\n>\n> A horizontal beam will be useless for direction finding. All it will do \n> is point to whatever is reflecting the energy into the strongest \n> horizontal component...\n>\n> Hummh...\n> Bob, WB4APR\n> _______________________________________________\n> Sent via [email protected]. Opinions expressed are those of the author.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n\n------------------------------\n\nMessage: 3\nDate: Thu, 16 Feb 2012 11:37:43 -0800 (PST)\nFrom: John Magliacane <[email protected]>\nTo: [email protected]\nSubject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?\nMessage-ID:\n<[email protected]>\nContent-Type: text/plain; charset=us-ascii\n\n--- On Thu, 2/16/12, Roger <[email protected]> wrote:\n\n> CB uses vertical beams...the difficulty is that they have to have\n> a non metallic mounting pole extending into the beam or be end\n> mounted (think torque)\n\nThe mounting pole may contribute some capacitive or inductive loading \neffects on the elements adjacent to it, but a smart antenna designer can \nmodify the antenna's element lengths to compensate for these effects.\n\nThe pole itself will have a negligible effect on antenna performance, unless \nit happens to be resonant (or very close to resonant) at the operating \nfrequency. Otherwise, it's essentially transparent.\n\n> On 2/16/2012 12:18 AM, Bob Bruninga wrote:\n>\n> Just wondering if anyone has a vertical beam.\n\nIf the signal is strong enough (and/or the receiver sensitive enough), an \nelectrically small loop antenna can be used for 28 MHz radio direction \nfinding purposes.\n\nA vertically oriented loop will respond to vertically polarized RF. (In \nreality, it's responding to the horizontally polarized H-field).\n\nThe ARRL Handbooks and Antenna Books have carried designs regarding 28 MHz \nRDF antenna for many decades.\n\n\n73, de John, KD2BD\n\n\n\n------------------------------\n\nMessage: 4\nDate: Thu, 16 Feb 2012 14:51:06 -0500\nFrom: \"Bob Bruninga\" <[email protected]>\nTo: \"'Joe'\" <[email protected]>, <[email protected]>\nSubject: [amsat-bb] Re: TransAtlantic Balloon on 28 MHz ?\nMessage-ID: <050b01ccece4$52829550$f787bff0$@edu>\nContent-Type: text/plain; charset=\"us-ascii\"\n\n>> Just wondering if anyone has a vertical beam.\n>> A horizontal beam [for this vertical balloon signal] will be\n>> useless for direction finding....\n\n> That is only true when receiving the signal\n> via direct line of sight propagation.\n\nThe transmitter is only 10 milliwatts, so we only expect line-of-sight\ncontact. So that is why I was assuming we'd need a reasonable polarization\nmatch. But who knows... maybe we will get some good OTH signals.? The\naltitude will not be super high though, (like in the ionosphere)..\n\nBob, WB4APR\n\n\n\n------------------------------\n\n_______________________________________________\nSent via [email protected]. Opinions expressed are those of the author.\nNot an AMSAT member? Join now to support the amateur satellite program!\nhttp://amsat.org/mailman/listinfo/amsat-bb\n\n\nEnd of AMSAT-BB Digest, Vol 7, Issue 79\n*************************************** \n\n", "attachments": [] }