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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/GOQOYN645SHOTUUHHBDT3MNHIVIDMUZX/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "GOQOYN645SHOTUUHHBDT3MNHIVIDMUZX",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/GOQOYN645SHOTUUHHBDT3MNHIVIDMUZX/?format=api",
    "sender": {
        "address": "al7eb (a) acsalaska.net",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "Edward R. Cole",
    "subject": "[amsat-bb] Re: Redundant geostaionary birds?",
    "date": "2007-01-30T10:16:55Z",
    "parent": null,
    "children": [
        "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/KIWHRYFAP2QENQUTM3MNMSXFURXNCWNG/?format=api"
    ],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "Dave and all:\n\nI wonder what all of you were thinking?  If a commercial communication\nsatellite were channeled on one of our mw ham bands, then we would be\nbooted off. \n\nC-band satellites used approx. 37-MHz wide channels with alternating linear\npolarity to afford more adjacent channel isolation.  On most of the TVRO\nunits one could manually adjust polarization angle for optimizing the\nsignal.  If you adjusted 90-degrees off then one often got a ghost of one\nof the adjacent channels.  The feedhorns had a rotating probe with the\nmotor on the backside of the feedhorn.\n\nTypically in the mid-1980's these TV sats cost over $100M before launch.\nYour not going to convince the satellite company to include ham radio in\nany manner.\nAS has been hashed out many times previous on this reflector the path loss\nto the Clarke Belt orbit is prohibitive.\n\nThis topic is going no-where!\n\n73, Ed - KL7UW\n\nAt 04:04 PM 1/29/2007 -0800, Dave hartzell wrote:\n>\n>It looks like the commonly adopted block conversion for C-band\n>transponders wouldn't land in our bands.  There seems to be a delta\n>for 2.2 GHz for the block conversion (e.g. 5.9 GHz up, 3.7 GHz down).\n>We'd need more like a 4 GHz conversion to land in our S-band, given a\n>5.8 GHz uplink.  I'm sure the filters aren't quite tuned to go below\n>out of band, either.\n>\n>Another issue I just realized is that these transponders use polarized\n>signals (left, right, vertical, horizontal, polka-dotted)....this\n>again makes using an old communications sat a bit more difficult (but\n>not impossible) for us hams.\n>\n>Looks like this was not meant to be!\n>\n>73,\n>\n>Dave\n>NøTGD\n>\n>\n>On 1/28/07, Karl Bullock <[email protected]> wrote:\n>>\n>> Dave hartzell wrote:\n>> > 3) Most of the uplink freq's are in the 5.9 GHz range (out of our\n>> > allocation) and downlink in the 3.7 GHz range, again, (out of our\n>> > allocation).\n>> >\n>> That may be _the_ problem.  I don't know the current capabilities of\n>> these birds, and if they have any capability of either \"retuning\" to a\n>> close amateur band, or if there are other assets on board, but inability\n>> to transmit/receive on one of our bands would probably make this a non\n>> sequitur.  Those with more intimate knowledge of current flying\n>> technology would need to speak to this.\n>\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",
    "attachments": []
}