Email Detail

HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/2RSL6MDOEL7DN3HYLORBXJDJL5PKSQLX/",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/",
    "message_id": "[email protected]",
    "message_id_hash": "2RSL6MDOEL7DN3HYLORBXJDJL5PKSQLX",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/P3TKK2YSXPZAJNQ3KKPRX6FDV5YF55J3/",
    "sender": {
        "address": "zleffke (a) vt.edu",
        "mailman_id": "57a24afb1cf641f98121841e6753c12e",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/57a24afb1cf641f98121841e6753c12e/emails/"
    },
    "sender_name": "Zach Leffke",
    "subject": "Re: [amsat-bb] EO-80 FM Transponder Tested",
    "date": "2015-06-17T15:23:18Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/AZDECAL3C6ZMN6PFODQ5VKBPH3BM7VNV/",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "Paul beat me to the punch as I was typing up my response, but I'm \nsending it anyway:\n\nPath Loss.  ->  function of lambda (wavelength) squared.\nSo all other things being equal (antenna gains, power levels, range, \netc.), you can look at the power ratio of the two.\n\nRough calculation (going from 2m to 70cm):\n10log[(0.70/2)^2] = -9.1 dB\nOR\nRough calculation (going from 70cm to 2m):\n10log[(2/0.7)^2] = +9.1 dB\n\nThe thing to watch out for is antenna gains on the ground.  The arrow \nfor example has more gain on 70cm (7el) than it does on 2m (3el).  So \nwhile 2m has a 9-ish dB improvement over 70cm in terms of path loss, the \nreceiver may not see the full 9dB because of the difference in gains on \nthe antenna between the two bands.\n\nAgain VERY rough approximation (for demonstration purposes only):\n3el yagi -> call it 7.5 ish dB of gain\n7el yagi -> call it 11.5 ish dB of gain\nso, about 4 dB of LOST gain (going from 70cm to 2m using the arrow example).\n\nSo net gain going from 70cm to 2m (all other things equal except the \ngains on the arrow antenna)\n9dB - 4dB = 5dB\n\nso your typo was actually fairly close :-) for those planning to use \ntheir existing setup for the new birds.\n\n-Zach, KJ4QLP\n\nOn 6/17/2015 10:43 AM, Andrew Koenig wrote:\n> *9dB (typo)\n>\n> On Wed, Jun 17, 2015 at 9:42 AM, Andrew Koenig <[email protected]> wrote:\n>\n>> Can you explain the 6dB advantage 2m has over 70cm? I've seen it here on\n>> the amsat-bb, and in the mesh realm when comparing 2.4GHz and 5.8GHz WiFi\n>> gear, but it still hasn't \"clicked.\"\n>>\n>> 73 de KE5GDB\n>>\n>> On Tue, Jun 16, 2015 at 6:56 PM, Paul Stoetzer <[email protected]> wrote:\n>>\n>>> Nick,\n>>>\n>>> It should be even stronger than AO-27's 500 mW, AO-27 had a 70cm\n>>> downlink, the EO-80 downlink is on 2 meters, so EO-80's signal should\n>>> be up to 9 dB stronger than AO-27 (12 dB stronger if they run it at 1\n>>> watt).\n>>>\n>>> 73,\n>>>\n>>> Paul, N8HM\n>>>\n>>> On Tue, Jun 16, 2015 at 7:49 PM, Nicholas Mahr <[email protected]>\n>>> wrote:\n>>>> Thats very good news, Hopefully the two get activated before field day?\n>>> Im\n>>>> most looking forward to EO-80, It should be like AO-27 with 500Mw or 1W.\n>>>> Good to know both are working well and wish a long life to them.\n>>>>\n>>>> 73 KE8AKW\n>>>> _______________________________________________\n>>>> Sent via [email protected]. AMSAT-NA makes this open forum available\n>>>> to all interested persons worldwide without requiring membership.\n>>> Opinions expressed\n>>>> are solely those of the author, and do not reflect the official views\n>>> of AMSAT-NA.\n>>>> Not an AMSAT-NA member? Join now to support the amateur satellite\n>>> program!\n>>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n>>> _______________________________________________\n>>> Sent via [email protected]. AMSAT-NA makes this open forum available\n>>> to all interested persons worldwide without requiring membership.\n>>> Opinions expressed\n>>> are solely those of the author, and do not reflect the official views of\n>>> AMSAT-NA.\n>>> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n>>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n>>>\n>>\n>>\n>> --\n>> Andrew Koenig\n>>\n>\n>\n\n\n",
    "attachments": []
}