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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/H4BKCO4RJUUGOOCEGFGHNO35ZD4DQEDS/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "H4BKCO4RJUUGOOCEGFGHNO35ZD4DQEDS",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/Q5ELUGPORQW5DIL27Q3AOA6TA3MFHL2L/?format=api",
    "sender": {
        "address": "dave (a) w0dhb.net",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "David W0DHB",
    "subject": "Re: [amsat-bb] Why too much uplink power is bad/eggbeater antennas\ton\txmit",
    "date": "2015-08-03T04:25:12Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/Q5ELUGPORQW5DIL27Q3AOA6TA3MFHL2L/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "I used eggbeaters and on SO-50 , 15 to 20 watts worked fine.\nHe does have the reflector spokes on the bottom I hope. \n\n-----Original Message-----\nFrom: AMSAT-BB [mailto:[email protected]] On Behalf Of Philip\nJenkins\nSent: Sunday, August 2, 2015 5:54 PM\nTo: [email protected]\nSubject: [amsat-bb] Why too much uplink power is bad/eggbeater antennas on\nxmit\n\nThe discussion on uplink power fits right in with a conversation I had last\nweekend...\n\nWhile I was not wearing my AMSAT badge at a hamfest on July 25, a married\ncouple - both hams, both fairly recently licensed - recognized me from a\nprevious hamfest when I was wearing that badge. Their question for me was to\nwhy they could hear  (a) satellite(s), but no one could hear them...\n\nThe satellite in question is SO-50 (and I did take a few minutes explaining\nthe difference between linear birds and FM-only ones).\n\nBefore the OM joined us, his YL told me that her husband doesn't want to use\nantennas like the Elk or Arrow, even on a tripod. I then suggested to her\nthat he consider a fixed elevation mount, so as to only have to track the\nazimuth.\n\nThen the OM showed up. He doesn't even want to consider the fixed-elevation,\nbecause he'd still have to track . I suggested he leave the tracking to a\ncomputer...still not acceptable\n\nHe then explained that they spend a lot of time in a motorhome. For his\nantennas now, he is using eggbeaters. On the 440 receive side, he is\nthankfully using a pre-amp, so he can hear adequately,\n\nFor the transmit, he is using 50 watts into an eggbeater, and still can't be\nheard on the satellite. He told me one recommendation he was given was to\nincrease the xmit power to 150 watts (*I visibly shuddered*) so as to\novercome the non-directionality of the eggbeater. (And I explained why too\nmuch uplink power is bad for both FM and linear sats, in terms of bandwidth\nand power consumption on the satellite.)\n\nOn further questioning, he knew about the PL tone to turn-on SO-50, but\ndidn't know about the different PL to actually access the satellite on each\ntransmission. I explained to him that it is like terrestrial repeaters; no\nmatter how much power you run, the repeater won't \"hear\" you unless you\ntransmit the PL every time.\n\nIn a follow-up email the next day, I passed on the SO-50 operating guide\n(PDF) from the AMSAT website, and advised him to try programming his radio\nwith the proper PL and frequencies for adjacent memories BEFORE consdering\nincreasing transmit power.\n\nI really think his problem is not using PLs, rather than inadequate power\nlevels on an omni antenna.\n\nMy question is two-fold (I still need to follow-up with him). 1) For those\nof you successfully using eggbeaters for the uplink (and he is adamant about\nnot using a yagi, despite my advice that the performance will suffer quite a\nbit with eggbeaters), what output power do you typically use? I think 50\nwatts into an eggbeater is probably still too much power, considering 5\nwatts into an Arrow is usually enough for successful communications.\n\n2) I know that various power levels are suggested for various gain antennas,\nbut I'm wondering what the suggested EIRP is for successful - not ones which\nwould hog the satellite  - uplinks.\n\nPhilip N4HF\n_______________________________________________\nSent via [email protected]. AMSAT-NA makes this open forum available to all\ninterested persons worldwide without requiring membership. Opinions\nexpressed are solely those of the author, and do not reflect the official\nviews of AMSAT-NA.\nNot an AMSAT-NA member? Join now to support the amateur satellite program!\nSubscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n\n",
    "attachments": []
}