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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/KMQNHF5PP237UCQ5CCXFEMEGOL6PHNRF/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "KMQNHF5PP237UCQ5CCXFEMEGOL6PHNRF",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/COHRCSKE2BB3OXES4ZCPEUCWGMEIUZOL/?format=api",
    "sender": {
        "address": "kd0ar (a) sbcglobal.net",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "Michael Heim",
    "subject": "Re: [amsat-bb] Re: HEO naïveté",
    "date": "2009-02-07T19:07:40Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/S3JO74PWRH6GABM4PGQUECJZDDW37VHN/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "I usually tend to keep quiet during arguements such as this, but I need to chime in on this one.\n\nI live in a location that frowns upon antennas.  I was able to put up a mode V/u as well as S band antenna to get me on AO-51.  This antenna has 3 ele on 2m, 6 ele on 70 cm, and the S band antenna is a 18 inch long yagi.\n\nThis system is way too small for a GEO or HEO bird.  I was on AO-10 + 13 when they were up.  My 2M was 22 ele crossed yagi, and a 10 turn 70 cm helix.  Very large antennas compared to what I'm using now.\n\nI'm not certain, but I believe I would be able to receive an S band SSB signal with my current S band receive setup from a geo sync orbit.  \n\nThere is a law of physics that states that if the antenna size remains the same and the frequency increases, the signal strength will also increase.  Notice I said antenna SIZE not GAIN, because as the frequency goes up and the antenna remains the same size, the gain will overtake the increased path loss.  I understand the reason for having to use microwaves for rideshare birds.  Thing is, the microwaves give you a distinct advantage, and that is a stronger signal and less noise.  the cost for that?  some new equipment.\n\nI recently bought myself a new laptop.  It wasnt a very high end unit, about $600.  I really didnt NEED it, but the same money would have bought me a new microwave band and had money left over.  Reason I didnt get the transverter?  lack of activity.  If a satellite would have been launched, hey, guess what I would have bought instead?  yep, you guessed it...  A new DX band!  \n\nLets say 5760 is used on an upcoming bird.  Ground station with a 19 inch dish with a simple homebrew feed will have almost 30 dB of gain!  thats 100 times more signal than your 2 meter arrow, and the antenna is a lot smaller!\n\nBy the way, I hold VUCC on terrestrial 10 GHz, so I think I have some idea as to what I'm talking about.\n\nMichael Heim\nARS KD0AR\nAmsat 36924\n\n\n--- On Sat, 2/7/09, Jeff Davis <[email protected]> wrote:\n\n> From: Jeff Davis <[email protected]>\n> Subject: Re: [amsat-bb] Re: HEO naïveté\n> To: [email protected]\n> Date: Saturday, February 7, 2009, 11:10 AM\n> On Sat, Feb 7, 2009 at 10:50 AM, Gary Joe Mayfield\n> <[email protected]> wrote:\n> > The microwave thing always gets me though.  If the\n> antennas are too big how\n> > come they can get them on cube sats?  I know the\n> correct statement is\n> > high-gain antennas are too big.  The problem is gain\n> antennas need some\n> > pointing mechanism (complicated and expensive) and\n> they need to be pointed\n> > no matter what band they are designed for.  When using\n> omni antennas the\n> > lower frequency will yield higher performance due to\n> lower path loss....\n> \n> CubeSats buzz around 180 miles over your head. At apogee,\n> AO-13 was\n> 23,000 miles from the ground.\n> \n> That's why the gain antennas were needed and when you\n> add up the power\n> required for a transponder to handle lots of stations at\n> the same\n> time, then the link budgets and antenna sizes (for more\n> gain) at\n> higher frequencies begin to make a LOT more sense.\n> \n> The tightrope the developers walked was always how to\n> deliver\n> performance on frequencies that stubborn members demanded\n> always be\n> used. The S-mode stuff held much promise with AO-40. James\n> Miller,\n> G3RUH presented all the superior reasons for S-mode (the\n> paper is\n> still in the archives) but for a large percentage of\n> members it was\n> always \"2 meters on the downlink or I will withhold\n> funding\".\n> \n> Just like those who raise a stink now whenever almost\n> anything is\n> proposed requiring more than a fifteen year old dual band\n> handheld and\n> an Arrow antenna...\n> \n> Sigh.\n> \n> As has been hinted around this thread, our problems are\n> almost 100%\n> self-inflicted. We have shot our toes off until we have\n> none left to\n> shoot. I don't blame the leadership -- this\n> \"club\" contains some of\n> the most stubborn individuals in all of hamdom. Perhaps if\n> AMSAT can\n> stick around long enough, the naysayers will all eventually\n> die off\n> and we can move forward with reality instead of dreamy-eyed\n> reminiscing about days gone by and what might have been.\n> \n> Jeff, KE9V\n> AMSAT-NA\n> AMSAT-DL\n> _______________________________________________\n> Sent via [email protected]. Opinions expressed are those\n> of the author.\n> Not an AMSAT-NA member? Join now to support the amateur\n> satellite program!\n> Subscription settings:\n> http://amsat.org/mailman/listinfo/amsat-bb\n\n",
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}