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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ZRZROMPTMCSHK7NZQIZX4JXL3WI4N36V/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "CABsMmtTHKgsxmHdm1Htky1Xc63BekZ0Ep+UC9rHG5BC9eDKqUQ@mail.gmail.com",
    "message_id_hash": "ZRZROMPTMCSHK7NZQIZX4JXL3WI4N36V",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/EAIBDMLT4EWV6PLKCDMRWBOKSJKWZ4MJ/?format=api",
    "sender": {
        "address": "johnnykludt (a) gmail.com",
        "mailman_id": "1052971820fa4c30a2a6e76a33ee243f",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/1052971820fa4c30a2a6e76a33ee243f/emails/?format=api"
    },
    "sender_name": "John Kludt",
    "subject": "Re: [amsat-bb] Preamp source",
    "date": "2019-11-10T02:34:51Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/EAIBDMLT4EWV6PLKCDMRWBOKSJKWZ4MJ/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "Nick,\n\nI also have several of their (ARR) preamps, some with the choke for\npower-over-coax and some without the choke for power via an independent\nline.  I have been following this thread and it is a little confusing at\ntimes as EME requirements get lumped in with the satellite requirements.  I\ndo both Sats and EME and I see them as very different animals.  With EME\nyou are running many hundreds of watts probably a KW or more.  Many EME\nstations used separate feeds for Tx and Rx.  The path loss is on the order\nof 252 dB which means noise figure is really important.  The\nrequired relays in an EME preamp system can cost more than the preamp\nitself.  The switching requirements are pretty steep and everyone uses a\nsequencer.  The noise figure of the preamp is everything\n\nFor satellite work 20 watts is QRO.  Most of us have gotten used to RF\nswitched preamps and that means no sequencer.  In satellite work there is\nmost often a single feedline for Tx and Rx.  Noise figure while still\nimportant is not as  strigent as with EME.  The one thing a\nsatellite preamp has in common with an EME preamp is the need to be mounted\nas close to the antenna as possible to be maximally effective.\n\nThe challenge I see with many of the cheaper preamps is all you are getting\nis the preamp.  Chances are you need to figure out how to box it up in a\nweather proof enclosure.  With a single feedline you will probably need at\nleast two relays to switch it in and out of line.  Either you are going to\nneed to build your own RF sensing circuit or most probably invest in a\nsequencer.\n\nMy point is when shopping around just make sure you are comparing apples to\napples  A bare bones preamp with no switching circuit may look cheaper\nuntil you look at everything else you are going to need to put it into\nservice.\n\n73,\n\nJohn\n\nOn Thu, Nov 7, 2019 at 6:24 PM Nicholas Mahr KE8AKW via AMSAT-BB <\[email protected]> wrote:\n\n> Thats interesting if thats the case that they arent making preamps anymore.\n> I ordered two of their Mast mounted 160W preamps 5 months ago. It took a\n> month to get them. They told me when I ordered that it would be a good\n> while before I got them because they did not have the parts in stock for\n> them to make them due to their supplier \"being back logged\". I have them\n> and are very happy with them they work very well but they are not cheap\n> like all other pre amps out there. Maybe someone out their can confirm for\n> sure they dont make them anymore?\n>\n> - Nick KE8AKW\n> _______________________________________________\n> Sent via [email protected]. AMSAT-NA makes this open forum available\n> to all interested persons worldwide without requiring membership. Opinions\n> 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: https://www.amsat.org/mailman/listinfo/amsat-bb\n>\n",
    "attachments": []
}