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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/KBCKKXOIBRZQE7X4OOMB3URVTRO7QHWZ/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "KBCKKXOIBRZQE7X4OOMB3URVTRO7QHWZ",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/FJCAWJSNPMIUE7FK33AQM55ORST4BSZU/?format=api",
    "sender": {
        "address": "zleffke (a) vt.edu",
        "mailman_id": "57a24afb1cf641f98121841e6753c12e",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/57a24afb1cf641f98121841e6753c12e/emails/?format=api"
    },
    "sender_name": "Zach Leffke",
    "subject": "Re: [amsat-bb] LNA Circuit for VHF and UHF homebrew",
    "date": "2018-12-07T17:55:10Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/SDEXTQEG4A4SG2MQRJWEOJQNCVLQDX5D/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "I've had a lot of luck with the PGA-103 device for homebrew pre-amps \nfrom Minicircuits, which works well for both VHF and UHF: \nhttps://www.minicircuits.com/WebStore/dashboard.html?model=PGA-103%2B. \nThe only downside is if you buy just the chips from them, the minimum \norder quantity is 20, at $1.99 a pop.  They also sell 'connectorized' \nversion in a small package with SMA connectors for around $50.00.  Main \nfeatures are 50 ohm input/output making impedance matching easy, sub 1.0 \ndB noise figure, high gain through UHF (greater than 20dB), and pretty \nhigh OIP3 for good linearity in the presence of strong signals.\n\nInspired by prior work done by hams (including a paper by WA5VJB), I did \nmy own layout in Eagle CAD which can be found here:  \nhttps://github.com/zleffke/eagle_pga103.  Main features on my version \nare a built in 5V, low noise, regulator so that I can supply it with \nstandard 13.8V.  The regulator also has an enable/disable pin that I use \nas a PTT control signal for TX/RX sequencing.\n\nThe form factor of the board was for a specific type of enclosure I \nhappened to have, so you may want to do your own layout, but the basic \nschematic might be helpful to get you going (basically taken from \nWA5VJB's paper, with slight tweaks).  For the filtering part, I was \ntargeting a specific chip level SAW filter for UHF applications, which \ncan by 'bypassed' (little jumper on the board in place of the filter \nchip) for VHF applications (I have yet to find a SAW filter for VHF that \nI like that's readily available on digikey/mouser).  You could toss out \nmy filtering chip piece and insert your own.  Minicircuits has detailed \nS parameters on their page to get the matching part fine tuned (though \nthey do claim 50 Ohm impedance on both input/output across the range of \noperation).\n\nI haven't done any rigourous testing of the three prototypes I built \n(impedance, gain, or Noise Figure measurements) yet, other than just \ngetting on the air with them.  They seem to perform well enough for me.\n\nThe github link might not be perfect for your application, but might be \na useful starting point for you.\n\n\nHope this helps, good luck!\n\n\n-Zach, KJ4QLP\n\nResearch Associate\nAerospace Systems Lab\nTed & Karyn Hume Center for National Security & Technology\nVirginia Polytechnic Institute & State University\nWork Phone: 540-231-4174\nCell Phone: 540-808-6305\n\nOn 12/7/2018 10:09 AM, Ed Krome wrote:\n> Go to wa5vjb.com; search for preamp cookbook. All kinds of useful circuits.\n>\n> Ed Krome K9EK\n>\n> Sent from my iPhone\n>\n>> On Dec 7, 2018, at 9:55 AM, \"[email protected]\" <[email protected]> wrote:\n>>\n>> Hi to all!\n>>\n>> In my club we are building a groundstation, and we want to make two LNA's one for VHF and other to UHF eggbeater antennas. Someone can share a circuit to do one for each band??? i can't find it in google (maybe i'm searching wrong).\n>>\n>> Thanks in advance\n>>\n>> Mati LU9CBL\n>>\n>>\n>> ---\n>> El software de antivirus Avast ha analizado este correo electrónico en busca de virus.\n>> https://www.avast.com/antivirus\n>>\n>> _______________________________________________\n>> Sent via [email protected]. AMSAT-NA makes this open forum available\n>> to all interested persons worldwide without requiring membership. Opinions expressed\n>> are solely those of the author, and do not reflect the official views of 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> Sent via [email protected]. AMSAT-NA makes this open forum available\n> to all interested persons worldwide without requiring membership. Opinions expressed\n> are solely those of the author, and do not reflect the official views of 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",
    "attachments": []
}