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GET /hyperkitty/api/list/[email protected]/email/7JGAE7J54M6LEV5QHG4GSFU26MFGR2TM/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/7JGAE7J54M6LEV5QHG4GSFU26MFGR2TM/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "[email protected]", "message_id_hash": "7JGAE7J54M6LEV5QHG4GSFU26MFGR2TM", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/QS4ZNLSO25FWR4LQYKRNIYRQWKS6ROD4/?format=api", "sender": { "address": "py2rn (a) arrl.net", "mailman_id": null, "emails": null }, "sender_name": "Eduardo PY2RN", "subject": "Re: [amsat-bb] RTL-SDR downlink", "date": "2016-06-16T23:08:36Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ACKP4PUUQW4GZDXTOXZCSL4Y6G4ZCDQK/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ZYW5FEHXAJ73D6MWRJTSDY6HEZQIMTVH/?format=api", "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/WZQIIKI6JIW7F27XE7JE2YNQB7F3BLPU/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "The cheap RTL dongles are as much sensible (or more) than the others more expensive.Lack of filtering is the big issue although there are some practical and easy workarounds to improve it.For ham satellites downlink frequency stability should not be an big issue, there are some models already been sold with 0.5PPM TCXO option which are still cheap.It is a great opportunity to operate full-duplex on amateur satellites with very low investment and improving operational capabilities.\nEME (Moon bounce) audible signal RX comparison between TS-2000 / RTL / FunCube Pro+ can be seen here:\nhttps://youtu.be/3OxyO5ylwfs\n\n73\nED PY2RN\n\n\n From: Patrick STODDARD (WD9EWK/VA7EWK) <[email protected]>\n To: \"[email protected]\" <[email protected]> \n Sent: Thursday, June 16, 2016 5:22 PM\n Subject: Re: [amsat-bb] RTL-SDR downlink\n \nHi, (name or call?)!\n\nThe inexpensive RTL-SDR dongles are a great way to get started with\nSDR receivers. For amateur satellite work, other than the ISS and maybe\nAO-85, they have a couple of significant drawbacks...\n\n1. These dongles were designed to be TV receivers, working with\nsignals much stronger than we have from our satellites or even the\nISS ham station.\n\n2. These dongles lack front-end filtering. This means that there could\nbe a strong signal near you that swamps the receiver that wipes out\nwhat you're trying to hear. If you are trying to work satellites\nfull-duplex, it is possible that your transmitter will shut down\nthe dongle until you end your transmission. This was a problem I\nexperienced early on when I tried using one of these dongles as\nmy downlink receiver, and quickly moved on to something else.\n\nUnfortunately there isn't anything in the middle ground between these\ndongles and devices like the SDRplay (sold by HRO in the US for $149)\nor the FUNcube Dongle Pro+ (sold by its UK manufacturer for around\n$200 depending on exchange rates, which includes FedEx next-day\nshipping from England to most addresses in the continental USA). Both\nof these devices do well as the downlink receiver for working\nsatellites. Both come with front-end filtering that the RTL-SDR\ndongles lack, and still have sensitive receivers. The SDRplay\nhas a low-noise amplifier that is engaged when receiving at VHF or\nhigher, but you can reduce the amount of gain from the built-in LNA.\nFor my work, I keep that gain reduction value set to 0, so I have\nmaximum gain to hear the downlinks.\n\nGood luck, and 73!\n\n\n\n\n\nPatrick WD9EWK/VA7EWK\nhttp://www.wd9ewk.net/\nTwitter: @WD9EWK\n\n\n\n\n\nOn Thu, Jun 16, 2016 at 2:30 PM, [email protected] <[email protected]>\nwrote:\n\n> Hello all! Been lurking a while here and just wanted to say hi and thanks\n> to everyone. Just started working the birds. VERY limited success so far\n> on the linear transponders. Limited budget leads me to either have to run\n> in half duplex (obviously not preferred) or come up with another low cost\n> receiving option. I bought an RTL-SDR to see if it could be any help. I\n> have to say I really like this little receiver. It’s a little buggy\n> figuring things out but it receives really pretty well…UNTIL I try\n> to receive CW and SSB on the transponders. I have no problem receiving FM\n> repeaters and simplex and have monitored a few SO50 passes with it no\n> problem, but for some reason I’m not hearing the same signals I can\n> hear on the receiver of my FT100 with the EXACT same antenna. I A/B them\n> and have nothing on the SDR. Is anyone using one of these? I am probably\n> missing something simple. When I started receiving HF I couldn’t make\n> it work until I figured out I had\n> to change the sampeling in the setup to direct from\n> quadrature…only learned that through a forum and I assume something\n> like that will make the thing come to life. Lack of documentation on some\n> of these things is kind of a pain. Thanks in advance for any help you can\n> offer and my apologies to anyone I have frustrated working half duplex! I\n> will figure out what I’m doing!\n> ____________________________________________________________\n>\n_______________________________________________\nSent via [email protected]. AMSAT-NA makes this open forum available\nto all interested persons worldwide without requiring membership. Opinions expressed\nare solely those of the author, and do not reflect the official views 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\n \n", "attachments": [] }