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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/QMJCABKXHAQDXPMNB4SWVQ5JRK7XI2BI/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "[email protected]", "message_id_hash": "QMJCABKXHAQDXPMNB4SWVQ5JRK7XI2BI", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/GVZGIFD54KVYYULPZ5XBC3EQA7AUOIBZ/?format=api", "sender": { "address": "ke4al (a) yahoo.com", "mailman_id": "816e2974d966450eab4046fcbf6c5cec", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/816e2974d966450eab4046fcbf6c5cec/emails/?format=api" }, "sender_name": "Robert Bankston", "subject": "Re: [amsat-bb] DJ-G7T and full-duplex satellite operating - the\t2018 sequel", "date": "2018-02-15T03:47:45Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/GVZGIFD54KVYYULPZ5XBC3EQA7AUOIBZ/?format=api", "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "As always, an excellent and insightful writeup. Thank you for taking the time to test and document the DJ-G7T.\n\nI was hoping for a better outcome, but can work around its shortcomings. I bought mine to provide a more portable solution for AO-92 and the soon to launch Fox-1Cliff and Funcube ESEO satellites. Even if I can only use it as an L-band uplink, I still think I made a smart choice.\n\nI will let you know how the eBay 5-element yagi performs, once that slow boat arrives from China (due NLT Mar8). \n\nThank you and 73,\n\nRobert Bankston | KE4AL\nWebsite: www.ke4al.wordpress.com\nTwitter: @KE4ALabama\n\n> On Feb 14, 2018, at 9:58 AM, Patrick STODDARD (WD9EWK/VA7EWK) <[email protected]> wrote:\n> \n> Hi!\n> \n> After dusting off my old Alinco DJ-G7T for use with AO-92's L/V\n> configuration, I have been using it for AO-92's U/V mode and on\n> other satellites. I wanted to see how it would do with U/V\n> satellites in particular, given how it performed with V/U\n> satellites like AO-27 and AO-51 when I bought the radio in 2009.\n> I have also seen some recent comments online stating that this\n> radio is good for satellite work. It can be, but only in certain\n> situations.\n> \n> Back in 2009, I was able to make the DJ-G7T work full-duplex with\n> AO-51, with a post titled \"DJ-G7T and full-duplex satellite\n> operating\":\n> \n> http://amsat.org/pipermail/amsat-bb/2009-May/019177.html\n> \n> I turned off the extended (non-ham) receive coverage in my DJ-G7T,\n> and it worked. I remember that, even at the city park I used for\n> much of my operating then, the radio would be very sensitive to\n> other signals way outside the 70cm band when working the U/V FM\n> satellites of that time. I never was able to work SO-50 full-duplex\n> then, with its weaker downlink compared to AO-51 and AO-27. After\n> almost 9 years, nothing has changed there. I just tried to work\n> SO-50 this morning with the DJ-G7T and Elk log periodic, yet I\n> never even heard the downlink once during a 39-degree pass. The\n> downlink VFO's S-meter was pegged for most of the pass, probably\n> from some other RF the radio was receiving. Even using the clock-\n> shift menu setting didn't improve things. I won't bother using my\n> DJ-G7T with SO-50 in the future, unless I have another radio for\n> the downlink.\n> \n> In the past couple of years, we have had some U/V FM satellites\n> (AO-85, AO-91, AO-92) that we never had back in 2009. Simply switching\n> the uplink and downlink bands has been a cure for receiver desense in\n> other radios like the Icom IC-W32 or Wouxun KG-UV9D when trying to work\n> full-duplex, but it's not so simple with the DJ-G7T. Depending on the\n> pass and the antenna I'm using, I can still have receiver desense on\n> 2m while transmitting on 70cm to any of these satellites. When I am\n> able to overcome the receiver desense on 2m, the DJ-G7T works fine for\n> the U/V FM satellites. This normally means I am using my Elk, and not\n> other antennas like the MFJ-1717 long duckie I have used with a few\n> other HTs. For higher passes, I am able to use the DJ-G7T with the\n> MFJ-1717 and hear myself while transmitting through AO-91 or AO-92,\n> but not near AOS or LOS when the receiver desense covers up the\n> downlink.\n> \n> If I am only receiving the 2m downlinks from the 3 current Fox-1\n> satellites, and not trying to transmit to the satellite, the DJ-G7T can\n> be a good receiver. All of this is dependent on the surrounding RF that\n> the DJ-G7T might pick up, of course. What works in one location, may\n> not work the same in another location. I demonstrated this with two\n> videos I recently posted on YouTube. Here is an AO-91 pass from 6\n> February:\n> \n> https://www.youtube.com/watch?v=jSK_v3L_RHk\n> \n> And an AO-92 pass, earlier on the same day:\n> \n> https://www.youtube.com/watch?v=E3nfO4tKEAI\n> \n> I have also posted some audio recordings and pictures of the DJ-G7T used\n> with these two antennas on AO-91 and AO-92 passes in my Dropbox space.\n> Go to http://dropbox.wd9ewk.net/ and look for the \"DJ-G7T\" folder. In\n> there, I have subfolders for different passes I have worked with this\n> radio. Some of the U/V passes were worked with the Elk as the antenna,\n> and some with the MFJ-1717.\n> \n> As an uplink radio, the DJ-G7T has performed well with the U/V FM\n> satellites and for AO-92's L-band uplink. I had to increase the mic\n> gain from 3 to 4 (maximum), and I have only received good reports on\n> my transmitted audio. My signals may be down a bit on 1.2 GHz if my\n> tuning isn't keeping up with the Doppler and AO-92's uplink AFC is\n> having to work, but I have been getting through with this HT (1W on\n> 1.2 GHz) and an old 5-band Yagi mounted on the antenna connector.\n> I have not tried using this radio for the uplink with SO-50, but I\n> am confident that using a DJ-G7T with a different radio for the\n> downlink would also be acceptable for SO-50.\n> \n> I went back and read through the QST review of this radio from April\n> 2010. The review mentioned trying this radio on AO-27. The reviewer\n> mentioned hearing slight interference when working full-duplex. That\n> must have been done from a very RF-quiet location, and on a very high\n> pass. When I heard any non-ham intermod on 70cm, that would tend to\n> cover up the downlinks from AO-27 or AO-51.\n> \n> I have liked my DJ-G7T for non-satellite uses, as it is a neat little\n> radio which includes 1.2 GHz. This HT, along with the 5-element Yagi I\n> have had for a long time, has been my uplink setup for AO-92's L/V\n> configuration over the past couple of weekends. For satellite use, I\n> think it would be great as an uplink radio for the 3 bands, and might\n> be useful for full-duplex operation on the U/V satellites, but comes\n> up way short with the only V/U FM satellite we currently have (SO-50).\n> I don't have an antenna that would let me see if the DJ-G7T could work\n> AO-92's L/V configuration full-duplex, but that would be interesting\n> to see. I won't sell my DJ-G7T, and will continue to recommend the\n> TH-D72 for anyone looking for an HT currently in production to work\n> V/U and U/V FM satellites full-duplex. Otherwise, there are many HTs\n> that can work V/U and U/V FM satellites that have been out of\n> production, or there is always the option of using two radios.\n> \n> 73!\n> \n> \n> \n> \n> Patrick WD9EWK/VA7EWK\n> http://www.wd9ewk.net/\n> Twitter: @WD9EWK or http://twitter.com/WD9EWK\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", "attachments": [] }