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GET /hyperkitty/api/list/[email protected]/email/F5SDRFYKNMAJQP52NHR3VY5HHIWQJDBB/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/F5SDRFYKNMAJQP52NHR3VY5HHIWQJDBB/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "[email protected]", "message_id_hash": "F5SDRFYKNMAJQP52NHR3VY5HHIWQJDBB", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/7RZFEHXPHJ2ZA3D5SLYII7JSLMH3M33J/?format=api", "sender": { "address": "davekn4ok (a) aol.com", "mailman_id": null, "emails": null }, "sender_name": "[email protected]", "subject": "[amsat-bb] Re: AO-7 is not OK", "date": "2010-04-14T17:45:40Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/YK4S7KIG5NY46ZKHHNG6WBFJF7VBVA6J/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/WF2ZNIKS2FHUZDWIYBSU22D2YPXTBE4N/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "\nGreat Reply Tim,\n\nI try to tell the ops on AO7 to watch there input power. This old lady just can't handle us old men pumping the high power into her.\n\nBy the way, I had some very distorted signal the other morning and was so afraid she was damaged.\n\nBest 73's AO7 ops,\n\nSee ya on the bird!\n\nDave, kn4ok\n\n\n\n\n\n\n\nMike, Piraja and all,\nPlease take a moment to visit the page on the AO-7 Web site that includes an \nssay from AO-7 Project Manager Jan King, W3GEY. You will find that essay here: \nttp://www.planetemily.com/ao7/history.php?PHPSESSID=5cc1e3be993405e687967faffcac4407\nAccording to Jan, AO-7 no longer uses batteries in its current condition. It is \nowered completely by the solar array. He explains fully what he believes to \nave happened. Here are some excepts for the full essay Jan wrote, which appears \nn the page I provided the link to (NOTE - scroll down toward the borrom of the \nage to find Jan's report):\n\"I am certain what has happened (and I know why): The battery did fail short. \nirtually all of the cells failed in a shorted mode eventually. This shorted \nondition placed a shunt across the solar arrays and prevented current from \noing to the satellite loads (i.e. the transponders, in particular). Some time \nefore G3IOR reported hearing the spacecraft again the short on one of the cells \n1 out of 10) failed a second time. This time, it went from short to \"open.\" \nhen it went open this released the shunt that was pulling the array voltage \nown and allowed the current to pass to the satellite loads. Since there is no \nattery at all now (because one cell went open), when AO-7 goes into eclipse \nith each orbit, the satellite has no power to operate and shuts down in the \nark.\"\n\nlso:\n\nPeople should realize that the solar arrays are old and they don't put out more \nhan a few watts now. That's the only power available to run the \nransponders.So, if they uplink too much power it will just cause the \nransmitter to sort of 'cave in.' The voltage on the satellite bus begins to sag \nadly when a heavy demand is placed on the transponder (by a large uplinking \nignal) since there is nothing there to regulate it and then the oscillators in \nhe receiver and transmitter chain start changing frequency. People call this \nFMing' and that is what is going on.\"\n\nan's entire essay is fascinating.\nThe primary reason I consider AO-7 the flagship of the amateur satellite fleet \ns her amazing story and legacy. I consider myself blessed and fortunate to have \nn opportunity to work the \"Grand Old Girl\" now, more than 25 years after she \neached orbit. Even on her bad days - and today appears to be one, as I write \nhis - I am able to clearly copy my CW signal on the downlink from about 20 \negrees elevation running only 5 watts out of a Yaesu FT-817 from my handheld \nlk dual-band yagi - and working from inside my home on the second floor, my \nplink signal shooting through the second-floor ceiling and roof. I believe she \npoils us on her good days with the ability to enable contacts that span oceans \nnd continents - even with a station like mine.\n\n am grateful for every orbit during which I am able to hear such an amazing \niece of amateur-radio hardware still working as hard as she can.\n\n3 to all,\n\nim - N3TL\n\n\n_______________________________\nrom: Mike Rupprecht <[email protected]>\no: ps8rf Piraja <[email protected]>; [email protected]\nent: Wed, April 14, 2010 12:25:03 PM\nubject: [amsat-bb] Re: AO-7 is not OK\nHi Piraja,\nYes, I made similar observations. If the CW is active on 70cm you can hear\nometimes a very strong deviation in frequency.\nhe CW beacon partly not decodable. I agree with you it could be an effect\ny low batteries or due heavy usage.\nee some graphs here: http://www.dk3wn.info/p/?cat=21\n73, Mike\nK3WN\n\n----Ursprüngliche Nachricht-----\non: [email protected] [mailto:[email protected]] Im\nuftrag von ps8rf Piraja\nesendet: Mittwoch, 14. April 2010 13:22\nn: [email protected]\netreff: [amsat-bb] AO-7 is not OK\n\nome days we are seeing very strange behavior in the AO-7. In some orbits\nan only hear the feedback on the downlink when the satellite is approaching\ny station at about 30 degrees elevation, before is impossible to hear any\nignal via AO-7. Using two pre-amplifier, one in the TS 2000x and the other\nith 0.6 noise with 20 dB gain. During the orbits we transmiting power with\nf 30 watts. The satellite does not respond. Tried with 15 watts It was\nhen that we hear at certain points on the downlink audio too low. Its best\nerformance is when the satellite is almost 90 degrees from my station.\net it seems that the satellite is asking for help.\nThis seems the batteries are not getting enough loads. Or maybe it's\nxcessive use of power by the users of the satellite.\nMaybe it's time for the users of AO-7 rethink the best ways to keep QSO\nhrough it, such as the use of LOW POWER so that over time the satellite is\ntabilized.\n\"Long live the AO-7\"\n73'\nPiraja, PS8RF\nThe Amateur Radio is supportive and helpful in any circumstance.\n\n \n________________________________________________________________\nocê sabia que seu navegador te ajuda a ficar longe de vírus? Leia mais\nobre isso.\nttp://www.microsoft.com/brasil/windows/internet-explorer/?WT.mc_id=1500\n______________________________________________\nent via [email protected]. Opinions expressed are those of the author.\not an AMSAT-NA member? Join now to support the amateur satellite program!\nubscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n______________________________________________\nent via [email protected]. Opinions expressed are those of the author.\not an AMSAT-NA member? Join now to support the amateur satellite program!\nubscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n______________________________________________\nent via [email protected]. Opinions expressed are those of the author.\not an AMSAT-NA member? Join now to support the amateur satellite program!\nubscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n", "attachments": [] }