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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/XGKK64GWFQQUYZUXDTDE4DKNLX2NXSDA/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "007c01c6d798$ec1aad90$6701a8c0@Mike2",
    "message_id_hash": "XGKK64GWFQQUYZUXDTDE4DKNLX2NXSDA",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/EQCSMA4XDQ6BXUUYXEU4PXDUN3EAQVGC/?format=api",
    "sender": {
        "address": "n1jez (a) verizon.net",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "Mike Seguin",
    "subject": "[amsat-bb] Re: L'ers equipment",
    "date": "2006-09-14T00:58:35Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/EQCSMA4XDQ6BXUUYXEU4PXDUN3EAQVGC/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "----- Original Message ----- \nFrom: <[email protected]>\nSubject: [amsat-bb] L'ers equipment\n\n\n> Hello\n> I would like an informal survey regarding what you are using for Mode L. \n> I am working on my system\n> and do not want reinvent the wheel.  The format of \n> radio-power-transmission line-antenna/gain.\n\nHi Bob,\n\nI posted this a while back, but it still should be good:\n\n====\nThe first AO-51 \"Experimenter's Wednesday\" took place on 08/04/2004. The\nsatellite was configured for L/u voice. For those that might have missed\nhearing the first pass, Patrick, KA9SCF recorded it and has an mp3 at:\n\nhttp://www.warpcore.com/AO-51-20040804-0227.mp3\n\nBased on information supplied by 13 of the satellite operators who worked\nL/u, I've extrapolated what I feel is a good starting point for those\ninterested in trying the L Band uplink. This is based purely on my own\nexperiences working other L Band stations and reviewing data sent by other\nsuccessful users.\n\nI am not going to recommend equipment, rather EIRP necessary for several\nlevels of performance. There are many ways to generate the necessary uplink\npower, so trying to list them all would be a huge task.\n\nEIRP is a combination of rig power output, coax losses, and antenna gain.\nYou'll want to make some basic calculations to arrive at your EIRP. Here are\na couple of URL's that may help. The first is for loss for various types of\ncoax at 1269 MHz.\n\nhttp://www.ocarc.ca/coax.htm\n\nOnce you know your rig power out, coax loss and antenna gain plug them in\nhere:\n\nhttp://www.csgnetwork.com/antennaecalc.html\n\nFirst I'd like to thank the following for sending data on their systems:\nCT1EAT, G3VZV, G3WDG, IZ1ERR, KE4AZN, N5TD, N8MH, NA2P,\nVE3NPC, VE7BPB, W2XB and WA1ECF.\n\nBased on data from the above, I'd like to recommend users consider putting\ntogether the following L Band systems to be used on L/u Voice:\n\nFor an occasional contact, 150 watts EIRP.\nFor medium level performance, 500 watts EIRP.\nFor superior performance, 1 kW EIRP or higher.\n\nCOMMENTS:\n1.) L Band doesn't like trees. Depending on your power level, you may need\nto see clear sky.\n\n2.) Doppler can run as high as +/- 28 kHz. You must tune your uplink to\ncompensate.\n\n3.) The satellite L Band receive antenna is linear. This would seem to\nindicate that a circular antenna on the ground would be best. Of the 13\nusers surveyed, 5 used linear and 8 had circular antennas.\n\nFor those that may not have seen it, here is a picture of the dual band L/S\nreceive antenna designed by Stan Wood, WA4NFY. It is essentially a 1/4 wave\ndesign. For size perspective, it is built on an SMA connector.\n\nhttp://members.aol.com/mike73/images/ls.jpg\n\n4.) As you reduce uplink power, Doppler correction and antenna pointing\naccuracy become more important. I was able to hold the L uplink with a mere\n50 watts EIRP, BUT only after I had fine tuned my antenna and carefully\nadjusted Doppler for the center of the receiver capture window. Mark, N8MH\nwas using about 170 watts EIRPc and we did make a contact. There was a bit\nof white noise on his signal, but he was quite readable.\n\n5.) At the 500 watt EIRP level, #4 is still important but it is much less\nsevere. Operation is pretty easy. An interesting observation was made by\nClare, VE3NPC. He runs 500 watts EIRPc. He was experiencing drop outs as he\ntalked. When his FM deviation was reduced, it seemed to clear up the\nproblem. This was a very limited test, so more work needs to be done here to\nsee if this is a factor or not. I have seen this effect on marginal signals\ninto FM repeaters where an operator will be dropping out. He is then told to\nback off his mic and he'll then hold the repeater.\n\n6.) At the 1 kW and above level, operation becomes very easy. There still is\nthe need for Doppler correction, but the window is easily +/- 5 kHz.\n\n7.) An HT with 5 kHz steps could perhaps work, but if the EIRP is small, it\nmight tend to be spotty unless Doppler were close to a 5 kHz step.\nUnfortunately, I'm not aware of anyone making contact with an HT this time\naround. The best I could do was test the effects of using lower power. It\n_did_ work! Who will make the first L/u contact with an HT and small beam on\nthe uplink?\n\nPlease remember this is all based on just one day of testing with a\nsatellite that is still being commissioned.\n\nFinally, don't be afraid to try whatever you might have. Hopefully some of\nthe suggestions above will aid in your success.\n\n73,\nMike, N1JEZ\nAMSAT #29649\nLocal Area Coordinator\n\"A closed mouth gathers no feet.\"\n---- \n\n",
    "attachments": []
}