Email Detail

HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/CMTMNAP24YUHIUUPTOXY2Z2NPLW4E2OK/",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/",
    "message_id": "001201c88897$039cb520$6400a8c0@sparkys",
    "message_id_hash": "CMTMNAP24YUHIUUPTOXY2Z2NPLW4E2OK",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/Q64EVZFWACNNAG4GRTHPQTJGRVMUF62M/",
    "sender": {
        "address": "sparkycivic (a) shaw.ca",
        "mailman_id": null,
        "emails": null
    },
    "sender_name": "Auke de Jong",
    "subject": "[amsat-bb] Re: Help with AO-16 and \"reverse tracking\"",
    "date": "2008-03-18T01:25:55Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/Q64EVZFWACNNAG4GRTHPQTJGRVMUF62M/",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "By the sounds of it, you'll just need to get some practice tuning for \ndoppler on the AO-16 downlink.  For this sat, it is not even necessary to \nuse doppler correction for your transmitter, but the FM might sound a little \nclearer, if you do.  No need to make things harder than they need to when \nyo're just getting started!\n\nYou can use either LSB or USB for listening to AO-16, but they will sound \nvery different.  listening to LSB with no doppler-correction causes tones to \ngo UP  in frequency as the sat passes, where they go DOWN when using USB. \nEither way, your receiver should be tuning downward all throughout the pass.\n\nYou will have to manually center your receiver before applying \ndoppler-correction as you will need to be within 100Hz of the actual signal \nto hear the audio correctly.  The computer can't get it fine enough on it's \nown.  Also, of note, the speed of the doppler-shift is orders-of-magnitude \nfaster while the satellite is directly overhead, compared to when it is \naproaching or receding.  This is less-pronounced when the satellite pass is \nnot directly overhead, but accross your horizon, and is much easier to track \non these lower passes.\n\nI have no automated doppler-correction, so I can only suggest what works for \nme... AO-16, when not in use, sends a constant tone.  You can use this tone \nto center your receiver at first, or if you get lost during the pass.  Just \nset your receiver to USB, and then look for the tone.  The tone should be \naround 30-60 Hz in order for the audio to be heard.  I think you will find \nthat you can hear yourself talking when this tone is anywhere below 60Hz. \nYou can test your computer's doppler-correction too, by seeing how well it \nfollows this tone during a quiet pass. If you have only basic antennas, you \nwon't need to send any more than 20 watts to hear yourself, unless, maybe if \nit's almost directly overhead and you're using vertical-omni's.  With better \nantennas, you might as well just crank your power all the way down, this is \na VERY sensitive satellite!  One last thing: the tone will shift, or \ndisappear completely when you key your transmitter -it's a nice clue that \nthe sat is hearing you, when this happens on-cue.\n\nEnjoy!\n\n73's\nAuke\nVE6PWN\nDO33go\n\n\n----- Original Message ----- \nFrom: \"Rick Mann\" <[email protected]>\nTo: \"AMSAT-BB Org\" <[email protected]>\nSent: Monday, March 17, 2008 5:13 PM\nSubject: [amsat-bb] Help with AO-16 and \"reverse tracking\"\n\n\n> Hi. I'm pretty new to all this. I've had one successful contact in my\n> life (with ISS, no less!), but I decided last night to try AO-16. I\n> have an ICOM IC-910H. I put it into satellite mode, and set it up to\n> receive LSB/USB on 437.0260 MHz, and transmit FM on 145.9200 MHz.\n>\n> One thing the IC-910H instructions said to do is transmit a tone (like\n> a whistle) and be sure one can receive that. After listening for some\n> time (to a nearly overhead pass), at 5am, I tried doing that. Now, I\n> *think* I heard myself, but a weird thing was if my whistle tone got\n> lower in pitch it sounded higher. Not sure if that was just my\n> imagination.\n>\n> In any case, MacDoppler seemed to be changing frequencies differently\n> for transmit vs. receive. The 910H's manual talks about reverse\n> tracking, where doppler on receive goes up while it goes down on\n> transmit.\n>\n> Could someone clarify these things for me? Why would they be different?\n>\n> Thanks!\n>\n> -- \n> Rick\n>\n> _______________________________________________\n> Sent via [email protected]. Opinions expressed are those of the author.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n>\n>\n> -- \n> No virus found in this incoming message.\n> Checked by AVG.\n> Version: 7.5.519 / Virus Database: 269.21.7/1332 - Release Date: 3/17/2008 \n> 10:48 AM\n>\n> \n\n",
    "attachments": []
}