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/6PPOF3NU2ISK67IBQOFIZYBCIFSAFS4X/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "6PPOF3NU2ISK67IBQOFIZYBCIFSAFS4X",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/6PPOF3NU2ISK67IBQOFIZYBCIFSAFS4X/?format=api",
    "sender": {
        "address": "john (a) papays.com",
        "mailman_id": "40c82fe75f644d01882ed3a91ae267dd",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/40c82fe75f644d01882ed3a91ae267dd/emails/?format=api"
    },
    "sender_name": "John Papay",
    "subject": "[amsat-bb]  AO-7 Mode A vs. Mode B Performance",
    "date": "2011-07-27T13:54:43Z",
    "parent": null,
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "There is a huge difference in signal quality between\nMode A and Mode B on AO-7.  I've been working Europe on\nMode A days and have found that the audio quality is\nexcellent.  I've experimented with higher power levels\nto see how the transponder performs and have found that\nit can handle the highest power levels on the uplink\nwithout fm'ing, distorting or creating images across\nthe passband.  Of course it is harder to hear with severe\nfading on a horizontal beam antenna, but it is very usable.\n\nThis morning there were three French stations on in Mode A.\nF6FLE was pounding away on CW and loud.  But there was no\napparent degradation of the other voice stations using the\ntransponder at the same time.  Strong CW on Mode B just kills\nvoice readability and strength on other stations.  No images\nwere heard, the passband was quiet except for other ham radio\ntransmissions.\n\nI have several antennas for 10m.  The one I use for Europe\nis a 5 element beam at 120'.  It can see the horizon in all\ndirections and can hear AO-7 when it is below the horizon.\nFor higher elevations I use a single element at about 15 feet.\n\nThe Mode B transponder never sounds very good.  And it seems\nto be in a power limited situation even when there are no\nham radio transmissions in the passband.  What you do hear is\nall kinds of noise and I suspect this noise is the culprit in\nrobbing all of the available power to run the transmitter.  The\nnoise moves and is probably being received from ground sources,\nhence the apparent doppler.  User stations sound choppy even when\nrunning minimal power.  When you run more power, signals FM and\nimages are heard within the passband.  The question is what is\nthe source of all the crud that AO-7 is hearing in Mode B?  After\nall, 432 is supposed to be used for weak signal operation and should be\nvery quiet.  Are there issues within the satellite that contribute\nto this?\n\nIf you were a user of AO-7 back in the 70's, what was Mode B like\nback then?  Of course it had a better power source when the batteries\nwere still functional, but was the signal/audio quality much better?\nDid it FM and was the audio choppy?\n\nWe are very fortunate to have AO-7 regardless of the performance issues.\nIt is challenging to work at low elevations but the payoff is worth it.\nWhat we would really appreciate here in North America is more activity\nfrom Europe on the passes that reach the across the Atlantic.  Last week\nI had a qso with IK8YSS in Mode B, 7554KM.  I have seen his callsign in\nthe AO-7 logbook for a long time and finally we had a mutual window with\ngood conditions.  LA4FPA/p was on yesterday as promised from JP22.  AO-7\nmight not be the HEO that many wish we had, but it is the highest bird\nwe have right now.  Let's use it while we still have it.\n\n73,\nJohn K8YSE\n\n",
    "attachments": []
}