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GET /hyperkitty/api/list/[email protected]/email/YFZAF7KA73YBOHZ66HNCFD25MC4UJE2G/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/YFZAF7KA73YBOHZ66HNCFD25MC4UJE2G/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "CAOsf+NR8gXiKEW6N=SiUr+pXxwGLzcjgtjvtuyhuNyroCj9H_g@mail.gmail.com", "message_id_hash": "YFZAF7KA73YBOHZ66HNCFD25MC4UJE2G", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/CGQ76XGMTNXP2X2V2W3LFEJSFKVYQHZG/?format=api", "sender": { "address": "w2hro.fn20 (a) gmail.com", "mailman_id": "56ad9360da124e679a8e571628e4a15d", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/56ad9360da124e679a8e571628e4a15d/emails/?format=api" }, "sender_name": "Paul Andrews", "subject": "Re: [amsat-bb] Geostationary & HEO Satellites", "date": "2019-02-08T23:17:27Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/VAAC74TN6Q6QVYZHFQ2TXVAGVABP2HMN/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/TXVCKUB2O5MOT3QWJK6DPTES3ZED77JM/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Yes! That delay is a problem for Internet (TCP/IP) connections. Special\nproxies are used to increase throughput.\n\nThe geosat is not even launched and the ham radio community is exchanging\ntechnics to overcome technical challenges.\n\nI was thinking of other geosat uses. A beacon in the sky for taking\nantenna patterns. A frequency reference for calibration. Verifying\nantenna G/T. Calibrating antenna AZ/EL pointing. Endless uses.\n\n\n\n\n\nOn Fri, Feb 8, 2019, 17:52 Jim Sanford <[email protected]> wrote:\n\n> Very much what I see with my satellite internet -- if I ping something,\n> I see delay between 600 - 800 msec.\n>\n> Jim\n>\n> [email protected]\n>\n>\n> On 2/8/2019 4:20 PM, Paul Andrews wrote:\n> > Simon,\n> >\n> > I spent 20 years building data circuits using geosynchronous satellites.\n> > During that time, my definition of round trip was\n> > uplink-dowlink-uplink-downlink or 4 x 150ms (plus or minus a small amount\n> > of Doppler).\n> >\n> > Yes - you're correct - the loopback delay is 300ms. But if you\n> communicate\n> > with another person on Earth, the round trip delay is 600ms.\n> >\n> > If you tell someone a joke, you won't hear the laugh until after a 600ms\n> > delay. This is only true for a good joke. Tell a bad joke and the delay\n> > will be infinite. :O\n> >\n> > 73 - Paul - W2HRO\n> >\n> >\n> >\n> >\n> > On Fri, Feb 8, 2019, 16:09 Simon Brown <[email protected]> wrote:\n> >\n> >> Paul,\n> >>\n> >> Unless there's significant latency inside the satellite, I think you're\n> >> out by a factor of two. Round trip is 2 x 40,000 km (*) = 80,000 km\n> total.\n> >> Speed of light and radio latency says we're looking at closer to 300 ms.\n> >>\n> >> (*) depending on where you are on the mother planet.\n> >>\n> >> Simon Brown, G4ELI\n> >> www.sdr-radio.com\n> >>\n> >>\n> >> -----Original Message-----\n> >> From: AMSAT-BB <[email protected]> On Behalf Of Paul Andrews\n> >> Sent: 08 February 2019 19:27\n> >> To: Les Rayburn <[email protected]>\n> >> Cc: AMSAT BB <[email protected]>\n> >> Subject: Re: [amsat-bb] Geostationary & HEO Satellites\n> >>\n> >> GEOSATs have another interesting characteristic. 600 ms round trip\n> >> delay due to the longer distance.\n> >>\n> >> Does anyone remember when MCI first started providing a discounted long\n> >> distance telephone service?\n> >>\n> >> This will make voice QSOs a little unnatural but certainly not\n> impossible.\n> >>\n> >> 73 - Paul - W2HRO\n> >>\n> >>\n> >>\n> >>\n> >>\n> >> On Fri, Feb 8, 2019 at 12:21 PM Les Rayburn <[email protected]>\n> wrote:\n> >>> I’m also a newcomer to the birds, but very excited about it. Likewise,\n> I\n> >> responded to the survey, but wanted to comment further regarding\n> >> geostationary and HEO satellites.\n> >>> In the camp of “Both, please.” The HEO birds would once again offer the\n> >> possibility of DXCC and make WAS more realistic—it also offers more\n> >> operating challenges.\n> >>> But a geostationary amateur satellite would have many interesting\n> >> benefits:\n> >>> Provide an easier introduction to satellite operation, and attract new\n> >> operators.\n> >>> Excellent tool for emergency communications during a natural disaster.\n> >>> Opportunity to experiment with microwave operations.\n> >>> The ability to enjoy satellite operation any time of the day/night. The\n> >> band is always open.\n> >>> I’m grateful for anyone who incorporates amateur radio into their\n> >> satellites, but feel that birds should include either linear, digital,\n> or\n> >> FM transponders whenever possible. Designers are asking a lot of hams\n> when\n> >> they solicit our monitoring their telemetry signals, and using amateur\n> >> spectrum for their purposes without much tangible benefit to us. My\n> opinion\n> >> only.\n> >>> It’s wonderful that they asked us. Dialogue is the key to most human\n> >> accomplishment.\n> >>>\n> >>> 73,\n> >>>\n> >>> Les Rayburn, N1LF\n> >>> Maylene, AL\n> >>> EM63nf\n> >>> AMSAT #38965, ARRL Life Member, CVHS Life Member, SVHF Member\n> >>>\n> >>>\n> >>>\n> >>>\n> >>> _______________________________________________\n> >>> Sent via [email protected]. AMSAT-NA makes this open forum available\n> >>> to all interested persons worldwide without requiring membership.\n> >>> Opinions expressed are solely those of the author, and do not reflect\n> >> the official views of AMSAT-NA.\n> >>> Not an AMSAT-NA member? Join now to support the amateur satellite\n> >> program!\n> >>> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n> >> _______________________________________________\n> >> Sent via [email protected]. AMSAT-NA makes this open forum available\n> to\n> >> all interested persons worldwide without requiring membership. Opinions\n> >> expressed are solely those of the author, and do not reflect the\n> official\n> >> views of AMSAT-NA.\n> >> Not an AMSAT-NA member? Join now to support the amateur satellite\n> program!\n> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n> >>\n> >> _______________________________________________\n> >> Sent via [email protected]. AMSAT-NA makes this open forum available\n> >> to all interested persons worldwide without requiring membership.\n> Opinions\n> >> expressed\n> >> are solely those of the author, and do not reflect the official views of\n> >> AMSAT-NA.\n> >> Not an AMSAT-NA member? Join now to support the amateur satellite\n> program!\n> >> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n> >>\n> > _______________________________________________\n> > Sent via [email protected]. AMSAT-NA makes this open forum available\n> > to all interested persons worldwide without requiring membership.\n> Opinions expressed\n> > are solely those of the author, and do not reflect the official views of\n> AMSAT-NA.\n> > Not an AMSAT-NA member? Join now to support the amateur satellite\n> program!\n> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb\n>\n> ---\n> This email has been checked for viruses by Avast antivirus software.\n> https://www.avast.com/antivirus\n>\n> _______________________________________________\n> Sent via [email protected]. AMSAT-NA makes this open forum available\n> to all interested persons worldwide without requiring membership. Opinions\n> expressed\n> are solely those of the author, and do not reflect the official views of\n> 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": [] }