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{
    "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/NRCFB6G6ZPO6RLDKD4UR2N6XPGXFECNC/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "CAAJiE8NKj0JY-fP8XTKZvabepk5vTRi2o6oO6hch5r8s+4kj2A@mail.gmail.com",
    "message_id_hash": "NRCFB6G6ZPO6RLDKD4UR2N6XPGXFECNC",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/IIDM2QB42ZR36XPYEA5CHYFFM3YIM4HY/?format=api",
    "sender": {
        "address": "kb2ysi (a) gmail.com",
        "mailman_id": "1ea455b723224992934ae02082411602",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/1ea455b723224992934ae02082411602/emails/?format=api"
    },
    "sender_name": "Don KB2YSI",
    "subject": "Re: [amsat-bb] Mount Carmel HS ARC marine buoy deployed and\ttransmitting",
    "date": "2020-07-17T00:12:50Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/NDRZVGBOY7F6XMYFFT4GGICTES2YF4XY/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "That is a really cool sounding project and thank you for sharing your\nprocess!\n\nOn Thu, Jul 16, 2020, 19:50 Greg via AMSAT-BB <[email protected]> wrote:\n\n> Great idea and thanks for sharing the technical details.\n>\n> Greg\n> N3MVF\n>\n> On Jul 16, 2020, at 7:20 PM, GEO Badger via AMSAT-BB <[email protected]>\n> wrote:\n>\n> Very cool Phil.. Thanks for sharing that.\n> As an ex-employee of MBARI, I can tell you that we threw a lot of stuff in\n> the water that took more development time and cost than yours with similar\n> results.\n> ---\n> Ciao baby, catch you on the flip side\n> 73 de W3AB/GEO\n>\n> http://www.w3ab.org\n>\n> You can say \"over\", you can say \"out\", you just can't say \"over and out\".\n>\n>    On Thursday, July 16, 2020, 03:48:27 PM PDT, Phil Karn via AMSAT-BB <\n> [email protected]> wrote:\n>\n> Over the past year, Randy, KQ6RS and I have mentored the MCHSARC in\n> designing and constructing a simple marine buoy that was deployed from\n> the R/V Sally Ride this morning about 700 km off the coast of southern\n> California. It is up and transmitting WSPR on 20m using the callsign\n> KQ6RS, and is being received all over the US and into Canada and Brazil.\n>\n> The electronics is the 20m WSPR version of the WB8ELK \"pico tracker\"\n> that has been flown quite a few times (including by us) on long duration\n> balloons. We removed the solar panels and substituted 21 ordinary\n> alkaline D-cells wired to supply 4.5V. We estimate battery lifetime will\n> be 6 months.\n>\n> The basic design was inspired by Bob, WB4APR, at the US Naval Academy.\n> Physically, the buoy is just a 5' section of 4\" PVC pipe, ballasted at\n> one end to float vertically in the water. The top is closed by a sewer\n> pressure test plug I found at Home Depot; it has a bolt in the center\n> that acts as a convenient feed-through and mounting point for the\n> antenna, a stainless steel CB whip with a matching network designed,\n> tested and carefully tuned by Randy. We use the sea as a counterpoise,\n> but to avoid direct metal/seawater contact we lined the inside of the\n> pipe with copper tape to form a capacitive connection. We probably spent\n> too much time on this; Randy even modeled the electrical fields in the\n> seawater with a professional RF analysis package.\n>\n> In our first flotation tests in Randy's swimming pool we found that the\n> ballasted pipe, by itself, was remarkably stable in pitch, roll, sway\n> and surge but oscillated a lot in heave (up and down). To damp this\n> Randy added cross arms at the water line to add drag in the vertical\n> direction. (It wasn't our intent to mimic a religious icon but that's\n> where the physics went.) Tuning the antenna required sea water, so Randy\n> did it from a dock on Mission Bay here in San Diego.\n>\n> We tried to make this thing as rugged as we could. (My favorite saying\n> to the students was that the sea *always* wins in the end, but we can\n> delay that long enough to be useful.) Everything inside is held in place\n> with epoxy or polyurethane foam. Randy reinforced the sewer plug with a\n> PVC end cap with a hole cut in the center. Although the antenna is\n> stainless steel, Randy covered it with a type of heatshrink with a\n> waterproofing compound inside. Activation was by removing an external\n> magnet placed over a parallel pair of normally closed magnetic reed\n> switches. (Using two instead of one was my idea.) We even argued how to\n> guard against the crew forgetting to remove the magnet before\n> deployment. Randy found some adhesive that would dissolve and let the\n> magnet fall away; I suggested a big REMOVE BEFORE FLIGHT tag and a float\n> that would pull it away if it was tossed into the water.\n>\n> That left the problem of deployment. We couldn't just drop it close to\n> the coast because it would quickly wash back up on the beach. We needed\n> a boat ride. We were originally going on a NOAA vessel in April, but\n> that trip was cancelled due to the pandemic. Randy secured a trip on the\n> R/V Sally Ride, a research ship operated by Scripps Institute of\n> Oceanography and home ported here in San Diego.\n>\n> This map shows the \"lawn mowing\" pattern they follow to measure and\n> sample sea water off southern California. We were deployed early this\n> morning at the most southwestern point shown here:\n>\n> https://calcofi.org/cruises/2020-cruises/calcofi-2007sr.html\n>\n> First report was at 12:52:30 UTC this morning from 29 51.25N, 123\n> 37.50W. That's grid square CL89eu, which I figure is pretty rare for\n> grid hunters. The current carried us east into CL89fu at 20:32:30. This\n> is a little surprising since we thought the currents in that area are to\n> the southwest. But that's why you do science!\n>\n> You can track us on aprs.fi here:\n>\n> https://aprs.fi/#!call=a%2FKQ6RS-1&others=1&timerange=604800&tail=3600\n>\n> We also show up on wsprnet.org\n>\n> http://wsprnet.org/drupal/wsprnet/map\n>\n> Because of the funky way Bill encodes position in WSPR (which was never\n> designed for this), you'll see some weird-looking callsigns (like\n> 0W7NFU) in addition to KQ6RS.\n>\n> This was our first buoy, just to get our feet wet (ha ha). Now to think\n> about what we want to put in our *second* buoy. Two-way links, satellite\n> tracking, sensors, the works. But remember the \"second system\" effect...\n>\n> 73, Phil\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. 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: https://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. 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: https://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. 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: https://www.amsat.org/mailman/listinfo/amsat-bb\n>\n",
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