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/3JDJYYTILFK3Q6VDXX3N4TNXOXBHVMLE/?format=api",
    "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api",
    "message_id": "[email protected]",
    "message_id_hash": "3JDJYYTILFK3Q6VDXX3N4TNXOXBHVMLE",
    "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/HGP5T6QCUVJZFAS2MKB7UR4XMT22GX7Q/?format=api",
    "sender": {
        "address": "K3IO (a) verizon.net",
        "mailman_id": "79a9b3ddaa4b44baae47f92374974ac4",
        "emails": "https://mailman.amsat.org/hyperkitty/api/sender/79a9b3ddaa4b44baae47f92374974ac4/emails/?format=api"
    },
    "sender_name": "Tom Clark, K3IO",
    "subject": "[eagle] Re: 2 Meter amplifier",
    "date": "2006-08-19T04:28:10Z",
    "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ZWTFHWT4SOEZEHCWHEK4QWZMHE6ACZVR/?format=api",
    "children": [],
    "votes": {
        "likes": 0,
        "dislikes": 0,
        "status": "neutral"
    },
    "content": "Dick Jansson-rr wrote:\n> Tom has an intesting suggestion of the 3x amplifiers/antennas. I have\n> been suggesting this antenna configuration as I just take the P3C\n> hardware and use it! Please help my poor brain understand how this gets\n> the desired RHCP? Is is just the three rotationally oriented antennas?\n>\n> Dick Jansson\n> ---------------------------\n> [email protected]\n> ---------------------------\n>   \nDick -- if you have 3 antennas at 0º,120º and 240º, you can make them be\ncircularly polarized by feeding them the same RF signal, but at relate\nphases of 0º,120º and 240º (or 0º,-120º and -240º which is equivalent to\n0º, 240º and 120º, i.e. swapping any two of the three, to get the\nopposite sense of circular). This is completely analogous to taking two\nelements 90º apart and feeding them in phase quadrature.\n\nOf course, since the elements do not have their centers at the same\nphysical point, the polarization purity degrades off-axis.\n\nFYI -- P3A, P3B=AO-10 and P3C=AO-13 all had 2M antennas sticking out the\nthree tips of the star and were fed in just this way. Of course, AO-10's\npolarization was screwed up when the launcher came up and \"bumped\" the\nsatellite just after separation. [I did the mathematical simulation of\nthe \"half ZL-special\" for Karl as we were building P3A. That was back in\nthe minicomputer fortrash-4 era. Because interactive graphics were\nunknown, the simulation was an inch-thick pile of computer paper.]\n\nMy suggestion was that we basically that, if we had 3 amplifiers we\ncould do the 0º/120º/240º phase split at low level, avoiding the \"cost\"\nof the inevitable losses in the 3-way power splitter that would be\nnecessary if we did the split at the amplifier output. And we would have\nsimple built-in redundancy too. As Bob pointed out, this might be too\ncomplicated for the DSP HELAPS to deal with.\n\n73, Tom\n\n",
    "attachments": []
}