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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ZD6ZM3CZVYOIVZE5NQ27VHGYJDBNC7CG/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "[email protected]", "message_id_hash": "ZD6ZM3CZVYOIVZE5NQ27VHGYJDBNC7CG", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/JAHMCBZOJLINBANTZA3RYJQWNO5JU6JJ/?format=api", "sender": { "address": "gary_mayfield (a) hotmail.com", "mailman_id": "fe442cdc520e4857a9168b9182091295", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/fe442cdc520e4857a9168b9182091295/emails/?format=api" }, "sender_name": "Gary \"Joe\" Mayfield", "subject": "[amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE", "date": "2009-10-03T01:27:13Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/MTNRQWTJBUFVUJTRN5HUX4TFFXDCSH7O/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/E4PYNV7ILKMKBTIYAONJMXBTFE24B3JJ/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "We are missing the easy answer. He had diplexer that was off spec. It\nhappens.\n\n73,\nJoe kk0sd\n\n-----Original Message-----\nFrom: [email protected] [mailto:[email protected]] On\nBehalf Of Jeff Yanko\nSent: Thursday, October 01, 2009 4:28 PM\nTo: Charles Suprin\nCc: Joe; AMSAT-BB; Gary \"Joe\" Mayfield\nSubject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE\n\nHi Charles and the group,\n\nFB on the numbers. Interesting to say the least and thanks for taking the\ntime to look further into this topic. \n\nQuestions? I have a few after looking at these numbers and performing more\nobservations.\n \nFirst, are you testing just the diplexer and not the diplexer and the\nantenna combined? This could result in an overall number and not just the\ndiplexer alone. How could there be a large discrepency between preliminary\nreports, 2.65dB and .5dB now. Could be equipment calibration, human error,\netc. from previously tested, or attempted testing of the device. I don't\nbelieve any improvements have been made to the Arrow diplexer, but who\nknows?\n \nSecond, I switched back to the Arrow diplexer and made another comparison\nwith the Comet diplexer. Again, no comparison, the Comet outperformed. Why\nwould this happen if the two are pretty close to one another in numbers.\nThe Comet has .25db loss at VHF and .26 at UHF.\n \nThird, with the Arrow diplexer I wouldn't begin to receive the birds until\nalmost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 minutes\nafter AOS. Yes, watch calibrated to WWV and multiple times of acquiring the\nbirds. I've tried both setups with the HT and D710 and they both show the\nsame results respectively, Arrow diplexer vs. Comet diplexer. The antenna\nand coax remain the same, the difference, the diplexer. May not be test lab\nquality but something is proving itself. What is it? \n\nFinally, is it just my Arrow diplexer? Doesn't appear to be shorted or any\ndefects to it. Actually looks great and assembled very well. I've\nencountered others saying the same thing. However, a very noticable\ndifference to the overall performance. \n\n\n73,\n\nJeff WB3JFS \n\n\n ----- Original Message ----- \n From: Charles Suprin \n To: Jeff Yanko \n Cc: Joe ; Gary \"Joe\" Mayfield ; AMSAT-BB \n Sent: Thursday, October 01, 2009 1:09 PM\n Subject: Re: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE\n\n\n Howdy Jeff,\n\n Someone asked and here we go. A file attachment follows. \n\n Actually the diplexer looks pretty good. Less than half a db of loss at\nVHF and around half a dB at UHF. I checked the calibration and that was\nwithin tenth of a dB over the entire range.\n\n Any questions. \n\n Charles\n AA1VS\n\n\n On Sat, Sep 26, 2009 at 6:26 AM, Jeff Yanko <[email protected]> wrote:\n\n Hi Joe and all,\n\n I doubt if the Arrow diplexer has 20dB of loss. If it did, we'd never\n receive a signal! :)\n\n I believe somebody here on the -bb will be performing a test on the\nArrow\n diplexer using a vector/network analyzer. It will be interesting to say\nthe\n least. There were preliminary reports saying the device had a loss\nanywhere\n from 2.65 to 2.80dB. That's close enough to 3dB which is technically\nhalf\n power loss. Add the loss of a short piece of coax and it will certainly\nbe\n pushed over the 3dB line.\n\n If I recall correctly, cross polarity is also a 3dB loss. I have\nnoticed\n that when I rotate the antenna I might get a stronger downlink but I\nnever\n lose it when I rotate it back. Before, when I would do that it would\ndrop\n once I rotated in either direction from the peak signal. Basically what\nis\n going on is the lossy device is removed and replaced with a more\nefficient\n one, that extra net gain you just boosted now shows how the system on\nthe\n antenna side of the diplexer is truly performing.\n\n I don't have an antenna analysis program to perform a test, but what\ndoes a\n 7 element 440 yagi pattern look like and what is its overall gain?\n\n What we need to do is break down the antenna configuration into 3\nsegments,\n see what their losses and gains are then combine them for the overall\n figure. The 3 segment would be the antenna, the diplexer and the coax.\n Each one will be tested individually to give an accurate number for\neach.\n\n\n\n 73,\n\n\n Jeff WB3JFS\n ----- Original Message -----\n\n From: \"Joe\" <[email protected]>\n To: \"Gary \"Joe\" Mayfield\" <[email protected]>\n Cc: \"'AMSAT-BB'\" <[email protected]>\n Sent: Friday, September 25, 2009 6:42 PM\n Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE\n\n\n\n > as in the texts below, there is something else going on here.\n >\n > That Diplexor can not be all that bad. two reasons.\n >\n > How many db down is the front to side of that antenna?\n >\n > and I can not imaging someone would sell a diplexor that has greater\n > than 20 db of losses.\n >\n > because of the statement that how criticalpolarity was with the\n > original, and now the antenna has to be nearly 90 degrees cross\n > polarized to make it drop out uhh\n >\n > that close to 30 db,\n >\n > at least 20,,\n >\n > something else is going on here\n >\n > Gary \"Joe\" Mayfield wrote:\n >\n >>>\n >>>Another issue I came across was how wide the beamwidth is of the\nArrow\n >>>Antenna between the Arrow diplexer and the new diplexer. I was\nwondering\n >>>\n >>>\n >>if\n >>\n >>\n >>>this was going to happen and it did. The reason that this happened\nwas\n >>>\n >>>\n >>with\n >>\n >>\n >>>the old diplexer, the signal attenuated so much that you had to be\n >>>pointed\n >>>right smack dab on the bird, a few degrees off and you lost the\nsignal.\n >>>Now, with the new diplexer, you can point the beam in the general\n >>>\n >>>\n >>direction\n >>\n >>\n >>>and still copy the bird. In most cases I had to turn the beam 90\ndegrees\n >>>before I completely lost the downlink! Twisting the antenna to make\n >>>polarization changes makes absolutely no difference now. This also\n >>>attributes to the fact that now I'm copying the entire pass without\n >>>\n >>>\n >>dropouts\n >>\n >>\n >>>or fades. Makes sense. What I've regained over the lossy diplexer\nmakes\n >>>\n >>>\n >>up\n >>\n >>\n >>>for any polarization differences, etc. for a better copiable signal.\n >>>\n >>>Next weekend I will have to try more passes and get a feel of how\nmuch\n >>>\n >>>\n >>this\n >>\n >>\n >>>system has changed.\n >>>\n >>>\n >>>73,\n >>>\n >>>Jeff WB3JFS\n >>>Las Vegas, NV\n >>>DM26\n >>>\n >>>\n >>>\n >>>\n >>>\n >>>\n >>>_______________________________________________\n >>>Sent via [email protected]. Opinions expressed are those of the\nauthor.\n >>>Not an AMSAT-NA member? Join now to support the amateur satellite\n >>>program!\n >>>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n >>>\n >>>\n >>>\n >>\n >>_______________________________________________\n >>Sent via [email protected]. Opinions expressed are those of the\nauthor.\n >>Not an AMSAT-NA member? Join now to support the amateur satellite\nprogram!\n >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n >>\n >>\n >>_______________________________________________\n >>Sent via [email protected]. Opinions expressed are those of the\nauthor.\n >>Not an AMSAT-NA member? Join now to support the amateur satellite\nprogram!\n >>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n >>\n >>\n >>\n \n>>------------------------------------------------------------------------\n >>\n >>\n >>No virus found in this incoming message.\n >>Checked by AVG - www.avg.com\n >>Version: 8.5.416 / Virus Database: 270.13.113/2395 - Release Date:\n >>09/25/09 17:52:00\n >>\n >>\n >>\n > _______________________________________________\n > Sent via [email protected]. Opinions expressed are those of the\nauthor.\n > Not an AMSAT-NA member? Join now to support the amateur satellite\nprogram!\n > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n >\n\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\nprogram!\n Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n\n_______________________________________________\nSent via [email protected]. Opinions expressed are those of the author.\nNot an AMSAT-NA member? Join now to support the amateur satellite program!\nSubscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n", "attachments": [] }