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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/E4PYNV7ILKMKBTIYAONJMXBTFE24B3JJ/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "EAADB1D6463D459D904A2D2DF08B9737@QUECREEK", "message_id_hash": "E4PYNV7ILKMKBTIYAONJMXBTFE24B3JJ", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/JAHMCBZOJLINBANTZA3RYJQWNO5JU6JJ/?format=api", "sender": { "address": "wb3jfs (a) cox.net", "mailman_id": "bdfc678d05af4f3f96c14d823fd3fbcf", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/bdfc678d05af4f3f96c14d823fd3fbcf/emails/?format=api" }, "sender_name": "Jeff Yanko", "subject": "[amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE", "date": "2009-10-03T06:26:38Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/ZD6ZM3CZVYOIVZE5NQ27VHGYJDBNC7CG/?format=api", "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Could very well be.\n\n73,\n\nJeff WB3JFS\n\n\n----- Original Message ----- \nFrom: \"Gary \"Joe\" Mayfield\" <[email protected]>\nTo: \"'Jeff Yanko'\" <[email protected]>; \"'Charles Suprin'\" <[email protected]>\nCc: \"'Joe'\" <[email protected]>; \"'AMSAT-BB'\" <[email protected]>\nSent: Friday, October 02, 2009 6:27 PM\nSubject: RE: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE\n\n\n> We are missing the easy answer. He had diplexer that was off spec. It\n> happens.\n>\n> 73,\n> Joe kk0sd\n>\n> -----Original Message-----\n> From: [email protected] [mailto:[email protected]] On\n> Behalf Of Jeff Yanko\n> Sent: Thursday, October 01, 2009 4:28 PM\n> To: Charles Suprin\n> Cc: Joe; AMSAT-BB; Gary \"Joe\" Mayfield\n> Subject: [amsat-bb] Re: Arrow antenna reconfiguration results - UPDATE\n>\n> Hi Charles and the group,\n>\n> FB on the numbers. Interesting to say the least and thanks for taking the\n> time to look further into this topic.\n>\n> Questions? I have a few after looking at these numbers and performing \n> more\n> observations.\n>\n> First, are you testing just the diplexer and not the diplexer and the\n> antenna combined? This could result in an overall number and not just the\n> diplexer alone. How could there be a large discrepency between \n> preliminary\n> reports, 2.65dB and .5dB now. Could be equipment calibration, human \n> error,\n> etc. from previously tested, or attempted testing of the device. I don't\n> believe any improvements have been made to the Arrow diplexer, but who\n> knows?\n>\n> Second, I switched back to the Arrow diplexer and made another comparison\n> with the Comet diplexer. Again, no comparison, the Comet outperformed. \n> Why\n> would this happen if the two are pretty close to one another in numbers.\n> The Comet has .25db loss at VHF and .26 at UHF.\n>\n> Third, with the Arrow diplexer I wouldn't begin to receive the birds until\n> almost 3 minutes after AOS, with the Comet diplexer a minute to 1.5 \n> minutes\n> after AOS. Yes, watch calibrated to WWV and multiple times of acquiring \n> the\n> birds. I've tried both setups with the HT and D710 and they both show the\n> same results respectively, Arrow diplexer vs. Comet diplexer. The antenna\n> and coax remain the same, the difference, the diplexer. May not be test \n> lab\n> quality but something is proving itself. What is it?\n>\n> Finally, is it just my Arrow diplexer? Doesn't appear to be shorted or \n> any\n> defects to it. Actually looks great and assembled very well. I've\n> encountered others saying the same thing. However, a very noticable\n> difference to the overall performance.\n>\n>\n> 73,\n>\n> Jeff 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 - \n> 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\n> VHF and around half a dB at UHF. I checked the calibration and that was\n> within 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\n> Arrow\n> diplexer using a vector/network analyzer. It will be interesting to \n> say\n> the\n> least. There were preliminary reports saying the device had a loss\n> anywhere\n> from 2.65 to 2.80dB. That's close enough to 3dB which is technically\n> half\n> power loss. Add the loss of a short piece of coax and it will \n> certainly\n> be\n> pushed over the 3dB line.\n>\n> If I recall correctly, cross polarity is also a 3dB loss. I have\n> noticed\n> that when I rotate the antenna I might get a stronger downlink but I\n> never\n> lose it when I rotate it back. Before, when I would do that it would\n> drop\n> once I rotated in either direction from the peak signal. Basically \n> what\n> is\n> going on is the lossy device is removed and replaced with a more\n> efficient\n> one, that extra net gain you just boosted now shows how the system on\n> the\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\n> does 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\n> segments,\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\n> each.\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\n> Arrow\n> >>>Antenna between the Arrow diplexer and the new diplexer. I was\n> wondering\n> >>>\n> >>>\n> >>if\n> >>\n> >>\n> >>>this was going to happen and it did. The reason that this happened\n> was\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\n> signal.\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\n> degrees\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\n> makes\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\n> much\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\n> author.\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\n> author.\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> >>Sent via [email protected]. Opinions expressed are those of the\n> author.\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> >>\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\n> author.\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> Sent via [email protected]. Opinions expressed are those of the \n> author.\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> Sent via [email protected]. Opinions expressed are those of the author.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n>\n> \n\n\n", "attachments": [] }