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GET /hyperkitty/api/list/[email protected]/email/AFHDGBEIONECAIGTKGGLUDFWHLWCAHKP/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/AFHDGBEIONECAIGTKGGLUDFWHLWCAHKP/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "A7394096EB2548ADAE503E030C5CDF43@KC6UQH", "message_id_hash": "AFHDGBEIONECAIGTKGGLUDFWHLWCAHKP", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/KUH6E3VF5G5HT2DXJNNMFUXOR57OMV2V/?format=api", "sender": { "address": "kc6uqh (a) cox.net", "mailman_id": "d9201820d18047e4a2772c86bda5e111", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/d9201820d18047e4a2772c86bda5e111/emails/?format=api" }, "sender_name": "Art McBride", "subject": "[amsat-bb] Re: Diplexer", "date": "2011-04-10T02:53:29Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/SZ3KPL4SB4QWXFQQDHLU7SDVFDIBMTHV/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/DODYVMNAEMDVYT5MZFLLJSP3LXL2WXS4/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Andrew,\nBoth Duplexer and Diplexer allow for transmit and receive at the same time.\n\nA duplexer, as used on a 2 meter repeater has an extremely narrow filter\nallowing transmit on IE: 146.000 MHz and receive on 146.600 MHz. They\ntypically use cavity resonators, each cavity is 30\" tall and 7-10\" in\ndiameter and it takes 6 of them to make it work well. They must be tuned to\nthe repeater transmit and receive frequencies. \n\nA Diplexer is a small box with two filters allowing you to transmit on two\nbands, receive on two bands, or transmit on one band and receive on the\nother band at the same time. The diplexer keeps the bands separate to\nprevent damage to the equipment on the other band.\n\nAlso there exists a Triplexer which is the same as a Diplexer but it\nsupports three bands. I have one here for 2M, 70cm, and 23cm. I use it on a\ntriband base antenna with a Kenwood TM 741A \n\nA Diplexer or Triplexer can be used to connect antenna connectors of radios\non different bands to a common coax, three antennas to a common coax or both\nto use one run of coax for two or more bands. \n\nThe Circulator mentioned for the radar is different from the Duplexer and\ndiplexer in that it allows the receiver and transmitter to be connected to\nthe antenna while the transmitter is operating. There are T/R and anti T/R\nswitches to prevent damage to the radar receiver during transmit and reflect\nreceive signals that reach the transmitter to the receiver. This is a pulse\necho system so receiver and Transmitter never function at the same time but\nrequire a fast antenna switching time. A typical marine radar, switches from\nTransmit to receive in 150 nS resulting in ~300 yards of \"blindness\"\nmeasured from the antenna to the first target the radar can see. \n\n\nI hope this clarifies the differences.\nArt,\nKC6UQH\n\n \n-----Original Message-----\nFrom: Andrew Rich [mailto:[email protected]] \nSent: Saturday, April 09, 2011 1:39 PM\nTo: [email protected]; 'i8cvs'; 'Amsat - BBs'; 'Anthony Monteiro'\nSubject: Re: [amsat-bb] Re: Diplexer\n\nDU = TX RX\nDI = RX\n----- Original Message ----- \nFrom: \"Art McBride\" <[email protected]>\nTo: \"'i8cvs'\" <[email protected]>; \"'Amsat - BBs'\" <[email protected]>;\n\n\"'Anthony Monteiro'\" <[email protected]>\nSent: Sunday, April 10, 2011 6:27 AM\nSubject: [amsat-bb] Re: Diplexer\n\n\n> As I understand it,\n> A Duplexer allows for transmission and reception to take place in the same\n> band using a single band antenna.\n> A Diplexer allows for transmission and reception to take place on \n> different\n> bands using a multi-band antenna.\n>\n> Art,\n> KC6UQH\n>\n> -----Original Message-----\n> From: [email protected] [mailto:[email protected]] On\n> Behalf Of i8cvs\n> Sent: Saturday, April 09, 2011 10:35 AM\n> To: Amsat - BBs; Anthony Monteiro\n> Subject: [amsat-bb] Re: Diplexer\n>\n> ----- Original Message ----- \n> From: \"Anthony Monteiro\" <[email protected]>\n> To: <[email protected]>\n> Sent: Saturday, April 09, 2011 5:15 PM\n> Subject: [amsat-bb] Re: Diplexer\n>\n>> A \"duplexor\" is a device that allows both transmitting and\n>> receiving over the same transmission line or antenna. It\n>> may or may not be a passive device and it may or may not\n>> be frequency selective.\n>>\n>> In WWII RADAR systems, a duplexor was used to allow\n>> the transmitter and receiver on the same frequency to\n>> share the same antenna. The duplexor was a waveguide\n>> device that had special gas-filled tubes to quickly\n>> switch the signal direction.\n>>\n>> 73,\n>> Tony AA2TX\n>>\n> Hi Tony, AA2TX\n>\n> I have in my hands the Instruction Book for Radar Recognition\n> Sets AN/UPX-6 of U.S. Navy Department Bureau of Ships.\n>\n> The UPX6 is a IFF transponder on board of aicrafts and was used\n> in WWII for Identification of Friend or Foe.\n>\n> The UPX-6 can transmit from 1010-1030 MHz and receive from\n> 1090-1110 MHz and allows both transmitting and receiving over\n> the same transmission line and antenna via a circuit made of coax\n> cable RG-58/CU that the manual calls a \"DUPLEXER\" and not\n> a \"duplexor\".\n>\n> This \"duplexer\" is working on the fact that a transmission line,\n> shorted at the far end a quarter wavelenght long for the incoming\n> signal,represent infinite impedance (an open circuit) at the sending\n> end of the line.\n>\n> The UPX-6 was converted in the early 1980's to be used on 1296 MHz\n> and an interesting article written by W6NBI was published in Ham\n> Radio Magazine march 1981\n>\n> I modified it and I got 40 watt output.......not too bad for that epoch\n> time !\n>\n> Best 73\" de\n>\n> i8CVS Domenico\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> __________ Information from ESET NOD32 Antivirus, version of virus \n> signature\n> database 6027 (20110408) __________\n>\n> The message was checked by ESET NOD32 Antivirus.\n>\n> http://www.eset.com\n>\n>\n>\n>\n> __________ Information from ESET NOD32 Antivirus, version of virus \n> signature\n> database 6029 (20110409) __________\n>\n> The message was checked by ESET NOD32 Antivirus.\n>\n> http://www.eset.com\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__________ Information from ESET NOD32 Antivirus, version of virus signature\ndatabase 6029 (20110409) __________\n\nThe message was checked by ESET NOD32 Antivirus.\n\nhttp://www.eset.com\n\n\n \n\n__________ Information from ESET NOD32 Antivirus, version of virus signature\ndatabase 6029 (20110409) __________\n\nThe message was checked by ESET NOD32 Antivirus.\n\nhttp://www.eset.com\n \n\n", "attachments": [] }