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GET /hyperkitty/api/list/[email protected]/email/DODYVMNAEMDVYT5MZFLLJSP3LXL2WXS4/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/DODYVMNAEMDVYT5MZFLLJSP3LXL2WXS4/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "[email protected]", "message_id_hash": "DODYVMNAEMDVYT5MZFLLJSP3LXL2WXS4", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/KUH6E3VF5G5HT2DXJNNMFUXOR57OMV2V/?format=api", "sender": { "address": "rogerkola (a) aol.com", "mailman_id": "8323dbe496014835b5bd2be9b5ff6f66", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/8323dbe496014835b5bd2be9b5ff6f66/emails/?format=api" }, "sender_name": "Roger Kolakowski", "subject": "[amsat-bb] Re: Diplexer", "date": "2011-04-10T13:07:04Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/AFHDGBEIONECAIGTKGGLUDFWHLWCAHKP/?format=api", "children": [ "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/3IARQLC54LFGNHKKTT2CZRDGG4W7JDHQ/?format=api" ], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Amsat needs a WIKI to store all of this valuable information for hams of \nthe future...\n\nRoger\nWA1KAT\n\nOn 4/9/2011 10:53 PM, Art McBride wrote:\n> Andrew,\n> Both Duplexer and Diplexer allow for transmit and receive at the same time.\n>\n> A duplexer, as used on a 2 meter repeater has an extremely narrow filter\n> allowing transmit on IE: 146.000 MHz and receive on 146.600 MHz. They\n> typically use cavity resonators, each cavity is 30\" tall and 7-10\" in\n> diameter and it takes 6 of them to make it work well. They must be tuned to\n> the repeater transmit and receive frequencies.\n>\n> A Diplexer is a small box with two filters allowing you to transmit on two\n> bands, receive on two bands, or transmit on one band and receive on the\n> other band at the same time. The diplexer keeps the bands separate to\n> prevent damage to the equipment on the other band.\n>\n> Also there exists a Triplexer which is the same as a Diplexer but it\n> supports three bands. I have one here for 2M, 70cm, and 23cm. I use it on a\n> triband base antenna with a Kenwood TM 741A\n>\n> A Diplexer or Triplexer can be used to connect antenna connectors of radios\n> on different bands to a common coax, three antennas to a common coax or both\n> to use one run of coax for two or more bands.\n>\n> The Circulator mentioned for the radar is different from the Duplexer and\n> diplexer in that it allows the receiver and transmitter to be connected to\n> the antenna while the transmitter is operating. There are T/R and anti T/R\n> switches to prevent damage to the radar receiver during transmit and reflect\n> receive signals that reach the transmitter to the receiver. This is a pulse\n> echo system so receiver and Transmitter never function at the same time but\n> require a fast antenna switching time. A typical marine radar, switches from\n> Transmit to receive in 150 nS resulting in ~300 yards of \"blindness\"\n> measured from the antenna to the first target the radar can see.\n>\n>\n> I hope this clarifies the differences.\n> Art,\n> KC6UQH\n>\n>\n> -----Original Message-----\n> From: Andrew Rich [mailto:[email protected]]\n> Sent: Saturday, April 09, 2011 1:39 PM\n> To: [email protected]; 'i8cvs'; 'Amsat - BBs'; 'Anthony Monteiro'\n> Subject: Re: [amsat-bb] Re: Diplexer\n>\n> DU = TX RX\n> DI = RX\n> ----- Original Message -----\n> From: \"Art McBride\"<[email protected]>\n> To: \"'i8cvs'\"<[email protected]>; \"'Amsat - BBs'\"<[email protected]>;\n>\n> \"'Anthony Monteiro'\"<[email protected]>\n> Sent: Sunday, April 10, 2011 6:27 AM\n> Subject: [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> __________ Information from ESET NOD32 Antivirus, version of virus 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>\n> __________ Information from ESET NOD32 Antivirus, version of virus 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", "attachments": [] }