Amsat needs a WIKI to store all of this valuable information for hams of the future...
Roger WA1KAT On 4/9/2011 10:53 PM, Art McBride wrote: > Andrew, > Both Duplexer and Diplexer allow for transmit and receive at the same time. > > A duplexer, as used on a 2 meter repeater has an extremely narrow filter > allowing transmit on IE: 146.000 MHz and receive on 146.600 MHz. They > typically use cavity resonators, each cavity is 30" tall and 7-10" in > diameter and it takes 6 of them to make it work well. They must be tuned to > the repeater transmit and receive frequencies. > > A Diplexer is a small box with two filters allowing you to transmit on two > bands, receive on two bands, or transmit on one band and receive on the > other band at the same time. The diplexer keeps the bands separate to > prevent damage to the equipment on the other band. > > Also there exists a Triplexer which is the same as a Diplexer but it > supports three bands. I have one here for 2M, 70cm, and 23cm. I use it on a > triband base antenna with a Kenwood TM 741A > > A Diplexer or Triplexer can be used to connect antenna connectors of radios > on different bands to a common coax, three antennas to a common coax or both > to use one run of coax for two or more bands. > > The Circulator mentioned for the radar is different from the Duplexer and > diplexer in that it allows the receiver and transmitter to be connected to > the antenna while the transmitter is operating. There are T/R and anti T/R > switches to prevent damage to the radar receiver during transmit and reflect > receive signals that reach the transmitter to the receiver. This is a pulse > echo system so receiver and Transmitter never function at the same time but > require a fast antenna switching time. A typical marine radar, switches from > Transmit to receive in 150 nS resulting in ~300 yards of "blindness" > measured from the antenna to the first target the radar can see. > > > I hope this clarifies the differences. > Art, > KC6UQH > > > -----Original Message----- > From: Andrew Rich [mailto:vk4...@tech-software.net] > Sent: Saturday, April 09, 2011 1:39 PM > To: kc6...@cox.net; 'i8cvs'; 'Amsat - BBs'; 'Anthony Monteiro' > Subject: Re: [amsat-bb] Re: Diplexer > > DU = TX RX > DI = RX > ----- Original Message ----- > From: "Art McBride"<kc6...@cox.net> > To: "'i8cvs'"<domenico.i8...@tin.it>; "'Amsat - BBs'"<amsat-bb@amsat.org>; > > "'Anthony Monteiro'"<aa...@comcast.net> > Sent: Sunday, April 10, 2011 6:27 AM > Subject: [amsat-bb] Re: Diplexer > > >> As I understand it, >> A Duplexer allows for transmission and reception to take place in the same >> band using a single band antenna. >> A Diplexer allows for transmission and reception to take place on >> different >> bands using a multi-band antenna. >> >> Art, >> KC6UQH >> >> -----Original Message----- >> From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On >> Behalf Of i8cvs >> Sent: Saturday, April 09, 2011 10:35 AM >> To: Amsat - BBs; Anthony Monteiro >> Subject: [amsat-bb] Re: Diplexer >> >> ----- Original Message ----- >> From: "Anthony Monteiro"<aa...@comcast.net> >> To:<amsat-bb@amsat.org> >> Sent: Saturday, April 09, 2011 5:15 PM >> Subject: [amsat-bb] Re: Diplexer >> >>> A "duplexor" is a device that allows both transmitting and >>> receiving over the same transmission line or antenna. It >>> may or may not be a passive device and it may or may not >>> be frequency selective. >>> >>> In WWII RADAR systems, a duplexor was used to allow >>> the transmitter and receiver on the same frequency to >>> share the same antenna. The duplexor was a waveguide >>> device that had special gas-filled tubes to quickly >>> switch the signal direction. >>> >>> 73, >>> Tony AA2TX >>> >> Hi Tony, AA2TX >> >> I have in my hands the Instruction Book for Radar Recognition >> Sets AN/UPX-6 of U.S. Navy Department Bureau of Ships. >> >> The UPX6 is a IFF transponder on board of aicrafts and was used >> in WWII for Identification of Friend or Foe. >> >> The UPX-6 can transmit from 1010-1030 MHz and receive from >> 1090-1110 MHz and allows both transmitting and receiving over >> the same transmission line and antenna via a circuit made of coax >> cable RG-58/CU that the manual calls a "DUPLEXER" and not >> a "duplexor". >> >> This "duplexer" is working on the fact that a transmission line, >> shorted at the far end a quarter wavelenght long for the incoming >> signal,represent infinite impedance (an open circuit) at the sending >> end of the line. >> >> The UPX-6 was converted in the early 1980's to be used on 1296 MHz >> and an interesting article written by W6NBI was published in Ham >> Radio Magazine march 1981 >> >> I modified it and I got 40 watt output.......not too bad for that epoch >> time ! >> >> Best 73" de >> >> i8CVS Domenico >> _______________________________________________ >> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> __________ Information from ESET NOD32 Antivirus, version of virus >> signature >> database 6027 (20110408) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.com >> >> >> >> >> __________ Information from ESET NOD32 Antivirus, version of virus >> signature >> database 6029 (20110409) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.com >> >> >> _______________________________________________ >> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 6029 (20110409) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > > __________ Information from ESET NOD32 Antivirus, version of virus signature > database 6029 (20110409) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
