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#1
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I suspect that there is a big misunderstanding of TERMS, going on here.
Definitions are being misused on both sides...... Lets get the TERMS Fixed and Understood first. Transmitter = Rf Source that has an impedance of 50 Ohms Transmission Line = Coaxial Feedline between Transmitter and Antenna Tuner. Antenna Tuner = Device that matches impedance of it's input (50 Ohms) to that of the antenna that connects to the tuners output. Antenna = Effectivly a wire, or pipe, or other conducting structure used to radiate RF Energy supplied by the Transmitter to the feedline. NOW that we have these definitions settled, Please continue the discussion. Bruce in alaska -- add a 2 before @ |
#2
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I think we all kind of sort of knew this Bruce.
Doug "Bruce in Alaska" wrote in message ... I suspect that there is a big misunderstanding of TERMS, going on here. Definitions are being misused on both sides...... Lets get the TERMS Fixed and Understood first. Transmitter = Rf Source that has an impedance of 50 Ohms Transmission Line = Coaxial Feedline between Transmitter and Antenna Tuner. Antenna Tuner = Device that matches impedance of it's input (50 Ohms) to that of the antenna that connects to the tuners output. Antenna = Effectivly a wire, or pipe, or other conducting structure used to radiate RF Energy supplied by the Transmitter to the feedline. NOW that we have these definitions settled, Please continue the discussion. Bruce in alaska -- add a 2 before @ |
#3
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In article ,
"Doug Dotson" wrote: I think we all kind of sort of knew this Bruce. Doug "Bruce in Alaska" wrote in message ... I suspect that there is a big misunderstanding of TERMS, going on here. Definitions are being misused on both sides...... Lets get the TERMS Fixed and Understood first. Transmitter = Rf Source that has an impedance of 50 Ohms Transmission Line = Coaxial Feedline between Transmitter and Antenna Tuner. Antenna Tuner = Device that matches impedance of it's input (50 Ohms) to that of the antenna that connects to the tuners output. Antenna = Effectivly a wire, or pipe, or other conducting structure used to radiate RF Energy supplied by the Transmitter to the feedline. NOW that we have these definitions settled, Please continue the discussion. Bruce in alaska -- add a 2 before @ Really, then why are folks talking about SWR on the Feedline as being 3:1 or sum such when the feedline in reference system above would have no SWR as it is at 50 Ohms on both ends???? TERMS are significant, and Larry, and the rest are mixing them thoughout this whole thread. Bruce in alaska -- add a 2 before @ |
#4
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TERMS are significant.
Bruce, Don't say that too loud. I've already been down that road with Jax. Ron |
#5
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One exception, in this case we are talking about an antenna tuner with
its output going to a coax line that then goes to the antenna. The antenna being something near 50 ohms but far enough from it to produce a 3:1 SWR on its feed line. So in this case we have 2 transmission lines. One between the transmitter and the tuner and one between the tuner and the antenna. Regards Gary On Fri, 21 Nov 2003 21:40:42 GMT, Bruce in Alaska wrote: I suspect that there is a big misunderstanding of TERMS, going on here. Definitions are being misused on both sides...... Lets get the TERMS Fixed and Understood first. Transmitter = Rf Source that has an impedance of 50 Ohms Transmission Line = Coaxial Feedline between Transmitter and Antenna Tuner. Antenna Tuner = Device that matches impedance of it's input (50 Ohms) to that of the antenna that connects to the tuners output. Antenna = Effectivly a wire, or pipe, or other conducting structure used to radiate RF Energy supplied by the Transmitter to the feedline. NOW that we have these definitions settled, Please continue the discussion. Bruce in alaska |
#6
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In article ,
Gary Schafer wrote: One exception, in this case we are talking about an antenna tuner with its output going to a coax line that then goes to the antenna. The antenna being something near 50 ohms but far enough from it to produce a 3:1 SWR on its feed line. So in this case we have 2 transmission lines. One between the transmitter and the tuner and one between the tuner and the antenna. Regards Gary Actually, in the "Marine Radio" context anything that connects to the High Impedance side of the tuner is considered not Feedline but part of the antenna. OK, if just call that part "Transmission Line" rather than a second feedline? this will allow discussee's to differentate between the two pieces of the reference system, and not get them confused while making their points..... Bruce in alaska -- add a 2 before @ |
#7
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On Sat, 22 Nov 2003 19:01:50 GMT, Bruce in Alaska
wrote: In article , Gary Schafer wrote: One exception, in this case we are talking about an antenna tuner with its output going to a coax line that then goes to the antenna. The antenna being something near 50 ohms but far enough from it to produce a 3:1 SWR on its feed line. So in this case we have 2 transmission lines. One between the transmitter and the tuner and one between the tuner and the antenna. Regards Gary Actually, in the "Marine Radio" context anything that connects to the High Impedance side of the tuner is considered not Feedline but part of the antenna. OK, if just call that part "Transmission Line" rather than a second feedline? this will allow discussee's to differentate between the two pieces of the reference system, and not get them confused while making their points..... Bruce in alaska Well, this thing started out as a discussion of SWR on a 50 ohm VHF feed line. Nothing to do with HF single ended antennas and associated couplers. HF got mixed in to the discussion because most are familiar with coax line antenna tuners. 50 ohm in 50 ohm or near that out. The principles are the same of course. With HF things are a little easier to manipulate to do test on than VHF. My referring to "feed line" or "transmission line" are all referring to coax cable. One is synonymous with the other. I think most are using the same terms. Sorry for any confusion. Regards Gary |
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