Article: 219481 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <9Amhf.24745$Zv5.22006@newssvr25.news.prodigy.net> Message-ID: Date: Fri, 25 Nov 2005 05:26:52 GMT Dave Heil wrote: > Cecil Moore wrote: >> I made the mistake at RS of asking for a Molex connector. > > They actually have a few of 'em, Cecil. Our area stores keep them in > metal drawers now rather than hanging them on the wall. Oh, they had them hanging on the wall but said they didn't have any. When I found them, they asked, "How do you know that's a Molex connector?" :-) Adopted from the IC-22S 30 years ago, I still use the 4-pin version for low current 12 volt power in my shack and in my pickup. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219482 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Antenna reception theory Date: Fri, 25 Nov 2005 00:46:57 -0800 Message-ID: <11odjs54affpl83@corp.supernews.com> References: Most authors explain how a wave is generated, then resort to reciprocity to explain the reception process. But a clear and simple direct explanation appears in Bailey, _TV and Other Receiving Antennas_ (pp. 141-2), of what happens when an electromagnetic wave strikes a conductor: "The second, and equally important effect [the first being reflection of much of the incident energy] is that some energy /does/ enter the outer skin of the conductor. That part of the energy, which is not reflected, must enter the conductor. The conditions at the surface of the conductor, as we have already seen, give rise to a small resultant electric vector and a large resultant magnetic vector. The presence of these at the conductor is direct evidence that power is entering the conductor. The small electric vector acts on the internal electrons of the conductor and impresses a direction force, tending to drive the electrons along the skin of the conductor in the direction of the electric vector. But from experience we know that /no/ electrons can ever be caused to move without gradually establishing their own magnetic field, and this usually takes /time/. The motion of electrons (which is electric current by definition) never takes place without the magnetic field. How, then, is the electric vector from the electromagnetic wave going to put these electrons in motion? It can only do so because the electromagnetic wave /also supplies a magnetic vector/ as well as an electric vector. And the value of this magnetic vector is exactly proportioned to supply just the right amount of magnetic field energy which the electrons require for immediate motion. Thus the electrons do not have to establish their own magnetic field, since this field is supplied by the electromagnetic wave. Hence, electromagnetic wave energy entering the conductor establishes immediate motion of electrons /along/ the conductor, the direction of motion at any instant corresponding to the direction of the electric vector. If the electric vector changes direction, the electrons will follow suit." Other posters have correctly pointed out that an antenna doesn't and can't receive a signal solely due to the E field; a time-changing E field can't exist without an accompanying time-changing H field. Roy Lewallen, W7EL Paul Taylor wrote: > Hi, > > I am looking for an explanation of how an antenna receives a signal due > to the E-field of an electromagnetic wave. > > I have looked in some books, and can understand transmission, but the > books I have looked in don't explain reception. > > I have found an explanation of how the H-field induces a signal in a loop > antenna: a changing magnetic flux will induce a current. > > But what about the E-field and a dipole antenna? I guess that the E-field > causes electrons to move in the antenna wire, because in a solid > conductor, electrons will move until the E-field inside the solid is > cancelled out? > > I have googled but having difficulty finding a good explanation. Any > pointers? > > Thanks & regards, > > Paul. > Article: 219483 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Radio Shack and my education Date: Fri, 25 Nov 2005 09:55:12 -0800 Message-ID: <11oek0b8to2mm42@corp.supernews.com> References: <43865eea$0$32203$39cecf19@news.twtelecom.net> It's interesting you mention that, Tom. I just got my Extra last month. Now, I admit I am not an electronics expert. I had to study really hard before I felt I could take the test. What was funny was actually taking the test. There were a total of six people testing. Myself and five others. Two going for Technician, two going for General, and two going for Extra (myself and one other guy I didn't know). So, I'm pounding away on the calculator and the other Extra finishes before anyone. He must have only taken ten minutes, if that. He had to of memorized the answers. Actually there were a total of three people who had to have memorized the questions. No way they could have finished so fast. Actually, I was the only one who brought a calculator, so that tells you something. What was really interesting to me was that the other Extra had now passed all the writtens, but had never passed the 5 WPM code test. So, no HF priveleges until he does that. I was licensed fifteen years ago and got up through Advanced and took the code tests. But I moved out of state and never got around to taking the Extra. Now, it's all changed and there are only three tests. Anyway, interesting experience. Rod KI7CQ Article: 219484 of rec.radio.amateur.antenna From: Allodoxaphobia Subject: Re: Radio Shack and my education Date: 25 Nov 2005 18:10:47 GMT Message-ID: References: <11ocbjrd4j4ar74@corp.supernews.com> <6Trhf.46856$Hs.45544@tornado.socal.rr.com> <438737BB.D753827A@shaw.ca> On Fri, 25 Nov 2005 16:11:28 GMT, Irv Finkleman wrote: > Phil Wheeler wrote: >> Michael wrote: >> > My son took and electronics course at Benson High School in Portland Oregon. >> > The teacher was totally clueless and just made things up as he went along. >> >> Ah yes. I attended Bensen Tech (so it was called then) in the Fall of >> 1953. We were taught to check light sockets for electricity be removing >> the bulb and putting our fingers in them. Harmless fun :-) > > I couldn't wait to be old enough to go to tech so I tried the light > socket test at home at age 7. Thus begun my lifetime love of communications > and electronics! The results of the experiments proved so valid that I never > again had the need to revalidate! I built my first light bulb at the age of 8 -- I used a test tube >from a chemistry set of mine and about 10" of bare copper wire that I found in my dad's ham shack (the original W3DHJ). Hell, it sure looked a lot like a light bulb! Then I poked it into the wall outlet in my bedroom. BIG TIME mistake! I was an Army Brat and we were living in conscripted housing in Bremerhaven, Germany at the time.... Thus began my lifetime love of of all things electronical. (-: I suppose this OT thread should be in rec.radio.amateur.homebrew. :-) Jonesy -- Marvin L Jones | jonz | W3DHJ | linux Pueblo, Colorado | @ | Jonesy | OS/2 __ 38.24N 104.55W | config.com | DM78rf | SK Article: 219485 of rec.radio.amateur.antenna From: "Ralph Mowery" References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Subject: Re: Radio Shack and my education Message-ID: Date: Fri, 25 Nov 2005 19:01:54 GMT "Rod Maupin" wrote in message news:11oek0b8to2mm42@corp.supernews.com... > It's interesting you mention that, Tom. > > I just got my Extra last month. Now, I admit I am not an electronics > expert. I had to study really hard before I felt I could take the test. > What was funny was actually taking the test. > > There were a total of six people testing. Myself and five others. Two > going for Technician, two going for General, and two going for Extra (myself > and one other guy I didn't know). So, I'm pounding away on the calculator > and the other Extra finishes before anyone. He must have only taken ten > minutes, if that. He had to of memorized the answers. Actually there were > a total of three people who had to have memorized the questions. No way > they could have finished so fast. Actually, I was the only one who brought > a calculator, so that tells you something. > > What was really interesting to me was that the other Extra had now passed > all the writtens, but had never passed the 5 WPM code test. So, no HF > priveleges until he does that. > > I was licensed fifteen years ago and got up through Advanced and took the > code tests. But I moved out of state and never got around to taking the > Extra. Now, it's all changed and there are only three tests. > > Anyway, interesting experience. > > Rod KI7CQ > Instead of studying electronics you should have been studying the qusetion and answer book. When the questions are the same as in the book , it is no use learning anything for a test. I had the tech license for about 25 years. Just did not want to take time for the code and did not care anything for the lowbands anyway. The job I had gave me some free time on the night shift so I finally decided to take in some code tapes and learn the code on company time. Went to Advanced and about a year later the Extra. I never did get a chance to look at the Q&A book. I did not need a calculator fo rthe tests. The answers are usualy broad enough you can almost guess at them and a quick check with a pencil and paper will do. I have not seen the new Extra exam but the old one was very easy compaired to the old Advanced exam. By the way, in 1972 when I took the First Class Phone license there were no calculators or Q&A books with the exect Q&As. Article: 219486 of rec.radio.amateur.antenna From: Paul Taylor Subject: Re: Antenna reception theory Date: Fri, 25 Nov 2005 19:08:54 +0000 Message-ID: References: Hi, Thanks for the replies. I also found a sentence in Joseph Carr's book, Practical Antenna Handbook second edition. On page 297: 'Large loop antennas are sensitive primarily to the electric field of the electromagnetic radio wave, but small loop antenna are primarily sensitive to the magnetic field of an EM wave.' I understand that the receiver antenna works in a reciprocal way to transmit, but if there are other descriptions out there concentrating on how antennas work at the receiving end, I would be interested to know. Regards, Paul. -- Remove _rem_ before replying by email. Article: 219487 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <438663b1$0$3759$39cecf19@news.twtelecom.net> Subject: Re: Happy Thanksgiving Date: Fri, 25 Nov 2005 14:24:42 -0500 Message-ID: <2902a$438764ff$97d56a33$4854@ALLTEL.NET> Exactly what we had for dinner... Turduken is the best eating there is! "Tom Ring" wrote in message news:438663b1$0$3759$39cecf19@news.twtelecom.net... > Fred W4JLE wrote: > > > A happy Thanksgiving to all... May your day be a joyous one with friends and > > family. > > > > 73 Fred W4JLE / NNN0AAG > > > > > > Mmmmmmmmm, Turducken.... > > tom > K0TAR > Article: 219488 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Message-ID: Date: Fri, 25 Nov 2005 19:35:07 GMT Cecil Moore wrote: > Rod Maupin wrote: > >> So, I'm pounding away on the calculator and the other Extra finishes >> before anyone. He must have only taken ten minutes, if that. He had >> to of memorized the answers. > > > Rod, I finished that trivial Extra exam in 10 minutes and > I can assure you, with a EE degree and MENSA membership, > I didn't memorize the answers. But it does happen. Back in the 20 WPM days, maybe ten years ago, one ham I know .. who was a former Navy telegraph op .. passed the written part by memorizing every Q&A. And it showed: He was a technical know-nothing. Nice guy, though. Phil Article: 219490 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Radio Shack and my education Date: Fri, 25 Nov 2005 11:41:47 -0800 Message-ID: <11oeq7qtm6m523f@corp.supernews.com> References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Well, that's impressive to me. I didn't know anything about electronics until I became a ham. I still don't know much. I know how to set up a station and how to put out a clean signal. But I don't know enough to build anything. Which is a shame. Seems like there are a lot of fun projects out there. Rod KI7CQ Article: 219491 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <11oeq7qtm6m523f@corp.supernews.com> Message-ID: Date: Fri, 25 Nov 2005 19:50:52 GMT Rod Maupin wrote: > Well, that's impressive to me. > > I didn't know anything about electronics until I became a ham. I still > don't know much. I know how to set up a station and how to put out a clean > signal. But I don't know enough to build anything. Which is a shame. > Seems like there are a lot of fun projects out there. > > Rod KI7CQ > There are. You should checkout the Elecraft website: Fun! Article: 219492 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <11ocbjrd4j4ar74@corp.supernews.com> <6Trhf.46856$Hs.45544@tornado.socal.rr.com> <438737BB.D753827A@shaw.ca> Message-ID: Date: Fri, 25 Nov 2005 21:45:07 GMT Amos Keag wrote: > Allodoxaphobia wrote: > > SNIPPED > >> >> >> I built my first light bulb at the age of 8 -- I used a test tube >> from a chemistry set of mine and about 10" of bare copper wire that >> I found in my dad's ham shack (the original W3DHJ). Hell, it sure >> looked a lot like a light bulb! Then I poked it into the wall outlet >> in my bedroom. BIG TIME mistake! I was an Army Brat and we were >> living in conscripted housing in Bremerhaven, Germany at the time.... >> Thus began my lifetime love of of all things electronical. >> >> (-: I suppose this OT thread should be in rec.radio.amateur.homebrew. >> :-) >> >> Jonesy > > > OR: rec.radio.amateur.need.insurance > Funny! Phil W7OX Article: 219493 of rec.radio.amateur.antenna From: "Old Ed" References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Subject: Re: Radio Shack and my education Message-ID: Date: Sat, 26 Nov 2005 01:01:05 GMT "Cecil Moore" wrote in message news:afJhf.20616$7h7.15873@newssvr21.news.prodigy.com... > Rod Maupin wrote: > > So, I'm pounding away on the calculator > > and the other Extra finishes before anyone. He must have only taken ten > > minutes, if that. He had to of memorized the answers. > > Rod, I finished that trivial Extra exam in 10 minutes and > I can assure you, with a EE degree and MENSA membership, > I didn't memorize the answers. > -- > 73, Cecil http://www.qsl.net/w5dxp Cecil, I'm glad you passed your Extra exam without difficulty. But I have to point out that there are many exam questions not covered in EE (e.g., band breaks and OSCAR schemes); and NONE of the exam questions are covered in MENSA. Thus at least some memory work is needed. I have three EE degrees (and could readily "qualify" for MENSA); but I nevertheless studied quite diligently for the Extra exam (2001). I was gratified to get 100%, but I readily admit taking more than 10 minutes. 73, Ed, W6LOL Article: 219494 of rec.radio.amateur.antenna From: "Ralph Mowery" References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Subject: Re: Radio Shack and my education Message-ID: <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> Date: Sat, 26 Nov 2005 02:43:08 GMT > > Instead of studying electronics you should have been studying the qusetion > > and answer book. When the questions are the same as in the book , it is no > > use learning anything for a test. > > Where do you get that, Ralph? That license isn't the final goal. It's > the beginning. If all a person wants to do is pass some test, I suppose > they could memorize Q and A. - although I might postulate that > memorizing over 800 questions for the Extra might be harder than simply > learning the material. > > Getting the license is the first goal. You have to memorize the rules to answer many of the questions. Might as well memorize the other parts too. You get your license and you can start to learn about ham radio. Sometimes the questions can be deceiving and what may be a correct answer may not be the "best" answer. As far as getting good answers about most anything at RAdio Shack or many other stores , what do you expect from someone making the wages they pay ? You do not get a salesman and electronics engineer for those wages. Try going into any store, say Wal-Mart and pick out an area and ask some specific questions about the products and see what they have to say. Chances are you will get the same dumb look and maybe a dumb answer. Article: 219495 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> Message-ID: Date: Sat, 26 Nov 2005 03:40:55 GMT Old Ed wrote: > But I have to point out that there are many exam questions not > covered in EE (e.g., band breaks and OSCAR schemes); Dang, Ed, I just developed the OSCAR schemes from first principles. ;-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219496 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: SWR again. Date: Fri, 25 Nov 2005 23:34:44 -0500 Message-ID: <11ofpdpioimdg06@corp.supernews.com> References: This is getting a bit far from antennas, but the way to know the uncertainty in knowing time is to have multiple clocks. NBS (whatever it now calls itself) has a bunch of clocks that are compared to each other. When I was young (and WWV was back East) the uncertainty indicated from multiple clocks was a few parts in ten to the eighth power. Today, that uncertainty is a few parts in ten to the 13th power! It takes multiple clocks to know the uncertainty. 73 Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net "Michael Coslo" wrote in message news:dm2gb7$1f72$1@f04n12.cac.psu.edu... > > > A man with a watch knows the time. > > A man with two watches is never sure...... > > > > - Mike KB3EIA - > Article: 219497 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Radio Shack and my education Date: Fri, 25 Nov 2005 20:34:10 -0800 Message-ID: <11ofpe5kh28mk09@corp.supernews.com> References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> Ralph Mowery wrote: > . . . > As far as getting good answers about most anything at RAdio Shack or many > other stores , what do you expect from someone making the wages they pay ? > You do not get a salesman and electronics engineer for those wages. Try > going into any store, say Wal-Mart and pick out an area and ask some > specific questions about the products and see what they have to say. > Chances are you will get the same dumb look and maybe a dumb answer. One of the reasons this is the only choice we have is that in times past, there were stores which did pay the employees enough to get people who understood the products. People would go in, get their questions answered, then go to the Wal-Marts and Radio Shacks to buy the item because it was cheaper there. We've gotten what we created and what we collectively deserve. Roy Lewallen, W7EL Article: 219498 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> <11ofpe5kh28mk09@corp.supernews.com> Message-ID: Date: Sat, 26 Nov 2005 04:43:06 GMT Roy Lewallen wrote: > Ralph Mowery wrote: > >> . . . >> As far as getting good answers about most anything at RAdio Shack or many >> other stores , what do you expect from someone making the wages they >> pay ? >> You do not get a salesman and electronics engineer for those wages. Try >> going into any store, say Wal-Mart and pick out an area and ask some >> specific questions about the products and see what they have to say. >> Chances are you will get the same dumb look and maybe a dumb answer. > > > One of the reasons this is the only choice we have is that in times > past, there were stores which did pay the employees enough to get people > who understood the products. People would go in, get their questions > answered, then go to the Wal-Marts and Radio Shacks to buy the item > because it was cheaper there. We've gotten what we created and what we > collectively deserve. > Thanks for the reminder, Roy. But that has been a long while. Phil w7ox Article: 219499 of rec.radio.amateur.antenna From: "Denton" Subject: Re: can I make this 20 meter antenna work on 30 also? Date: Fri, 25 Nov 2005 21:51:08 -0800 Message-ID: <11oftujtfb44t98@corp.supernews.com> References: <1132981239.429441.291730@g47g2000cwa.googlegroups.com> Here is one little trick I tried a couple of years ago, when I had an elevated 20 meter vertical with the feed point about 10 feet in the air with 4 16 ft radials. I fed it at the base with a 4 to 1 balun, mounted in reverse. I then ran 450 ohm twin lead to the shack with a Johnson Matchbox to tune the feeders..it worked 40 thru 10 meters (some loss on 40 but it did work there ok). If you try this..you need to do something to keep the twin lead from swinging in the wind..or the impendence will change quite a bit. wrote in message news:1132981239.429441.291730@g47g2000cwa.googlegroups.com... > All, > > I'm finally putting together a vertical antenna that I hope will work > on 20 meters. > > Soil is sandstone with occasional bits of granite, impossible to drill > into, it has to be > chiseled out with a hand pickaxe. I won't begin to tell you the agony > involved in > chipping out a 2 1/2 foot cubic hole into this stuff, but I managed to > do it. > > But in any case forget about soil conductivity, and forget about ground > rods! There > is a single ground rod courtesy of the electrical company... probably > not at good > depth for RF but it is the only game in town. > > Construction: > > The ground half of the antenna starts with 5 foot of 1 inch diameter > iron pipe, > sunk halfway into hole filled with concrete. 2 1/2 half feet of iron > pipe are exposed > above the dirt. This is connected to 10 foot of 3/4 inch copper pipe. > > > At the 12 foot level I am mounting 4 radials, 8 foot 1 1/2 inches in > length, of 1/2 inch > diameter copper pipe. I am also mounting 4 copper guy wires, same > length, that are > intended to also work as additional radials. > > The radiative half of the antenna starts with 10 foot of 3/4 copper > pipe, topped with > a 9 foot carbon fiber fishing pole. A thin copper wire of about 6 foot > 3 inches in length > will be run up the fishing pole, for a total length of 16 foot 3 > inches. I will be mounting > rope guy wires on the botttom of the radiative half. > > The ground half and radiative half are connected together with a PVC > coupler, and make > contact with each other inside the coupler via a thick styrofoam > spacer. > > Question: > > This antenna is designed to hopefully work on 20 meters. If I run a > wire of 14 feet 4 1/2 inches up the fishing pole instead of the 6 foot > 3 inches, and if I use guy wires of 12 foot 2 1/4 inches, leaving the > radial lengths unchanged: will I get a vertical that I can work on > both 30 and 20 meters? > > Thanks in advance, > > The Eternal Squire > Article: 219500 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> Message-ID: Date: Sat, 26 Nov 2005 14:44:36 GMT Mike Coslo wrote: > Ralph Mowery wrote: > >>>> Instead of studying electronics you should have been studying the >> >> >> qusetion >> >>>> and answer book. When the questions are the same as in the book , >>>> it is >> >> >> no >> >>>> use learning anything for a test. >>> >>> >>> Where do you get that, Ralph? That license isn't the final goal. It's >>> the beginning. If all a person wants to do is pass some test, I suppose >>> they could memorize Q and A. - although I might postulate that >>> memorizing over 800 questions for the Extra might be harder than simply >>> learning the material. >>> >>> >> >> >> Getting the license is the first goal. You have to memorize the rules to >> answer many of the questions. Might as well memorize the other parts >> too. >> You get your license and you can start to learn about ham radio. > > > Hmmm, I suspect that someone who wanted to learn about ham radio > would start that process during the preparations for the test. Those who > would want to memorize entire question pools probably won't be too > interested in actually learning anything both before or afterward the > memorization. As well as not too bright. > I've seen it done both ways. And I've seen "rote learners" blossom in their knowledge and breadth of the hobby after getting licensed that way. Also the opposite. Since it is a hobby, what works for the individual seems to be all that is important. Phil w7ox Article: 219501 of rec.radio.amateur.antenna Date: Sat, 26 Nov 2005 09:09:20 -0600 From: Tom Ring Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> <11ofpe5kh28mk09@corp.supernews.com> Message-ID: <43887aa0$0$32199$39cecf19@news.twtelecom.net> Roy Lewallen wrote: > > One of the reasons this is the only choice we have is that in times > past, there were stores which did pay the employees enough to get people > who understood the products. People would go in, get their questions > answered, then go to the Wal-Marts and Radio Shacks to buy the item > because it was cheaper there. We've gotten what we created and what we > collectively deserve. > > Roy Lewallen, W7EL Support your local hardware store, support your local ham store.... I have paid a slight price penalty plus state and local tax to buy from my local ham store for almost 20 years. I can also sometimes get break when I have a rig that needs fixing 3 days before a contest or trip to FL and the service wait sign says "3 weeks". Buy local if you want good service from people you know and who know you. Tom K0TAR Article: 219502 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> Message-ID: Date: Sat, 26 Nov 2005 15:14:27 GMT Phil Wheeler wrote: > I've seen it done both ways. And I've seen "rote learners" blossom in > their knowledge and breadth of the hobby after getting licensed that > way. Also the opposite. At 14 years of age in 1952, I had little choice except to mostly memorize the 90 or so general class questions and answers in The License Manual. Being an amateur radio operator is what motivated me through a EE degree and a long career in electrical engineering. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219503 of rec.radio.amateur.antenna From: "RB" Subject: is voltage balun right choice? Message-ID: Date: Sat, 26 Nov 2005 09:33:02 -0600 I've recently put up a 140' dipole fed with ladderline. My tuner is separate from my rig, and is an unbalanced unit. So, I use a balun on the tuner output to hook the ladderline to. I've been told that I should have a voltage balun in this application. I was surprised to hear this, as I expected to hear use a current balun. Is the voltage balun the right one for this application? Article: 219504 of rec.radio.amateur.antenna From: ehramm@dk3uz.ampr.org (Edmund H. Ramm) Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> <11ofpe5kh28mk09@corp.supernews.com> Message-ID: Date: Sat, 26 Nov 2005 13:58:49 GMT In <11ofpe5kh28mk09@corp.supernews.com> Roy Lewallen writes: > [...] > One of the reasons this is the only choice we have is that in times > past, there were stores which did pay the employees enough to get people > who understood the products. People would go in, get their questions > answered, then go to the Wal-Marts and Radio Shacks to buy the item > because it was cheaper there. We've gotten what we created and what we > collectively deserve. Full ACK. This el-cheapo mentality hurts economy. 73, Eddi ._._. -- e-mail: dk3uz AT darc DOT de | AMPRNET: dk3uz@db0hht.ampr.org If replying to a Usenet article, please use above e-mail address. Linux/m68k, the best U**x ever to hit an Atari! Article: 219505 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: is voltage balun right choice? References: Message-ID: Date: Sat, 26 Nov 2005 15:55:55 GMT RB wrote: > I've recently put up a 140' dipole fed with ladderline. My tuner is > separate from my rig, and is an unbalanced unit. So, I use a balun on the > tuner output to hook the ladderline to. > > I've been told that I should have a voltage balun in this application. I > was surprised to hear this, as I expected to hear use a current balun. > > Is the voltage balun the right one for this application? Only if you want your feedline currents to be unbalanced. Your antenna is a lot like the one described on my web page below that uses a 1:1 choke-current-balun and needs no conventional tuner, the most efficient configuration I could come up with. As can be seen from the current maximum point graph on my web page, ~100 feet is a good compromise length for the ladder-line for such an antenna. A lot of hams will tell you to throw up a random length of ladder-line and feed it through a 4:1 voltage balun. That's usually not good advice and often results in a poor balun function on one or more bands. If one doesn't know approximately what impedance is being seen by the balun, one cannot predict if it will function or not. The free version of EZNEC can predict the approximate impedance seen by the balun. www.eznec.com -- 73, Cecil http://www.qsl.net/w5dxp/notuner.htm Article: 219506 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> <11ofpe5kh28mk09@corp.supernews.com> Message-ID: Date: Sat, 26 Nov 2005 15:57:31 GMT Edmund H. Ramm wrote: > Full ACK. This el-cheapo mentality hurts economy. Some TV or cable station is advertising a program called: "Is Walmart good or bad for the country?" -- 73, Cecil http://www.qsl.net/w5dxp Article: 219507 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> Message-ID: Date: Sat, 26 Nov 2005 17:25:04 GMT Cecil Moore wrote: > Phil Wheeler wrote: > >> I've seen it done both ways. And I've seen "rote learners" blossom in >> their knowledge and breadth of the hobby after getting licensed that >> way. Also the opposite. > > > At 14 years of age in 1952, I had little choice except to > mostly memorize the 90 or so general class questions > and answers in The License Manual. Being an amateur radio > operator is what motivated me through a EE degree and a long > career in electrical engineering. Similar to my history. General Class at 16 in 1953. That motivated me to get (eventually) three degrees in EE. Extra Class came 40+ years later when I finally wrenched my code speed up to a reliable 20 WPM .. not that it would matter now :) 73, Phil w7ox Article: 219508 of rec.radio.amateur.antenna From: Phil Wheeler Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oek0b8to2mm42@corp.supernews.com> <0ZPhf.5587$wf.1166@newsread3.news.atl.earthlink.net> <11ofpe5kh28mk09@corp.supernews.com> Message-ID: Date: Sat, 26 Nov 2005 17:26:08 GMT Edmund H. Ramm wrote: > In <11ofpe5kh28mk09@corp.supernews.com> Roy Lewallen writes: > > >>[...] >>One of the reasons this is the only choice we have is that in times >>past, there were stores which did pay the employees enough to get people >>who understood the products. People would go in, get their questions >>answered, then go to the Wal-Marts and Radio Shacks to buy the item >>because it was cheaper there. We've gotten what we created and what we >>collectively deserve. > > > Full ACK. This el-cheapo mentality hurts economy. > Yeah .. like buying rigs made in some other country :) Article: 219509 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: 30/20 vertical? References: <1133023175.424981.104610@g43g2000cwa.googlegroups.com> Message-ID: <%w2if.33945$6e1.9744@newssvr14.news.prodigy.com> Date: Sat, 26 Nov 2005 19:17:15 GMT eternalsquire@comcast.net wrote: > If I add another 4 radials cut an eight wavelength for 30m, will it be > easier to operate on 30? Doesn't much matter if they are buried radials. I'm wondering if a short vertical with long elevated radials would result in an "off-center-fed" vertical. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219510 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: is voltage balun right choice? Date: Sat, 26 Nov 2005 20:17:16 +0000 (UTC) Message-ID: References: Cec, As an aside, there appears to be a little confusion about the various uses of baluns which arises from their uncertain perhaps misleading descriptions. Because of the way balun winding-wires are run, they are often described as transmission line transformers. There are -- Voltage Baluns, Current Baluns and Choke baluns. As I see it, Voltage Baluns have a definite voltage/impedance/turns ratio and are true impedance transformers. They may be used as either balanced-to-unbalanced windings, or be balanced-to-balanced, or be unbalanced-to-unbalanced. Balanced windings may be centre-tapped. One winding may be common to both primary and secondary windings. Choke Baluns consist of a pair of wires wound together around a ferrite core. The two wires may be of coaxial form or may consist of a twisted pair or just a pair of wires laid alongside each other. The two wires together form a transmission line of calculable impedance and loss. But a Choke Balun hss no impedance or voltage ratio. It is incorrect to refer to it as having an impedance ratio such as 1-to-1. A Choke Balun does indeed behave as an impedance transformer from one end of its line to the other. But the transformation ratio is indeterminate. The ratio depends on frequency and line length as with any other transmission line. The effects of inserting a Choke Balun between an unbalanced tuner and a balanced transmission line to the antenna can be beneficial insofar as tuner settings are concerned. But in general, the length of line on a choke balun should not exceed 1/8th or 1/10th of a wavelength at the highest frequency of use. This is not too difficult to achieve in the HF range of 1.8 or 3.5 to 30 MHz. But I do not understand what is meant by a Current Balun. Perhaps Roy, who is very good at it, could define what is a Current Balun if there is such a thing. And while he is about it, Voltage and Choke Baluns. He may choose to give them different names. But his views can only be beneficial to the mislading waffle which surounds them. ---- Reg. Article: 219511 of rec.radio.amateur.antenna From: "Fred W4JLE" References: Subject: Re: is voltage balun right choice? Date: Sat, 26 Nov 2005 16:42:59 -0500 Message-ID: No, a current balun is the desired beasty in this case. "RB" wrote in message news:sd%hf.36598$6y4.31271@bignews3.bellsouth.net... > I've recently put up a 140' dipole fed with ladderline. My tuner is > separate from my rig, and is an unbalanced unit. So, I use a balun on the > tuner output to hook the ladderline to. > > I've been told that I should have a voltage balun in this application. I > was surprised to hear this, as I expected to hear use a current balun. > > Is the voltage balun the right one for this application? > > Article: 219512 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: is voltage balun right choice? Date: Sat, 26 Nov 2005 22:55:12 +0000 (UTC) Message-ID: References: A choke (or current) balun is the correct choice. The input impedance of the transmission line to the antenna varies all over the shop from one band to another. So there is no definite impedance to which the transmitter is to be matched. A voltage balun is designed to match between two definite known impedances of a given ratio, for example 4-to-1, 300-to-75 ohms, values which never exist at your particular place in the system. A choke or current balun is not intended to match one impedance to another. It is intended only to allow, without loss, the transition >from a balanced line to an unbalanced tuner or transmitter. Because the choke balun is in fact a short length of transmission line wound on a ferrite core, an impedance transformation does occur between one end and the other. But what the antenna line input impedance is transformed to doesn't matter. It is just another impedance for the tuner to handle and, as likely as not, the tuner will handle it just as well. Just a change in L and C settings. ---- Reg, G4FGQ. Article: 219513 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: is voltage balun right choice? References: Message-ID: Date: Sat, 26 Nov 2005 23:22:51 GMT Reg Edwards wrote: > A choke or current balun is not intended to match one impedance to > another. Reg, there are 4:1 current baluns. See Figs A3-3,4 in Roy's Balun article. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219514 of rec.radio.amateur.antenna From: Cecil Moore Subject: WorldRadio Magazine Article Message-ID: Date: Sat, 26 Nov 2005 23:32:55 GMT Part 1 of my WorldRadio Oct. 2005 energy analysis article is now available on my web page in Microsoft Word .doc format. -- 73, Cecil http://www.qsl.net/w5dxp/energy.doc Article: 219515 of rec.radio.amateur.antenna Message-ID: <4lan53-g8n.ln1@mail.specsol.com> From: jimp@specsol.spam.sux.com Subject: Re: SWR again. References: Date: Sun, 27 Nov 2005 00:20:01 GMT Reg Edwards wrote: > ******* Copied from uk.radio.amateur newsgroup. ******** > > Reg spoke of the SWR meter as a resistance bridge. It is possible to > build a > > meter that is a bridge > =================================== > The so-called SWR meter is ALWAYS a resistance bridge (although it may > be described in other terms). Utter nonsense. There are numerous ways to measure SWR without using a bridge of any kind. A bridge implementation is mearly a simple and cheap way to do it and hence the most likely to be found in use by a hobbiest. -- Jim Pennino Remove .spam.sux to reply. Article: 219516 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: is voltage balun right choice? Date: Sun, 27 Nov 2005 00:34:02 +0000 (UTC) Message-ID: References: Cec, a choke balun has an indeterminate ratio. A choke balun which the man asked about, is, as you say, a current balun. I don't doubt that there are some forms of current baluns which have a definite ratio. But they have more than two wires. They can be used to transform one admittance or susceptance to another. ;o) One thing for sure - they are all transmission line transformers - for the want of a better name! In some ways they are remarkable components. They should have been invented 100 years before alongside ordinary L,C, R & G. But they had to wait for the invention of ferrites which I understand did not occur until the early 1940's in wartime Holland. But I would not be surprised if somebody comes along with the idea that the invention was in Bell Labs in the 1930's. Even before the Smith Chart which was an adaption of similar charts in use in the late Victorian Age. In the 1950's I met an American engineer who told me that in 1945 there were Americans looking round bombed-out German radio factories and by chance came across some tiny top hats with narrow brims and with 3 fine wires sticking out of one end. "What on Earth are these" they asked. I could go on. It's the Devil which makes me say such things. ;o) ---- Reg. Article: 219517 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Sun, 27 Nov 2005 01:06:23 +0000 (UTC) Message-ID: References: <4lan53-g8n.ln1@mail.specsol.com> > > > Reg spoke of the SWR meter as a resistance bridge. It is possible to > > build a > > > meter that is a bridge > > =================================== > > > The so-called SWR meter is ALWAYS a resistance bridge (although it may > > be described in other terms). > > Utter nonsense. > > There are numerous ways to measure SWR without using a bridge of any > kind. > > A bridge implementation is mearly a simple and cheap way to do it and > hence the most likely to be found in use by a hobbiest. > ===================================== I'm sorry to say you are all banging your heads against a brick wall. The so-called SWR meter does NOT measure SWR. For starters, there is no transmission line on which to measure anything. Can you find one? It is NOT the one which goes between tuner and antenna. To measure SWR on THAT line the meter has to be located in the air at the antenna end of the line and has to be read using an astronomical telescope mounted on a tripod. But it would still give the wrong answers. Go and think about it some more. ---- Reg, G4FGQ Article: 219518 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: is voltage balun right choice? Date: Sat, 26 Nov 2005 17:44:48 -0800 Message-ID: <11oi3sj7sagavf4@corp.supernews.com> References: You might find it instructive to take a look at http://eznec.com/Amateur/Articles/Baluns.pdf. Roy Lewallen, W7EL RB wrote: > I've recently put up a 140' dipole fed with ladderline. My tuner is > separate from my rig, and is an unbalanced unit. So, I use a balun on the > tuner output to hook the ladderline to. > > I've been told that I should have a voltage balun in this application. I > was surprised to hear this, as I expected to hear use a current balun. > > Is the voltage balun the right one for this application? > > Article: 219519 of rec.radio.amateur.antenna Message-ID: <40gn53-lf7.ln1@mail.specsol.com> From: jimp@specsol.spam.sux.com Subject: Re: SWR again. References: <4lan53-g8n.ln1@mail.specsol.com> Date: Sun, 27 Nov 2005 01:55:01 GMT Reg Edwards wrote: > > > > Reg spoke of the SWR meter as a resistance bridge. It is > possible to > > > build a > > > > meter that is a bridge > > > =================================== > > > > > The so-called SWR meter is ALWAYS a resistance bridge (although it > may > > > be described in other terms). > > > > Utter nonsense. > > > > There are numerous ways to measure SWR without using a bridge of any > > kind. > > > > A bridge implementation is mearly a simple and cheap way to do it > and > > hence the most likely to be found in use by a hobbiest. > > > ===================================== > I'm sorry to say you are all banging your heads against a brick wall. It feels that way when trying to discuss SWR with you. > The so-called SWR meter does NOT measure SWR. Depends on what you call a SWR meter and what you mean by measure, but this has already been hashed to bits. > For starters, there is no transmission line on which to measure > anything. Can you find one? It is NOT the one which goes between > tuner and antenna. It depends on how you implement the hardware to measure SWR, but you are so obsessed with bridge circuits you have little chance of understanding there is more in the world. What do tuners have to do with anything? Tuners are irrelevant to the original post. Are you deliberately trying to confuse the issue or do tuners confuse you? > To measure SWR on THAT line the meter has to be located in the air at > the antenna end of the line and has to be read using an astronomical > telescope mounted on a tripod. But it would still give the wrong > answers. > Go and think about it some more. I did in EE class about 30 years ago and numerous times since. Guess what, the physics hasn't changed. You are so obsessed on this issue that the small nugget of information you have to offer is swamped by the enormous amount of arm waving and babble. > ---- > Reg, G4FGQ -- Jim Pennino Remove .spam.sux to reply. Article: 219520 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Sun, 27 Nov 2005 02:59:42 +0000 (UTC) Message-ID: References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> > You are so obsessed on this issue that the small nugget of information > you have to offer is swamped by the enormous amount of arm waving > and babble. > ================================== I'm afraid your reduction to personalities is a positive indication to bystanders you have lost the argument and have accepted defeat. No hard feelings! Have a good day! ---- Reg, G4FGQ Article: 219521 of rec.radio.amateur.antenna From: "Dick, AA5VU" Subject: Got Lucky on Six meters w/Fan Dipole Message-ID: Date: Sun, 27 Nov 2005 03:06:26 GMT I picked up a new (to me) TS-570S(G) so I can start working six meters. I do not have a dedicated six meter antenna so I decided to try my Fan dipole. It was a 40/80 W9INN dipole that I modified for 18 MHz and 10 MHz by adding two sets of wires. I tried it on 50.125 and rig loves it. I can get full power with whisper of SWR that the TS-570S can easily handle. The SWR on 51 and 52 MHz is not that good; however, the auto-tuner makes the 570 smile. I am not really concerned as I plan operate mostly at 50 MHz. Something tells me the 18 MHz wires are semi-resonant at 50 MHz and I got lucky. 73, Dick AA5VU Article: 219522 of rec.radio.amateur.antenna From: Butch Magee Subject: Re: Radio Shack and my education Date: Sat, 26 Nov 2005 21:08:54 -0600 Message-ID: <11oi8q6p45q8fde@corp.supernews.com> References: <43865eea$0$32203$39cecf19@news.twtelecom.net> Whut is wrong with memorizing the test questions? I did that all through school, from pre-kindergarten to the present. Thats why I know so much stuff..........well, I sorta know a bunch of stuff. Buttt, I R Retired now and I don't have to know anything anymore. Now, aint that some shit. Ole' Butch said that.. Tom Ring wrote: > Owen Duffy wrote: > >> On 23 Nov 2005 20:29:37 GMT, Allodoxaphobia >> wrote: >> >> >> >>> Too much ruckus has been focused on the 'No Code License' issue. >>> The ruckus should, instead, be focused on the 'No Clue License'. >> >> >> >> I never mentioned the no-code licence... we got over that over a year >> ago down under. >> >> I suggest it is not a matter of the no-clue licence, but the no-clue >> licensee, who could be licensed in any grade. >> >> Owen >> (Spelling correct for country of origin!) >> -- > > > Correct. I have personally met more extras without a clue than > generals, and that's not percentage-wise. Your personal mileage may > vary, but a lot of extras seem to be really code oriented or contest > oriented, and did nothing but memorize the technical questions answers > (US) to pass. > > I do not maean to disparage anyone who got their license by legitimate > means. > > Wasn't there a scandal around that sort of thing a while ago. The name > West comes to mind, but I truthfully don't remember anything more than > that. > > tom > K0TAR Article: 219523 of rec.radio.amateur.antenna Date: Sat, 26 Nov 2005 21:14:02 -0600 From: Tom Ring Subject: Re: SWR again. References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> Message-ID: <4389248a$0$3756$39cecf19@news.twtelecom.net> Reg Edwards wrote: >>You are so obsessed on this issue that the small nugget of > > information > >>you have to offer is swamped by the enormous amount of arm waving >>and babble. >> > > ================================== > > I'm afraid your reduction to personalities is a positive indication to > bystanders you have lost the argument and have accepted defeat. > > No hard feelings! Have a good day! > ---- > Reg, G4FGQ > > Reg As someone who has watched from the sidelines for quite a while, I think you need to consult a psychiatrist, You really are obsessed over this. I am not kidding, no shit. You seem normal in most of your responses, but when it comes to SWR meters you really do seem to lose it. tom K0TAR Article: 219524 of rec.radio.amateur.antenna Date: Sat, 26 Nov 2005 21:18:21 -0600 From: Tom Ring Subject: Re: Radio Shack and my education References: <43865eea$0$32203$39cecf19@news.twtelecom.net> <11oi8q6p45q8fde@corp.supernews.com> Message-ID: <4389258d$0$3756$39cecf19@news.twtelecom.net> Well, I guess he summed it up quite succinctly. tom K0TAR Butch Magee wrote: > Whut is wrong with memorizing the test questions? I did that all > through school, from pre-kindergarten to the present. Thats why I know > so much stuff..........well, I sorta know a bunch of stuff. Buttt, I R > Retired now and I don't have to know anything anymore. Now, aint that > some shit. > Ole' Butch said that.. > > > Tom Ring wrote: > >> Owen Duffy wrote: >> >>> On 23 Nov 2005 20:29:37 GMT, Allodoxaphobia >>> wrote: >>> >>> >>> >>>> Too much ruckus has been focused on the 'No Code License' issue. >>>> The ruckus should, instead, be focused on the 'No Clue License'. >>> >>> >>> >>> >>> I never mentioned the no-code licence... we got over that over a year >>> ago down under. >>> >>> I suggest it is not a matter of the no-clue licence, but the no-clue >>> licensee, who could be licensed in any grade. >>> >>> Owen >>> (Spelling correct for country of origin!) >>> -- >> >> >> >> Correct. I have personally met more extras without a clue than >> generals, and that's not percentage-wise. Your personal mileage may >> vary, but a lot of extras seem to be really code oriented or contest >> oriented, and did nothing but memorize the technical questions answers >> (US) to pass. >> >> I do not maean to disparage anyone who got their license by legitimate >> means. >> >> Wasn't there a scandal around that sort of thing a while ago. The >> name West comes to mind, but I truthfully don't remember anything more >> than that. >> >> tom >> K0TAR Article: 219525 of rec.radio.amateur.antenna From: Butch Magee Subject: Re: WorldRadio Magazine Article Date: Sat, 26 Nov 2005 21:25:50 -0600 Message-ID: <11oi9pv3me11fe4@corp.supernews.com> References: Cecil Moore wrote: > Part 1 of my WorldRadio Oct. 2005 energy analysis article is > now available on my web page in Microsoft Word .doc format. Yo, I can''t get to you're web site. Must be because I memorized everything coming up. Yep, ats where I mussed up. Butch Article: 219526 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Got Lucky on Six meters w/Fan Dipole References: Message-ID: <2R9if.24834$q%.23288@newssvr12.news.prodigy.com> Date: Sun, 27 Nov 2005 03:36:30 GMT Dick, AA5VU wrote: > Something tells me the 18 MHz wires are semi-resonant at 50 MHz > and I got lucky. If the 40m dipole is still intact, 50/7.14 = 7 -- 73, Cecil http://www.qsl.net/w5dxp Article: 219527 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Sun, 27 Nov 2005 04:39:17 +0000 (UTC) Message-ID: References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> <4389248a$0$3756$39cecf19@news.twtelecom.net> "Tom Ring" wrote > As someone who has watched from the sidelines for quite a while, I think > you need to consult a psychiatrist, You really are obsessed over this. > I am not kidding, no shit. > > You seem normal in most of your responses, but when it comes to SWR > meters you really do seem to lose it. ---------------------------------------------------------------------- ----- Doctor Tom, Hasn't it occurred to you that if most of my responses are normal then there's no reason to suppose my response to so- called SWR meters should be otherwise. If ever I should feel the need to consult a psychiatrist then I would make arrangements to see one. I would ignore the unqualified opinions of quacks and old-wives on this newsgroup who have allowed themselves to be brainwashed just by the mis-naming of an indicating instrument. My only reason for continuing with the subject is to provide some education to novices although it seems some of the 'experts' are also in need of it. If YOU wish to continue with the subject then please say which of my very few earlier technical statements you think are incorrect, and why you think so. If the discussion should drift towards my personal character then it will be taken as an indication you have lost the argument and have nothing further to say. Otherwise go QRT ---- Reg, G4FGQ Article: 219528 of rec.radio.amateur.antenna From: "Charlie" Subject: Re: SWR again. Date: Sat, 26 Nov 2005 22:59:11 -0600 Message-ID: <11oif98lke3rk15@news.supernews.com> References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> <4389248a$0$3756$39cecf19@news.twtelecom.net> I wonder how many band openings both of you have missed while participating in this cyber pissing contest? -- Charlie "Reg Edwards" wrote in message news:dmbd9l$34e$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com... > > "Tom Ring" wrote >> As someone who has watched from the sidelines for quite a while, I > think >> you need to consult a psychiatrist, You really are obsessed over > this. >> I am not kidding, no shit. >> >> You seem normal in most of your responses, but when it comes to SWR >> meters you really do seem to lose it. > ---------------------------------------------------------------------- > ----- > > Doctor Tom, > > Hasn't it occurred to you that if most of my responses are normal then > there's no reason to suppose my response to so- called SWR meters > should be otherwise. > > If ever I should feel the need to consult a psychiatrist then I would > make arrangements to see one. I would ignore the unqualified opinions > of quacks and old-wives on this newsgroup who have allowed themselves > to be brainwashed just by the mis-naming of an indicating instrument. > > My only reason for continuing with the subject is to provide some > education to novices although it seems some of the 'experts' are also > in need of it. > > If YOU wish to continue with the subject then please say which of my > very few earlier technical statements you think are incorrect, and why > you think so. > > If the discussion should drift towards my personal character then it > will be taken as an indication you have lost the argument and have > nothing further to say. > > Otherwise go QRT > ---- > Reg, G4FGQ > > Article: 219529 of rec.radio.amateur.antenna From: "RB" References: <11oi3sj7sagavf4@corp.supernews.com> Subject: Re: is voltage balun right choice? Message-ID: Date: Sun, 27 Nov 2005 01:29:29 -0600 Good replies. Thanks. So: does the commonly available choke balun (round cylinder with coax connectors on each end, and ferrite beads inside the cylinder) allow us to put unbalanced feed in one end, and get balanced feed on the other? Or, are they ununs? Article: 219530 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: is voltage balun right choice? Date: Sun, 27 Nov 2005 02:55:25 -0800 Message-ID: <11oj4514qm9bne4@corp.supernews.com> References: <11oi3sj7sagavf4@corp.supernews.com> A properly operating choke (current) balun will cause the currents in the two conductors to be balanced (equal and opposite) at both ports. So I guess you could call it a balbal if you want. Why would anyone want a device that causes the currents at both ports to be unbalanced? Roy Lewallen, W7EL RB wrote: > Good replies. Thanks. > > So: does the commonly available choke balun (round cylinder with coax > connectors on each end, and ferrite beads inside the cylinder) allow us to > put unbalanced feed in one end, and get balanced feed on the other? > > Or, are they ununs? > > Article: 219531 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: is voltage balun right choice? References: <11oi3sj7sagavf4@corp.supernews.com> Message-ID: Date: Sun, 27 Nov 2005 14:59:54 GMT RB wrote: > So: does the commonly available choke balun (round cylinder with coax > connectors on each end, and ferrite beads inside the cylinder) allow us to > put unbalanced feed in one end, and get balanced feed on the other? > Or, are they ununs? Since they function by choking RF on the outside braid, they can function as either baluns or ununs. If RF is choked and not flowing on the outside braid, then differential currents are forced to flow in the two remaining conductors be they parallel wires or the inside wire and braid of the coax. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219532 of rec.radio.amateur.antenna Date: Sun, 27 Nov 2005 09:03:09 -0600 From: Tom Ring Subject: Re: SWR again. References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> <4389248a$0$3756$39cecf19@news.twtelecom.net> <11oif98lke3rk15@news.supernews.com> Message-ID: <4389cabd$0$3756$39cecf19@news.twtelecom.net> Charlie wrote: > I wonder how many band openings both of you have missed while participating > in this cyber pissing contest? > Let's see, I have made one comment on the subject of Reg and SWR measurement. Ever. So probably none. And all I said was that he seemed to be obsessive. I never said anything about the validity of his arguments, so I cerainly was not involved in a pissing contest. I think it's all quite amusing actually. tom K0TAR Article: 219533 of rec.radio.amateur.antenna From: 'Doc Subject: Re: Station ground/2nd floor References: Message-ID: Date: Sun, 27 Nov 2005 17:27:04 GMT Mark, Sounds like a 'balanced' antenna to me, why a ground other than for electrical purposes (not RF)? - 'Doc Article: 219534 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Got Lucky on Six meters w/Fan Dipole References: <2R9if.24834$q%.23288@newssvr12.news.prodigy.com> Message-ID: Date: Sun, 27 Nov 2005 18:45:12 GMT Scott wrote: > Maybe it's warm where you are, but antenna modification season has ended > here in Wisconsin (for the most part!) Here in East Texas close to Texas A&M, the expected high is 84 degrees today with lots of sun and wind. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219535 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> Message-ID: <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> Date: Sun, 27 Nov 2005 18:49:30 GMT Mark Sheffield wrote: > I'm not quite balanced in the feed, as I'm using coax out to the > dipole feedpoint, but probably close enough. A W2DU choke would probably eliminate the need for an RF ground and also be good engineering practice. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219536 of rec.radio.amateur.antenna From: "John, N9JG" References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> Subject: Re: Station ground/2nd floor Message-ID: <_Tnif.606420$xm3.396820@attbi_s21> Date: Sun, 27 Nov 2005 19:35:22 GMT I have a 2nd floor shack too, and the antenna is a ground mounted vertical (Butternut HF6V). I use a W2DU choke to connect my coax feedline to the vertical and a 2nd W2DU choke between my Orion and Drake L-4B. Finally, I found that the only way to prevent feedback on SSB was to NOT connect my system to the #8 ground wire that runs out the window sill and down to a ground rod. "Cecil Moore" wrote in message news:_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com... > Mark Sheffield wrote: >> I'm not quite balanced in the feed, as I'm using coax out to the >> dipole feedpoint, but probably close enough. > > A W2DU choke would probably eliminate the need for > an RF ground and also be good engineering practice. > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 219537 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11oi3sj7sagavf4@corp.supernews.com> Subject: Re: is voltage balun right choice? Date: Sun, 27 Nov 2005 14:50:26 -0500 Message-ID: A choke balun allows you to go from unbalanced to balanced. If you check Walter Maxwells site and review Chapter 21 (IIRC) of reflections. He gives a test setup that will aid in understanding. "RB" wrote in message news:Tddif.89036$ty1.39736@bignews1.bellsouth.net... > Good replies. Thanks. > > So: does the commonly available choke balun (round cylinder with coax > connectors on each end, and ferrite beads inside the cylinder) allow us to > put unbalanced feed in one end, and get balanced feed on the other? > > Or, are they ununs? > > Article: 219538 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> Message-ID: Date: Sun, 27 Nov 2005 20:03:27 GMT John, N9JG wrote: > Finally, I > found that the only way to prevent feedback on SSB was to NOT connect my > system to the #8 ground wire that runs out the window sill and down to a > ground rod. Yep, everyone should realize that a ground wire is N*1/4 wavelength at certain frequencies, and at those frequencies, is an RF transformer that locates the standing-wave voltage maximum points at the transmitter. (ouch!) That's what artificial grounds do - change that *electrical* length to N*1/2 wavelength. For anyone insisting on an RF ground for an upper floor, an artificial ground is probably the way to go. I, myself, prefer balanced antennas and feedlines. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219539 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <2R9if.24834$q%.23288@newssvr12.news.prodigy.com> Subject: Re: Got Lucky on Six meters w/Fan Dipole Date: Sun, 27 Nov 2005 15:21:39 -0500 Message-ID: <70f23$438a1555$97d56a33$23027@ALLTEL.NET> We are having a real cold snap here in South Carolina, it only reached 73 today. "Cecil Moore" wrote in message news:Y8nif.19155$BZ5.18183@newssvr13.news.prodigy.com... > Scott wrote: > > Maybe it's warm where you are, but antenna modification season has ended > > here in Wisconsin (for the most part!) > > Here in East Texas close to Texas A&M, the expected high > is 84 degrees today with lots of sun and wind. > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 219540 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1133101079.399556.132760@z14g2000cwz.googlegroups.com> Subject: Re: Source for good trap boots for tri-bander??? Date: Sun, 27 Nov 2005 15:23:52 -0500 Message-ID: <4464e$438a15da$97d56a33$23125@ALLTEL.NET> Check with your local motorcycle shop. They have boots for the the front shock absorbers that I have used in the past. "Dave - KB8NNU" wrote in message news:1133101079.399556.132760@z14g2000cwz.googlegroups.com... > Howdy all....I am in the process of rebuilding an older tribander that > I have and need some input. I want to replace all of the trap boots, > but don't know where to get such a thing. I'm not sure what kind of > antenna it is. I originally thought it was a TA-33 jr...??? The traps > have a diameter of 1.5'' and the anntenna diameter is .75''. Any help > would greatly be appreciated. > > Thanks, > > Dave - KB8NNU > Article: 219541 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Sun, 27 Nov 2005 20:27:48 +0000 (UTC) Message-ID: References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> <4389248a$0$3756$39cecf19@news.twtelecom.net> <11oif98lke3rk15@news.supernews.com> <4389cabd$0$3756$39cecf19@news.twtelecom.net> > I think it's all quite amusing actually. > > tom > K0TAR =================================== So do I. ---- Reg, G4FGQ Article: 219542 of rec.radio.amateur.antenna From: "Jerry" References: <2R9if.24834$q%.23288@newssvr12.news.prodigy.com> Subject: Re: Got Lucky on Six meters w/Fan Dipole Message-ID: Date: Sun, 27 Nov 2005 16:13:28 -0500 "Cecil Moore" wrote in message news:Y8nif.19155$BZ5.18183@newssvr13.news.prodigy.com... > Scott wrote: >> Maybe it's warm where you are, but antenna modification season has ended >> here in Wisconsin (for the most part!) > > Here in East Texas close to Texas A&M, the expected high > is 84 degrees today with lots of sun and wind. > -- > 73, Cecil http://www.qsl.net/w5dxp Ya like to rub it in, eh? ;) Jerry (Here, 40's with a chilly rain. :( ) Article: 219543 of rec.radio.amateur.antenna From: Korbin Dallas Subject: Re: Radio Shack and my education Message-ID: References: <43866294$0$3756$39cecf19@news.twtelecom.net> Date: Sun, 27 Nov 2005 21:30:34 GMT On Thu, 24 Nov 2005 19:01:57 -0600, Tom Ring wrote: > And from what I've seen, nothing has changed, Bose is still selling > millions of dollars of crap. > > tom > K0TAR Man ain't that the truth. I have never understood this Bose thing, the speakers are some of the worst ones on the market and they are flying out the doors all day long. Its all marketing BS like the Wizbang cables to hook things up. -- Korbin Dallas The name was changed to protect the guilty. Article: 219544 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <43866294$0$3756$39cecf19@news.twtelecom.net> Message-ID: <43qif.25182$Zv5.24376@newssvr25.news.prodigy.net> Date: Sun, 27 Nov 2005 22:03:44 GMT Korbin Dallas wrote: > I have never understood this Bose thing, the speakers are some of the > worst ones on the market and they are flying out the doors all day long. > Its all marketing BS like the Wizbang cables to hook things up. Sharper Image does the same thing. Their room air filter has got to be close to the worst-case design I have ever seen. The guy in their commercial who says, "I have tried every air purifier on the market and ..." is an UNETHICAL LYING SOB!!!! 'Course, most TV commercials are made by unethical liars. I doubt that many of the alleged cancer sufferers actually have cancer. They look more like professional models to me. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219545 of rec.radio.amateur.antenna From: Wayne Watson Subject: Antennas-History (What's Going On?) Message-ID: Date: Sun, 27 Nov 2005 22:05:08 GMT I hardly know where to start with this topic. If one picks up some of the fairly popular (available?) books on the matter, the authors invariably start throwing different types of antennas at the reader, yagi, helical, dipole, folded dipole, parabolic, loop, dish, microwave, quads, etc. For example, I'm looking at an older book on the topic I bought some 20 years ago, The Radio Amateur Handbook by Orr and Cowan. The book is basically for builders. Many such books are. What about the underlying methodology behind this? More generally, here's my question. I would guess that in the beginning (late 1800s) the simple dipole was it. As years passed, the complexity of antennas has increased. What was the driving force for these changes? For example, how did the inventor of the Yagi (Yagi-Uda) ever dream up the idea for the antenna? Was it the application of theory or did he just get lucky? In fact, is there some underlying theory that drives the design of antennas? For example, the computation of radiation patterns. I'm sure these days the computer would be an aid, but what theory and application drove the development of varied designs before 1960? When did Maxwell's equations seriously get used for this? What suggested a tin can could become an antenna? How did anyone think up the idea of a microwave antenna? I would think that in the case of antennas that are used for different parts of the EM spectrum a driving force would be the consideration of the wave itself. For example, it would seem unlikely an x-ray antenna (I believe there is such a thing on one of the space satellites used in astronomy) would be anything like one used to receive TV. Certainly the 'antenna' to collect visible light is different than that for AM radio. -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: Article: 219546 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antennas-History (What's Going On?) References: Message-ID: Date: Sun, 27 Nov 2005 22:13:42 GMT Wayne Watson wrote: > For example, it would seem unlikely an x-ray antenna (I believe > there is such a thing on one of the space satellites used in astronomy) > would be anything like one used to receive TV. Certainly the 'antenna' to > collect visible light is different than that for AM radio. Is it easier to pick up a twig than to pick up a tree? Methinks you need a better understanding of wavelength. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219547 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <43866294$0$3756$39cecf19@news.twtelecom.net> <43qif.25182$Zv5.24376@newssvr25.news.prodigy.net> Subject: Re: Radio Shack and my education Date: Sun, 27 Nov 2005 17:18:21 -0500 Message-ID: Come on Cecil, next you will be telling me there is no Santa Clause... "Cecil Moore" wrote in message news:43qif.25182$Zv5.24376@newssvr25.news.prodigy.net... > Korbin Dallas wrote: > > I have never understood this Bose thing, the speakers are some of the > > worst ones on the market and they are flying out the doors all day long. > > Its all marketing BS like the Wizbang cables to hook things up. > > Sharper Image does the same thing. Their room air filter has got > to be close to the worst-case design I have ever seen. The guy > in their commercial who says, "I have tried every air purifier > on the market and ..." is an UNETHICAL LYING SOB!!!! 'Course, most > TV commercials are made by unethical liars. I doubt that many > of the alleged cancer sufferers actually have cancer. They look > more like professional models to me. > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 219548 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> <1133129531.934671.87410@o13g2000cwo.googlegroups.com> Message-ID: Date: Sun, 27 Nov 2005 22:21:45 GMT jgboyles@aol.com wrote: > Cecil, Don't you mean that when a ground wire is N*1/4 wavelength at > a particular frequency it locates the voltage mininum (current maximum) > at the transmitter, and the voltage maximum well away from the > transmitter. Nope, Mother Earth dictates the boundary conditions. A well-designed ground system positions the current maximum point at the ground system, i.e. minimum impedance to ground. The voltage maximum point would, therefore, be located at the transmitter, not a desirable condition. Of course, if you are not actually connected/ coupled to Mother Earth, your milage may vary. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219549 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Radio Shack and my education References: <43866294$0$3756$39cecf19@news.twtelecom.net> <43qif.25182$Zv5.24376@newssvr25.news.prodigy.net> Message-ID: <8qqif.25193$Zv5.10176@newssvr25.news.prodigy.net> Date: Sun, 27 Nov 2005 22:28:20 GMT Fred W4JLE wrote: > Come on Cecil, next you will be telling me there is no Santa Clause... It's hard to argue that there's no Santa Claus when one can observe a real live Santa Claus in every mall. What's seems harder to argue is the existence of a God whom nobody alive has ever sensed with any of their allegedly God-given senses. :-) (The Devil made me say that.) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219550 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> <438A3123.AC0E860D@shaw.ca> Message-ID: Date: Sun, 27 Nov 2005 22:35:26 GMT Irv Finkleman wrote: > Why not run two ground wires in parallel -- one twice as long as the > other? When one is Hi-Z the other will be Lo-Z and vice versa. That will help on some frequencies but it is akin to trying to erect a 1/2WL fan dipole for all frequencies - can't be done. Sooner or later, you will run into a frequency where length #1 is N*1/4WL and length #2 is (N+1)1/4WL. "It's not nice to fool Mother Nature." -- 73, Cecil http://www.qsl.net/w5dxp Article: 219551 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> <1133129531.934671.87410@o13g2000cwo.googlegroups.com> <1133131540.142286.97990@f14g2000cwb.googlegroups.com> Message-ID: Date: Sun, 27 Nov 2005 22:57:12 GMT jgboyles@aol.com wrote: > That is where an artifical ground can help by locating > the voltage minimum at the transmitter. Yes, that's true. An artifical ground equalizes the voltage at the ground point AND at the transmitter so both are voltage minimum (current maximum) points. That's exactly what an antenna tuner does when feeding a resonant 1/2WL dipole fed with ladder-line through an antenna tuner. I hope I didn't misunderstand what you were trying to say. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219552 of rec.radio.amateur.antenna From: "W. Watson" Subject: Re: Antennas-History (What's Going On?) References: Message-ID: Date: Sun, 27 Nov 2005 23:01:51 GMT Cecil Moore wrote: > Wayne Watson wrote: > >> For example, it would seem unlikely an x-ray antenna (I believe >> there is such a thing on one of the space satellites used in astronomy) >> would be anything like one used to receive TV. Certainly the 'antenna' to >> collect visible light is different than that for AM radio. > > > Is it easier to pick up a twig than to pick up a tree? > Methinks you need a better understanding of wavelength. Why not provide it then? -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: Article: 219553 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Antennas-History (What's Going On?) Date: Sun, 27 Nov 2005 15:20:20 -0800 Message-ID: <11okfpommc4nd0b@corp.supernews.com> References: Wayne Watson wrote: > I hardly know where to start with this topic. If one picks up some of > the fairly popular (available?) books on the matter, the authors > invariably start throwing different types of antennas at the reader, > yagi, helical, dipole, folded dipole, parabolic, loop, dish, > microwave, quads, etc. For example, I'm looking at an older book on > the topic I bought some 20 years ago, The Radio Amateur Handbook by > Orr and Cowan. The book is basically for builders. Many such books > are. What about the underlying methodology behind this? More > generally, here's my question. > > I would guess that in the beginning (late 1800s) the simple dipole > was it. As years passed, the complexity of antennas has increased. > What was the driving force for these changes? Since the beginning of radio, antenna design has been driven mostly by specific needs, to name just a very few examples: -- By broadcasters to increase their coverage areas -- By military users: to increase portability and range to decrease detectable emissions in some directions to allow broadband performance for frequency hopping -- By satellite system designers to concentrate limited energy in particular regions. -- By cell phone companies to provide coverage to well-defined regions The list is endless. Take a trip to your local library and get an index to the I.R.E. (now the IEEE) Transactions on Antennas and Propagation. You'll see that many advances were made in the '20s and '30s in AM broadcast antennas, in the '40s and '50s in aircraft antennas, in the '60s and '70s in satellite antennas. Much of today's development work involves compact antennas for the wireless networks now proliferating. Antennas provide a limitless pool of tradeoffs involving size, cost, ruggedness, and a large handful of performance characteristics such as directionality, gain, and bandwidth. This pretty much guarantees that new designs will continue to be created. > For example, how did the inventor of the Yagi (Yagi-Uda) ever dream > up the idea for the antenna? Was it the application of theory or did > he just get lucky? How is any creative design accomplished? How did Armstrong come up with the idea for FM, Watt for the steam engine? I've spent most of my career doing circuit design, and it requires a deep knowledge of theory, but also involves a creative synthesis not unlike what an artist has in deciding what to paint or an architect in deciding what form a building will take. > In fact, is there some underlying theory that drives the design of > antennas? For example, the computation of radiation patterns. You're confusing design and analysis. Design is driven primarily by a need for a particular set of performance parameters. Analysis is done by computation. Analysis is an important part of the design process, in that a design, once created, is analyzed to see if and how well it meets design goals. The design is then often modified and re-analyzed many times until the goal is reached, the design abandoned, or the goal redefined. And yes, indeed, there's solid theory underlying antenna operation. > I'm sure these days the computer would be an aid, but what theory and > application drove the development of varied designs before 1960? Hopefully what I've said above has answered this. A lot more physical modeling and experimentation were required before computers were available, but design was still driven by need, and theory hasn't changed significantly for many decades. There's no magic computer program that you can put some numbers into and out comes the optimum aircraft design, or bridge, or car, or house. Antennas are no different. Computers can be used to optimize a particular class of antenna (e.g., Yagi or patch) for a particular set of performance criteria, just as they can be used to fine-tune an aircraft or bridge once the basic structure is designed. But not to design an antenna from nothing. > When did Maxwell's equations seriously get used for this? They were used long ago as the basis of equations more directly applicable to antenna analysis, and those equations are still used by modern computer programs. In that sense, Maxwell's equations are still being used, although not directly. > What suggested a tin can could become an antenna? It's obvious to anyone who understands the most basic of principles. Any conductor can act as an antenna. A tin can is a conductor. > How did anyone think up the idea of a microwave antenna? Actually, some of the first experiments with radio waves by Heinrich Hertz were done in the microwave region, so some of the very first antennas were microwave antennas. As for modern microwave antennas, once you have microwave energy (which first became available at high power levels with the invention of the cavity magnetron in 1940), the need for an antenna becomes obvious. > I would think that in the case of antennas that are used for > different parts of the EM spectrum a driving force would be the > consideration of the wave itself. For example, it would seem unlikely > an x-ray antenna (I believe there is such a thing on one of the > space satellites used in astronomy) would be anything like one used > to receive TV. Certainly the 'antenna' to collect visible light is > different than that for AM radio. All antennas obey the same fundamental physical laws. But you're correct that the wavelength of the signal to be transmitted or received plays a big role in determining which antenna designs are practical and optimum. That's just one of the many factors that have to be considered when designing an antenna. All bridges obey the same physical laws, but the optimum design for a bridge crossing a creek is quite different from one crossing the Golden Gate. In fact, if you change "antenna" to "bridge" in your questions, you'll probably find most of the answers to be pretty obvious. Roy Lewallen, W7EL Article: 219554 of rec.radio.amateur.antenna From: "Dick, AA5VU" Subject: Re: Got Lucky on Six meters w/Fan Dipole References: <2R9if.24834$q%.23288@newssvr12.news.prodigy.com> Message-ID: Date: Sun, 27 Nov 2005 23:47:54 GMT In article , Cecil Moore wrote: > > Maybe it's warm where you are, but antenna modification season has ended > > here in Wisconsin (for the most part!) > > Here in East Texas close to Texas A&M, the expected high > is 84 degrees today with lots of sun and wind. Winter was cancelled in 2004 due to lack of participation and I think we are in for the same this year. Like Cecil, the high in the Capital was about 86 yesterday. Article: 219555 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antennas-History (What's Going On?) References: Message-ID: <_Grif.19209$BZ5.11403@newssvr13.news.prodigy.com> Date: Sun, 27 Nov 2005 23:54:34 GMT W. Watson wrote: > W. Watson wrote: >>> Wayne Watson wrote: > Let me try to make it easier on you. Are you bipolar? :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219556 of rec.radio.amateur.antenna Message-ID: <438A539F.B05A771D@shaw.ca> From: Irv Finkleman Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> <438A3123.AC0E860D@shaw.ca> Date: Mon, 28 Nov 2005 00:47:26 GMT Cecil Moore wrote: > > Irv Finkleman wrote: > > Why not run two ground wires in parallel -- one twice as long as the > > other? When one is Hi-Z the other will be Lo-Z and vice versa. > > That will help on some frequencies but it is akin to trying to > erect a 1/2WL fan dipole for all frequencies - can't be done. Sooner > or later, you will run into a frequency where length #1 is N*1/4WL > and length #2 is (N+1)1/4WL. "It's not nice to fool Mother Nature." > -- > 73, Cecil http://www.qsl.net/w5dxp OK then, I'll use 3 wires and take my chances! :-) Irv -- -------------------------------------- Diagnosed Type II Diabetes March 5 2001 Beating it with diet and exercise! 297/215/210 (to be revised lower) 58"/43"(!)/44" (already lower too!) -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada Article: 219557 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: SWR again. References: <4lan53-g8n.ln1@mail.specsol.com> <40gn53-lf7.ln1@mail.specsol.com> <4389248a$0$3756$39cecf19@news.twtelecom.net> <11oif98lke3rk15@news.supernews.com> <4389cabd$0$3756$39cecf19@news.twtelecom.net> Message-ID: Date: Mon, 28 Nov 2005 02:02:13 GMT Reg Edwards wrote: >>I think it's all quite amusing actually. >> >>tom >>K0TAR > > =================================== > > So do I. > ---- > Reg, G4FGQ > > It ceased to be amusing 500 posts ago, but Reg has a point, however strained. 73, Tom Donaly, KA6RUH Article: 219558 of rec.radio.amateur.antenna From: "W4WNT" References: <1133023175.424981.104610@g43g2000cwa.googlegroups.com> Subject: Re: 30/20 vertical? Message-ID: Date: Mon, 28 Nov 2005 02:02:58 GMT You did not say what your vertical radiator material is. Make it out of wire (support it with PVC tubing), then you can put up 2 vertical radiators, one for 20m, the other for 30m fed by the same coax. I guess this would be a "Fan Vertical". Its based on a W6SAI design published in 1990. I've done it with 10/15/20m radiators and it works well with elevated radials made >from TV rotator wire. Good luck, Bill, W4WNT wrote in message news:1133023175.424981.104610@g43g2000cwa.googlegroups.com... > Hi, > > For 20m I am planning a quarter wavelength vertical radiator with 4 > eighth wavelength radials, mounted 12 feet high. > > If I add another 4 radials cut an eight wavelength for 30m, will it be > easier to operate on 30? > > Thanks, > > The Eternal Squire > Article: 219559 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <43866294$0$3756$39cecf19@news.twtelecom.net> <43qif.25182$Zv5.24376@newssvr25.news.prodigy.net> <8qqif.25193$Zv5.10176@newssvr25.news.prodigy.net> Subject: Re: Radio Shack and my education Date: Sun, 27 Nov 2005 22:56:42 -0500 Message-ID: <3f67$438a7ffd$97d56a33$32124@ALLTEL.NET> He has been sensed by the heart when a child is delivered from an illness, a mother gives birth to a newborn child, and in the smile of someone you have given a kindness. Just remember, he will always believe in you... "Cecil Moore" wrote in message news:8qqif.25193$Zv5.10176@newssvr25.news.prodigy.net... > Fred W4JLE wrote: > > Come on Cecil, next you will be telling me there is no Santa Clause... > > It's hard to argue that there's no Santa Claus when one can > observe a real live Santa Claus in every mall. What's seems > harder to argue is the existence of a God whom nobody alive > has ever sensed with any of their allegedly God-given senses. > :-) (The Devil made me say that.) > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 219560 of rec.radio.amateur.antenna From: "W. Watson" Subject: Re: Antennas-History (What's Going On?) References: <11okfpommc4nd0b@corp.supernews.com> Message-ID: <%nCif.2054$Hk1.1653@newsread1.news.pas.earthlink.net> Date: Mon, 28 Nov 2005 12:05:15 GMT Roy Lewallen wrote: > Wayne Watson wrote: > >> I hardly know where to start with this topic. If one picks up some of >> the fairly popular (available?) books on the matter, the authors >> invariably start throwing different types of antennas at the reader, >> yagi, helical, dipole, folded dipole, parabolic, loop, dish, >> microwave, quads, etc. For example, I'm looking at an older book on >> the topic I bought some 20 years ago, The Radio Amateur Handbook by >> Orr and Cowan. The book is basically for builders. Many such books >> are. What about the underlying methodology behind this? More >> generally, here's my question. >> >> I would guess that in the beginning (late 1800s) the simple dipole was >> it. As years passed, the complexity of antennas has increased. What >> was the driving force for these changes? > > > > Since the beginning of radio, antenna design has been driven mostly by > specific needs, to name just a very few examples: > > -- By broadcasters to increase their coverage areas > -- By military users: > to increase portability and range > to decrease detectable emissions in some directions > to allow broadband performance for frequency hopping > -- By satellite system designers to concentrate limited energy in > particular regions. > -- By cell phone companies to provide coverage to well-defined regions > > The list is endless. > > Take a trip to your local library and get an index to the I.R.E. (now > the IEEE) Transactions on Antennas and Propagation. You'll see that many > advances were made in the '20s and '30s in AM broadcast antennas, in the > '40s and '50s in aircraft antennas, in the '60s and '70s in satellite > antennas. Much of today's development work involves compact antennas for > the wireless networks now proliferating. > > Antennas provide a limitless pool of tradeoffs involving size, cost, > ruggedness, and a large handful of performance characteristics such as > directionality, gain, and bandwidth. This pretty much guarantees that > new designs will continue to be created. > >> For example, how did the inventor of the Yagi (Yagi-Uda) ever dream up >> the idea for the antenna? Was it the application of theory or did he >> just get lucky? > > > How is any creative design accomplished? How did Armstrong come up with > the idea for FM, Watt for the steam engine? I've spent most of my career > doing circuit design, and it requires a deep knowledge of theory, but > also involves a creative synthesis not unlike what an artist has in > deciding what to paint or an architect in deciding what form a building > will take. > >> In fact, is there some underlying theory that drives the design of >> antennas? For example, the computation of radiation patterns. > > > You're confusing design and analysis. Design is driven primarily by a > need for a particular set of performance parameters. Analysis is done by > computation. Analysis is an important part of the design process, in > that a design, once created, is analyzed to see if and how well it meets > design goals. The design is then often modified and re-analyzed many > times until the goal is reached, the design abandoned, or the goal > redefined. And yes, indeed, there's solid theory underlying antenna > operation. > >> I'm sure these days the computer would be an aid, but what theory and >> application drove the development of varied designs before 1960? > > > Hopefully what I've said above has answered this. A lot more physical > modeling and experimentation were required before computers were > available, but design was still driven by need, and theory hasn't > changed significantly for many decades. > > There's no magic computer program that you can put some numbers into and > out comes the optimum aircraft design, or bridge, or car, or house. > Antennas are no different. Computers can be used to optimize a > particular class of antenna (e.g., Yagi or patch) for a particular set > of performance criteria, just as they can be used to fine-tune an > aircraft or bridge once the basic structure is designed. But not to > design an antenna from nothing. > >> When did Maxwell's equations seriously get used for this? > > > They were used long ago as the basis of equations more directly > applicable to antenna analysis, and those equations are still used by > modern computer programs. In that sense, Maxwell's equations are still > being used, although not directly. > >> What suggested a tin can could become an antenna? > > > It's obvious to anyone who understands the most basic of principles. Any > conductor can act as an antenna. A tin can is a conductor. > >> How did anyone think up the idea of a microwave antenna? > > > Actually, some of the first experiments with radio waves by Heinrich > Hertz were done in the microwave region, so some of the very first > antennas were microwave antennas. As for modern microwave antennas, once > you have microwave energy (which first became available at high power > levels with the invention of the cavity magnetron in 1940), the > need for an antenna becomes obvious. > >> I would think that in the case of antennas that are used for different >> parts of the EM spectrum a driving force would be the consideration of >> the wave itself. For example, it would seem unlikely >> an x-ray antenna (I believe there is such a thing on one of the space >> satellites used in astronomy) would be anything like one used to >> receive TV. Certainly the 'antenna' to collect visible light is >> different than that for AM radio. > > > All antennas obey the same fundamental physical laws. But you're correct > that the wavelength of the signal to be transmitted or > received plays a big role in determining which antenna designs are > practical and optimum. That's just one of the many factors that have to > be considered when designing an antenna. All bridges obey the same > physical laws, but the optimum design for a bridge crossing a creek is > quite different from one crossing the Golden Gate. > > In fact, if you change "antenna" to "bridge" in your questions, you'll > probably find most of the answers to be pretty obvious. > > Roy Lewallen, W7EL Thanks. Well said. Makes sense to me. I have a very modest understanding of how antennas work, but from my simplistic view I just find it a bit odd that if one thinks of an EM wave shape and content (electric and magnetic) to all sorts of radiation that to observe much of this radiation different devices are required. From my underdeveloped perspective, I'd probably trying to design everything with some wild combinations of dipoles. Maybe I'm thinking of (hoping for) some grand unified radio or telescope (and methodology) that sucks up any EM wave one can throw at it. One size fits all. Apparently, we've got a long way to go on that. :-) -- Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet Traveling in remote places in the winter. What's the best tool to carry with you? An axe. -- Survivorman, Discovery (SCI) Channel Web Page: Article: 219561 of rec.radio.amateur.antenna From: K7JEB Subject: Re: Antennas-History (What's Going On?) Message-ID: References: <11okfpommc4nd0b@corp.supernews.com> <%nCif.2054$Hk1.1653@newsread1.news.pas.earthlink.net> Date: Mon, 28 Nov 2005 07:20:05 -0700 On Mon, 28 Nov 2005 12:05:15 GMT, "W. Watson" wrote: > ...Maybe I'm thinking of (hoping for) some grand > unified radio or telescope (and methodology) that > sucks up any EM wave one can throw at it. One size > fits all. Apparently, we've got a long way to go > on that. :-) The methodology (and perhaps the viewpoint) you are looking for is... Optics. >From an Optics viewpoint, you're born with two antennas in your head (that you are using to read this). >From an Optics viewpoint, a hole in a piece of cardboard is an antenna (an aperture). >From an Optics viewpoint, radio antennas (monopoles, dipoles, yagis, Sterba curtains) are just minor peculiarities one encounters when wavelength becomes "human-sized". >From an Optics viewpoint, we've been at this for an awfully long time. Maxwell's equations and quantum mechanics are just frosting on a very large cake. A great deal of Physics has been devoted to studying electromagnetic radiation over the centuries. Unfortunately, the study of Optics is not for the faint of heart. It leads directly into the heart of the Physical Universe and things tend to get very messy, and very mathematical. However, even from the periphery, the insights are rewarding. Every time you pick up a camera, you think "antenna". Every time you see an incandescent lamp, you think "antennas" (jillions of them). Every time you see a satellite dish, you think "telescope". And so on... Jim, K7JEB Article: 219562 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Mon, 28 Nov 2005 14:33:31 +0000 (UTC) Message-ID: References: <1133173268.768403.217280@f14g2000cwb.googlegroups.com> "Saandy wrote > you can't measure SWR. ========================================= I am pleased you agree with me. ========================================= > You can CALCULATE the SWR using the formula. ========================================= But of what use is the SWR it after you have calculated it? To what transmission line does it apply? Where is it? What are the locations of max-volts and min-volts? It does NOT apply to the line between transmitter and antenna. I suggest it exists only in your imagination. ;o) It is the name of "SWR Meter" which leads to confusion, misunderstandings and arguments. The name says the instrument does something which it does not do. With the help of old-wives, novices are led astray and are stuck with incorrect ideas about standing-waves for the rest of the lives. Just change the name to TLI (Transmitter Loading Indicator) which is what it is and does very well. The true meaning and associations of SWR will then emerge and all will be flooded with the light of reason. ---- Reg, G4FGQ. Article: 219563 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antennas-History (What's Going On?) References: <11okfpommc4nd0b@corp.supernews.com> <%nCif.2054$Hk1.1653@newsread1.news.pas.earthlink.net> Message-ID: Date: Mon, 28 Nov 2005 15:20:15 GMT K7JEB wrote: > From an Optics viewpoint, we've been at this for an > awfully long time. Maxwell's equations and quantum > mechanics are just frosting on a very large cake. A > great deal of Physics has been devoted to studying > electromagnetic radiation over the centuries. In particular: An understanding of how RF reflections can be eliminated by a 1/4WL series matching section can be had from understanding how a 1/4WL layer of thin-film on glass can eliminate coherent light reflections from the surface of the thin-film. The irradiance equations which predict the power distribution of light waves undergoing interference can be used to understand RF energy flow in a transmission line with reflections. Staring at oneself in a mirror should convince any skeptical RF engineer that reflected energy actually makes a round trip to the reflection point and back and doesn't flow directly from the image-source to the eye (or to the circulator load resistor). :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219564 of rec.radio.amateur.antenna From: dt@dt.prohosting.com (David B. Thomas) Subject: Re: vert dipole vs vert Date: 28 Nov 2005 09:31:35 -0700 Message-ID: References: >>>>> "ml" == ml writes: ml> i was trying to figure loosly in real world case what the ml> difference would be (generally speaking) between say a ml> verticle all band commercial antenna on my roof (of my tall ml> apt building) i'd naturally install it's radial kit ml> vs ml> a equal all band (yeah i know it'd be tall) virticle dipole ml> (tweeked w/a tuner sgc at feedpoint The commercial vertical probably uses traps or other means to act like a quarter wave ground plane on all bands. This would be roughly equivalent, performance-wise, to a separate vertical dipole cut for each band. The issue with using the tuner is that a tall dipole used on a high frequency will throw a lot of energy up at high angles. On 15 and 10 meters, you'd probably rather have a nice low angle pattern. Then again, when those bands are open, you can usually afford to have an inefficient antenna as propagation tends to be excellent. So, if you're looking to put up something fast and cheap, the dipole and tuner idea can certainly work. If you do that, try to keep the feed line perpendicular as long as you can before it drops down. David N5IZU -- M.C. Escher had to walk to school, uphill both ways. Article: 219565 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antennas-History (What's Going On?) Date: Mon, 28 Nov 2005 10:55:40 -0600 Message-ID: <7955-438B368C-194@storefull-3256.bay.webtv.net> References: Wayne Watson wrote: "What about the underlying methodology behind this?" Please refer to the 3rd. edition of "Antennas for All Applications", by John D. Kraus with a host of other professors, for answers to nearly all your questions. Kraus organizes antennas by types. The dipole is the simplest complete antenna. But, the first practical antenna was patented by Marconi. He was interested in communications over the ocean, so only 1/2 of a dipole is needed. The return circuit is provided by the ocean. Sea water is nearly lossless. Marconi imagined the antenna as a capacitor plate.. Then he discovered the antenna worked about as well with just the connectng wires inplace, without the plate. As the 19th century turned into the 20th century, Marconi spanned the Atlantic with signals from his antennas. Best regards, Richard Harrison, KB5WZI Article: 219566 of rec.radio.amateur.antenna From: "Christopher O'Callaghan" Subject: Send spam this way Date: Mon, 28 Nov 2005 17:36:02 -0000 Message-ID: sallowswayne@aol.com send all the spam you want to this address..I can then forward this to piss of my enemy..... Article: 219567 of rec.radio.amateur.antenna From: "Caveat Lector" References: Subject: Re: Antennas-History (What's Going On?) Message-ID: Date: Mon, 28 Nov 2005 09:50:10 -0800 I think many antenna designs arose as a matter of "necessity is the mother of invention" For example here is a Yagi antenna quote from URL: http://ieee.cincinnati.fuse.net/newsletters/200405.pdf At Tohoku, Yagi initiated a research program in radio-electronics drawing on what he had learned from Barkhausen, Fleming, and Pierce. Other members of the faculty and advanced students, including Okabe and Shintaro Uda, became participants in a collective research effort. A perceived need for better communication between islands and with ships led them to focus on short wave communication with directive antennas. The Yagi group received financial support for the research from a private foundation in Sendai. In February 1926, Yagi and Uda published their first report on the wave projector antenna in a Japanese publication. For the Cubical Quad see URL: http://www.antennex.com/preview/Jan501/quad1.htm Clarence Moore, the station engineer at HCJB in Quito, and some colleagues took along with them a stack of antenna and engineering texts and a Bible on a Sabbatical in 1942. Their urgent goal was to come up with an antenna that wouldn't consume itself by corona discharge when fed with high power, as was happening to their Yagi, at the high Andean altitude of their station. A full wave loop solved the problem. Some remarkable antenna designs today because of the need to fit an antenna on a cell phone. For direction finding, loops, interferometers, etc were needed ETC -- CL -- I doubt, therefore I might be ! "Wayne Watson" wrote in message news:o4qif.1890$Hk1.1683@newsread1.news.pas.earthlink.net... >I hardly know where to start with this topic. If one picks up some of the > fairly popular (available?) books on the matter, the authors invariably > start throwing different types of antennas at the reader, yagi, helical, > dipole, folded dipole, parabolic, loop, dish, microwave, quads, etc. For > example, I'm looking at an older book on the topic I bought some 20 years > ago, The Radio Amateur Handbook by Orr and Cowan. The book is basically > for > builders. Many such books are. What about the underlying methodology > behind > this? More generally, here's my question. > > I would guess that in the beginning (late 1800s) the simple dipole was it. > As years passed, the complexity of antennas has increased. What was the > driving force for these changes? For example, how did the inventor of the > Yagi (Yagi-Uda) ever dream up the idea for the antenna? Was it the > application of theory or did he just get lucky? In fact, is there some > underlying theory that drives the design of antennas? For example, the > computation of radiation patterns. I'm sure these days the computer would > be > an aid, but what theory and application drove the development of varied > designs before 1960? When did Maxwell's equations seriously get used for > this? What suggested a tin can could become an antenna? How did anyone > think > up the idea of a microwave antenna? > > I would think that in the case of antennas that are used for different > parts > of the EM spectrum a driving force would be the consideration of the wave > itself. For example, it would seem unlikely an x-ray antenna (I believe > there is such a thing on one of the space satellites used in astronomy) > would be anything like one used to receive TV. Certainly the 'antenna' to > collect visible light is different than that for AM radio. > > -- > Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA) > (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) > Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet > > Traveling in remote places in the winter. What's the best > tool to carry with you? An axe. > -- Survivorman, Discovery (SCI) Channel > > Web Page: > > > Article: 219568 of rec.radio.amateur.antenna From: "Jerry Martes" References: <1133173268.768403.217280@f14g2000cwb.googlegroups.com> Subject: Re: SWR again. Message-ID: Date: Mon, 28 Nov 2005 17:54:35 GMT "Reg Edwards" wrote in message news:dmf4fr$4cu$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com... > > "Saandy wrote > >> you can't measure SWR. > ========================================= > > I am pleased you agree with me. > > ========================================= >> You can CALCULATE the SWR using the formula. > ========================================= > > But of what use is the SWR it after you have calculated it? > > To what transmission line does it apply? Where is it? What are the > locations of max-volts and min-volts? It does NOT apply to the line > between transmitter and antenna. I suggest it exists only in your > imagination. ;o) > > It is the name of "SWR Meter" which leads to confusion, > misunderstandings and arguments. The name says the instrument does > something which it does not do. With the help of old-wives, novices > are led astray and are stuck with incorrect ideas about standing-waves > for the rest of the lives. > > Just change the name to TLI (Transmitter Loading Indicator) which is > what it is and does very well. The true meaning and associations of > SWR will then emerge and all will be flooded with the light of reason. > ---- > Reg, G4FGQ. Hi Reg I recognize that you know far more about VSWR and measuring complex load impedances than I do. I'm writing this to represent the "other side" of an arguement that states that VSWR *cant* be measured. I claim that VSWR *can* be measured and that VSWR can be used to identify the impedance terminating the transmission line. Jerry Article: 219569 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: SWR again. References: <1133173268.768403.217280@f14g2000cwb.googlegroups.com> Message-ID: <6lIif.25353$Zv5.17910@newssvr25.news.prodigy.net> Date: Mon, 28 Nov 2005 18:51:46 GMT Jerry Martes wrote: > I claim that VSWR *can* be measured and that > VSWR can be used to identify the impedance terminating the transmission > line. The tuner SWR meter only indicates the SWR on the 50 ohm coax between the transmitter and the tuner. However, I have an SWR meter on the antenna side of my tuner and it does indeed indicate the SWR on my transmission line. XMTR--SWR meter#1--tuner--SWR meter#2--50 ohm coax to a G5RV SWR meter#2 does indeed indicate the SWR on the coax feed to my G5RV. It obviously does not indicate the SWR at the antenna. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219570 of rec.radio.amateur.antenna From: Bruce in Alaska Subject: Re: Station ground/2nd floor References: <4asjo1hv946ve2l5u17c1j8bmcruubei6t@4ax.com> <_cnif.19157$BZ5.14535@newssvr13.news.prodigy.com> <_Tnif.606420$xm3.396820@attbi_s21> <438A3123.AC0E860D@shaw.ca> <438A539F.B05A771D@shaw.ca> Message-ID: Date: Mon, 28 Nov 2005 18:55:08 GMT In article <438A539F.B05A771D@shaw.ca>, Irv Finkleman wrote: > Cecil Moore wrote: > > > > Irv Finkleman wrote: > > > Why not run two ground wires in parallel -- one twice as long as the > > > other? When one is Hi-Z the other will be Lo-Z and vice versa. > > > > That will help on some frequencies but it is akin to trying to > > erect a 1/2WL fan dipole for all frequencies - can't be done. Sooner > > or later, you will run into a frequency where length #1 is N*1/4WL > > and length #2 is (N+1)1/4WL. "It's not nice to fool Mother Nature." > > -- > > 73, Cecil http://www.qsl.net/w5dxp > > OK then, I'll use 3 wires and take my chances! :-) > > Irv If you are on in a building that has prestressed concrete floors, and coloums, try using the ReBar in the concrete as your RF Ground. When I built my house on a concrete slab, before the pour I brought up a steel strap bonded to the rebar and steel mesh in the radio room. it was a very effective RF Ground clear down to 500Khz. Bruce in alaska -- add a <2> before @ Article: 219571 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: SWR again. Message-ID: <5kmmo1tmlbj5s3chhgqi5a0a7tk35ggj4s@4ax.com> References: <1133173268.768403.217280@f14g2000cwb.googlegroups.com> Date: Mon, 28 Nov 2005 19:36:28 GMT On Mon, 28 Nov 2005 17:54:35 GMT, "Jerry Martes" wrote: >that VSWR *cant* be measured. I claim that VSWR *can* be measured and that >VSWR can be used to identify the impedance terminating the transmission >line. Jerry, unless you redefine the term "impedance", you cannot generally measure impedance with a typical reflectometer style SWR meter. Impedance is a complex quantity (ie with real and imaginary parts). There are an infinite number of different impedances (being combinations of the real and imaginary parts) that could cause a given SWR on a given line in most cases. (The exception is the case when VSWR=1, you do know the impedance, it is the nominal Zo for which the instrument was calibrated.) Whilst you can work out the SWR that will result from a specific impedance on a specific Zo line, you cannot do the inverse, you don't have enough information. Owen -- Article: 219572 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: SWR again. Date: Mon, 28 Nov 2005 20:10:13 +0000 (UTC) Message-ID: References: <1133173268.768403.217280@f14g2000cwb.googlegroups.com> "Jerry Martes" wrote > I'm writing this to represent the "other side" of an arguement that states > that VSWR *cant* be measured. I claim that VSWR *can* be measured and that > VSWR can be used to identify the impedance terminating the transmission > line. ======================================== The only way to measure SWR on a transmission line is to run a voltmeter along it. At least TWO measurements are needed. Not ONE. And line length is involved. The voltmeter readings will indeed tell you what the SWR is. But nothing else. It will be possible to calculate from the readings and the distance between max and min what the velocity of propagation is. But it is essential to add extra critical information before anything else can be deduced. Without this EXTRA information knowledge of the SWR (if it can be obtained) is useless. The so-called SWR meter does not and cannot provide this information. To calculate the terminating impedances from the SWR it is neccsary also to know the line impedance, its velocity and the exact locations of the max-volts and min-volts relative to the ends. The meter will not tell you. And the foregoing is on a line which exists only in one's imagination. I am sorry to repeat, the indications of the SWR meter apply only to the input impedance of the line from the transmitter to the antenna. The meter, in itself, tells you nothing about what is happening to conditions along the line. It c