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On Tue, 12 Apr 2005 22:09:38 -0700, Frank Gilliland
wrote: On Tue, 12 Apr 2005 08:02:09 -0400, Dave Hall wrote in : On Fri, 08 Apr 2005 18:27:15 -0700, Frank Gilliland wrote: On Fri, 08 Apr 2005 13:59:47 -0400, Dave Hall wrote in : snip Maybe you had difficulty, but there are a very large number of hams -and- CBers who don't share your ineptitude. A dipole is a dipole. It has 0 db of gain, Wrong. A 1/2-wave Hertzian dipole has a gain of roughly +3 dBi in free space. Isotropic is a theoretical spherical reference model which does not exist in reality. A dipole is THE reference antenna, by which most credible gain claims are based against. Antennas are referenced to either or both because both are constants. Yes but referencing a theoretical model whose characteristics cannot be realized in the real world, is somewhat disingenuous. A 1/2 wave dipole is a standard reference antenna in the real world. It has 0 dB when referenced to itself. Isn't that what I just said? Unfortunately, yes, that's exactly what you said, and it's absolutely dumb since -every- antenna has 0 dB gain in reference to itself. But we don't reference an antenna against itself, we reference it against a 1/2 wave dipole, a reference antenna which has unity gain. Then it's no longer a half wave dipole. You are now talking double ended zepp designs, which do exhibit gain over a 1/2 wave dipole But you didn't say "half wave dipole". You said only "dipole" which could be any kind of dipole, be it a double-ended Zepp or the rabbit ears perched on top of your overused television set. When the facts fail, argue semantics. When that fails, make unfounded speculations about another's recreational habits. But that just makes me smile :-) If the dipole is non-resonant and requires a tuner to force an impedance match, it will have further losses. Wrong again. A tuner only adds insertion loss, which is usually quite small if it's built with quality components. The insertion loss is easily overcome by slightly increasing the length of the elements, which is no big deal since the antenna is already non-resonant. You fail to consider the standing waves which will still be present in the feedline due to the mismatch. A tuner only presents a proper match to the transmitter. With a high mismatch in the feedline, losses increase as well and creating a tendency to radiate from the feedline. In order to compensate for this the tuner should be mounted at the feedpoint of the 4:1 balun that is normally used to feed 450 Ohm ladder line to such designs. But such is impractical for guys who change bands and frequency often, unless the tuner is automatic. -YOU- failed to notice that I made no mention of a transmission line, although I -did- reference a page from a ham that used ladder line. A lot of inexpensive tuners include a 4:1 balun for a balanced output, and SWR losses on ladder line are negligible. The only SWR you need to worry about is between the radio and tuner. Silly me for assuming that an antenna needs feedline to connect to it. Only an idiot would run 200 feet or more of open 450 Ohm ladder line. Unless of course, you don't care about feedline radiation and RFI issues. Most antennas which are designed to use ladder line, are also spec'ed for a certain fixed length of the ladder line as part of its impedance match. At that point a balun is connected and the rest of the feedline completes the usual configuration. If you were a ham, you'd know this. But keeping with the original perspective, of a simple antenna system for Vinnie, this falls far short of that objective. Simplicity dictates buying an Imax or Antron and sticking it in a tree or on a pole. Plug-n-play. You can't get much simpler than that. The complexity arose when you threw a fit after my suggestion that Vinnie might want to try and make his own antenna. I threw a "fit"? Hardly. I have no problem with anyone making their own antennas. That's what ham radio is all about. BUT, when the suggestions you made were for antennas which do not perform well for the intended use, I felt compelled to point this out. You are not going to throw a couple of wires up in a tree, tune them with a tuner and expect it to perform as well as a commercial (or homemade if you're so inclined) gain-type, purpose-built, vertical antenna. It won't stand a chance against a commercially produced (or home made if you are so-inclined) 5/8th wave vertical (with proper radials, not an Imax). Well guess what, Dave -- a 5/8-wave antenna is a non-resonant antenna and requires some method of impedance matching. Thank you. A 5/8 wave is most certainly resonant. It's just that the feedpoint impedance is high and needs to be transformed. It's a different issue than forcing a match from something that is not resonant naturally. You never fail to amaze me with your repeated offerings of technical ignorance. Time for your next lesson: Spare me your sanctimony. You still don't get it. A tuner is a device that is used to transform impedances. It has two ends: an input and an output. Therefore, it connects to two devices: a source (transmitter in Tx) and a load (antenna in Tx). The input of the tuner is adjusted to match the output impedance of the source, and the output of the tuner is adjusted to match the input impedance of the load. And I hope it's safe to assume that you already know that much. Thanks for pointing that out. I was beginning to wonder if you knew what a tuner actually did. But what you fail to realize is that impedance can be resistive, reactive, or both. And since a tuner isn't limited to transformation of resistances only, you can use a tuner to compensate for the reactive component of the load (e.g, a feedline with SWR or a non-resonant antenna). My god! An antenna has reactive components? Who'd have thunk it? That's for sharing yet another revelation. Now what happens when you use a tuner to cancel the reactive component of a load? Think hard, Dave..... reactive components cancel..... can you figure it out by yourself? No, I didn't think so. The tuner and the load become RESONANT. So you use a tuner to make a resonant antenna -system- using a non-resonant antenna! And that's exactly what is happening when the input impedance of a 5/8-wave antenna is "transformed" so it can be driven from a resistive source -- a non-resonant antenna is brought to resonance with a tuner. A tuner forces a resonant load from something which isn't resonant naturally. That's sort of like keeping someone alive with a respirator. You can (and I have) loaded up large metal objects (like rain gutters and bedsprings), and force them to have a 1:1 SWR. But that doesn't mean that the antenna is an efficient radiator. That's my whole point. Now for your lesson in real life application of antenna principles: I was completely out of CB between 1990 and 1993, and I took down all of my CB antennas. When I got the bug to get back into CB again, I had the following antennas: a horizontal 10 meter dipole, a 5/8th wave 2 meter Ringo Ranger 2, a 6 meter 3 element beam (horizontal), a 2 meter 10 element Cushcraft "twistbeam" (horizontal & vertical), and a Diamond tri-band 146, 220 and 440 Mhz vertical. Now, I also had at my disposal a tuner. I could load up every antenna in that list on the CB band, with a less than 1.5:1 SWR. Out of that list of antennas, the only one which worked somewhat acceptably was the 2 meter Ringo Ranger, as it was about a 1/4 wave long at CB frequencies. It was also at the top of my tower. The 10 meter dipole loaded the easiest, but being horizontal, wasn't much use for local talking. Sometime later, I put my Avanti Sigma 4 back up, and it wasabout 2 "S" units stronger transmitting to others, on average, than the 2 meter Ringo through the tuner. THAT is the difference between theory and practice. Sure you can load up a non-resonant antenna and it will "work". But it won't work as well as an antenna designed for the band. Geez Dave, you sure are a dumbass. I'm not the one reading a book on antenna theory and trying to pass it off as actual experience. A horizontal dipole can have a wide variation in take-off angle depending on height above ground, ground resistance, proximity to other structures or objects, etc. Yea, so? And the noise floor may be slightly lower but that's a product of it's directivity, as compared to a vertical which is omnidirectional. No, it's a product of the fact that most atmospheric and man-made noise tends to be vertically polarized. Wrong. Noise "tends" to have the polarity of the sources. The sources of noise can be mostly vertical -or- horizontal depending on a number of factors, not the least of which are geographic location, time of day (as well as season), solar activity, band of operation...... Time to read another book Frank. Or better yet ask a ham. The greatest majority of noise is vertically polarized. Maybe if you have been paying attention in those theory classes instead of "teaching" logic classes, and trying to book whip your way through psychology 101, you might know this. Like I said before, just throw some wire up into the trees (or whatever tall object happens to be available). Didn't you read the link I posted? Of course. But a dipole is a basic antenna. It has no gain. Wrong again. As I said before, a 1/2-wave Hertzian dipole in free space has about 3 dB gain over an isotropic antenna; but a dipole is merely an antenna with two elements and is not limited to a 1/2-wave Hertzian configuration. Not only that, but a tuner isn't limited to dipole antennas -- they can load up a long-wire just as easily. Ah, so you're changing the parameters of the discussion. Long wires are inefficient on CB as well. Been there, done that. I changed nothing. You probably had a problem with the long-wire antenna because you were expecting an omnidirectional pattern, which a long-wire does not have. It does (at least in the "H" plane) if it's mounted vertically. But that's impractical for HF use. It -does- have very sharp lobes with high gain, and if you know where to point them then a long-wire antenna works just dandy; as you say, "been there, done that". Where Frank? Where have you "been there and done that? You don't have a ham license. Commercial radio stations don't play with wire antennas. Wire antennas are awkward and do not work well on CB for local talking. So where Frank? What's your call sign Frank? I understand that you have a problem with reading comprehension, but what part of "I am not a ham" did you not understand? You are starting to sound like Twisty -- are you going to start accusing me of being five different hams? The point is, as it has always been, that you glaringly lack the necessary experience to back up your claims. Frank, all the king's horses and all the books you read will not make up for your glaring lack of experience. Get out from behind the table and DO something, and then report back. Are you suggesting that after being a CBer since I was a kid, serving several years in the USMC working on radios from LF to microwaves, several more years in a commercial radio shop, several -more- years as a BE, being self-employed as a both a tech and an engineer for most of my life, and currently experimenting with weak-signal reception on the 1750m band and below 9khz, that I don't have any experience in radio? Exactly. Other than the military (Which doesn't have the time to play with gimmicky wire antennas) I have had way more experience. I was playing with the 170 Khz band when I was a kid, along with 35 years of CB experience, 24 years of ham experience, and being employed as a tech and engineer for a few high tech firms as well as 30 years of hands on CB, ham radio, and stereo repair. Dave, you're an idiot. Takes one to know one ;-) Antenna tuners were available as an accessory for CB for less than the cost of a good SWR meter. Granted they were simple coaxial in and out tuners. A tuner requires readjustment when changing channels within the CB, and most CBers don't want to deal with the hassle. So you are now claiming that CB'ers are too "dumb" to handle that? Where did I suggest anything of the sort? By suggesting tha using a tuner is a "hassle". It's not if you understand how to use it. And to add further evidence to your lack of experience with CB, it was common that "matchboxes" were often used by CB'ers to "correct" a mismatch within their antennas. Instead of taking the time to properly tune the antenna, they forced the match with the tuner. The radio was happy, as it saw a 1:1 SWR, but the signal was not so good. When a more knowledgable person would finally retune the antenna, and the tuner was removed, signal improved considerably. Wrong. Those little matchboxes (I still have a couple Johnsons) were popularized during a time when a 1:1 SWR was widely considered to be the holy grail of antenna tuning, that you needed to squeeze every milliwatt from the radio. That attitude changed, and fewer CB tuners were built, as more and more CBers learned that a few points on the meter make very little difference. Maybe that's what your inexperience has taught you, but that's not what actually happened. Yes, there were a few people out there who cringed when their SWR crept above 1.5:1. The difference that a matchbox provided did not overcome the insertion loss. But that's not the cases I was making. There were people who had serious mismatch problems (over 3:1) because they did not know how to properly tune the antenna. They then compensated for their blunder by forcing the SWR to 1:1 with a tuner. The radio was happy, but the antenna was not radiating efficiently and their signal potential was cut considerably. When the real problem was corrected, and the tuner removed, their signals increased. The point, of course, is that if what you stated before was correct, you should be able to radiate a signal just as well with an antenna which was not in tune (non-resonant) through the use of a tuner to "force" a resonance, than with a naturally resonant antenna. My own personal experience in this exact scenario proves exactly the opposite. Regardless, there are still many CBers that do indeed use a tuner, not just with prefab antennas but also with homebrew and beverage-can hooks. None of which are worth a tinker's dam for local CB communications. You say that as if you have evaluated every antenna ever built. No, but I have played with most of more the common home made antennas which a CB'er would be most likely to utilize. When you're young and have a lot of time, you tend to experiment alot. I did. Yet you haven't been here to evaluate -my- antennas..... have you been playing with your crystal ball again, Dave? What, you have some "miracle" antenna design that no one else has ever played with? What could possibly be so special about YOUR antennas Frank? Let me guess, you spray them with Teflon? You should give up on the crystal ball Frank. It didn't work for you, so you should know that it wouldn't work for me. And just about every CBer who runs a tube linear uses a tuner because it's built into the amp, which by itself blows big holes in your "practical" argument. Not at all. A tube amplifier requires a tuner because the impedance of a tube is much higher than 50 ohms, and needs to be transformed. It's not practicality, it's necessity. It's not "necessity" since the amp is not a necessity -- there is always the alternative of using a solid-state amp, or no amp at all. It's a necessity if you use a tube amp and want it to work. Please stop with the semantics. If your argument is that weak, you should just stop. A non-resonant dipole has ONE big advantage. It's a compromise antenna that will work on all the HF bands. That's great if you don't have the room to put up single band antennas for each band. But like any compromise, it will not work as well as a dedicated antenna for each band. Such a compromise is usually acceptable for a ham who has 1500 watts on tap. But for a 4 watt CB'er, who needs to squeeze every watt of ERP he can for best local range, he needs a high gain efficient antenna. If that were the case then every CBer would have a 5-el yagi on a 30' mast and a 9' whip on their vehicles. Most high performance CB'ers do. So most high performance CBers spend their time and money on equipment designed to maximize their 4 watts? A typical high performance CB'er will spend his money on the best antennas that he can afford. Whether he stays at 4 watts is a personal choice. It makes little sense to spend money on a big "honkin'" amp and then **** that power into a poor antenna. The name of the game is ERP, and that's a combination of transmitter power (minus feedline and other losses) and antenna gain. The fact that you keep asking, makes me all the less likely to tell you. Yet another cop-out. You probably sent in for one of those mail-order schools and never finished it. Sort of like that college degree that you allege that you have (yet you tend bar). I don't have to provide any credentials to you or anyone else. As long as there are people here who won't even fess up to their real names, I owe no one any of my personal information. Frank, your experience with both ham and CB radio is sorely lacking. You read a few books and web sites and think you have all the answers. OTOH, I've walked the walk for the last 30+ years and have played with more antennas and equipment than I can remember. I have also been in contact with people in the know when it comes to antennas. What I know, I know through experience, and that's worth 10X what you read in any book. Which explains why your theory is severely lacking. If you took the time to actually learn why these things work and -then- applied them to your experiences, you could be the guru you think you already are. But you don't and you're not. Instead you do things backwards: you theorize about radio based on your own experience, then read only enough to validate your own conclusions whether they are right or not. If the evidence supports the theory, then it's valid. If not, then the theory is wrong. Then where are the facts to support your theories, Dave? I provided them. The results of my experience. .....gee, that sounds familiar..... I seem to recall challenging you to produce facts in previous discussions, but you never came up with any. Why should this time be any different? I've provided plenty of information when I felt you were worthy of such. But after you discarded them as rubbish due to your intrinsic bias, I decided that you were not one who wanted any enlightenment. Your mind was made up and anything I provided, you would simply categorize as "propaganda". When I provided a link to the usage of the term "drying out" in reference to electrolytic capacitors, you similarly discarded that as "erroneous". Therefore I am not about to waste any of my time trying to prove anything to you. You have basically joined Twisty in my bucket of punch clowns, a verbal sparring partner. Your biggest problem is your pompous arrogance. You are a perfect example of someone who is book-smart and street foolish. You will sit there and tell people, who do these things every day, exactly why they can't possibly work. Where have I -ever- said anything of the sort? I would be wasting my time to suggest that you revisit your past performances here in an objective fashion. While we sit here and laugh at you, because we've been there and done that. Who is "we"? You and your imaginary groupies? Look around and you'll see. Check the archives Frank. You've been on the butt end of many other debates with people who possessed clearly superior knowledge. All of the fancy obscure terminology and tap dancing you used couldn't hide your lack of experience. Check this out, Dave: Education doesn't come from a textbook that some geek sat down and wrote just for ****s and giggles. It's a compendium of knowledge that has been collected from over a century of research, experimentation and practical experience by experts in all aspects of the field. Those experts didn't become experts simply by playing with CB radios as a hobby for 30 years. And an education doesn't include a couple textbooks, a few lectures and a test -- it also includes years of experience with the practical application of that knowledge. No kidding. You seemed to have failed the "practical application" aspect. Hell, you never even heard of the term "drying out" in reference to electrolytic capacitor aging, Where did I say that I had never heard the term before? I didn't. What I -did- say was that it was an inappropriate term. According to you. Many others, who I hold a much higher level of respect for, don't see it that way. And not to forget that the subject came up because you deviated from the topic of how you used your crystal ball to divine the cause of a CB malfunction. Based on my own extensive personal experience. A doctor doesn't have to see a pathogen in a patient to properly diagnose it. He bases his diagnoses on symptoms and past experience. It's not 100% accurate, but it's a good start. It's better than random generic suggestions of checking this and checking that. and you try to cover this glaring hole by claiming a pompous, superior attitude as if this was beneath you. No, -you- are beneath me, Dave, and that's where you'll stay until you pull your head out of your ass. You know, the no-code license is not that hard Frank. A guy with time on his hands like you, should have no trouble with it.... When you mock those that have a formal education and extensive experience in electronic communication then you mock the same people who made the television set you watch way too much, the telephone and cell-phone infrastructure that keeps this world talking, the NASA and JPL engineers who communicate with space probes billions of miles away, etc, etc, etc. I'm not mocking them. Of course you are. You mock the very idea that anyone with an education could know more about radio than what you have learned from playing with toys for 30 years. I'm not mocking them, I am them. I just played in the sandbox of experimentation before I got my schooling. With that perspective, I was able to concentrate on practical theory and discard the stuff that we never use. You think that just because you learned something on your own that nobody else has the right to profess such knowledge, and just because they didn't 'earn' it like you did. Now who's projecting with the crystal ball? Yet instead of improving yourself by learning something new you focus on the biggest difference between us -- an education -- and try to hold it against me as some kind of professional malfeasance. But there is no real difference in education. You ASSUME that I don't have a comparable education to you because I refuse to devulge that information. But I can tell you that I'm not the one tending bar right now. I am putting my education AND experience to work for me. Well, that has to be one of the most ridiculous arguments that was ever conceived: "You is dumber'n me cuz you gots a ed-u-kashun." No, you are not "dumber" than me because you have an education. You are "less informed" because you have much less practical experience. My beef with your education is your over reliance on it and how you hold it up as some sort of badge of honor, not too unlike some hams do with their licenses. An education, without the ability to apply it, is almost useless. They know what they are doing. And I work with many of them on a daily basis. You probably have products in your home (or will) that I have had a part to play in their development. You delivered the pizza for the engineers when they were burning the midnight oil. BFD. When all else fails, resort to pure insults. What will you do, when your bar starts a delivery service and they ask you to participate? You are far closer to a delivery boy than I'll ever be. You might want to save now for a 10 year old vehicle that's more dependable. I work in the field every day. What "field" is that, Dave? The field of dreams? The field of communications technology. I work in the field. You, on the other hand, are like the farmer, out standing in it. I am not mocking them, I am mocking you. You who CLAIM to be educated, but evidence suggests you are sorely lacking in practical application of whatever it is you might have learned. Shall I make a list of what I have taught you about radio and electronics since the last list? How long ago was that.... just a couple months ago, wasn't it? You now arrogantly claim to have taught me something? You're as bad a Twisty who thinks he teaches me about radio law. Neither one of you do anything more than dance to smoke and mirrors and the twisting of words. While I may not have participated in any world-changing technology, I certainly have an education and the experience in the field that puts you to shame. While you tend bar and drive a 20+ year old truck...... Now your memory is failing, Dave -- did you forget so soon that I'm currently designing and building a studio? So you claim. That and 50 cents can't even buy a decent cup of coffee. I can claim that I'm installing the new digital video links at ABC too. It's going to take an extra week because of the late-season snow in the pass (can't get any decent acoustic panels in Spokane), but I didn't lose any money because of the delay -- I still get $5k for the job when it's done, which is a lot more than you get delivering pizzas in your lime-green Gremlin. He he heh heeh hoo hooo hoo LOL. I love it when you get personal Frank. I can almost see the beads of spit on your monitor. My bonus this year was more than that, and I didn't have to drive through snow to get it. Yet -you- try to teach -me- theory based on your education from a third-rate vocational tech school, a few years in a CB shop, and your experience in =amateur= radio. As far as you know. Don't even -hint- that you have any kind of technical or engineering job in the radio/electronics field because I'm not buying it for one second. You have proven your ignorance on the subject so many times that it's well beyond the realm of probability. Yet it is a true fact nonetheless , which only outlines just how far off you are. But it is evidently light years ahead of those internet websites you lift your information from while you sit at home alone with no other people to "relate" to. And here's the kicker: Do you have any idea where I came up with the idea to just throw a couple wires in the air and load them up with a tuner? A ham. Not all hams are mensa candidates. Finally..... you have provided proof for one of your claims! Ok, so you provided the proof -before- you made the claim, but at least it's a start. Ironically, what I said was not "proof" of anything. Unless, you now consider my personal observations and experience as proof. But then again, you wouldn't know that. You're not a ham (or CB'er). Dave, go back to rec.boats and learn how to float -- your boat sank here a long time ago. Frank, I was here long before you came, and I'll be here long after you leave. Call me the B.S. meter, if you will. If it stinks, I'll call attention to it. Right now you are high on the effluent level. Dave "Sandbagger" http://home.ptd.net/~n3cvj |
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