|
Best Books/Websites for Antenna Theory and Building Recommendations
Hello All,
I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Many thanks for taking the time to respond! 73's to you all! Alain...San Diego |
Best Books/Websites for Antenna Theory and Building Recommendations
On Fri, 02 Feb 2007 11:14:29 -0800, Joaquin Tall
wrote: I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Hi Alain, You can certainly buy more books than there are antennas, but really, the ARRL manual (any one of them) is enough to make your first foray. This will make it easier to ask questions, and to focus on specific needs instead of shotgunning what is available. The best advice is to remark that all antenna designs can be scaled to any other frequency. The building details are the sticky part. 73's Richard Clark, KB7QHC |
Best Books/Websites for Antenna Theory and Building Recommendations
Joaquin Tall wrote:
Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Many thanks for taking the time to respond! 73's to you all! Alain...San Diego Alain Here is one of the best single sources on the net, L. B. Cebik. Worthwhile reading, and lots of it, about antennas of all types, and a lot more besides. Did I get the commas correct Richard? http://www.cebik.com/radio.html tom K0TAR |
Best Books/Websites for Antenna Theory and Building Recommendations
On Fri, 02 Feb 2007 18:15:19 -0600, Tom Ring
wrote: Did I get the commas correct Richard? No. Commas can be used to clear cloudy sentences. You did that in the first sentence, but you also had the suggestion of a comma splice later. Proper usage would have been to replace it with a semicolon, or eliminate it (break the splice) to make another sentence. However the second sentence is not a sentence, much less two of them. There is no predicate. So discussion of proper comma usage is largely moot. I am sure most followed the thoughts through to completion without a blip in understanding. English is quite flexible in that regard. 73's Richard Clark, KB7QHC |
Best Books/Websites for Antenna Theory and Building Recommendations
Alain
The ARRL Antenna Hand book is considered a standard http://www.arrl.org/catalog/?categor...+Propaga tion L. B. Cebik, W4RNL has a weath of antenna information - see URL: http://www.cebik.com/radio.html Lots of Antenna projects on the web (homebrew) at URL: http://ac6v.com/antprojects.htm This links to many other web sites -- kinda of a roundup of antenna web sites Also a very popular author of Antennas is William I. Orr -- His books can be found on Amazon.com http://www.amazon.com/W6Sai-Hf-Anten...e=UTF8&s=books 73 and good radiating CL "Joaquin Tall" wrote in message ... Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Many thanks for taking the time to respond! 73's to you all! Alain...San Diego |
Best Books/Websites for Antenna Theory and Building Recommendations
Richard Clark wrote:
On Fri, 02 Feb 2007 18:15:19 -0600, Tom Ring wrote: Did I get the commas correct Richard? No. Commas can be used to clear cloudy sentences. You did that in the first sentence, but you also had the suggestion of a comma splice later. Proper usage would have been to replace it with a semicolon, or eliminate it (break the splice) to make another sentence. However the second sentence is not a sentence, much less two of them. There is no predicate. So discussion of proper comma usage is largely moot. I am sure most followed the thoughts through to completion without a blip in understanding. English is quite flexible in that regard. 73's Richard Clark, KB7QHC Well, I knew it was botched up, since I botched it intentionally, which is why I asked. I was sure that you would have an answer worth reading. ;) I am curious as to why I seldom see my own posts, and even then only after a long delay, while I get most others almost immediately. Obviously my post showed on your news server within minutes of my sending it. I still haven't seen it here. tom K0TAR |
Best Books/Websites for Antenna Theory and Building Recommendations
On Fri, 02 Feb 2007 19:26:27 -0600, Tom Ring
wrote: Well, I knew it was botched up, since I botched it intentionally, which is why I asked. I was sure that you would have an answer worth reading. ;) Hi Tom, Commas are a recent invention for language and quotation marks even more modern. One writer, outraged by his publisher's demand that he use punctuation put them all at the end of his book and invited readers to draw from them and season his words as they pleased. I am curious as to why I seldom see my own posts, and even then only after a long delay, while I get most others almost immediately. Obviously my post showed on your news server within minutes of my sending it. I still haven't seen it here. NNTP feeds are a strange thing. I'm surprised that it works. There have been years when I had to wait quite long to see my own posts. I am also surprised how computers can flip their bits a billion times a second, and manage to not get lost (so often). 73's Richard Clark, KB7QHC |
Best Books/Websites for Antenna Theory and Building Recommendations
"Caveat Lector" wrote in message ... Alain The ARRL Antenna Hand book is considered a standard http://www.arrl.org/catalog/?categor...+Propaga tion L. B. Cebik, W4RNL has a weath of antenna information - see URL: http://www.cebik.com/radio.html Lots of Antenna projects on the web (homebrew) at URL: http://ac6v.com/antprojects.htm This links to many other web sites -- kinda of a roundup of antenna web sites Also a very popular author of Antennas is William I. Orr -- His books can be found on Amazon.com http://www.amazon.com/W6Sai-Hf-Anten...e=UTF8&s=books 73 and good radiating CL "Joaquin Tall" wrote in message ... Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Many thanks for taking the time to respond! 73's to you all! Alain...San Diego Some elementary books have some strange explanations, this is because they are trying to explain something to someone who probably doesnt have the proper background yet.They are well meaning and are a great help at getting the novice on the air. One such mistake is calling a 4 ft long antenna that has a coil to make it resonate on the 10M band a "10M loaded 1/4 wavelength antenna" . Actually this would be an 1/8 wl antenna more or less. So watch out Jimmie |
Best Books/Websites for Antenna Theory and Building Recommendations
Jimmie D wrote:
One such mistake is calling a 4 ft long antenna that has a coil to make it resonate on the 10M band a "10M loaded 1/4 wavelength antenna". They should be more careful and specify that they are talking about electrical lengths, not physical lengths. For instance, the following stub is electrically 90 degrees long even though it is physically only 38 degrees long. 1/4WL stub -------------------+-------- 27 deg, Z0=500 11 deg, Z0=50 Incidentally, this is how a loaded antenna can be 90 degrees long electrically while being physically much shorter than 90 degrees. -- 73, Cecil http://www.w5dxp.com |
Best Books/Websites for Antenna Theory and Building Recommendations
On Feb 2, 11:14 am, Joaquin Tall
wrote: Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. Many thanks for taking the time to respond! After you thrash your way through the ARRL Antenna book (which includes a CD with the entire searchable text.. very handy, as well as some useful planning programs like HFTA)... Another book that is quite useful are ON4UN's Low Band DXing... yes, the focus is on 40m and down, but there's lots of good construction info, as well as matching networks, etc. And, finally, I think everyone who's seriously fooling with antennas should get a copy of J. Kraus, "Antennas". This is a standard textbook on the subject, and I find it much more accessible than, say, Balanis, although the theoreticians tend to prefer Balanis, because of the rigor. Finally, if you need math stuff for antennas.. Sophocles Orfanidis at Rutgers has an online electromagnetics and antennas textbook that I find very handy (because it's online, and you can download the pdfs and carry it with you on your laptop)... http://www.ece.rutgers.edu/ ~orfanidi/ewa/ Orfanidis also has a bunch of very useful Matlab (or Octave) routines as an appendix to the book. Jim, W6RMK |
Best Books/Websites for Antenna Theory and Building Recommendations
"Cecil Moore":
Jimmie D wrote: One such mistake is calling a 4 ft long antenna that has a coil to make it resonate on the 10M band a "10M loaded 1/4 wavelength antenna". They should be more careful and specify that they are talking about electrical lengths, not physical lengths. ______________ They also should point out that, although a radiator physically/electrically shorter than needed for first self-resonance can be "loaded" to resonance, this does not mean that loaded and self-resonant radiators perform equally well in an installed system. In some applications there can be as much as a 100:1 difference in their radiated powers, for a given power at the transmitter output connector. RF |
Best Books/Websites for Antenna Theory and Building Recommendations
Richard Fry wrote:
"Cecil Moore": Jimmie D wrote: One such mistake is calling a 4 ft long antenna that has a coil to make it resonate on the 10M band a "10M loaded 1/4 wavelength antenna". They should be more careful and specify that they are talking about electrical lengths, not physical lengths. They also should point out that, although a radiator physically/electrically shorter than needed for first self-resonance can be "loaded" to resonance, this does not mean that loaded and self-resonant radiators perform equally well in an installed system. In some applications there can be as much as a 100:1 difference in their radiated powers, for a given power at the transmitter output connector. Good point, Richard. An antenna's ability to "load" is proportional to its electrical length. An antenna's ability to radiate seems to be proportional to the physical length of the antenna that is carrying the highest current. In 75m shootouts, the mobile antennas with the loading coil furtherest away from the feedpoint (closest to top-loaded) generally won the shootout. -- 73, Cecil http://www.w5dxp.com |
Best Books/Websites for Antenna Theory and Building Recommendations
"Cecil Moore" :
An antenna's abilty to "load" is proportional to its electrical length. An antenna's ability to radiate seems to be proportional to the physical length of the antenna that is carrying the highest current. __________ Perhaps unexpectedly, the intrinsic pattern and directivity of a physically/electrically short, unloaded monopole radiator are not greatly different than those of a self-resonant 1/4-wave monopole. The big problem with an unloaded, short radiator is the reactance at its feedpoint, which means that very little current will flow into the short radiator from any practical r-f source. But for the current that DOES flow in it, its radiation performance will not be much different than that of a self-resonant 1/4-wave monopole, at that same current flow (as NEC will show). Using a "loading" reactance to resonate the radiator allows maximum power transfer from the r-f source into the feedpoint. But the remaining issue is the low radiation resistance of the short radiator even when it is resonant, which is a small fraction of the other series resistances in the antenna system (ground and coil loss, mostly). As a result, much of the available transmitter power produces heat rather than EM radiation. RF |
Best Books/Websites for Antenna Theory and Building Recommendations
"Richard Fry" wrote in message ... "Cecil Moore" : An antenna's abilty to "load" is proportional to its electrical length. An antenna's ability to radiate seems to be proportional to the physical length of the antenna that is carrying the highest current. __________ Perhaps unexpectedly, the intrinsic pattern and directivity of a physically/electrically short, unloaded monopole radiator are not greatly different than those of a self-resonant 1/4-wave monopole. The big problem with an unloaded, short radiator is the reactance at its feedpoint, which means that very little current will flow into the short radiator from any practical r-f source. But for the current that DOES flow in it, its radiation performance will not be much different than that of a self-resonant 1/4-wave monopole, at that same current flow (as NEC will show). Using a "loading" reactance to resonate the radiator allows maximum power transfer from the r-f source into the feedpoint. But the remaining issue is the low radiation resistance of the short radiator even when it is resonant, which is a small fraction of the other series resistances in the antenna system (ground and coil loss, mostly). As a result, much of the available transmitter power produces heat rather than EM radiation. RF I had an electronics instructor (not sure what he knew about antennas) say thet there was a 10/90 rule about antennas. That an antenna 10 % as long as a 1/4 wl will radiate 90%as well, wile he didnt say it I assume this means with all other sources of loss minimized. Is this anywhere near true? /Jimmie |
Best Books/Websites for Antenna Theory and Building Recommendations
"Jimmie D":
RF I had an electronics instructor (not sure what he knew about antennas) say thet there was a 10/90 rule about antennas. That an antenna 10 % as long as a 1/4 wl will radiate 90%as well, wile he didnt say it I assume this means with all other sources of loss minimized. Is this anywhere near true? _____________ Theoretically yes, but not so much in practice. Without losses, an "infinitesimally short" linear dipole has 91% of the peak directivity of a self-resonant 1/2-wave dipole (1.5 vs 1.64). And for a given applied power both of them would radiate the same total amount of power, just with marginally different pattern shapes. The problem is that system losses in a real, "loaded" short antenna can be much higher than the radiation resistance, so a loaded short antenna may not radiate much of the available power -- in some applications not even 1% of it. RF |
Best Books/Websites for Antenna Theory and Building Recommendations
"Joaquin Tall" wrote in message ... Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. I will make my (usual) pitch for the j-pole antenna. Take a look at http://www.hamuniverse.com/jpole.html and see what can be done at UHF/VHF with a few pieces of pipe, some solder and a torch. The j-pole is a good match after a little fiddling, It's durable, requires no ground plane and can be mounted almost anywhere. I have made about two dozen of them for myself, for RACES and for friends in the local club. My first one (early 90's) is on the roof of my house and I used it on 2m earlier this evening, as I do most evenings. Search google.com for jpole antenna and see about 40,000 other links. The "quad antenna" and its cousin the "quagi," a quad/yagi hybrid, are also possible, but I've never built any of them, myself. The venerable whip-over-downward-radials is easy but can be tedious to tune for a good match. (I built one of them onto a construction hardhat as an novelty; got a good match, too.) I'm next door to you in Chula Vista, by the way. KD6VKW http://members.cox.net/sobars/ |
Best Books/Websites for Antenna Theory and Building Recommendations
On Tue, 6 Feb 2007 20:55:54 -0800, "Sal M. Onella"
Don't ever sell the good ol' Di-Pole short! Besides being CHEAP, it's easy to set up and take down, and not too annoying to the neighbors ether. If you got one set up, you can sling a wire under it and turn it into a "Cloud Warmer", and that has a whole lot of interesting possibility right there too. 73's FFF wrote: "Joaquin Tall" wrote in message .. . Hello All, I have just gotten my tech license and am eager to get my station up and running. I am starting on a shoestring; currently, I have no equipment whatsoever and don't know what I should buy just yet. In absence of a rig, I am now studying to pass my General license exam next month. I am very interested in building my own HF/VHF/UHF antennas. I've seen the ARRL books, but I was hoping that you good folks might have some favorite websites, book titles or magazine issues [old or new] that you'd be willing to pass along that could get me started. I will make my (usual) pitch for the j-pole antenna. Take a look at http://www.hamuniverse.com/jpole.html and see what can be done at UHF/VHF with a few pieces of pipe, some solder and a torch. The j-pole is a good match after a little fiddling, It's durable, requires no ground plane and can be mounted almost anywhere. I have made about two dozen of them for myself, for RACES and for friends in the local club. My first one (early 90's) is on the roof of my house and I used it on 2m earlier this evening, as I do most evenings. Search google.com for jpole antenna and see about 40,000 other links. The "quad antenna" and its cousin the "quagi," a quad/yagi hybrid, are also possible, but I've never built any of them, myself. The venerable whip-over-downward-radials is easy but can be tedious to tune for a good match. (I built one of them onto a construction hardhat as an novelty; got a good match, too.) I'm next door to you in Chula Vista, by the way. KD6VKW http://members.cox.net/sobars/ |
| All times are GMT +1. The time now is 08:56 AM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com