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Inverted V Question
- Thread starter Phil501
- Start date
Doc hit the nail on the head with what I was referring to with Jay's experimenting on yagis. I don't think I would argue about needing a balun on these types of antennas, but there are many different types and designs of baluns. What Jay was running into was that even though Amidon specs said it would work up to 50mhz and handle up to 10KW, as he increased power and operated around 27mhz, the balun started to have negative effects on the antenna's performance and also producing a fairly significant higher SWR. After reworking the balun design a bit, the problem was resolved. It would seem that not all manufacturer "specs" are so accurate, so you have to do a bit of research and testing before believing everything they say. That really my only point with that example.
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Doc hit the nail on the head with what I was referring to with Jay's experimenting on yagis. I don't think I would argue about needing a balun on these types of antennas, but there are many different types and designs of baluns. What Jay was running into was that even though Amidon specs said it would work up to 50mhz and handle up to 10KW, as he increased power and operated around 27mhz, the balun started to have negative effects on the antenna's performance and also producing a fairly significant higher SWR. After reworking the balun design a bit, the problem was resolved. It would seem that not all manufacturer "specs" are so accurate, so you have to do a bit of research and testing before believing everything they say. That really my only point with that example.
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Hehehe...I'm not sure I understand where you're coming from on that one, but that's OK <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/tongue.gif ALT=":b"> . If everything that was said was covered in the 12 pages, then how do you know it wasn't read? LOL Anyway, I'll admit it...I'm at work...I can't take the time right now to read it, but I will later.
I wasn't making a recommendation one way or the other on using a balun or not using a balun. I was saying that some of the manufacturer's specs on stuff is off, so be careful and check it out when you do. In the example I used, Jay was running about 3KW, not 5KW, and certainly not 10KW. And with no power, only an MJF analyzer at 27 mhz with a 50 ohm resistor across the balun (not an antenna at all), it didn't show the flat SWR that was claimed. That's called bad design or bad quality control or bad something. Again, I'm not saying baluns are bad, or don't use one. What I am saying is that noone wants to introduce a problem like Jay found into their system, so sometimes a little testing is a good idea before installation.
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I wasn't making a recommendation one way or the other on using a balun or not using a balun. I was saying that some of the manufacturer's specs on stuff is off, so be careful and check it out when you do. In the example I used, Jay was running about 3KW, not 5KW, and certainly not 10KW. And with no power, only an MJF analyzer at 27 mhz with a 50 ohm resistor across the balun (not an antenna at all), it didn't show the flat SWR that was claimed. That's called bad design or bad quality control or bad something. Again, I'm not saying baluns are bad, or don't use one. What I am saying is that noone wants to introduce a problem like Jay found into their system, so sometimes a little testing is a good idea before installation.
</p>
Hehehe...I'm not sure I understand where you're coming from on that one, but that's OK <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/tongue.gif ALT=":b"> . If everything that was said was covered in the 12 pages, then how do you know it wasn't read? LOL Anyway, I'll admit it...I'm at work...I can't take the time right now to read it, but I will later.
I wasn't making a recommendation one way or the other on using a balun or not using a balun. I was saying that some of the manufacturer's specs on stuff is off, so be careful and check it out when you do. In the example I used, Jay was running about 3KW, not 5KW, and certainly not 10KW. And with no power, only an MJF analyzer at 27 mhz with a 50 ohm resistor across the balun (not an antenna at all), it didn't show the flat SWR that was claimed. That's called bad design or bad quality control or bad something. Again, I'm not saying baluns are bad, or don't use one. What I am saying is that noone wants to introduce a problem like Jay found into their system, so sometimes a little testing is a good idea before installation.
</p>
I wasn't making a recommendation one way or the other on using a balun or not using a balun. I was saying that some of the manufacturer's specs on stuff is off, so be careful and check it out when you do. In the example I used, Jay was running about 3KW, not 5KW, and certainly not 10KW. And with no power, only an MJF analyzer at 27 mhz with a 50 ohm resistor across the balun (not an antenna at all), it didn't show the flat SWR that was claimed. That's called bad design or bad quality control or bad something. Again, I'm not saying baluns are bad, or don't use one. What I am saying is that noone wants to introduce a problem like Jay found into their system, so sometimes a little testing is a good idea before installation.
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OK, I read most of it real quick at work (shhhhh! don't tell the boss!).
Sec. 21.1, 21.2, 21.5, and 21.7 say exactly what I was referring to. The amidon balun is a transformer type balun and behaved exactly as Maxwell described it would. In fact, you'll notice in 21.7, he notes that almost all commercially available baluns are transformer baluns and thus voltage baluns. Also, you'll notice in 21.5, he says above 14mhz, a simple coax choke balun is very effective (I think someone earlier said that). For wideband coverage, in 21.6 he just says to use 50 ferrite beads over the coax, and he calls that the W2DU balun. Notes on coax choke baluns and ferrite bead usage can also be found in the ARRL antenna book.
Just going off Maxwell's material, if most commercial baluns are voltage baluns, then that's the wrong tool for the job (you need a current balun). And if operating above 14 mhz, you don't need to buy a balun when you can make a simple coax choke balun (21.5) when using a simple dipole. Also in 21.4 (effects of not using a balun), he says for 160-40 meters, the effects of current on the feedline is not a big deal, unless you're using a directional antenna like a yagi with some type of unbalanced matching system.
It looks to me like everyone is pretty much saying the same thing, but arguing about it.
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Sec. 21.1, 21.2, 21.5, and 21.7 say exactly what I was referring to. The amidon balun is a transformer type balun and behaved exactly as Maxwell described it would. In fact, you'll notice in 21.7, he notes that almost all commercially available baluns are transformer baluns and thus voltage baluns. Also, you'll notice in 21.5, he says above 14mhz, a simple coax choke balun is very effective (I think someone earlier said that). For wideband coverage, in 21.6 he just says to use 50 ferrite beads over the coax, and he calls that the W2DU balun. Notes on coax choke baluns and ferrite bead usage can also be found in the ARRL antenna book.
Just going off Maxwell's material, if most commercial baluns are voltage baluns, then that's the wrong tool for the job (you need a current balun). And if operating above 14 mhz, you don't need to buy a balun when you can make a simple coax choke balun (21.5) when using a simple dipole. Also in 21.4 (effects of not using a balun), he says for 160-40 meters, the effects of current on the feedline is not a big deal, unless you're using a directional antenna like a yagi with some type of unbalanced matching system.
It looks to me like everyone is pretty much saying the same thing, but arguing about it.
</p>
OK, I read most of it real quick at work (shhhhh! don't tell the boss!).
Sec. 21.1, 21.2, 21.5, and 21.7 say exactly what I was referring to. The amidon balun is a transformer type balun and behaved exactly as Maxwell described it would. In fact, you'll notice in 21.7, he notes that almost all commercially available baluns are transformer baluns and thus voltage baluns. Also, you'll notice in 21.5, he says above 14mhz, a simple coax choke balun is very effective (I think someone earlier said that). For wideband coverage, in 21.6 he just says to use 50 ferrite beads over the coax, and he calls that the W2DU balun. Notes on coax choke baluns and ferrite bead usage can also be found in the ARRL antenna book.
Just going off Maxwell's material, if most commercial baluns are voltage baluns, then that's the wrong tool for the job (you need a current balun). And if operating above 14 mhz, you don't need to buy a balun when you can make a simple coax choke balun (21.5) when using a simple dipole. Also in 21.4 (effects of not using a balun), he says for 160-40 meters, the effects of current on the feedline is not a big deal, unless you're using a directional antenna like a yagi with some type of unbalanced matching system.
It looks to me like everyone is pretty much saying the same thing, but arguing about it.
</p>
Sec. 21.1, 21.2, 21.5, and 21.7 say exactly what I was referring to. The amidon balun is a transformer type balun and behaved exactly as Maxwell described it would. In fact, you'll notice in 21.7, he notes that almost all commercially available baluns are transformer baluns and thus voltage baluns. Also, you'll notice in 21.5, he says above 14mhz, a simple coax choke balun is very effective (I think someone earlier said that). For wideband coverage, in 21.6 he just says to use 50 ferrite beads over the coax, and he calls that the W2DU balun. Notes on coax choke baluns and ferrite bead usage can also be found in the ARRL antenna book.
Just going off Maxwell's material, if most commercial baluns are voltage baluns, then that's the wrong tool for the job (you need a current balun). And if operating above 14 mhz, you don't need to buy a balun when you can make a simple coax choke balun (21.5) when using a simple dipole. Also in 21.4 (effects of not using a balun), he says for 160-40 meters, the effects of current on the feedline is not a big deal, unless you're using a directional antenna like a yagi with some type of unbalanced matching system.
It looks to me like everyone is pretty much saying the same thing, but arguing about it.
</p>
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<img src=http://users.joplin.com/dutch64804/wav.gif ALT=":wav">
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<blockquote>Quote:<hr>I'm up to three posts without getting into trouble.... <hr></blockquote>
See, now you're getting the hang of it
<img src=http://users.joplin.com/dutch64804/bigok.gif ALT=":bogok">
<img src=http://users.joplin.com/dutch64804/posticon24.gif ALT=":lmao">
<img src=http://users.joplin.com/dutch64804/wav.gif ALT=":wav">
</p>
See, now you're getting the hang of it
<img src=http://users.joplin.com/dutch64804/bigok.gif ALT=":bogok">
<img src=http://users.joplin.com/dutch64804/posticon24.gif ALT=":lmao">
<img src=http://users.joplin.com/dutch64804/wav.gif ALT=":wav">
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