End Fed 1/2 wave antenna

[HomerBB]

If I read your NB models correctly, it appears that I benefit in three ways from being at 36' isolated and with a choke over 27' without isolation and without choke.

36' has the huge vertical lobe of the 27' model split into two more useful high elevation lobes, an isolated mast should reduce/eliminate the more significant currents on the mast over the 27' non-isolated model, and likewise the choke should reduce /eliminate the potential CMC the current on the mast of the models suggest it would have without a choke.
1. My real world setup at 36' ought to have lower elevation - 14* vs 19* and
2. a second higher but useful lobe vs the useless vertical blob of the 27' model.
3. Additionally, my isolation from mast and choke should benefit me with currents on the mast/coax that now should radiate toward the destination.

The 7.36 gain of the 36' model versus the 7.84 of the lower 27' model is too miniscule to be of measurable consequence and is virtually a dead heat.

So far, I think I'll hang with the bang. I will still study the other models.

 

[HomerBB]

Well Homer that is missing my point, but it is typical for CB'rs to use a choke without knowing whether one is needed, or if it is working as intended.

Here is the idea that guides me in the use of a common mode choke.

View attachment 7452

I read what was there. It was one page of it. He described common mode currents very well, but all I read of good currents was when the identical currents are on the intended radiator which we tend to call radiation currents. As far as the information on that page goes Cebik does not portray the CMC on the feedline as in any way being good.

 

[bob85]

im with homer, when the cm currents are on a folded dipole, coaxial dipole like a bigstick, or on the sleeve of a vector 4000 they are good,
on the mast they are not good.

 

[HomerBB]

picture of the choke:

I told you it looks cool.

 

[bob85]

here are Cebik's closing words from his conclusion of his common mode picture show,

"However, in most amateur installations, we have no accurate method for determining the exact electrical length of our coaxial cable as it proceeds from the antenna to the equipment and then via an earth ground line to the actual ground. For the average amateur antenna installation, the safest strategy relative to common-mode currents is prevention. Adding a common-mode current attenuator to the system should be a standard part of any installation involving a coax-fed antenna"

 

[bob85]

eddie,
i asked my buddy if he would unwind the choke to see if the tv trouble came back, he said he's not climbing up to remove it because it definitely did stop the problem for a while until he moved the tv

 

[Marconi]

eddie,
i asked my buddy if he would unwind the choke to see if the tv trouble came back, he said he's not climbing up to remove it because it definitely did stop the problem for a while until he moved the tv

Well I figured as much and posted same earlier. So, we still can't be sure what might have happened, and I don't buy the fact Bob, that a fix that you did only worked for a short time...is really to be considered a fix, because of the following............

This is not out of disrespect, but like Homer said, there may be multiple things at play in this scenario. If your suggesting this fix successful and worked for a couple of days, and then it just stopped its 100 watts prevention of TVI, that is not logical to me.

Else that would suggest to me that the Gain Master's choke, which appears from all reports to work flawlessly, may necessarily have to be located in a specific place in space, in order to allow the antenna to work as intended...and any other place it was located would render it totally useless, like you and Homer are suggesting is what happened and was likely due to simply moving a TV.

Man, that's taking two steps forward and three steps backward to reach that conclusion.

Maybe Sirios choke is better designed and located in its application on the GM than the choke that ya'll added, but IMO the only judgment we could ever have using a choke is whether it works or not. Just a few days of seeming good results, and then on moving a TV see it all stop working, dead in it's tracks, should create a big question in the reader's mind...whether the fix was a success or not.

A real goober posted a thread the other day claiming some results on his 259B, suggested he had to add 11.5" to the top element in his Imax, that is before his meter would show a good match, somewhere in the CB band I presume.

Well, after he added a 11.5" piece of 1/2" diameter all thread with suitable fittings to mate up, he recounted to us a couple of wild and unbelievable advantages he observed while working his new modified rig on the air...in addition to his 259B showing a perfect match.

Then almost in the same breath he claimed after adding 11.5" the 259B reported a perfect match up over 28.000 mhz somewhere. I of course took exception to his claim, just like I'm trying to do here. You might have seen the thread on Mauldroppers: http://www.mauldroppers.com/showthread.php?20349-Imax-2000-1-1-Match-Lasted-1-1-2-Hours

He is still claiming the mode was a success, but I believe that was a failed attempt to modify his Imax. He admits it only lasted for 1.5 hours before it stopped working.

Does this sound like a similar story to what you're telling us, regarding your buddy's problem with TVI and the choke you added as a fix. I think so.

All I've got to ask now: Is your ego so inflated that everything you touch or talk about has always got to be considered a total success and the truth regardless of the end results? It's great to have confidence in one's own efforts, and I've always had a good feeling of that in hearing and reading your post on the Internet, but this reminds me of a comment from the character Fletcher...we've all seen and heard from an old Clint Eastwood movie, "Outlaw Josey Wales,"

"Senator: Don't piss down my back and tell me it's raining."​

Bob, you know where I'm going with my idea here, we talked about this idea that height affects common mode currents in such a way as to possibly control the magnitude enough to mitigate the problem in such a way as to not be a problem. It was of course all hypothetical, because the only source of info I had was some remarks made by W8JI and/or Cebik on the subject of baluns.​

Of course I have read Cebik's last remarks, and that stuck a note in my thinking not to forget. I repeated this idea a few times, that to use height to mitigate CMC would be iffy at best, simply because we'll likely never know how far away we are from the true ground on the shield side of the feed line. That gives a reader the idea that the ground ain't likely to be any where near as short as the feed line, itself, that we might use. That said would change the noted height I see in modeling, because it is plan for me to see the ground is always right at the bottom of the mast in most of my models, and that is likely very different than a real life response. Don't you think the idea of how height alone affects CMC is worthy of consideration. That is my point in this whole discussion, and is probably why W8JI and Cebik mentioned the idea too. I surely am NOT the one that discovered the idea, I'm just the only one talking about it here.​

This all came to my mind on reading W8JI on the topic of the Imax and his making a claim that this CMC issue could all be due a "worst case scenario," regarding a particular bad install height. ​

So with that said, I made an assumption that there could also possibly be a "best case scenario," and I talked and emailed you about it...maybe as far back as 2009." ​

I recall you dismissed my idea out of hand, so maybe you don't recall.​

This is long I know, but I hope this helps explain my thinking on this subject.​

 

[nav2010]

I'm not sure where you are going with this Marconi, are you suggesting that chokes will not get rid of TVI or some will and some won't? In this particular area I have seen Bob cure dozens of TVI problems with chokes including myself. In the last case the choke was placed a certain electrical length down the coax for a specific reason. By the nature of your wording in your replies to Bob I kinda get the message you are trying to prove him wrong with words and long winded arguments. Words don't mean Jack in this business, neither do Eznec models that don't work in real case scenario's. You are arguing with one of the most knowledgeable and well respected radio enthusiasts is this Country and around the world for that matter who has dedicated most of his adult life to this hobby.
When I first came on here many moons ago and first read your posts Marconi, you were an OK type of person who was willing to discuss and take in others opinions. Over the past 12 months there has been a change in you. You have now adopted an 'all knowing' cantankerous, self important 'legend in your own mind' attitude that doesn't wash well.
Most of your claims are unfounded, your testing techniques for antenna's are just plain rubbish and you do nothing but fill this board with mis- information.
There are young radio enthusiasts reading these forums who are influenced with what people write on here, what is written on here should at least have a degree of accuracy about it, yours has none. You seriously ought to take a step back from the keyboard dude at times.

 

[Needle Bender]

I'm not sure where you are going with this Marconi, are you suggesting that chokes will not get rid of TVI or some will and some won't? In this particular area I have seen Bob cure dozens of TVI problems with chokes including myself. In the last case the choke was placed a certain electrical length down the coax for a specific reason. By the nature of your wording in your replies to Bob I kinda get the message you are trying to prove him wrong with words and long winded arguments. Words don't mean Jack in this business, neither do Eznec models that don't work in real case scenario's. You are arguing with one of the most knowledgeable and well respected radio enthusiasts is this Country and around the world for that matter who has dedicated most of his adult life to this hobby.
When I first came on here many moons ago and first read your posts Marconi, you were an OK type of person who was willing to discuss and take in others opinions. Over the past 12 months there has been a change in you. You have now adopted an 'all knowing' cantankerous, self important 'legend in your own mind' attitude that doesn't wash well.
Most of your claims are unfounded, your testing techniques for antenna's are just plain rubbish and you do nothing but fill this board with mis- information.
There are young radio enthusiasts reading these forums who are influenced with what people write on here, what is written on here should at least have a degree of accuracy about it, yours has none. You seriously ought to take a step back from the keyboard dude at times.

I don't see it that way Nav, I see Marconi as someone very interested in antennas who has read, tested and knows plenty but has a talent for moving a debate forward, sometimes using tactics a little edgy but all the while knowing we're all here for the learning & discussion, though your posts are getting a bit L-O-N-G, Marconi!!

Me thinks thou doth protest too much... like something else is bothering you - but I could be wrong - sometimes people just get on certain others nerves, but Mr Marconi is one of the cornerstones of this forum, like Bob85, Shockwave, Audioshockwav, Homer and several others without whom these topics would just fizzle out in 6 or 8 posts.

Next thing you know, you'll be saying that I'm full of myself just because I know I'm never wrong

 

[Marconi]

I'm not sure where you are going with this Marconi, are you suggesting that chokes will not get rid of TVI or some will and some won't? In this particular area I have seen Bob cure dozens of TVI problems with chokes including myself. In the last case the choke was placed a certain electrical length down the coax for a specific reason. By the nature of your wording in your replies to Bob I kinda get the message you are trying to prove him wrong with words and long winded arguments. Words don't mean Jack in this business, neither do Eznec models that don't work in real case scenario's. You are arguing with one of the most knowledgeable and well respected radio enthusiasts is this Country and around the world for that matter who has dedicated most of his adult life to this hobby.
When I first came on here many moons ago and first read your posts Marconi, you were an OK type of person who was willing to discuss and take in others opinions. Over the past 12 months there has been a change in you. You have now adopted an 'all knowing' cantankerous, self important 'legend in your own mind' attitude that doesn't wash well.
Most of your claims are unfounded, your testing techniques for antenna's are just plain rubbish and you do nothing but fill this board with mis- information.
There are young radio enthusiasts reading these forums who are influenced with what people write on here, what is written on here should at least have a degree of accuracy about it, yours has none. You seriously ought to take a step back from the keyboard dude at times.

No Nav2012, that won't happen based on your words, I'm sure.

You sound like our whining President of the USA, who recently announced a new "Kings" rule that he doesn't want any decent in his presence, or anywhere else for that matter.

Over here it's like he controls everything, including wanting to control you Brits' someday. You guys should be bitching about his actions in the start of his administration, when he returned the bust of Winston Churchill that resided in the White house for some time now. But, no we in America never hear a word about that anymore, while 1/2 our country sits around doing nothing but clapping and listening up for his pathetic words.

Don't get me wrong, I don't forgive Churchill or Roosevelt for what they divided-up' at Yalta, giving up on the direction for the future of China and maybe the whole of the FarEast. They were an ally during the big War, and they were cast aside for an alliance with Russia...who hated us from the beginning. How did that turn out with them num-nuts poked out over into Europe for all those years with a constant threat. We are not your enemy. See how I can get off point with my words.

Forums are for discussion, argument, opinion, and for presenting any evidence, or no evidence at all...that the writer deems important to his position or claim. I don't agree with a lot of stuff I hear on these threads or on the air, and sometimes I will argue, and maybe even ask questions. It is often when questions are asked, when we never see an answer. That probably happens when everyone else, looking in, knows that CB BS is bouncing around the room like an echo.

You can disagree and say what you want, but until someone gives me a reason to ignore what affects common mode currents seem to have on our antennas, then I'll continue to speak out. In reality I don't disagree with much of what others have said. I just was looking at the issue with a different point of view, and that is where you get all bitched out, and you say right here and now "...you ain't having none of it."

I've got another little modeling project that should provide a little more evidence as to how height and length of feed line affects CMC. But, I doubt you will consider it. However, if you do I will talk with you sensibly about how I see that issue.

Maybe tomorrow.

Thanks for your pitching in, even though I think your crude and hateful regarding the opinions of others, that just don't happen to agree with your own opinions.

You also play it safe all the time, just using words and never producing any proof of work or even a description of efforts that you could have done in support of those words.

Concerning my words and exhibits, I have never intentionally or knowingly tried to claim anything that was intended to mislead any one. I have made some mistakes, I get off track with my words sometimes, and my ideas and models might seem strange to most who only have a dissenting opinion of the subject of modeling already.

I can't tell you how many times I have suggested that some of my remarks fly in the face of the common ideas floating around, and folks like you are the loudest critics...and in the same breath your likes pounce at every chance...to complain about CB BS.

Hang in there bud, you may get over your bitterness and ignorance some day.

BTW, your casting respected names around as if your something special, and that is you only experience or evidence for your opinions...does not impress me. If we all agreed with each other on every issue, it would get real dull around here fast, and it would sound like there was an echo in the room.

So, carry on my Limey' friend, lets hear more of your sage wisdom, and maybe you'll consider to produce a bit of evidence to support your words every once in a while, OK?

I made this long, just for you!

 

[Marconi]

I don't see it that way Nav, I see Marconi as someone very interested in antennas who has read, tested and knows plenty but has a talent for moving a debate forward, sometimes using tactics a little edgy but all the while knowing we're all here for the learning & discussion, though your posts are getting a bit L-O-N-G, Marconi!!

Me thinks thou doth protest too much... like something else is bothering you - but I could be wrong - sometimes people just get on certain others nerves, but Mr Marconi is one of the cornerstones of this forum, like Bob85, Shockwave, Audioshockwav, Homer and several others without whom these topics would just fizzle out in 6 or 8 posts.

Next thing you know, you'll be saying that I'm full of myself just because I know I'm never wrong

NB'r, I know what you mean and I try my best, but I don't know short hand with my thoughts. But I do hear you.

I also tend to try and support my ideas and points of view with words and images. So, until I'm convinced that I might be wrong, the discussion probably gets detailed, and that is hard to do...just making one line comments.

I could be totally categorical like most do, and just post disagreements on everything I fancy, but I prefer to try and make myself clear on my thoughts. Maybe I'm only clear to myself, and that is not too good...if true.

I'll try the shorter version for a while.

 

[HomerBB]

Marconi:

nav2010:

Marconi and nav2010?

 

[Marconi]

Marconi:

nav2010:

Marconi and nav2010?

There you go Homer, we're communicating now. I just started this one liner idea and I like it. I really do.

 

[HomerBB]

 

[nav2010]

No Nav2012, that won't happen based on your words, I'm sure.

You sound like our whining President of the USA, who recently announced a new "Kings" rule that he doesn't want any decent in his presence, or anywhere else for that matter.

Over here it's like he controls everything, including wanting to control you Brits' someday. You guys should be bitching about his actions in the start of his administration, when he returned the bust of Winston Churchill that resided in the White house for some time now. But, no we in America never hear a word about that anymore, while 1/2 our country sits around doing nothing but clapping and listening up for his pathetic words.

Don't get me wrong, I don't forgive Churchill or Roosevelt for what they divided-up' at Yalta, giving up on the direction for the future of China and maybe the whole of the FarEast. They were an ally during the big War, and they were cast aside for an alliance with Russia...who hated us from the beginning. How did that turn out with them num-nuts poked out over into Europe for all those years with a constant threat. We are not your enemy. See how I can get off point with my words.

Forums are for discussion, argument, opinion, and for presenting any evidence, or no evidence at all...that the writer deems important to his position or claim. I don't agree with a lot of stuff I hear on these threads or on the air, and sometimes I will argue, and maybe even ask questions. It is often when questions are asked, when we never see an answer. That probably happens when everyone else, looking in, knows that CB BS is bouncing around the room like an echo.

You can disagree and say what you want, but until someone gives me a reason to ignore what affects common mode currents seem to have on our antennas, then I'll continue to speak out. In reality I don't disagree with much of what others have said. I just was looking at the issue with a different point of view, and that is where you get all bitched out, and you say right here and now "...you ain't having none of it."

I've got another little modeling project that should provide a little more evidence as to how height and length of feed line affects CMC. But, I doubt you will consider it. However, if you do I will talk with you sensibly about how I see that issue.

Maybe tomorrow.

Thanks for your pitching in, even though I think your crude and hateful regarding the opinions of others, that just don't happen to agree with your own opinions.

You also play it safe all the time, just using words and never producing any proof of work or even a description of efforts that you could have done in support of those words.

Concerning my words and exhibits, I have never intentionally or knowingly tried to claim anything that was intended to mislead any one. I have made some mistakes, I get off track with my words sometimes, and my ideas and models might seem strange to most who only have a dissenting opinion of the subject of modeling already.

I can't tell you how many times I have suggested that some of my remarks fly in the face of the common ideas floating around, and folks like you are the loudest critics...and in the same breath your likes pounce at every chance...to complain about CB BS.

Hang in there bud, you may get over your bitterness and ignorance some day.

BTW, your casting respected names around as if your something special, and that is you only experience or evidence for your opinions...does not impress me. If we all agreed with each other on every issue, it would get real dull around here fast, and it would sound like there was an echo in the room.

So, carry on my Limey' friend, lets hear more of your sage wisdom, and maybe you'll consider to produce a bit of evidence to support your words every once in a while, OK?

I made this long, just for you!

A few points to consider Marconi:-
1. I'm interested in Antennae, I couldn't give 2 hoots what the president is doing, what the pope is doing or why people believe in a fake God which was created to brainwash you.
2. I wanna know what brought race into the issue with you calling me a Limey?
3. You said forums are for discussion? You've taken it way, way, way past discussion, you've taken it to a different level altogether, you've taken it to a point that you are right and everyone else is wrong.
4. I never said you mislead anyone rather that you don't know what you're doing.
5. You keep saying that people have no proof of what they are doing or saying. That automatically assumes you have a distrust of what people are saying on here, you don't believe them, you want video's with signal meters and so forth. Personally, i am an optimist about people in general, I will believe people and what they say if they havn't made any obvious mistakes.
You on the other hand think that if people don't agree with your own conclusions then they are liars.
I don't and would never disrespect you as a person Marconi, I do however disrespect your skills as a radio operator, antenna tester and conclusion former. I'm just glad people like you havn't got their finger on nuclear weapons.