King of the toroid

[kopcicle]

Been trying to pound that into people's heads for years. A lot of amateurs stop adding ground radials when the SWR on their ground mounted vertical hit 1:1. I tell them to keep going until they see something more like 1.4:1 or so or better yet use an analyzer to watch the impedance and shoot for 32-36 ohms. The small SWR is nothing and the antenna will be much more efficient.

1:1 VSWR = resonance

resonance happens only at 1:1 VSWR

Trim the vertical 'till it's 50 ohms input (I'll watch)*

Trim that half wave dipole to 1:1 (again , I'll watch)

Then almost right, the center feed point impedance of a dipole sufficiently above ground is 75 ohms so (yeah here is where they loose their way...) the feed point impedance of a ground mounted or mobile mounted antenna is 75 ohms because the ground or the car body forms the other half of the dipole.
^^^Ii resort to Maxwell and they refuse to read it because they know what they know and don't need to be confused or bothered by the facts.

Big coil mobile antennas. Low loss at best , bling at worst and nothing magical in the slightest.

My current favorite...

If you have to use a tuner you don't know what you're doing.

If you don't use a tuner you don't know what you're doing

Explain a OCFD > Guanella Balun (4:1 w/ current choke in this case) > Approximate 66 to 80% of 130 ft feed point to a windo licking , back of the bus, flat match trimming, VSWR worshiping, multiple of half wave feedline, ugly balum, drunken , drug addled, mouth breathing, just passed my General exam (note: I'm the one that gave you the exam moron) and watch his eyes glaze over , roll up into his head and his extremities begin to twitch

We have much to overcome and the above motivates me rather than frustrates. .

* Had to get back to this soon or I'd forget. Curiously if you add length rather than subtract it in this case you actually end up approaching 50 ohms out of resonance at about 1/4 wave plus 15 to 18% . Now shunt feed it, better yet add capacitive hat. Seems backwards but it works. YMMV

 

[oldtymer]

1:1 VSWR = resonance

resonance happens only at 1:1 VSWR

Trim the vertical 'till it's 50 ohms input (I'll watch)*

Trim that half wave dipole to 1:1 (again , I'll watch)

Then almost right, the center feed point impedance of a dipole sufficiently above ground is 75 ohms so (yeah here is where they loose their way...) the feed point impedance of a ground mounted or mobile mounted antenna is 75 ohms because the ground or the car body forms the other half of the dipole.
^^^Ii resort to Maxwell and they refuse to read it because they know what they know and don't need to be confused or bothered by the facts.

Big coil mobile antennas. Low loss at best , bling at worst and nothing magical in the slightest.

My current favorite...

If you have to use a tuner you don't know what you're doing.

If you don't use a tuner you don't know what you're doing

Explain a OCFD > Guanella Balun (4:1 w/ current choke in this case) > Approximate 66 to 80% of 130 ft feed point to a windo licking , back of the bus, flat match trimming, VSWR worshiping, multiple of half wave feedline, ugly balum, drunken , drug addled, mouth breathing, just passed my General exam (note: I'm the one that gave you the exam moron) and watch his eyes glaze over , roll up into his head and his extremities begin to twitch

We have much to overcome and the above motivates me rather than frustrates. .

* Had to get back to this soon or I'd forget. Curiously if you add length rather than subtract it in this case you actually end up approaching 50 ohms out of resonance at about 1/4 wave plus 15 to 18% . Now shunt feed it, better yet add capacitive hat. Seems backwards but it works. YMMV

Great post Kop, always look for the least reactence that's the resonant freq.

 

[kopcicle]

Great post Kop, always look for the least reactence that's the resonant freq.

Just a thought
May need a shorted or open stub near the feedpoint to get several thousand ohms resonant feedpoint impedance down to something manageable

 

[Captain Kilowatt]

Then almost right, the center feed point impedance of a dipole sufficiently above ground is 75 ohms so (yeah here is where they loose their way...) the feed point impedance of a ground mounted or mobile mounted antenna is 75 ohms because the ground or the car body forms the other half of the dipole.
^^^Ii resort to Maxwell and they refuse to read it because they know what they know and don't need to be confused or bothered by the facts.

So amidst the rambling here I think you are saying that a ground mounted vertical is around 75 ohms because the ground plane makes up the other half of the dipole?? That would be true if it was in-line with the radiator but it is not. It is 90 degrees to it and that brings the impedance down to about 35-36 ohms. An antenna can be resonant at almost any impedance since resonance is defined as the point at which there is zero reactance. A half wave end fed antenna is resonant but may be several hundreds or even thousands of ohms.

 

[loosecannon]

I found this book about 20 years ago in an antique shop in Sacramento CA.

If people are looking for a book on antennas that gets all into the nitty gritty, but still explains everything as if you are a newbie greenhorn, then this is a great book to pick up.

LC

 

[Redbeard U812]

Captain kilowatt, what do you mean by my attitude? Have you quizzed any other members on this in regard to this discussion? I don't like to see this kind of culture anywhere. That is namely the one where people ridicule a defenceless person and pretend to know everything. I don't claim to know everything, but what I do know is that there were a couple of good examples of effective use of ferrites in his vid. Sure, there were quite a few you may question, however, is it so simple as to say ferrites are a band aid solution and that's it! For instance, my friend was having issues with the neighbours solar panels, they were generating a lot of rfi. Do you think he offered to replace his entire solar system to solve the problem? No, it was fixed quite simply, you know how, and it works both ways. I employ well designed ferrite chokes to prevent common mode current, I do not have all of these rf grounding crap that you all seem to talk about a lot, and I do more than well without any problems. I have some grounding at the base of my antenna purely for lightning, some members seem to be confused by this. So you mention your grounding and shielding, care to enlighten me on this?

Even though I find your comments to be quite thin skinned and lack some knowledge, I wish to present this book to you. Reflections ~ Walter Maxwell. Save it, and read it at will. This book will enlighten you and educate you.

There are many here on this site who are willing to help you. I have learned much from being here.

Respectfully,

Redbeard

 

[Redbeard U812]

I ran a 6 foot piece of wire from the antenna mount to the frame. That's not really bonded at 27mhz. I thought I knew what I was doing because the symptoms went away.

Had to jump from base of mount connected to headache rack to rack. Base of rack to bed. Bed to frame. All Body Panels to frame. Then for kicks and giggles one from antenna base to frame. Ground neg of power lead close to receiver to frame or cab. My neg goes to neg lug on battry also, contrary to some beliefs.

 

[Redbeard U812]

CB fight!!!!

Didn't we used to have a popcorn emoji on this forum? I need one for this post.

 

[arc1]

Who's got their knickers in a bunch?

I didn't make fun of his video to make myself feel superior, i made fun of it because it was funny.

If his intention was to teach someone how to wrap wires around a donut, then he did that.
If his intention was to teach people what wrapping wires in ferrite actually does, or why you would or would not choose that method to solve your rfi problems, then he did not do any of that.

This guy is not running dirty CB amplifiers and clipped modulation limiters, he is running amateur radio gear, and he is getting into everything in his house, and even his neighbor's house.

nowhere in the video does he describe his station, his grounding setup, or his antenna, nor does he show us why he didn't start there to solve his problem.

he could just be doing something dumb like operating from his 2nd floor and running 30 feet of wire down to a ground rod, or not tying his station ground in with his home electrical ground.

If he was doing either of those things and thought that he had solved his rfi problems just because he's not bleeding on the telephone anymore, then he is the one who needs a lesson.

Now here you are assuming that we are just a bunch of jerks who make fun of people that are trying to fix their problems, and that we don't know what we are talking about.

you should do yourself a favor and start searching around the past posts in this forum.

we have covered grounding for lightning, rf grounding, vehicle bonding, NEC conformation, and just about anything else that involves copper, and we have run those subjects right into the ground. pun intended.

If you would like some specific help with an issue you are having at your station, there are many of us who love to help, just start a thread and ask.
LC

That's a good reply, I don't think you necessarily fit the description for what I was talking about. And I am not the ferrite guy by the way. Anyway I have lost interest in this already, have my sights on something else.

 

[arc1]

Even though I find your comments to be quite thin skinned and lack some knowledge, I wish to present this book to you. Reflections ~ Walter Maxwell. Save it, and read it at will. This book will enlighten you and educate you.

There are many here on this site who are willing to help you. I have learned much from being here.

Respectfully,

Redbeard

Ha ha, thanks, but I'll be right. It would seem that a lot of members have their grounding theory confused with ground plane theory, and that within the ground plane theory. I mean with a ground mounted monopole antenna, the purpose of the ground radials is primarily to reduce ground losses, screen out the lossy ground or poor ground efficiency if you will. The number and length of these wires (combined) is important, it's not a set length like a quarter or half wave, and the number and other factors contribute to that critical length also, that is if you wish to optimise this. Same goes for elevated ground plane antennas. The popular quarter wave droopy will work at it's best based on a combination of ground radial lengths (number of radials again), their angle and this all in respect to the vertical driven element length and then height above ground. Tricky combination to work out in the real world.

 

[kopcicle]

So amidst the rambling here I think you are saying that a ground mounted vertical is around 75 ohms because the ground plane makes up the other half of the dipole?? That would be true if it was in-line with the radiator but it is not. It is 90 degrees to it and that brings the impedance down to about 35-36 ohms. An antenna can be resonant at almost any impedance since resonance is defined as the point at which there is zero reactance. A half wave end fed antenna is resonant but may be several hundreds or even thousands of ohms.

Actually you and I agree. A ground mounted quarter wave is around 36 ohms feedpoint impedance. I've watched people turn blue trying to tell me otherwise.

 

[arc1]

Even though I find your comments to be quite thin skinned and lack some knowledge, I wish to present this book to you. Reflections ~ Walter Maxwell. Save it, and read it at will. This book will enlighten you and educate you.

There are many here on this site who are willing to help you. I have learned much from being here.

Respectfully,

Redbeard

Oh and by the way, I lack some knowledge, how do you know this for a fact? Well I guess we all lack something, we can't possibly know it all. But I sure ain't wasting my time to talk about whether a quarter wave is around 36 ohms like some.

 

[Redbeard U812]

Ha ha, thanks, but I'll be right. It would seem that a lot of members have their grounding theory confused with ground plane theory, and that within the ground plane theory. I mean with a ground mounted monopole antenna, the purpose of the ground radials is primarily to reduce ground losses, screen out the lossy ground or poor ground efficiency if you will. The number and length of these wires (combined) is important, it's not a set length like a quarter or half wave, and the number and other factors contribute to that critical length also, that is if you wish to optimise this. Same goes for elevated ground plane antennas. The popular quarter wave droopy will work at it's best based on a combination of ground radial lengths (number of radials again), their angle and this all in respect to the vertical driven element length and then height above ground. Tricky combination to work out in the real world.

Possibly digest some of that book by Maxwell first.....

Now it seems to me you are some kind of troll, pull those knickers out of the unknown, you are not omnipotent.

 

[arc1]

I found this book about 20 years ago in an antique shop in Sacramento CA.

If people are looking for a book on antennas that gets all into the nitty gritty, but still explains everything as if you are a newbie greenhorn, then this is a great book to pick up.

LC

Yes I think I have studied articles that reference this book.

 

[Redbeard U812]

Aluminum foil is not just for making hats anymore.

Say What?