Hello All,
The below questions turned up in the good thread of Bob "modified Vector 4000"
Since were going a bit of topic and we dont want too mix up the thread too much...
a new thread.
Again i am not a antenna "doctor" just repeating what i have been told in the past by others..
Henry: Are you asking in your first part about:
1-have we all never seen this before?
No, I'm asking if you have ever produced a voltage distribution report using your Eznec? Or stated another way: Henry do you have an option in Eznec to produce a distribution of voltage report like you do with the current distribution?
Marconi:
My question was rhetorical and that may not be fair considering your native language, sorry.
Henry:
2-Do you want to know if it is current or voltage wich you are seeing? (ps it is current that you see.)
Marconi:
No! and I agree.
Henry:
It is only to show what the current does.
Marconi:
The current distribution detail certainly does show what the current does, as you note. It also indicates how much and where on the element the current is graphically and in addition it shows the magnitude in amps statistical in the report. Does Eznec do the same for voltage?
NEW ANSWER HENRY:
I dont think Eznec has got the oppertunity to show the Voltage, but than again voltage isnt that intresting for us. It should be the opposite of the current.
Henry:
This is interesting to reduce the corona effect with high powers or to know where you can "attach" something to your antenna.
Marconi:
Maybe, but you'll have to explain how this applies to the question.
NEW ANSWER HENRY:
It is only to indicate why showing a current bow is intresting.
Henry:
To show what the radiation does for your antenna you need to have the far field pattern.
Marconi:
But this was not the question Henry. SW and I disagree where the RF emanates from on the element, at the voltage node or the current node, nothing more.
NEW ANSWER HENRY:
Oke..here goes...
A antenna doesnt radiate equal along its ax. Depening on type of antenne you can determine where maximum "close by" radiation is strong.
The magnetick field is determind by current. There where the current is high the magnetical field will be the strongest. There where the voltage is high the electrical field will be the strongest. Now close by the antenna it is very difficult to get "honest' readings.
Both fields are not equal near the antenna..
Both fields expand at some point away from the antenna untill they are in "balance".
There is the beginning of the Far-field. The far field is the "true" radio wave and there for the one of intrest for us.
And that is where the bottle neck is i guess.. it isnt intresting to know where the antenna radiates most close by, cause close by its ax they are not in phase...nor equal in strength..
In the farfield they are in balance.
To be clear...there where the current is high thats the point of "most" radiation.
Henry:
Originally Posted by Henry HPSD
Both the elevation and azimuth or of intrest.
Marconi:
Maybe, but you'll have to explain how this applies to the question.
NEW ANSWER HENRY:
Well, you can produce many types of "diagrams"
The one with all the colours in the "M.V.4K." thread is for intstance the EM field close by the antenna given by 4Nec2. That is nice to know it exist and can tell you something about where to cook your chicken when applied 100kw...but futher it is for us guys of less influence.
The Azimuth and elevation patterns in the Far field are those of intrest. Those are the ones we use for communication.
Henry:
The second part..you lost me..ill try tomorrow with a translater (bed time here!)..sorry again.
Marconi:
I have an idea what you mean when you refer to "the second part," but rather than speculate and be wrong, I’ll wait for another time.
It concerend what marconi wrote, this:
MO these currents that we see indicated as magnitude of the current over the length of the element, as noted in Bob's charts, are representative of the potential RF emitted. This also suggest the potential and magnitude of RF power at a point on the element that may be generated, regardless of the Far Field or Near Field issues being raised here, that do not apply to the issue of where the RF emanates from.
NEW ANSWER HENRY:
Thinking you are asking about where the antenna radiates wich i anwered above.The thing that worries me is that you are speaking of "regardless the near or far field".. I hope i interperted that correct. It is not regardless of the near or far field it is essential of both.
Henry:
The third part...if you want to know where does something radiate..you need to know how to measure it.
Marconi:
That is true if you are talking about where the RF radiates too and how far, but again that is not the question. The question is, where does the current emanate from, the current node or the voltage node.
NEW ANSWER Henry:
Well i hope i answered your question with the above answer? What also shouldnt be forgotten that often a fieldstrength measurment device is made up out of "diode detector" it receives almost everything...
HENRY:
The fourth part...
I am not intrested in a discussion about far or near field either...
But, one needs to know what one does.
The near field is not so "intresting" for antenna use..
The far field is what we use to make a qso..
I am looking at it as a car.. i do not want to know how much heat is produced in the engine..i wanne know what distance i can drive and at what speed.
MARCONI:
Agreed, and some consideration for near and far fields is important, but again that is not the question.
HENRY:
Ps..attached you can find a JPEG of the E field of the near Field pattern.
MARCONI:
You will have to describe how this image relates to the question.
NEW ANSWER HENRY:
Well the picture is a "diagram" of in this case the E part of the electro magnetic field.
Of the near field. This is what you can measure near the antenna...
As you can see it expandes and "shapes" up towards the more familiar raddiation patterns we alway produce with eznec.
It was to indicate that it is not so intresting for us to do close by measurments...
The radiation pattern is esthabilished futher away..
I hope i interperted your questions correct and the above is usefull to you.
If not..well i hope you can appriciate the effort
)
Kind regards,
Henry!
The below questions turned up in the good thread of Bob "modified Vector 4000"
Since were going a bit of topic and we dont want too mix up the thread too much...
a new thread.
Again i am not a antenna "doctor" just repeating what i have been told in the past by others..
Henry: Are you asking in your first part about:
1-have we all never seen this before?
No, I'm asking if you have ever produced a voltage distribution report using your Eznec? Or stated another way: Henry do you have an option in Eznec to produce a distribution of voltage report like you do with the current distribution?
Marconi:
My question was rhetorical and that may not be fair considering your native language, sorry.
Henry:
2-Do you want to know if it is current or voltage wich you are seeing? (ps it is current that you see.)
Marconi:
No! and I agree.
Henry:
It is only to show what the current does.
Marconi:
The current distribution detail certainly does show what the current does, as you note. It also indicates how much and where on the element the current is graphically and in addition it shows the magnitude in amps statistical in the report. Does Eznec do the same for voltage?
NEW ANSWER HENRY:
I dont think Eznec has got the oppertunity to show the Voltage, but than again voltage isnt that intresting for us. It should be the opposite of the current.
Henry:
This is interesting to reduce the corona effect with high powers or to know where you can "attach" something to your antenna.
Marconi:
Maybe, but you'll have to explain how this applies to the question.
NEW ANSWER HENRY:
It is only to indicate why showing a current bow is intresting.
Henry:
To show what the radiation does for your antenna you need to have the far field pattern.
Marconi:
But this was not the question Henry. SW and I disagree where the RF emanates from on the element, at the voltage node or the current node, nothing more.
NEW ANSWER HENRY:
Oke..here goes...
A antenna doesnt radiate equal along its ax. Depening on type of antenne you can determine where maximum "close by" radiation is strong.
The magnetick field is determind by current. There where the current is high the magnetical field will be the strongest. There where the voltage is high the electrical field will be the strongest. Now close by the antenna it is very difficult to get "honest' readings.
Both fields are not equal near the antenna..
Both fields expand at some point away from the antenna untill they are in "balance".
There is the beginning of the Far-field. The far field is the "true" radio wave and there for the one of intrest for us.
And that is where the bottle neck is i guess.. it isnt intresting to know where the antenna radiates most close by, cause close by its ax they are not in phase...nor equal in strength..
In the farfield they are in balance.
To be clear...there where the current is high thats the point of "most" radiation.
Henry:
Originally Posted by Henry HPSD
Both the elevation and azimuth or of intrest.
Marconi:
Maybe, but you'll have to explain how this applies to the question.
NEW ANSWER HENRY:
Well, you can produce many types of "diagrams"
The one with all the colours in the "M.V.4K." thread is for intstance the EM field close by the antenna given by 4Nec2. That is nice to know it exist and can tell you something about where to cook your chicken when applied 100kw...but futher it is for us guys of less influence.
The Azimuth and elevation patterns in the Far field are those of intrest. Those are the ones we use for communication.
Henry:
The second part..you lost me..ill try tomorrow with a translater (bed time here!)..sorry again.
Marconi:
I have an idea what you mean when you refer to "the second part," but rather than speculate and be wrong, I’ll wait for another time.
It concerend what marconi wrote, this:
MO these currents that we see indicated as magnitude of the current over the length of the element, as noted in Bob's charts, are representative of the potential RF emitted. This also suggest the potential and magnitude of RF power at a point on the element that may be generated, regardless of the Far Field or Near Field issues being raised here, that do not apply to the issue of where the RF emanates from.
NEW ANSWER HENRY:
Thinking you are asking about where the antenna radiates wich i anwered above.The thing that worries me is that you are speaking of "regardless the near or far field".. I hope i interperted that correct. It is not regardless of the near or far field it is essential of both.
Henry:
The third part...if you want to know where does something radiate..you need to know how to measure it.
Marconi:
That is true if you are talking about where the RF radiates too and how far, but again that is not the question. The question is, where does the current emanate from, the current node or the voltage node.
NEW ANSWER Henry:
Well i hope i answered your question with the above answer? What also shouldnt be forgotten that often a fieldstrength measurment device is made up out of "diode detector" it receives almost everything...
HENRY:
The fourth part...
I am not intrested in a discussion about far or near field either...
But, one needs to know what one does.
The near field is not so "intresting" for antenna use..
The far field is what we use to make a qso..
I am looking at it as a car.. i do not want to know how much heat is produced in the engine..i wanne know what distance i can drive and at what speed.
MARCONI:
Agreed, and some consideration for near and far fields is important, but again that is not the question.
HENRY:
Ps..attached you can find a JPEG of the E field of the near Field pattern.
MARCONI:
You will have to describe how this image relates to the question.
NEW ANSWER HENRY:
Well the picture is a "diagram" of in this case the E part of the electro magnetic field.
Of the near field. This is what you can measure near the antenna...
As you can see it expandes and "shapes" up towards the more familiar raddiation patterns we alway produce with eznec.
It was to indicate that it is not so intresting for us to do close by measurments...
The radiation pattern is esthabilished futher away..
I hope i interperted your questions correct and the above is usefull to you.
If not..well i hope you can appriciate the effort
)Kind regards,
Henry!
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