Re: Topband: return current - what is it?

2012-08-05 Thread Yuri Blanarovich
Here we go again, speaking of misinformation, peer review, spreading false guru stuff. You can not apply Kirchoff law from DC circuits to the current behavior along the STANDING WAVE RF radiator. Current magnitude changes along the standing wave radiator, on the resonant dipole it is maximum at

Re: Topband: return current - what is it?

2012-08-05 Thread Tom W8JI
You can not apply Kirchoff law from DC circuits to the current behavior along the STANDING WAVE RF radiator. Yes, we can. Kirchhoff's law is Kirchhoff's law, and is not frequency dependent. I can't imagine anyone thinking otherwise. Thinking Kirchhoff's law applied only to dc circuits is

Re: Topband: return current - what is it?

2012-08-05 Thread Yuri Blanarovich
Sooo, there is no current and voltage variation along the standing wave resonant dipole? S, Jasik et al, all those antenna books, modeling programs showing RF CURRENT and/or RF VOLTAGE distribution along the (standing wave) solid antenna wire are thinking otherwise? Like parallel LC circuit

Re: Topband: return current - what is it?

2012-08-05 Thread Tom W8JI
Sooo, there is no current and voltage variation along the standing wave resonant dipole? S, Jasik et al, all those antenna books, modeling programs showing RF CURRENT and/or RF VOLTAGE distribution along the (standing wave) solid antenna wire are thinking otherwise? Like parallel LC

Re: Topband: return current - what is it?

2012-08-05 Thread Richard (Rick) Karlquist
On 8/4/2012 10:47 AM, Tom W8JI wrote: The reason I say this is because I know for an absolute fact.base impedance can vary all over the place with unrelated or unexpected changes in efficiency. A radial system here that made base impedance of a 1/4 wave vertical 50 or 60 ohms delivered

Re: Topband: return current - what is it?

2012-08-05 Thread Robert Carroll
-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Yuri Blanarovich Sent: Sunday, August 05, 2012 9:51 AM To: topband@contesting.com topband@contesting.com Subject: Re: Topband: return current - what is it? Here we go again, speaking of misinformation, peer review, spreading

Re: Topband: return current - what is it?

2012-08-05 Thread Tom W8JI
to make a confirming measurement. When he did arrive at the chosen measurement point he would find nearly but never all of the injected current had disappeared. This would not have been a surprise to him but maybe to the rest of us. How could this have happened? With an infinitely long

Re: Topband: return current - what is it?

2012-08-04 Thread K4SAV
Bob Kupps wrote: So I modeled a half wave dipole in free space and sure enough the wire segments on each side of the feed point carried equal current. I then placed a resistive load at the center of one half-element (to simulate? a lossy return) and now see that those segments no longer

Re: Topband: return current - what is it?

2012-08-04 Thread w4buw
DOES ANYONE REMEMBER Gustav Kirchhoff -Original Message- From: K4SAV radi...@charter.net To: topband topband@contesting.com Sent: Sat, Aug 4, 2012 11:04 am Subject: Re: Topband: return current - what is it? Bob Kupps wrote: So I modeled a half wave dipole in free space and sure

Re: Topband: return current - what is it?

2012-08-04 Thread HAROLD SMITH JR
That is correct, as Mr Kirchoff said. Price W0RI You are misinterpreting what you are seeing.  When you put a resistor in one side of a dipole you modify the current distribution in both sides of the dipole and the side with the resistor has a large decrease in current at the point where

Re: Topband: return current - what is it?

2012-08-04 Thread Tom W8JI
So I modeled a half wave dipole in free space and sure enough the wire segments on each side of the feed point carried equal current. I then placed a resistive load at the center of one half-element (to simulate? a lossy return) and now see that those segments no longer carry equal currents,

Re: Topband: return current - what is it?

2012-08-04 Thread K4SAV
Tom W8JI wrote: If you use enough segments so the program calculates small steps along length, and a ground independent current source, you'll find current on each side of the feedpoint exactly equal no matter what resistance you insert. Yes current on each side of the feedpoint is

Re: Topband: return current - what is it?

2012-08-04 Thread Tom W8JI
Hi Bill, Tom, it's worth adding to this that trying to make current measurements in the ground using 60hz is pretty useless for another reason: induced currents from the ac power system (especially in north america). 60hz will be present on just about anything -- you'll even see it on a

Re: Topband: return current - what is it?

2012-08-04 Thread K4SAV
Tom W8JI wrote: I think you may be selecting the wrong type of source, if you are using EZNEC. In the source-type selection, chose SI, not I. A split source places the source at a segment junction, so you can see current leaving each terminal of the source. I forgot about the SI