The EF vs dipole Full Wave pattern anomoly

[freecell]

"The voltage distribution on the antenna does not contribute to radiation..."

quoting an fcc field report for the field strength of a signal @ a frequency of 1640 kHz measured at 14,500 microVOLTS per meter (uV/m) at 62 meters. (203.41 feet)

if we measure the RADIATED field strength of an antenna in microVOLTS, explain to me how the VOLTAGE is not being radiated.


this is not about who is right, it's about what is right. telling people that voltage induced into an antenna is not radiated is disingenuous and completely contrary to everything commonly known regarding the propagation of a transverse electromagnetc signal while exactly the opposite (voltage is radiated) is evidenced right in front of your eyes using a simple field strength meter which measures the intensity of the signal radiated from the antenna in microVOLTS.

i'm letting everyone know that these two statements are unequivocally false.

"The current is 100% responsible for all radiation from an antenna."
"The voltage distribution on the antenna does not contribute to radiation."

as these are the only two statements that i have taken issue with, all you have to do is show me a properly functioning field strength meter @ maximum input sensitivity producing absolutely no meter deflection whatsoever in the presence of an electro (voltage) magnetically (current) radiated field and i will absolutely believe that both statements are true. fortunately for radio operators everywhere and all currently related technology, that is never going to happen.

this is what is right. both voltage and current are equally responsible for the radiation of the TransverseElectroMagnetic field from any antenna.

transverse electromagnetic radiation
voltage is in red, current is in blue.:

https://www.worldwidedx.com/search/108694855/

 

[The DB]

"The voltage distribution on the antenna does not contribute to radiation..."

if we measure field strength in microVOLTS, explain to me how the VOLTAGE is not being radiated.

So you didn't bother to answer my question, yet expect me to answer yours? Its just like you to try and latch onto something that you think you can "win" on while ignoring all the evidence that is mounting against you... Next, your going to declare victory, but as usual that victory will exist only in your own mind. Its a tactic you have used multiple times since coming back to this forum, I'm just waiting to see how you use it this time... This is gonna be good.

Anyway... How about this, you answer my question and I will answer yours. And I do have the answer to your question... I'll give you a hint, it was actually touched on in my last post although talking about something else. I said something like "it is a bit much for you so I won't waste either of our time", so all you did with your question is demonstrate that my assumption was right, you don't actually know how this works...


The DB

 

[TheBlaster]

Hi The DB... I still need to read through more of the above when time permits but spotted your question. Well.... no near or far field ground reflections for a start and it is like having an antenna in an infinite void. I imagine it was because some antennas have greater influence from ground than others and that "focus gain" is not coming from magical extra few meters of wire added on top because of the physical size itself ? And maybe to demonstrate the out of phase currents in a 5/8 subtracting gain from the pattern without the constructive summation from the phase inversion in the ground of the out of phase portion.

I also was thinking regards current focus I imagine this is why we call alternating electrical energy flows as AC and not AV.... even though they both have to co-exist.

As an aside: Just to add a further thing with models I recently discovered that concrete fence posts usually have multiple thick steel wires in them. Not helpful to SWR or radiation patterns ! So many obstacles some not even immediately evident, making a model a purely best case scenario. Many people's ground has their house in between it and the antenna.

 

[The DB]

Hi The DB... I still need to read through more of the above when time permits but spotted your question. Well.... no near or far field ground reflections for a start and it is like having an antenna in an infinite void. I imagine it was because some antennas have greater influence from ground than others and that "focus gain" is not coming from magical extra few meters of wire added on top because of the physical size itself ? And maybe to demonstrate the out of phase currents in a 5/8 subtracting gain from the pattern without the constructive summation from the phase inversion in the ground of the out of phase portion.

I also was thinking regards current focus I imagine this is why we call alternating electrical energy flows as AC and not AV.... even though they both have to co-exist.

Good answer, its actually close to what I was looking for. I might have actually said this above, but an antenna model in freespace shows where an antenna is directly putting its signal, while an antenna modeled over an earth shows where the signal goes after the earth has played its part. IMHO, knowing what the antenna is doing with said radiation is the whole point of modeling. That being said, I was surprised that your freespace models in mmana-gal only had half a horizon, like an earth was present, yet they clearly said freespace. When I model freespace in 4nec2 I get a full 360 degree view of the vertical pattern. I wonder if there is a setting in mmana-gal to change that? There are times when you want the antenna to put a signal lower than the horizon. RF steering for a repeater on top of a mountain for example, you want to steer its output to the town/city down in the valley, not go straight out and overshoot it. Also, in general, any time where you are determining how well an antenna works locally, depending on how its mounted you want to see the 0 degree mark, and in many cases the area just below the horizon.

As an aside: Just to add a further thing with models I recently discovered that concrete fence posts usually have multiple thick steel wires in them. Not helpful to SWR or radiation patterns ! So many obstacles some not even immediately evident, making a model a purely best case scenario. Many people's ground has their house in between it and the antenna.

If there is anything within two wavelengths of an antenna, I would assume that to some extent it is affecting the antenna's impedance, and by extension SWR. If the antenna is longer than a half wavelength then this reach is actually further than two wavelengths. When I purchased my first VNA, one that could scan through a bunch of frequencies, I noticed that on the CB band a car passing over 30 feet away would affect SWR as it passed by, it would increase SWR by .2 before dropping back to normal, and hte next scan this bump would be gone. It actually took me a while to figure out the cause. Another thing that affected the SWR curve was birds that when they flew right by the antenna. Of course these things affect the radiation pattern as well, and sometimes you will be surprised by how much, while others you will be surprised by how little.


The DB

 

[TheBlaster]

I also have thought this about modelling.. it would be nice for example to model sloping ground and its possible influences. I am skimming this at the moment due to lack of time.

I do know that the faster a slope off gradient on a hill the better the influence on lower angle radiation. This in theory and in practice as at one such location I use for DXing I produce a surprisingly huge signal to countries 5-6 thousand miles away broadly in that direction with just a vertical that has a steep/fast slope away. I suspect it greatly increases 10 degrees and lower radiation. Clearly the altered ground reflection from the steep slope creates constructive phase interaction/ interference at a significantly lower angles.

I have been thinking about this quite a lot recently regarding QTH's and different bands and that what may work well for one may possibly not work well for another band. Given we know as HF frequencies go upwards DX radiation angles on the F2 layers hop drop.