Donald I agree, at first I did not see the 1/4 wave pattern for the cone looking like the pattern for a 1/2 wave radiator. The reason is, I did not think such was possible, but I did see that the pattern did not look like I expected for a 1/4 wave radiator.
I do see this pattern that CST produces as an anomaly that I don't understand. Even if you're right and there are CMC on the outside of the radials like you suggest, they would be radiating down from the top of the radials in a upside down 1/4 wave pattern and not in a 1/2 wave patter like we see in the CST image.
See EzBob images below:
This is a pattern from a S4 styled antenna with the currents turned on, and there are only two currents to be noted in the cone area. The fact that the antenna has two currents flowing on it does indicate it is collinear, but IMO that doesn't mean the antenna will manifest collinear gain.
We see the exactly same thing in a 5/8 wave antenna...a collinear antenna with no added gain over a 1/2 wave or 1/4 wave if the current maximums are at the same height. Thus the only difference we see is a height difference.
The EzBob image below is of a variety of wavelength patterns as noted. The open sleeve also shows only two currents flowing. They appear to have similar current magnitudes that are out or phase, thus there will be no RF flowing from the bottom of this open sleeve antenna. Only the top 1/2 wave has effective radiation into the far field.
This is a pattern below is from a S4 styled antenna with the current turned off, and we still only see two currents flowing in the cone area. CMC, only flows on coax with an imbalance at the load
Donald, I can only guess this new idea of a 1/4 wave showing a 1/2 wave pattern is new for Bob as well, because he does not indicate it in his image ideas at the top. I would like to know what Bob thinks about this idea.
