i have a NOS avanti astroplane on its way to me,
never gave my first astroplane a fighting chance the first time around so i decided i would have another go,
Good luck with your new/old A/P Bob. I think you will appreciate what it can be...if you get the current maximum even close to the same point on radiator for the longer high gain antennas.
At my location, I don't even have to get this particular antenna to the same tip height...just close. You'll notice the difference in my antenna image above with my Gain Master and there is still a relatively small difference, most of the time, in DX signals for sure. I see more of a difference in local signals, but again with the DX I was working in Friday's contact contest...the difference was first one then the other with the best signal...even with my Galaxy 2547's RF gain turned way down of fully on.
I consider my GM to be an exceptional antenna regarding how quiet it operates, and how well it works to reduce CMC type TVI, but my New Top One is even quieter when conditions are really nice, and that is a noticeable difference.
NOTE: The NTO is no where near as well behaved as the GM at the height I had it however.
At some point I was talking to Audio Shockwave (AS), and he told me Homer was on the air. I cleared off with AS, and I heard him talking to Homer. Conditions were really quiet at the time, and I could faintly hear Homer responding, but I could not copy him on either antenna. I tried breaking for him on both antennas, but never felt he heard me. I think Jeff can confirm this, but I'm not sure...as we didn't talk about it again. I have talked to Homer before however.
i just read the avanti astroplane patent again and realised avanti talked as much technobull back then as all but one cb antenna builders talk today,
prior art antennas such as 1/2wave and 5/8wave endfeds do NOT have maximum current near the radial/monopole junction as claimed, nor do they radiate most from the bottom,
I agree there is some antenna BS in patents, but the patent adviser (attorney) is the one that has the understanding to follow the Patent Office rules for applications. In the process however, someone with lots of experience with the technical understanding of the product...also has to be involved and sign-off on what is said or not said.
I don't think the Avanti guys were ill-informed at all, but I don't think you meant it that way either.
I do tend to agree with you on the points you made however, but I only see that as a result of studying my Eznec models of the different versions.
My practical real world experiences with this design...only shows me that it works just as good as my other CB vertical antennas of all shapes and sizes with it being a bit quieter when conditions are really good and quiet. If conditions are not so good...then all bets are off on anything being quieter.
the astroplane has a 4ft height advantage in current maxima at best when mounted at the same tip height as prior art antennas,
Bob, I've been curious about how this idea for equal current maxima's works for years, and with the tip of the A/P at an equal height...I would likely see a signal as good or better. However, I think some of this has to do with the height of the feed point, and the fact that the current distribution on the shorter antenna has to be compressed producing more current per inch and thus showing the gain it does. It might not be a net gain increase, but it might somehow just respond like and increase...from such a short antenna.
Actually if the tips are equal, then center of the A/P's current maxima will also be higher, relative to the longer radiator.
I have also been curious, how and why this particular antenna works as it appears to me to work so well. It seems to defy what we often hear reported by many operators. Before I got one, I was intrigued, and after I put my first one up...just a few years back...I was really amazed...and I don't typically get amazed at the performance I see in the several CB vertical antennas I own and compare...considering the fact I see the performance of my antennas more similar that most.
they also can't make their mind up about the effect on bandwidth and efficiency when you hat load the upper 1/4wave of the antenna,
whoever wrote the patent did not know much about antennas imho,
I disagree here however. I think these guys from Avanti had a responsibility to make their ideas shine in the eye of the reader, and they are trying to cover many bases of ideas with Patent, that if necessary will be fruitful in litigation. If they fudge too much...then who knows what might happen if a good attorney gets hold of a case in dispute.
seems like you can say anything you like to get a patent so long as you don't mention over unity & upset the oil company,
im avanti's number one fan, i just don't like technobull.
I'm Avanti's number 2 fan. What's wrong with unity gain Bob?
Personally, I think too much is made of gain anyway...at times yesterday I was working with only 5 watts output, and if I was already talking with a contact...IMO they did not notice...we just kept on talking like nothing had changed.
I did find it difficult sometimes to make a contact with less than the 15 watts my radio shows at maximum output, but I did make several contacts with only 5 watts, plus I used my New Top One all day. I only checked with my Gain Master at times...and I seldom saw a difference of note in the RX signals.
Good luck with your New/Old AstroPlane...and keep us posted.
