For some years now I've made claims based on the following article I found in ARRL's Antenna Compendium Volume I, page 101-106, published in 1985, by Donald K. Reynolds, see his credits in his obituary: Obituaries | Donald K. Reynolds, Professor, Engineer, Musician, Storyteller | Seattle Times Newspaper. This review article was based on studies by RF Engineering notables in the early 20's-30's. These engineers were charged with doing RF studies for the newly developing US Broadcast Radio Industry of the times, and this fact is noted in Reynold's review. The principals involved in these theoretical studies are listed and captioned at the end of this article. You can go to this article in this periodical by selecting page 101 in the task field at the bottom of the page and clicking the enter key. 6769788 the ARRL Antenna Compendium Vol I have also referred to another article about the same time that discussed Japanese RF Engineers refuting the 5/8 wave idea...as being wrong and that the vertical .64 wavelength monopole would show the most gain under the guidelines set forth in the US study. Reynold's review does mention the US study for Broadcast Radio, but mentions nothing about the Japanese idea I remember reading. Maybe one day I'll locate this Japanese report and maybe even be able to understand why the .64 wl idea never took much of hold in the US, excepting maybe in CB. BTW, the idea of .64 wavelength radiator is not totally absent in the armature radio antenna world, and its lack of seeming popularity is not meant to be suggested in this work either. The very popular Extended Double Zepp is noted to be a .64 wavelength antenna, so the idea for this particular length radiator as being new or an idea developed by the Japanese is not true either...or suggested by me. A little history for the Zepp: G3ZPS HF radio antennas The point of this post is to again try and shed some light on the subject of real world vertical antenna gain and the affects of Earth on the patterns vs. the theoretical ideas presented in these reports for Broadcast Radio from the 1920-1930's. IMO this topic of 5/8 and .64 wave antennas are discussed a lot in CB circles, and the source may well have been taken from these very reports. However, I contend that if you read very closely you will see the errors in the common CB thinking on this subject, and it may change you mind a bit about real antenna gain, and how theory and real world results may not be at odds as many seem to think.