Jim: Good points regarding my statement about "proven architecture" - I should have more properly stated "as proven thus far by those in the field."
73, Jack On 7/31/2012 4:13 PM, W0UCE wrote: > One aspect of the K2AV FCP is KISS. However, experimenting with change of > components and proven architecture should anyone opt to do so will produce > unfavorable results. Jack, "It seems to work good in the places it's been tried" but has never been compared in a disciplined manner to something of known performance is hardly "proven architecture." Guy has done some excellent engineering here, and published it. Now he's getting some serious peer review, with suggestions for possible variations on his work. That's how the "state of the art" progresses. From where I sit, it appears that the most important aspects of his design are the compact dimensions and the field cancellation in the dirt, not the transformer. As an example of this peer review process, Rudy Severns, N6LF, published some excellent and disciplined work several years ago on his measurements of slightly elevated radial systems for a 40M vertical. That work showed that, on 40M, four radials elevated only a foot or two were nearly equivalent to many long radials on the ground (he set up those and many other conditions and MEASURED the field strength). When I tried to scale his hypothesis to 160M (that is, multiply the radial heights by a factor of 4x) on an antenna I had built, I could not duplicate his result -- that is, the gain of the antenna was at least 3dB less than I had expected. I discussed this over dinner this spring with Tom Schiller, N6BT, who has also done a lot of work with radials and verticals for 160M. He observed that you can't simply scale the radial height by the difference in wavelength because "the earth is very different at 160M as compared to 40M, and the radials must be much higher." When I asked him "how high," he suggested 16 ft. This summer, with a lot of help from W6GJB, I got them up to at least 16 ft for most of their length, and preliminary testing suggests that I'm now getting the gain I had hoped. When I've got more performance data, I'll publish it. Peer review is a wonderful thing. It is an important part of the scientific method. I've learned a lot by publishing what I think I know and having folks fill in my weak spots. 73, Jim K9YC _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK