Here's a more current reference, with good citations: P. R. Winniford, et al., "New Analysis and Design Techniques for Arbitrary Reactance Trap Dipoles," IEEE Open Journal of Antennas and Propagation
A safety point: A good motor cap can hold the instantaneous value of the alternating voltage at the moment of disconnect. It's good to short it before touching the terminals. I use a jumper, and the
I still think of the foreground slope concept as "Moxon Slopes," from the work and publications of Les Moxon, G6XN, who was a great personal inspiration to me. An interesting related question for whi
A couple more re ground and antennas: J. Breakall, "Maximizing Performance of HF Antennas with Irregular Terrain," 2021, https://www.contestuniversity.com/wp-content/uploads/2021/01/Contest-Universit
For a start, see https://web.archive.org/web/20200711193004/https://k7nv.com/notebook/ppinfo/ See also https://ve3vn.blogspot.com/2015/11/choices-on-adapting-prop-pitch-motors.html: "On a bench test
This is a great step, but I find I can't access all of the subfiles at that URL http://www.hamoperator.org/k7nv.com/. However, you can find the whole site at https://web.archive.org/web/2021012914531
Please be sure to use redundant means of supporting the mast and antennas. There was an frightening accident a number of years ago when the bolts on a thrust bearing holding a mast snapped and it fel
Note that the return loss measurement should be made with an open, short or non-dissipative reactive load, not a dummy load. Dave, W6NL/HC8L Loss = 10 Log ((SWR+1)/(SWR-1)) After determining the loss
In designing some Yagis to be built without further adjustment at a DX contest station, I experimented with calculating the shortening of the driven element tip to compensate for balun leads. As a si
You can also download the associated spreadsheets at https://www.dropbox.com/scl/fo/u4o0teln9hkn7hagbs5eu/h?rlkey=fy1rj0kw4vjld2ddjc17m4rza&dl=0 Dave, W6NL/HC8L 73, Mike W4EF..................... On
From "Physical Design of Yagi Antennas," ARRL 1992, pg. 9-2: "This problem is resolved in a short paper by Jaggard [D. Jaggard, "On Bounding the Equivalent Radius," IEEE Trans AP, Vol. AP-28, May 198
Considering it as a conductive sheet, from Jaggard the equivalent radius for a triangular tower shape comes out about 42% of the face width (equivalent diameter is 84%). There are formulas for two pa
I've used both drawn 6061-T6 and 6063-T832, the yield strength and other parameters are essentially the same. The yield strength for both is around 35-40k psi. Many other tempers of 6063 are not as s
Along with your tower and antennas, you have relays and connectors, perhaps with a rotator, a directional antenna switch or even a remote station. Theres a common but difficult-to-diagnose problem yo
Yes, good point. Of course, I've used Mil-Spec and many other contact cleaners for as long as I can remember. But for me, it's an easy choice between a a self-healing "wetting" design with a few inex
Brian, the photos you mention of K6STI, W7EL and WA3FET at W6NL are on slide 27 of my 2007 Dayton talk at https://www.kkn.net/dayton2007/w6nl_ant.pdf Dean, N6BV, wasn't able to be there, but we all c
Apparently a more complete link to download "Physical Design of Yagi Antennas" is this: https://www.dropbox.com/scl/fi/j7kkt63nyyh2pag0g9avj/Physical-Design-Of-Yagi-Antennas-D-B-Leeson-V2.pdf?rlkey=8
I also want to give a shout-out to the contributions to this subject of Tom N6BT, Dan AC6LA, Steve K6OIK, and Stu K6TU, among many others. See for example the discussion noted by AC6LA: "Seeing the E
Try "Break Free CLP," which is much more aggressive than any other solvent I've used. It's primary use is gun cleaning, but our local fire department recommended it for freeing stuck nuts and bolts,
A problem we have with our TIC ring is that the big gear isn't exactly concentric, and it often skips a tooth or two in the wind. This offsets the pot, making it vulnerable to running up against the