[TowerTalk] 160 meter vertical on sloping ground

Leeson leeson at earthlink.net
Wed Jan 15 21:38:58 EST 2025


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 Effects of Local 
Terrain on Radiation Patterns," 
https://forums.qrz.com/index.php?threads/seeing-the-effects-of-local-terrain-on-radiation-patterns.733041/

A lot of good thinking has gone into the details of sloping ground 
reflection over the years, including many early works cited in various 
publications, talks and postings.

BTW, as noted in my talks, the issue of elevation angle has a key impact 
on the timing of band openings, favoring a station with the advantage of 
very low angle signal while others have no path yet. Except for 
saltwater foreground, the cancellation at the horizon and at low angles 
"under the radar" is characteristic of flat sites. Foreground slope was 
a major design factor in our Galápagos Islands contest station, HC8N as 
a multiop and HC8A as a single op. See 
https://www.dropbox.com/scl/fi/qapxpma2hrf71d0l4wlmx/HC8_10a.pdf?rlkey=5zdp1xag9jjm5441z65bk7urm&dl=0

Dave, W6NL/HC8L

On 1/15/25 4:16 PM, Leeson wrote:
> 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=8hktxgv5wi2j3o880lb5ao4jk&st=2x7w21ya&dl=0
> 
> Dave, W6NL/HC8L



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