[TowerTalk] New N6LF Ground Probe Designs

[Leeson]

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-University-HF-Propagation-in-Irregular-Terrain.pdf

D. B. Leeson, "Antenna Topics," 2007, 
https://www.kkn.net/dayton2007/w6nl_ant.pdf

On 3/4/24 12:15 PM, Leeson wrote:
> 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 which I don't find many references 
> is the HF propagation over a foreground knife-edge ridge that, while 
> lower than the antenna that "sees" over it, is close and high enough to 
> block ground reflection angles up to, say, 12-15°. This includes the 
> complication of diffraction as well as ray tracing. A start is "HF 
> Terrain Assessment" by KR7C, see especially pp. 15-18,
> https://k0rv.files.wordpress.com/2015/01/hf-terrain-analysis.pdf
> 
> I think the pattern above the ridge, after giving effect to diffraction, 
> is pretty much the same as without the blockage, with "diffraction 
> wiggles" at the point it hits the ridge. But from that elevation angle 
> down to the horizon it seems the lack of ground reflection denies the 6 
> dB potential gain, but removes the cancellation at the horizon, yielding 
> a regime more like the free-space pattern of the antenna.
> 
> For an antenna high enough to see over a ridge, it will typically be 
> high enough to have a substantial number of nulls, once it finally can 
> clear the blockage angle. Any additional comments, techniques and 
> references would be appreciated.
> 
> Here are some additional online references that may be of interest in 
> the general subject of ground reflection and slope.
> 
> M. Weissberger, et al., "Radio Wave Propagation: A Handbook of Practical 
> Techniques for Computing Basic Transmission Loss and Field Strength," 
> 1962, https://apps.dtic.mil/sti/tr/pdf/ADA122090.pdf
> 
> P. D. Rockwell, "Station Design for DX, Part I -- Antenna Topics and 
> Siting," QST, Sept 1966, pp. 50-54, 
> https://www.rfcafe.com/references/qst/station-design-dx-september-1966-qst.htm 
> 
> 
> G. Hagn, "HF Receiving Antenna Directivity Patterns and Gain for 
> Ionospheric Propagation Model Predictions for Short-Wave Broadcasting," 
> IEEE Trans Broadcasting, Volume 34, Issue 2, June 1988, pp. 221-229, 
> https://ieeexplore.ieee.org/document/1439
> 
> J. K Breakall, et al., "The modeling and measurement of HF antenna 
> skywave radiation patterns in irregular terrain," IEEE Transactions on 
> Antennas, Volume 42, Issue 7, July 1994, pp. 936-945, 
> https://ieeexplore.ieee.org/document/299595
> 
> R. D. Straw, "What I've Learned in Two Decades of Terrain Assessment by 
> N6BV," video, 2013, https://www.youtube.com/watch?v=D6nRpeVseSc
> 
> R. D. Straw, "Terrain Assessment for HF Contesting," 2014, 
> https://seapac.org/seminars/2014/sea-pac2014-n6bv-Terrain%20Assessment.pdf
> 
> D. B. Leeson, "Match HF Antennas to the Ionosphere & Terrain," 2017, 
> https://www.dropbox.com/s/hhc00iy6t4h509c/Ionospheric%20Radio%20REDXA_sm.pdf?dl=0 
> 
> 
> D. B. Leeson, "Siting and Installation of Yagi Antennas," Ch. 10 in 
> "Physical Design of Yagi Antennas," 1992, available online at 
> https://www.dropbox.com/s/hmhkeofz0igrg1e/Physical%20Design%20Of%20Yagi%20Antennas%20D%20B%20Leeson%20V2.pdf?dl=0 
> 
> 
> 73 de Dave, W6NL/HC8L
> 
> 
> On 3/3/24 4:43 PM, Brian Beezley wrote:
>> Just a note that Rudy Severns, N6LF, has put all 35 of his published 
>> Antenna Compendium, Communications Quarterly, NCJ, QEX, and QST 
>> articles in one place. Each article is a PDF file in magazine format. 
>> So much good stuff. Just click on the article you want:
>>
>> https://www.antennasbyn6lf.com/
>>
>> The reference I gave to his original soil parameter article was 
>> actually to a preliminary version. Here's the final article:
>>
>> https://rudys.typepad.com/files/qex-nov-dec-2006-soil-parameters-at-hf.pdf 
>>
>>
>> The article N6RK mentioned about determining ground parameters with a 
>> low dipole is here:
>>
>> https://rudys.typepad.com/files/qex-nov-dec-2016-soil-characteristics-using-low-dipole.pdf 
>>
>>
>> Brian
>>
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