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1. Topband: FYI (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Thu, 16 Jan 2003 09:38:04 -0800 (PST); Friends in Radio Land In a recent posting Tom, KN4LF, said "medium frequency path skewing is that the transmitted RF signal will "always" seek to propagate along the path with least absorption, which; /archives//html/Topband/2003-01/msg00090.html (7,955 bytes)
2. Topband: Last word? (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 17 Jan 2003 06:13:50 -0800 (PST); Friends in Radio Land - While Tom, KN4LF, says that the simplest way to look at skewing or refraction is by means of a "principle of least absorption" , I still maintain that principle does not exist; /archives//html/Topband/2003-01/msg00106.html (7,883 bytes)
3. Topband: A few words (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Sat, 18 Jan 2003 11:12:35 -0800 (PST); Friends in Radio Land - Given the recent interest in skewing, a few words of explanation would seem in order. In simple terms, skewing is just a case of horizontal refraction and results from a wave; /archives//html/Topband/2003-01/msg00137.html (8,922 bytes)
4. Topband: A few words (score: 1): Author: Robert Brown <bobnm7m@cnw.com> (Robert Brown); Date: Sat, 18 Jan 2003 15:33:48 -0800 (PST); Hello Earl, My remarks were focused on refraction, a more gradual change in propagation direction. Scatter and reflection are other means that can alter propagagtion direction and give larger effects; /archives//html/Topband/2003-01/msg00141.html (8,163 bytes)
5. Topband: Good conditions on 160? (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Thu, 19 Dec 2002 14:16:31 -0800 (PST); Friends in Radio Land, How about night at the winter solostice during Solar Minimum? "Soon, maybe not tomorrow but soon!" 73, Bob, NM7M; /archives//html/Topband/2002-12/msg00241.html (6,290 bytes)
6. Topband: Re: 160 Propagation and weather (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 1 Nov 2002 06:29:29 -0800 (PST); Friends in Radio Land - With regard to low-band propagation and weather being related, it is fairly obvious from some basic facts: 1) The ionosphere floats or is suspended in the atmosphere, with ele; /archives//html/Topband/2002-11/msg00006.html (7,506 bytes)
7. Topband: Full Moon, Oct 21-Questions (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 18 Oct 2002 06:14:32 -0700 (PDT); Don, Energetic, UV photons, are required for photo-ionization of the atmospheric constituents that go to make up the ionosphere. The table below gives the energies and UV thresholds: N2 < 1270 A > 9.; /archives//html/Topband/2002-10/msg00068.html (7,489 bytes)
8. Topband: The Moon (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Mon, 21 Oct 2002 08:55:17 -0700 (PDT); Friends in Radio Land - The discussion of the "full moon effect" has now reached "tidal proportions", with a question from Bob, G3REP, as to whether the moon could influence the earth's magnetic fiel; /archives//html/Topband/2002-10/msg00108.html (6,954 bytes)
9. Topband: Re: Large TSTM Areas (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Tue, 29 Oct 2002 09:04:45 -0800 (PST); Friends in Radio Land - Lightning discharges in the D-region, "sprites" as observesd by the University of Minnesota, could give rise to momentary bursts of Xrays and electrons but the ionization woul; /archives//html/Topband/2002-10/msg00154.html (6,737 bytes)
10. Topband: Displacement current (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Thu, 5 Sep 2002 02:46:56 -0700 (PDT); Friends in Radio Land The electromagnetic variable D and the displacement current density dD/dt were introduced in Maxwell's Equations so as to make current continuous around a circuit containing cap; /archives//html/Topband/2002-09/msg00040.html (7,142 bytes)
11. Topband: Displacement current (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Thu, 5 Sep 2002 07:45:42 -0700 (PDT); Joe, Thanks for the note. I used to teach E&M at UC Berkeley and our order of Maxwell's Equations in teaching was as follows: Div D = rho, Coulomb's Law Div B = 0, no magnetic poles Curl H = j + dD/d; /archives//html/Topband/2002-09/msg00042.html (7,006 bytes)
12. Topband: Reciprocity (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Sat, 28 Sep 2002 11:05:28 -0700 (PDT); Friends in Radio Land - Recently, the reflector carried some remarks about reciprocal propagation. Unfortunately, they did not convey the idea that low-band propagation is magneto-ionic in nature, i.; /archives//html/Topband/2002-09/msg00205.html (7,645 bytes)
13. Topband: Power Coupling for K1B (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Thu, 2 May 2002 07:53:39 -0700 (PDT); Friends in Radio Land - With the recent discussion about magneto-ionic power coupling and the present interest in the K1B DXpedition, I have calculated the insertion loss to and from the lower ionosp; /archives//html/Topband/2002-05/msg00012.html (8,682 bytes)
14. Topband: More on Power Coupling (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 3 May 2002 07:03:59 -0700 (PDT); Friends in Radio Land - In connection with magneto-ionic power coupling for the K1B operation, it should be noted that similar effects would be expected for other locations near the geomagnetic dip e; /archives//html/Topband/2002-05/msg00022.html (7,736 bytes)
15. Topband: Power Coupling in the USA (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 3 May 2002 07:39:40 -0700 (PDT); Friends in Radio Land - With the recent postings about magneto-ionic power coupling for the K1B DXpedition, I have received a number of private inquiries about the power coupling across the USA. In t; /archives//html/Topband/2002-05/msg00023.html (10,002 bytes)
16. Topband: Power Coupling in the USA (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 3 May 2002 20:25:51 -0700 (PDT); John, In regard to your question about power coupling and take-off angles (TOA) of antennas, power coupling is greatest when the E- field from an antenna is parallel to the geomagnetic field and the; /archives//html/Topband/2002-05/msg00029.html (10,809 bytes)
17. Topband: Topband Angle changes at sunrise/sunset (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Fri, 3 May 2002 20:54:04 -0700 (PDT); Earl, Yes, the downward tilt of ionospheric layers is to the east as the sun rises. As a result, signals coming from the west are refracted downward at steeper angles and heard better on high angle a; /archives//html/Topband/2002-05/msg00031.html (7,218 bytes)
18. Topband: A small point (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Sat, 4 May 2002 08:24:36 -0700 (PDT); Friends in Radio Land - While the consensus is that vertical antennas seem best for DXpeditions, a good number go into the field with the Battle Creek Special. In that connection, the recent remarks; /archives//html/Topband/2002-05/msg00034.html (6,623 bytes)
19. Topband: March LBM Article on Polarization (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Sun, 5 May 2002 15:05:31 -0700 (PDT); Friends in Radio Land - I don't see the problem that Bill, W4ZV, cites in making reference to K9LA's figure for D44 in the March 2002 issue of LBM and the strong signals from nearby C56CW/C56DX in Ma; /archives//html/Topband/2002-05/msg00048.html (10,019 bytes)
20. Topband: March LBM Article on Polarization (score: 1): Author: bobnm7m@cnw.com (Robert Brown); Date: Sun, 5 May 2002 20:01:13 -0700 (PDT); Friends in Radio Land - The results from my power coupling program are normally used in a pie-chart format, as in my article in the March/April issue of the DX Magazine. All calculations are done for; /archives//html/Topband/2002-05/msg00058.html (9,721 bytes)

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