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1. Re: Topband: dynamic range (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Thu, 5 Feb 2004 11:21:37 -0500; Correction: 100 uV plus 60 dB is 100 mV, still a strong signal but a long way from 100V. Decibels (for voltages) are defined as dB = 20*log(V2/V1) Correction: 30 dB down from 100 uV is about 3 uV. Se; /archives//html/Topband/2004-02/msg00075.html (9,380 bytes)
2. Re: Topband: BDR redux (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Thu, 5 Feb 2004 15:42:24 -0500; I found exactly the same thing during my first extended operating time with the Orion during the recent CQ160 contest. I realized immediately that the 3uV default AGC threshold value is way too low f; /archives//html/Topband/2004-02/msg00086.html (8,789 bytes)
3. Re: Re: Topband: BDR redux (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 6 Feb 2004 10:00:18 -0500; There are a couple issues to consider with hard-limiters like back-to-back diodes. The first is harmonic distortion. For IF signals that are substantially sub-octave, i.e. occupy much less than one o; /archives//html/Topband/2004-02/msg00106.html (9,602 bytes)
4. Re: Topband: Topband at solar maximum (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 10 Mar 2004 14:27:51 -0500; I've said this before and I'll repeat it again. By far the best years on 160m propagation-wise in New England in the last 3 decades were in the 1986-87 period, around or just after the solar minimum.; /archives//html/Topband/2004-03/msg00136.html (8,426 bytes)
5. Re: Topband: Modeling a shunt fed tower with EZNEC (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 19 Mar 2004 13:52:05 -0500; The two-media model is probably OK for calculating impedance data, as Bill's results appear to confirm. However, the model has a known problem, confirmed by EZNEC author W7EL, in predicting far-field; /archives//html/Topband/2004-03/msg00211.html (10,193 bytes)
6. Re: Topband: Long Path Direction! (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Tue, 30 Mar 2004 14:46:44 -0500; What we call "long path" is a matter of semantics. It can be whatever we define it to be. The strictest interpretation would be the path that's 180 degress reversed from the great circle short path.; /archives//html/Topband/2004-03/msg00339.html (9,860 bytes)
7. Re: [Fwd: Re: Topband: Long Path Direction!] (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 31 Mar 2004 14:23:04 -0500; I never give direction of arrival in exact degrees because you are right that it is not that easy to estimate with any accuracy with the types of directional antennas most of us use. For that reason; /archives//html/Topband/2004-03/msg00353.html (10,143 bytes)
8. Re: RE: Topband:mode separation...small stndx oppty (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 23 Apr 2004 15:10:14 -0400; I have a DSL modem at home and I don't see any trace of interference on 160 (or any other band) from the modem. I do sometimes cause the modem to lose sync when I transmit but that's a different issu; /archives//html/Topband/2004-04/msg00215.html (8,351 bytes)
9. Re: Re: Topband: Analog to Digital converter for 1.8MHz (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 2 Jul 2004 18:12:37 -0400; Spurious-free dynamic range has to be referenced to a measurement noise bandwidth to have any meaning because dynamic range is measured against a noise floor. Furthermore SFDR varies nonlinearly with; /archives//html/Topband/2004-07/msg00011.html (8,662 bytes)
10. Topband: Re: Coax capacitor losses (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 17 Dec 2004 10:42:15 -0500; Let me update my earlier post about losses in coax lines, where I cautioned people about using them as reactance elements (capacitors or inductors). If you are familiar with the Smith Chart, you can; /archives//html/Topband/2004-12/msg00235.html (8,425 bytes)
11. Re: Topband: JA sp/lp from east coast (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 09 Mar 2005 14:23:41 -0500; I dug back into the Topband Reflector archives and found these references of mine to LP JA openings: http://lists.contesting.com/archives//html/Topband/2000-01/msg00006.html http://lists.contesting.c; /archives//html/Topband/2005-03/msg00105.html (8,759 bytes)
12. Re: Topband: Top-band Prop along grayline (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 11 Mar 2005 11:23:19 -0500; Most of us use the term "long path" rather loosely. In my case when the JA's are strongest on my SE Beverage, I call it LP. That Beverage happens to be aimed at 135 degress. However, because of the b; /archives//html/Topband/2005-03/msg00123.html (8,283 bytes)
13. Re: Topband: Better low band conditions? (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 16 Mar 2005 09:15:22 -0500; I think the perspective from the more northerly latitudes is quite different than further south. In W1 land we're more adversely affected by absorption associated with high auroral activity. I monito; /archives//html/Topband/2005-03/msg00167.html (8,687 bytes)
14. Topband: 1820.4 carrier (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Fri, 09 Dec 2005 09:16:31 -0600 (CST); I listened this morning around 1300Z, about one hour after sunrise, and there was absolutely no QSB on the signal here in FN42gk (about 25 mi west of Boston). This suggests the source is within groun; /archives//html/Topband/2005-12/msg00100.html (7,436 bytes)
15. Re: Topband: conditions this morning (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 25 Jan 2006 10:23:21 -0600 (CST); Yes, in W1 land this was the best JA opening in at least 2 years. Conditions like this are definitely rare. I got on at 1140Z and managed to log JA7NI, JL8GFB, JA8ISU, JA0QNJ, JH0BBE, JA5DQH, JH2FXK; /archives//html/Topband/2006-01/msg00360.html (7,725 bytes)
16. Re: Topband: noise (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Wed, 17 Jan 2007 09:25:58 -0600 (CST); Absolutely correct. The engineering definition of white noise is that the noise is statistically uncorrelated at any two different frequencies. Ambient background noise is generally white. In practic; /archives//html/Topband/2007-01/msg00298.html (8,441 bytes)
17. Re: Topband: Beverage In Woods (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Thu, 22 Feb 2007 09:43:11 -0600 (CST); Not only should you take a compass reading at the start of your run but you should take the compass with you as you trek through the woods. Check compass headings from tree to tree. In some of the wo; /archives//html/Topband/2007-02/msg00240.html (7,627 bytes)
18. Topband: AIM4170 antenna analyzer (score: 1): Author: John Kaufmann <john.kaufmann@verizon.net>; Date: Tue, 04 Sep 2007 09:17:38 -0500 (CDT); A some of you may know, the AIM4170 antenna/impedance analyzer was introduced recently. It retails for about 500 USD. More information is available at: http://www.arraysolutions.com/Products/AIM4170.; /archives//html/Topband/2007-09/msg00013.html (8,793 bytes)
19. Re: Topband: Hi-Z Antennas back in business (score: 1): Author: "John Kaufmann" <john.kaufmann@verizon.net>; Date: Mon, 28 Mar 2011 18:14:32 -0400; Here is the latest on the court case: http://docs.justia.com/cases/federal/district-courts/ohio/ohndce/5:2010cv028 06/171142/24/. It appears that the pending patent infringement lawsuit has been susp; /archives//html/Topband/2011-03/msg00079.html (7,248 bytes)
20. Re: Topband: "Artificial" Propagation...? (score: 1): Author: "John Kaufmann" <john.kaufmann@verizon.net>; Date: Sun, 11 Mar 2012 11:45:01 -0400; Some of you may be thinking of "Project West Ford", conducted in the early 1960's by MIT Lincoln Laboratory (where I work now). Many millions of tiny "needles" were launched into orbit to generate an; /archives//html/Topband/2012-03/msg00021.html (9,643 bytes)

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