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41. TopBand: 160M RF into Create RC5A3 Rotor Box (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 8 Sep 1997 10:32:25 +0000; To: <topband@contesting.com> Hi Jeff The beads might be only "half a cure". RF is attenuated by having a low shunt impedance in conjunction with a high series impedance. The bead will add some serie; /archives//html/Topband/1997-09/msg00076.html (8,591 bytes)
42. [AMPS] Re: TopBand: Followup Beverage Box (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 23 Sep 1997 06:01:22 +0000; To: <topband@contesting.com> Hi Phil, Thanks for the info. IMHO, it's better to use a IMD-immune device rather than filter the input/ output of a device that by itself offers marginal performance. R; /archives//html/Topband/1997-09/msg00234.html (11,835 bytes)
43. Re[2]: [AMPS] Re: TopBand: Followup Beverage Box (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 24 Sep 1997 11:15:02 +0000; To: <topband@contesting.com> I need "speaking clearly lessons". What I was referring to was this. If a FIXED amplifier gain block like an MMIC is used, the traditional way to reduce gain is to add a; /archives//html/Topband/1997-09/msg00255.html (9,770 bytes)
44. TopBand: Slinky Beverages (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 1 Aug 1997 09:24:36 +0000; Hi Carl, I won't repeat your tirade. The surge impedance of a conductor is greatly affected by distributed inductance and capacitance. Impedance is governed by the surge impedance of the structure, n; /archives//html/Topband/1997-08/msg00003.html (7,252 bytes)
45. TopBand: Re: Fact and Fantasy about Beverage Antennas (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 1 Aug 1997 10:10:54 +0000; To: <topband@contesting.com> Correct termination would produce a smooth uniform taper in voltage or current, with minimal fluctuations. I use a clamp on RF current meter. Properly terminated, my 500; /archives//html/Topband/1997-08/msg00004.html (10,650 bytes)
46. TopBand: Slinky (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sat, 2 Aug 1997 17:06:17 +0000; To: <topband@contesting.com> The actual measurement of a slinky antenna--necessary to guarantee optimum performance-- would be simple. Wouldn't it be nice, if BEFORE someone sold something...or told; /archives//html/Topband/1997-08/msg00012.html (9,223 bytes)
47. TopBand: EM1 on 160 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 4 Aug 1997 10:36:20 +0000; Worked EM1HO Paul near sunrise (1130 Z). Good signal but no sunrise peak, and a few South Americans were on also. 73, Tom W8JI (My opinions are my own. I am an independent consultant for several manu; /archives//html/Topband/1997-08/msg00022.html (6,968 bytes)
48. TopBand: verticals (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 14 Aug 1997 11:38:43 +0000; To: <topband@contesting.com> One could use the IRE definition of radiation resistance as the NET current causing radiation. In that case the radiation resistance would remain exactly the same. This; /archives//html/Topband/1997-08/msg00077.html (13,900 bytes)
49. TopBand: Radials and resonance (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 14 Aug 1997 22:23:03 +0000; To: <topband@contesting.com> Hi John, I wouldn't rethink anything without field strength measurements. Neither current distribution nor impedance tells you a thing about what happens in the far fiel; /archives//html/Topband/1997-08/msg00090.html (8,770 bytes)
50. TopBand: ground losses (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 14 Aug 1997 22:23:03 +0000; To: <topband@contesting.com> To: <topband@contesting.com> Several wavelengths with many hundreds of radials if you are worried about low angle radiation. If you don't do that, a 1/4 wave out will ge; /archives//html/Topband/1997-08/msg00091.html (9,066 bytes)
51. TopBand: Resonance Value-meals (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 15 Aug 1997 11:48:00 +0000; To: <topband@contesting.com> That's right Peter, lowest SWR is NOT necessarily at resonance. It depends on how fast the reactance changes compared to the resistance. If the resistance change is slow; /archives//html/Topband/1997-08/msg00099.html (9,327 bytes)
52. TopBand: Slinky test results (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 19 Aug 1997 15:09:13 +0000; I tested some common Slinky's, purchased at Toy-R-Us in a shopping mall ($1.65 each). I'm not sure if they are the same as the Slinky's everyone else is using or not. This what I've found for a heigh; /archives//html/Topband/1997-08/msg00120.html (9,673 bytes)
53. TopBand: Slinky test results (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 07:58:52 +0000; I should have posted the size I measured, it was about 2 - 3/4 inch mean diameter. Ratios traditionally are used to compare the same "units". If "d" is in inches "s" must also be inches. Translated t; /archives//html/Topband/1997-08/msg00124.html (7,843 bytes)
54. TopBand: Rohn SSV as 160M antenna? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 12:39:56 +0000; To: <topband@contesting.com> Hi George, When a structure tapers to a narrower point at the outer end, it looks electrically shorter and the bandwidth gets narrower. Think of it as a backwards fed di; /archives//html/Topband/1997-08/msg00129.html (8,139 bytes)
55. TopBand: Slinky test results (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 17:44:05 +0000; To: <topband@contesting.com> NO. For different s/d's (turn spacings divided by turn diameters): s/d = 0.5 Zo 1280 ohms Vp= .42 s/d = 0.75 Zo 1060 ohms Vp= .55 s/d = 1.0 Zo 930 ohms Vp= .63 A Vp of .; /archives//html/Topband/1997-08/msg00135.html (8,706 bytes)
56. TopBand: Ducting (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 3 Jul 1997 09:36:12 +0000; I decided to post this after several e-mails about ducting. I'm not convinced ionospheric ducting is anything beyond pure speculation. Even the experts admit there is no way to measure the effect, th; /archives//html/Topband/1997-07/msg00008.html (11,283 bytes)
57. TopBand: Why the duct? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 6 Jul 1997 12:09:19 +0000; Hi Frank, Here in Georgia I can hear and work the JA's almost anytime between their sunset and my sunrise most days, but the signals PEAK at my sunrise. At sunrise I can work the third and fourth la; /archives//html/Topband/1997-07/msg00021.html (8,482 bytes)
58. TopBand: Ducting (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 7 Jul 1997 00:00:18 +0000; Hi Bob, Along the same lines, who measured ducting? when I asked if there was any way to measure ducting, the answer was no. So I guess no one measured either, except with OTHR you can see ground ref; /archives//html/Topband/1997-07/msg00023.html (10,315 bytes)
59. TopBand: Re: Why the duct? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 7 Jul 1997 08:04:56 +0000; Hi Frank, Thanks for the data. In both Toledo and Cleveland, Ohio, I could work JA's from sunset in JA to sunrise in Ohio. I'll guarantee there was almost never a time the east coast guys would be w; /archives//html/Topband/1997-07/msg00024.html (10,649 bytes)
60. TopBand: Ducting (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 7 Jul 1997 00:00:17 +0000; That has been my experience also, working with an OTHR system on the east coast. Enter the ionosphere at a low incident angle far below the MUF, and absorption is much greater than the same path with; /archives//html/Topband/1997-07/msg00027.html (9,928 bytes)

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