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41. Topband: Pulse response (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Thu May 1 07:28:45 2003; I don't think this is a valid worry. The duration of a lightning discharge is relatively long, in the order of hundreds of milliseconds to a few seconds. Even if the pulse were very short and abrupt; /archives//html/Topband/2003-05/msg00005.html (8,326 bytes)
42. Topband: Multiple drops and vertical antennas (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Thu May 1 16:48:01 2003; I've received a few e-mails on this. The topic of multiple drops comes up over and over again. Some of this is on my web page under radiation resistance and radiation topics. Multiple drops actually; /archives//html/Topband/2003-05/msg00010.html (8,783 bytes)
43. Topband: Re: Pulse response (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Fri May 2 14:20:03 2003; Antennas and systems we use have very poor (if effectively any) response to and frequencies. In this application higher frequency sinewaves can not pass through any part of the system without rapidl; /archives//html/Topband/2003-05/msg00016.html (9,250 bytes)
44. Topband: Re: Preamp response to broadband noise; noise power ratios (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Fri May 2 15:32:51 2003; Notched noise tests are good for some things, and not for others. It is a good test for multiple channels carrying similar amplitude signals of constant level. It is not a good test for SSB transmitt; /archives//html/Topband/2003-05/msg00021.html (8,663 bytes)
45. Topband: preamps homemade ... (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Mon May 5 05:48:57 2003; It makes no difference if we use output or input TOI. We just need to use a common standard in comparisons. No matter how we do it, we need to know TOI, noise figure, and gain if we are going to make; /archives//html/Topband/2003-05/msg00027.html (6,958 bytes)
46. Topband: Re: Pulse response (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Tue May 6 08:19:30 2003; Hi Brad, The overall accumulated power level from our antennas is what causes problems. Unless we are very close to a station (or stations) that reduces field strength at night, the overall power lev; /archives//html/Topband/2003-05/msg00039.html (9,921 bytes)
47. Topband: 160 Meters Mobile Antenna (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Thu May 8 14:19:41 2003; The largest effect of dielectrics (insulation) on 160-meter mobile loading inductors is the insulation noticeably increases unwanted stray capacitance between turns and across the coil. Any increase; /archives//html/Topband/2003-05/msg00055.html (9,987 bytes)
48. Topband: 160 Meters Mobile Antenna (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Thu May 8 16:43:45 2003; Bill brings up a good point. Heatshrink not only won't help much with detuning, if you do get water between the coil and the shrink it will stay a long time. Heatshrink will noticeably reduce Q in a; /archives//html/Topband/2003-05/msg00058.html (9,099 bytes)
49. Topband: 160 Meters Mobile Antenna Suggestions (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sat May 10 06:52:24 2003; Hi Joe, Contrary to popular rumor or opinion, bandwidth is not a good indicator of antenna efficiency. This is the case even in something that appears simple, such as a mobile antenna. Bandwidth is; /archives//html/Topband/2003-05/msg00067.html (9,217 bytes)
50. Topband: Key clicks (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sat May 10 08:47:31 2003; issue? Perhaps the FCC should only "type accept" amateur I think we need to have a grass-roots effort. Yaesu recently released a factory mod for one of their clicky radios, engineered by the factory,; /archives//html/Topband/2003-05/msg00068.html (8,791 bytes)
51. Topband: 160 Meters Mobile Antenna (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sat May 10 08:47:34 2003; That might be true in some HF applications but certainly not for coil forms! Dissipation factor is one of the lesser worries in a coil form. 73 Tom; /archives//html/Topband/2003-05/msg00069.html (9,217 bytes)
52. Topband: Key clicks (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:34 2003; The spectrum of a OOK (CW) signal at 3 wpm is different from the spectrum at will signal Bandwidth is set entirely by the rise and fall time and shape of the rise and fall of the signal. My keyclicks; /archives//html/Topband/2003-05/msg00081.html (9,389 bytes)
53. Topband: Re: 160 Meters Mobile Antennas (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:37 2003; rapidly true and I agree with most of what you say Barry, but I disagree with the above. Current in ANY *non-radiating* two-terminal device or component is exactly the same at each end, this include; /archives//html/Topband/2003-05/msg00082.html (7,856 bytes)
54. Topband: Key clicks (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:38 2003; The ARRL Handbook is quite lacking in its analysis of keyclicks and descriptions of CW keying Earl. It is one of the worse areas of the Handbook. The **required** bandwidth is given by that formula,; /archives//html/Topband/2003-05/msg00083.html (7,991 bytes)
55. Topband: 160 Meters Mobile Antenna (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:41 2003; forms! Yes, that is what I am saying. It is HOW we use the material that is important! Pure Teflon will significantly de-Q a coil if placed in an area of strong electric fields because the dielectri; /archives//html/Topband/2003-05/msg00084.html (10,227 bytes)
56. Topband: Mobile Antenna bandwidth (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:44 2003; Hi Bill, If I have a fixed antenna design and add the same effective inductance with two different loading coils, one coil with considerable shunting capacitance and the other without, it is quite po; /archives//html/Topband/2003-05/msg00085.html (9,412 bytes)
57. Topband: Mobile and small antennas (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Sun May 11 17:40:50 2003; I'm going to do a short presentation on small transmitting antennas at the Topband dinner. After the Hamfest, I'll put an expanded article up on my website. I'm not sure how much we can cover about e; /archives//html/Topband/2003-05/msg00087.html (8,586 bytes)
58. Topband: Re: 160 Meters Mobile Antennas(Barry, W9UCW) (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Mon May 12 08:53:32 2003; that The coil primarily cancels reactance or corrects power factor. The very short antenna being almost a pure capactance, has voltage and current nearly 90 degrees out-of-phase. The coil brings cur; /archives//html/Topband/2003-05/msg00090.html (9,433 bytes)
59. Topband: Re: Mobile Antenna bandwidth (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Mon May 12 12:11:19 2003; I haven't looked at this closely, but I know it happens when the self-resonant frequency of the inductor is twice the operating frequency or closer. This is typical of several commercial coil design; /archives//html/Topband/2003-05/msg00094.html (8,453 bytes)
60. Topband: Key clicks (score: 132): Author: w8ji at contesting.com (Tom Rauch); Date: Tue May 13 08:42:33 2003; How else would we set bandwidth in a communications system? No matter how fast or how slow we send readable Morse code, when we listen on a receiver or system that allows us to copy the CW, we hear; /archives//html/Topband/2003-05/msg00101.html (8,882 bytes)

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