Mail Archive Search: <+from:g3sek@ifwtech.co.uk>

Results:

References: [ +from:g3sek@ifwtech.co.uk: 291 ]

Total 291 documents matching your query.

61. [Amps] Muffin Fan on Swan Mark 1 (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Fri, 26 Jul 2002 17:47:12 +0100; They used to say that about antennas too, until MININEC and NEC became available free to anyone who wants them. Certainly there are big pitfalls in computer modeling, but antenna modeling has also sh; /archives//html/Amps/2002-07/msg00494.html (11,324 bytes)
62. [Amps] Muffin Fan on Swan Mark 1 (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Sat, 27 Jul 2002 08:49:20 +0100; In all areas of engineering, professionals routinely do both modeling and measurement, and use each to check the other. Setting up modeling "versus" measurement, and turning it into an argument, is s; /archives//html/Amps/2002-07/msg00500.html (10,363 bytes)
63. [Amps] Low-noise high-voltage power supplies. (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 6 Jun 2002 11:06:00 +0100; Interesting - I've noticed the same thing in active shunt stabilizers for screen supplies. To handle some of the heat dissipation, I use a resistor in series with the drain of the MOSFET shunt device; /archives//html/Amps/2002-06/msg00041.html (9,099 bytes)
64. [Amps] Driving Impedance (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Wed, 12 Jun 2002 07:42:15 +0100; With the correct DC voltages applied to the control grid and screen, any tetrode will work fine with both grids at RF ground. This is very common at VHF and above, and occasionally seen at HF. Accord; /archives//html/Amps/2002-06/msg00077.html (8,022 bytes)
65. [Amps] 8877 Max Grid Current (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Tue, 18 Jun 2002 10:07:27 +0100; Remember there's a difference between the maximum grid current you would normally expect to run, and the maximum level you *could* run without damaging the tube. Depending on the speed of the trip ci; /archives//html/Amps/2002-06/msg00134.html (9,315 bytes)
66. [Amps] Rectifier diode strings (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Sun, 5 May 2002 17:31:53 +0100; Why not? It is quite common to see mains spikes of 1kV and more on the *primary* side of the transformer. According to ANSI/IEEE statistics, "medium exposure" sites in the USA can expect several hun; /archives//html/Amps/2002-05/msg00031.html (12,653 bytes)
67. [Amps] Rectifier diode strings (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Mon, 6 May 2002 15:05:47 +0100; These are incoming spikes on the 115/230V mains. The issue is how much they are stepped up by the transformer, and then damped down by the rectifier/capacitor. I accept Tom's statement that a power t; /archives//html/Amps/2002-05/msg00049.html (12,079 bytes)
68. [Amps] Transformer secondary resistance (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Tue, 7 May 2002 07:43:48 +0100; All these questions can be answered by Duncan Munro's excellent PSU Designer software. There's a link from the 'In Practice' page on my web site, where you can also pick up a file containing rectifie; /archives//html/Amps/2002-05/msg00063.html (9,045 bytes)
69. [Amps] Transformer oil? (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 30 May 2002 10:19:09 +0100; That's about right. Ordinary hydrocarbon-based transformer oil smells quite different... like oil. A simple test which is used commercially is to take a very small drop of the oil on the end of an ir; /archives//html/Amps/2002-05/msg00470.html (10,470 bytes)
70. [Amps] Re: [Amps} Transformer oil? (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Fri, 31 May 2002 10:32:56 +0100; On the other hand, you need to protect yourself against over-zealous officials. "PCBs" is one of their trigger-words, the very mention of which can make them imagine you're operating a "Love Canal" d; /archives//html/Amps/2002-05/msg00478.html (8,467 bytes)
71. [Amps] Re: [Amps] Re: [Amps] Re: [Amps] Bird® 43 Ma nual (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 4 Apr 2002 10:56:09 +0100; I'm not disputing Tom's measurement data, but the theory still is not convincing. Reviewing where we've got to so far: hopefully, we all now agree that the capacitive coupling produces an RF voltage; /archives//html/Amps/2002-04/msg00137.html (13,563 bytes)
72. [Amps] Re: [Amps] Re: [Amps] Re: [Amps] Re: [Amps ] Bird® 43 Manual (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 4 Apr 2002 13:09:44 +0100; That's only one particular type of directional coupler. Something like a Bruene bridge doesn't have any internal transmission line, and can be considered as making true single-point samples of curren; /archives//html/Amps/2002-04/msg00149.html (11,529 bytes)
73. [Amps] Re: [Amps] Re: [Amps] Re: [Amps] Re: [Amps ] Bird® 43 Ma nual (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 4 Apr 2002 17:17:59 +0100; Quite - no argument here. Obviously the real-world physical current at any given instant is only flowing one way - but it can be *mathematically* resolved into components of "forward" and "reflected"; /archives//html/Amps/2002-04/msg00155.html (14,832 bytes)
74. [Amps] Re: [Amps] Re: [Amps] Re: [Amps] Re: [Amps ] Re: [Amps ] Bird® 43 Ma nual (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Fri, 5 Apr 2002 08:15:36 +0100; Bruene's fault, Tom's fault, and mine: we each should have said: "All impedances except infinity, that is." The actual reading was meaningless. There are no watts delivered into an infinite load - ob; /archives//html/Amps/2002-04/msg00170.html (13,639 bytes)
75. [Amps] Does a Russian GI7B like horizontal mount?` (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Mon, 8 Apr 2002 18:03:03 +0100; It's almost certainly OK. I'm 99% sure that it's built like a GS31/35, with a flat cathode and a dome-shaped mesh grid, so there are no long, thin grid or filament structures that can sag if gravity; /archives//html/Amps/2002-04/msg00244.html (7,402 bytes)
76. [Amps] Re: [Amps] G3SEK´s homepage (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 18 Apr 2002 17:10:39 +0100; A few weeks ago, I lost the ifwtech.com domain (or rather, my incompetent ISP let it go). Fortunately I also had ifwtech.co.uk registered, so that's where you will find the pages now. I made an annou; /archives//html/Amps/2002-04/msg00428.html (7,869 bytes)
77. [Amps] RE: Solid State HF amps and kits (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Sat, 20 Apr 2002 11:18:52 +0100; To: <amps@contesting.com> Also http://www.olimex.com/pcb/ have low-cost offers for particular board sizes, so long as you want double-sided FR4 with top-side component ID and bottom-side solder mask; /archives//html/Amps/2002-04/msg00491.html (9,579 bytes)
78. [Amps] homebrew glitch resistors (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 25 Apr 2002 19:18:08 +0100; A copy of the original Eimac Bulletin is at: www.ifwtech.co.uk/g3sek/misc/bull17.pdf They mention limits of both 40A and 4J, for tubes up to 1500W dissipation. -- 73 from Ian G3SEK Editor, 'The VHF/U; /archives//html/Amps/2002-04/msg00557.html (7,790 bytes)
79. [Amps] G3SEK change of e-mail (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Tue, 19 Mar 2002 18:19:45 +0000; Sorry to say that I've lost the ifwtech.com domain... If anyone has e-mailed me in the past week, please can you send it again to the new address. Also please update e-mail address books and bookmark; /archives//html/Amps/2002-03/msg00423.html (6,672 bytes)
80. [Amps] calculations (score: 1): Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK); Date: Thu, 21 Mar 2002 21:14:58 +0000; The step-by-step worked example is exactly your pi-network problem. -- 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) New e-mail: g3sek@ifwtech.co.uk New we; /archives//html/Amps/2002-03/msg00480.html (7,916 bytes)

Current List: 61 - 80
Page: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]