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101. [AMPS] Power out indicator (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 19 Feb 2002 20:01:06 -0500; Looking at a typical inductor Q=300 and capacitor Q=5000 matching 50 ohms to 1000 ohms with 1500 watts on 1.83 MHz: L network Qeff=4.36 C=380pF L=18.96uH and loss = 25.7watts T network Qeff=4.7 C=38; /archives//html/Amps/2002-02/msg00204.html (9,879 bytes)
102. [AMPS] Antenna tuner (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Feb 2002 07:23:24 -0500; Current in that link capacitor system is always equal to the line current, so you can get the approximate current using standard power formula's in the Handbook and other places. I=sqr root of P/R,; /archives//html/Amps/2002-02/msg00216.html (7,789 bytes)
103. [AMPS] Heathkit HA-10 Warrior Parts (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 24 Feb 2002 11:53:54 -0500; You can electrically remove the choke and use the same transformer for 572's. I would not sell the choke or change the transformer, because the "return" isn't worth the potential losses. The current; /archives//html/Amps/2002-02/msg00257.html (7,345 bytes)
104. [AMPS] mof resistors (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 24 Feb 2002 11:53:54 -0500; In Europe, small resistors are available in both carbon film (cheaper, World-wide, there are now metal composition resistors available. They are off-the-shelf, inexpensive, temperature and life stabl; /archives//html/Amps/2002-02/msg00258.html (8,161 bytes)
105. [AMPS] 1500 W Dummy Load Resistor (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 1 Jan 2002 17:37:58 -0500; Whatever you do, just be sure the resistor is designed to be submerged in oil. Some resistors are not coated, and gradually soak up oil causing resistance to increase over time. 73, Tom W8JI W8JI@co; /archives//html/Amps/2002-01/msg00008.html (7,306 bytes)
106. [AMPS] Building new 4-1000A amp (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 4 Jan 2002 08:47:29 -0500; Because they use a different power meter than you do? A Bird 43 is spec'd at + - 5% of full-scale anywhere on the scale, IF it is properly working. Maybe because the "low-gain" amps are laid out to; /archives//html/Amps/2002-01/msg00048.html (9,686 bytes)
107. [AMPS] Building new 4-1000A amp (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 4 Jan 2002 08:47:29 -0500; Before using coaxial stubs, you might check the impedances by measuring them or running numbers on them, and make sure the system will tolerate the loss in Q. Coaxial stubs (and capacitors made from; /archives//html/Amps/2002-01/msg00049.html (9,005 bytes)
108. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 14 Jan 2002 06:45:23 -0500; 812's have higher driving impedances than 811's, and less gain in GG. They also take high bias voltage. A matching system in a GG class B or AB amplifier serves three important functions: 1.) It mat; /archives//html/Amps/2002-01/msg00097.html (8,537 bytes)
109. [AMPS] Need 4X15 Chimney (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 15 Jan 2002 22:41:11 -0500; I need a chimney for a 4CX15,000 tube. Since it is used near 100MHz, I need a real Eimac chimney that doesn't arc or melt from RF. I also need some large contactors that will carry (not hot-switch) 1; /archives//html/Amps/2002-01/msg00108.html (6,800 bytes)
110. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 11:18:09 -0500; It is much more complex than that, because the load is very nonlinear over the RF cycle causing harmonics to be generated, so you have to look at the real action which is much more complex than just; /archives//html/Amps/2002-01/msg00124.html (9,218 bytes)
111. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 11:18:08 -0500; I just assume everyone understands a bandpass or low pass circuit with a reasonable working resonant Q also can not abruptly change voltage. But I believe the low-pass low-cathode-impedance descript; /archives//html/Amps/2002-01/msg00125.html (9,256 bytes)
112. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 17:31:45 -0500; So what is it you question or doubt? Do you doubt a device that conducts less than 360 degrees of the RF cycle produces harmonics? Do you doubt the harmonics fed back into the output of a radio will; /archives//html/Amps/2002-01/msg00131.html (8,920 bytes)
113. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 19:43:02 -0500; Hi Jim, Why waste everyone's time asking a question if (in your own mind) you already know you won't accept any answer except the one you want to hear? Why not just post the answer, instead of a ques; /archives//html/Amps/2002-01/msg00137.html (9,368 bytes)
114. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 20:08:41 -0500; With low enough swamping resistance it will certainly work OK. The swamping resistance simply has to be a fraction of the lowest expected impedance of the load throughout each portion of the RF cycl; /archives//html/Amps/2002-01/msg00140.html (10,083 bytes)
115. [AMPS] Input matching experiment (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 18 Jan 2002 20:23:41 -0500; Hi Mark, Actually swamping does attenuate harmonics. Remember the loss goes both ways, so if the incoming signal is attenuated by the resistive load with only a fraction actually driving the tube...t; /archives//html/Amps/2002-01/msg00142.html (11,720 bytes)
116. [AMPS] New to the Amps list (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 22 Jan 2002 14:16:51 -0500; No. The AL811H is neutralized and has a few other changes. I'd go for the AL811H. You can drop in 572B's, but it would be a bear to add a fourth tube to the AL811. Three 811's are just on the edge o; /archives//html/Amps/2002-01/msg00172.html (8,341 bytes)
117. [AMPS] New to the Amps list (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 22 Jan 2002 21:44:49 -0500; No, but the gain is virtually identical because the driving impedance of the tubes is virtually identical. You do not lose any gain, since in grounded grid the ratio of driving impedance to load imp; /archives//html/Amps/2002-01/msg00176.html (7,822 bytes)
118. [AMPS] Shunt regulated high voltage psu (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 29 Jan 2002 11:57:32 -0500; Yes.....but a shunt regulator with a two-transistor regulator is very simple and reliable, and has no response time problems. So it is possible to use a very simple circuit that uses zeners if you "; /archives//html/Amps/2002-01/msg00268.html (9,627 bytes)
119. [AMPS] Shunt regulated high voltage psu (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 29 Jan 2002 11:57:32 -0500; Is this anything like the only person in the world claiming parasitics cause all sorts of problems in amplifiers being the person who sells nichrome suppressors? 73, Tom W8JI W8JI@contesting.com --; /archives//html/Amps/2002-01/msg00269.html (9,802 bytes)
120. [AMPS] Shunt regulated high voltage psu (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 29 Jan 2002 19:34:46 -0500; Why would that be true, if you run nearly constant current through the diodes??? If the source voltage is at least twice the screen operating voltage, the maximum possible screen dissipation is equa; /archives//html/Amps/2002-01/msg00291.html (11,063 bytes)

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