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101. Re: [Amps] Need some 220K 2 watt carbon resistors (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Wed, 29 Mar 2006 09:07:14 +0200 (CEST); It's fair to say that there's no such thing as a non-capacitive resistor, too. Which one it is depends on the frequency, so it's probably more correct to say 'There's no such thing as a non-reactive; /archives//html/Amps/2006-03/msg00726.html (8,551 bytes)
102. Re: [Amps] *** SPAM *** Re: Need some 220K 2 watt carbon resistors (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Wed, 29 Mar 2006 14:08:26 +0200 (CEST); inductive reactance is typically more consequential than the effect of its capacitive reactance.< Depends on the value. For values above a few hundred ohms, capacitive effects are more prevalent. Eve; /archives//html/Amps/2006-03/msg00729.html (7,825 bytes)
103. Re: [Amps] Need some 220K 2 watt carbon resistors (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Wed, 29 Mar 2006 16:49:44 +0200 (CEST); wouldn't the inductance be kind of so-what? < Precisely. At high frequencies, the shunt capacitance would probably dominate. And with values this high, it's not usually anything other than academic a; /archives//html/Amps/2006-03/msg00733.html (8,840 bytes)
104. Re: [Amps] "I gotta tell this" (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 30 Mar 2006 09:34:01 +0200 (CEST); If one calls 10 times in a pile up to work the DX with 100 watts, and once with a kW, the product of power times time is equal. So from a ecological viewpoint, the two are theoretically equal, provid; /archives//html/Amps/2006-03/msg00771.html (8,821 bytes)
105. Re: [Amps]SS vs. Tubes (was "I gotta tell this") (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 30 Mar 2006 09:39:14 +0200 (CEST); The mechanics of the cooling of the SS amp, plus the low voltage, high current wiring and PSU, make the kW SS amp a bit more complicated than the tube amp, at least to my mind. The overall efficiency; /archives//html/Amps/2006-03/msg00772.html (8,048 bytes)
106. Re: [Amps] AL80A (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Fri, 31 Mar 2006 12:56:29 +0200 (CEST); or so inch square of 3/4" plywood, two Edison medium screw-base lamp sockets, #16 wire, and two 300W 120v incandescent lamps.< Good heavens, Rich, that's far too old fashioned for the modern digital; /archives//html/Amps/2006-03/msg00794.html (7,601 bytes)
107. Re: [Amps] tube impedance, figuring tank circuit values (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Sat, 1 Apr 2006 13:03:31 +0200 (CEST); You have to figure on the supply volts under load. Let's assume we're in AB1 for an example. From the tube data sheet, we can choose the plate voltage when the grid volts are zero - usually just abou; /archives//html/Amps/2006-04/msg00000.html (7,099 bytes)
108. Re: [Amps] Hotswitching (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Sat, 8 Apr 2006 13:51:40 +0200 (CEST); Maybe. What I read was that during ground testing, the supply was unregulated, and went up to around 70 volts, causing the thermostat to arc because the voltage it was trying to switch was too much -; /archives//html/Amps/2006-04/msg00111.html (7,568 bytes)
109. Re: [Amps] *** SPAM *** Re: Hotswitching (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Sun, 9 Apr 2006 08:51:22 +0200 (CEST); on vehicle weight,< Do you remember 6 volt electrical systems in cars? Kilovac at one time in their publicity had a whole load of stuff about the vacuum conactors used to switch th 270 volt DC bus us; /archives//html/Amps/2006-04/msg00123.html (7,511 bytes)
110. Re: [Amps] Plate impedance (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Mon, 10 Apr 2006 15:17:03 +0200 (CEST); I seem to remember my RCA TT4 handbook listed the load impedance as the plate swing divided by Ib0, the quiescent plate current. A typo, obviously. 73 Peter G3RZP ____________________________________; /archives//html/Amps/2006-04/msg00135.html (6,939 bytes)
111. Re: [Amps] Plate impedance (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Tue, 11 Apr 2006 09:34:36 +0200 (CEST); Will, those are the classic definitions. Rp = dVa/dIa gm = dIa/dVg mu = dVa/dVg (Va being anode volts, Ia being anode current and Vg being grid volts) and of course, mu = ra.gm. where d is the delta.; /archives//html/Amps/2006-04/msg00165.html (9,025 bytes)
112. Re: [Amps] RCA load impedance calculation (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Tue, 11 Apr 2006 09:46:44 +0200 (CEST); Isn't the load impedance Rl = Vs*2/2Po Vs*2 is the peak to peak anode voltage swing squared Po is the max output power Interestingly, if you look at the anode ac resistance curves and figure the effi; /archives//html/Amps/2006-04/msg00166.html (7,079 bytes)
113. Re: [Amps] RCA load impedance calculation (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Tue, 11 Apr 2006 10:37:03 +0200 (CEST); Sorry, yes, Vs is half the peak to peak swing. In Class B it's exact, in AB, it's near enough. Few things in radio are that critical - thus my irritation with simulations to 4 and 5 places of decimal; /archives//html/Amps/2006-04/msg00168.html (7,226 bytes)
114. Re: [Amps] Plate Impedance, ARRL (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Wed, 12 Apr 2006 18:53:44 +0200 (CEST); I think you'll find that's the theoretical tube efficiency, and the real world has to take into account tank circuit transfer efficiency, too. And if your tank circuit when you've tuned and loaded fo; /archives//html/Amps/2006-04/msg00199.html (8,282 bytes)
115. Re: [Amps] working backwards to setup tank (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 20 Apr 2006 11:26:02 +0200 (CEST); For L and C measurement, I recommend the LC meter from AADE http://www.aade.com/ $99.95 as a kit, $129.95 built. I got an earlier version as a kit some years back, and am very pleased with it. I did; /archives//html/Amps/2006-04/msg00308.html (9,115 bytes)
116. Re: [Amps] Strange power supply (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 20 Apr 2006 11:39:32 +0200 (CEST); Like Peter, I would suspect one of the diode stacks has gone open circuit. If it was the filter capacitors, the hum would be 120Hz. If it was the cat, the hum caused by purring is modulated at a lowe; /archives//html/Amps/2006-04/msg00309.html (7,515 bytes)
117. Re: [Amps] Strange power supply (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 20 Apr 2006 18:34:45 +0200 (CEST); Will, You have more faith in semiconductors than I have retained after being in the industry for the last 27 years! Interestingly, over that period, I have had more semiconductor failures in my equip; /archives//html/Amps/2006-04/msg00313.html (8,928 bytes)
118. Re: [Amps] New Elecraft Amps (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Wed, 26 Apr 2006 16:56:00 +0200 (CEST); What happened to the proposal from FCC to drop the requirement for making sure amplifiers didn't cover 11 metres? Once that went, what is the point of having Type Approval for amateur stuff other tha; /archives//html/Amps/2006-04/msg00383.html (7,470 bytes)
119. Re: [Amps] Love those rules that keep us on the straight and narrow! (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Fri, 28 Apr 2006 10:56:14 +0200 (CEST); I thought that the FCC do require 3rd party testing, which is, in many cases, just a way for test houses to get money. They really aren't necessary , as a responsible manufacturer will design/test et; /archives//html/Amps/2006-04/msg00415.html (8,066 bytes)
120. Re: [Amps] tank coil heating (score: 1): Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>; Date: Thu, 11 May 2006 09:34:56 +0200 (CEST); bypassing. < Figure that you can have 10 or 20 amps of RF running through that cap, so you can easily get a fair amount of dissipation in it. The application needs an NP0 cap. 73 Peter G3RZP - will b; /archives//html/Amps/2006-05/msg00074.html (7,394 bytes)

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