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121. [AMPS] 8877 Grid Dissipation (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 8 Aug 1997 10:38:13 +0000; To: <amps@contesting.com> Amen. Since the waveform is complex the grid dissipation can only be found by knowing the time integrated grid to cathode voltage and current over the whole RF cycle, but i; /archives//html/Amps/1997-08/msg00076.html (8,862 bytes)
122. [AMPS] Grid dissipation (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 8 Aug 1997 20:56:14 +0000; To: <amps@contesting.com> You are mixing conduction currents with cathode-grid emission currents, in the attempt to mislead people into thinking a few hundred mA of cathode-grid emission current is; /archives//html/Amps/1997-08/msg00084.html (10,396 bytes)
123. [AMPS] adding a second tube (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 10 Aug 1997 18:53:48 +0000; To: <amps@contesting.com> That may be your opinion, but it is most likely not a real concern. There is no rule or law that says the Q needs to be "twelve". The minimum Q for a conventional Pi is esta; /archives//html/Amps/1997-08/msg00092.html (8,835 bytes)
124. [AMPS] Alpha 77's (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 10 Aug 1997 21:37:25 +0000; To: <amps@contesting.com> If the choke had excessive dc voltage drop, it would be on fire or glowing red hot...hi. I gave up on figuring out where manufacturers get their kVA ratings. The AL1200/150; /archives//html/Amps/1997-08/msg00096.html (10,449 bytes)
125. [AMPS] Dissipation Science (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 11 Aug 1997 07:16:01 +0000; To: <amps@contesting.com> <snip> Nice to have you welcoming people as they arrive at "weird world". ;-) While all charges follow the rules of dissipation in a resistance, this NOT the primary heatin; /archives//html/Amps/1997-08/msg00101.html (9,571 bytes)
126. [AMPS] Q of twelve (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 11 Aug 1997 12:28:51 +0000; To: <amps@contesting.com> Hi Peter, While the figures you gave seem reasonable, I'm sure you know most linear PA's aren't operated at 180 degree conduction angles, just as most multipliers or class; /archives//html/Amps/1997-08/msg00108.html (10,666 bytes)
127. [AMPS] Tank Tuning range (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 11 Aug 1997 16:05:19 +0000; In response to Rich's guess reduced Q would hurt matching range.......for a the ETO Q of 5.3 into 50 ohms..... and pi- tank inductor fixed at 21.57 uH and L inductor fixed at 7.255 uH..... 760 ohm lo; /archives//html/Amps/1997-08/msg00111.html (7,892 bytes)
128. [AMPS] Re: Tank Tuning range (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 12 Aug 1997 06:25:31 +0000; To: <amps@contesting.com> Woops. The 22.8 ohm load value is 1720 pF, not 895. Excuse the entry error. 73 Tom -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Adm; /archives//html/Amps/1997-08/msg00114.html (7,329 bytes)
129. [AMPS] Tank Tuning range (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 12 Aug 1997 07:25:41 +0000; To: <amps@contesting.com> Earlier you gave 1000 ohms, I used that figure. It certainly does. This operational example is for a "Q" of approx 5.3 into a 50 ohm load (using your Rp value of 1000 ohms); /archives//html/Amps/1997-08/msg00115.html (9,662 bytes)
130. [AMPS] Tank Tuning range (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 12 Aug 1997 14:32:56 +0000; To: <amps@contesting.com> Rich, Let me walk you through this step by step. 1.) I calculated the Q based on the ETO values you bantered about, of a 500 pF cap and 1000 ohm Rp. 2.) The anode C for 1.9; /archives//html/Amps/1997-08/msg00120.html (9,123 bytes)
131. [AMPS] 8877 Grid Dissipation (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 12 Aug 1997 14:32:56 +0000; Rich, You claim the loss is I^2 R loss. Resistance is easy to define, even if it has a slope with frequency due to skin effect. If the loss causing heat was I^2 R loss, Eimac COULD publish a current; /archives//html/Amps/1997-08/msg00121.html (10,464 bytes)
132. [AMPS] Selling 3CPX5000's (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 13 Aug 1997 10:20:57 +0000; I have a batch of 3CPX5000 pull-outs from an equipment changeover (they went to solid state) available. The tubes are mixed unused (spare equipment) and used but full power pulls from RF pulse transm; /archives//html/Amps/1997-08/msg00125.html (7,449 bytes)
133. [AMPS] Vacuum Relays. (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 17 Aug 1997 00:13:24 +0000; To: <amps@contesting.com> Try Fair Radio, in Lima Ohio. Maybe someone has a fresh catalog and can look up the price for you. They are the cheapest source I've found. 73 Tom -- FAQ on WWW: http://www; /archives//html/Amps/1997-08/msg00129.html (7,879 bytes)
134. [AMPS] Tuning Up? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 17 Aug 1997 20:54:42 +0000; To: <amps@contesting.com> The best way depends on the type of amp. Most amps are best tuned just slightly beyond the maximum output power they can produce (loading control moved to slightly **less**; /archives//html/Amps/1997-08/msg00135.html (9,939 bytes)
135. [AMPS] Tuning Up? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 18 Aug 1997 21:29:28 +0000; To: <amps@contesting.com> Not quite. ;-) I'd follow ETO's instructions, unless there is something lacking or incorrect. Dick Erhorn is a successful amp designer with a good reputation, and likely wo; /archives//html/Amps/1997-08/msg00147.html (8,906 bytes)
136. [AMPS] Q Swing (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 11:48:15 +0000; To: <amps@contesting.com> If your PA works OK at 2500 volts with full rated current it'll likely be just fine at the higher voltage, although tank losses will increase (especially on ten and 15 mete; /archives//html/Amps/1997-08/msg00152.html (8,279 bytes)
137. [AMPS] Q Swing (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 17:44:05 +0000; To: <amps@contesting.com> Not a good method in the real world. Inductance changes by the square of the turns if the inductor has 100% flux linkage from end to end. If it has no flux linking the turn; /archives//html/Amps/1997-08/msg00154.html (9,419 bytes)
138. [AMPS] Properly setting inductance (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 22:13:54 +0000; To: <amps@contesting.com> KM1H: I had no idea most people didn't know such a simple fact!! The reality of the world is this. Air coils are greatly affected by the surroundings, since the field... un; /archives//html/Amps/1997-08/msg00156.html (9,573 bytes)
139. [AMPS] Q Swing (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 20 Aug 1997 22:13:54 +0000; Carl, Your nasty index is rising, but there is one good technical point hidden inside: Anyone owning a GDO, a simple common antenna analyzer, or a transceiver and a low power SWR meter, and a few cap; /archives//html/Amps/1997-08/msg00157.html (10,320 bytes)
140. [AMPS] Thanks for the L4B info (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 21 Aug 1997 21:08:20 +0000; Don't do that! The input system really needs to be a low pass type, and present a very low Z at the third and higher harmonics right at the cathode. The T net tuner will help the rig, but it won't h; /archives//html/Amps/1997-08/msg00161.html (7,958 bytes)

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