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341. [Amps] Power Supply Turn Off Under Load (score: 1): Author: TexasRF@aol.com; Date: Mon, 17 Jan 2011 11:17:29 EST; There have been a couple of recent mentions of the bad effects of turning off a hv power supply that is under full load. A google search didn't turn up useful information so I am wondering if a reade; /archives//html/Amps/2011-01/msg00170.html (7,070 bytes)
342. Re: [Amps] Fireing up a old Tl922 amplifier. (score: 1): Author: TexasRF@aol.com; Date: Fri, 21 Jan 2011 08:30:00 EST; Hi Jean, there several ways to measure the 1A current flow. One method is to measure voltage drop across the 47 ohm resistor. If you are doing that with a typical digital voltmeter it will display a; /archives//html/Amps/2011-01/msg00210.html (13,982 bytes)
343. Re: [Amps] Help with HL2200 6 meter conversion (score: 1): Author: TexasRF@aol.com; Date: Sat, 22 Jan 2011 06:58:38 EST; Hi Gary, it sounds like you are close to success on this project. On the issue of efficiency, it will be the better at higher drive levels for a couple of reasons. One, as drive is lowered, the plate; /archives//html/Amps/2011-01/msg00225.html (11,709 bytes)
344. Re: [Amps] variable capacitors (score: 1): Author: TexasRF@aol.com; Date: Wed, 26 Jan 2011 07:57:48 EST; So what application is the big demand for butterfly caps? I don't recall ever using one here. 73, Gerald K5GW In a message dated 1/25/2011 11:53:24 A.M. Central Standard Time, slash_dot@msn.com write; /archives//html/Amps/2011-01/msg00306.html (12,106 bytes)
345. Re: [Amps] Power Supply Turn Off Under Load (score: 1): Author: TexasRF@aol.com; Date: Wed, 26 Jan 2011 08:14:40 EST; All this reverse EMF stuff has me concerned about some KAPOW events seen in the past. I saw one event that destroyed circuit board traces in the primary circuit of a power supply located in another p; /archives//html/Amps/2011-01/msg00307.html (10,279 bytes)
346. Re: [Amps] I answered it. (score: 1): Author: TexasRF@aol.com; Date: Sat, 29 Jan 2011 09:38:32 EST; I missed this question on the first pass. When the amplifier is tuned for maximum power out, the Q has virtually nothing to do with peak tank circuit voltages. It has everything to do with circulatin; /archives//html/Amps/2011-01/msg00397.html (8,871 bytes)
347. Re: [Amps] finger stock (score: 1): Author: TexasRF@aol.com; Date: Mon, 7 Feb 2011 12:13:02 EST; Finger stock is available from Richardson Electronics. 73, Gerald K5GW In a message dated 2/7/2011 10:10:26 A.M. Central Standard Time, kg7hf@comcast.net writes: Hi Gang, Anyone know where I can get; /archives//html/Amps/2011-02/msg00044.html (7,299 bytes)
348. Re: [Amps] SB 200 blown diodes in power supply (score: 1): Author: TexasRF@aol.com; Date: Thu, 24 Mar 2011 13:55:22 EDT; Kathy, considering the SB200 has been around more than 40 years and yours lasted that long without the soft start modifications, one might hope it would continue on a few more years without them. Wha; /archives//html/Amps/2011-03/msg00190.html (9,604 bytes)
349. Re: [Amps] SB-200 power supply diodes (score: 1): Author: TexasRF@aol.com; Date: Sun, 27 Mar 2011 09:00:54 EDT; Think about this again. The SB200/220 both use a voltage doubler capacitor filter hv supply. We know that peak currents in these type supplies can be five to ten times the average current. So, with a; /archives//html/Amps/2011-03/msg00212.html (11,424 bytes)
350. Re: [Amps] SB-200 power supply diodes (score: 1): Author: TexasRF@aol.com; Date: Mon, 28 Mar 2011 08:11:30 EDT; Hi Jim, the math is well known so I won't repeat it here. You are 100% correct about the THOUSANDS of SB200/220 units in service. The discussion had addressed replacing BLOWN diodes and it only makes; /archives//html/Amps/2011-03/msg00222.html (13,995 bytes)
351. Re: [Amps] Homebrew is back.. (score: 1): Author: TexasRF@aol.com; Date: Mon, 28 Mar 2011 18:01:19 EDT; Eddy and all, here are some old and well known facts and thoughts on too much output C. Eddy already suggested the biggest help; a series L between the plate and tune C. In addition, the tube does no; /archives//html/Amps/2011-03/msg00233.html (13,463 bytes)
352. Re: [Amps] what is a 4 wire 240VAC service (score: 1): Author: TexasRF@aol.com; Date: Mon, 4 Apr 2011 09:29:46 EDT; Perhaps the switch location has a dual role: up/on = occupied, down/off = unoccupied? 73, Gerald K5GW In a message dated 4/4/2011 8:24:42 A.M. Central Daylight Time, kg7hf@comcast.net writes: That mu; /archives//html/Amps/2011-04/msg00088.html (8,798 bytes)
353. Re: [Amps] 4 wire 240VAC service? What to do now? (score: 1): Author: TexasRF@aol.com; Date: Mon, 4 Apr 2011 15:22:50 EDT; In a typical sub panel, is the buss bar that is used to common the neutral leads insulated from the box chassis? I have installed a couple of sub panels through the years but never paid any attention; /archives//html/Amps/2011-04/msg00121.html (14,186 bytes)
354. Re: [Amps] Transformer i.d. (score: 1): Author: TexasRF@aol.com; Date: Tue, 5 Apr 2011 23:06:07 EDT; Glen,you can tell a lot about the transformer by connecting 12vac to the primary and making some voltage checks on the secondary terminals. That will at least identify the turns ratio and presence of; /archives//html/Amps/2011-04/msg00201.html (9,274 bytes)
355. Re: [Amps] Where is power measured ? (score: 1): Author: TexasRF@aol.com; Date: Thu, 7 Apr 2011 12:26:44 EDT; Glen, as you know, we both live within a few miles of the KRLD 50KW transmitter/antenna site. I have measured over 5 volts of rf on one of the upper tower guys at my QTH. When I drive up the driveway; /archives//html/Amps/2011-04/msg00285.html (9,385 bytes)
356. Re: [Amps] DIN vs N (score: 1): Author: TexasRF@aol.com; Date: Sat, 23 Apr 2011 23:31:27 EDT; Don, the advantage of the 7-16 DIN connector is it is very robust in the power handling department. They have excellent vswr characteristics and work very well through several GHz. The disadvantage i; /archives//html/Amps/2011-04/msg00497.html (6,858 bytes)
357. Re: [Amps] Teflon Chimneys (score: 1): Author: TexasRF@aol.com; Date: Sat, 14 May 2011 07:23:30 EDT; Bob, I have made Teflon chimneys like that for 2m, 70cm and 23cm amplifiers using small aluminum pop rivets to join the ends of the sheet. The lower rivet was spaced away from the amplifier tube anod; /archives//html/Amps/2011-05/msg00098.html (7,690 bytes)
358. Re: [Amps] 3cx400A7 and 8877 (score: 1): Author: TexasRF@aol.com; Date: Sat, 21 May 2011 08:26:58 EDT; Hi Paul, your understanding of the buck/boost windings is right on the money. Ameritron amplifiers have used this technique for years. The voltage tripler idea seems less feasible considering the poo; /archives//html/Amps/2011-05/msg00180.html (8,461 bytes)
359. Re: [Amps] load resistor (score: 1): Author: TexasRF@aol.com; Date: Sun, 22 May 2011 12:10:23 EDT; Carey, you can confirm resonance with the plate tuning capacitor. If you see a peak in output power while adjusting the control, there is resonance. A slight increase in C will lower the frequency of; /archives//html/Amps/2011-05/msg00194.html (9,537 bytes)
360. Re: [Amps] arrrrgggg!! (score: 1): Author: TexasRF@aol.com; Date: Mon, 23 May 2011 08:16:58 EDT; Hi Carey, flapper tuning is the best (maybe only) method for resonating a strip line plate circuit. There are always losses in these circuits due to unavoidable resistance in the metal parts and rf c; /archives//html/Amps/2011-05/msg00198.html (8,304 bytes)

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