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181. [Amps] Arc distance (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 07:53:22 -0400; I wouldn't want people to walk away with the false idea that spacing is the only major parameter that determines arc distance in a given dielectric media. The shape is extremely important, as are any; /archives//html/Amps/2006-07/msg01232.html (6,840 bytes)
182. [Amps] Arc distance and plasma (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 10:51:44 -0400; Rather than claim I can look at a tube and magically tell what happened years ago with my magnifying glass, I thought I would add a picture of a 3-500Z under RF plasma conditions. The photos clearly; /archives//html/Amps/2006-07/msg01236.html (6,908 bytes)
183. Re: [Amps] plexiglas isolation in coils (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 12:11:39 -0400; The AL12 series bower was downsized after the first six months of production because no one wanted a high speed blower. On SSB and CW the change wasn't an issue. If people read the manual, which few; /archives//html/Amps/2006-07/msg01241.html (9,812 bytes)
184. Re: [Amps] Arc distance (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 13:52:36 -0400; There are multiple causes of flashovers. The most common are unwanted sharp points, gas, and/or debris. Eimac accepts the fact even perfectly good new tubes do that on occasion. 73 Tom _____________; /archives//html/Amps/2006-07/msg01249.html (7,425 bytes)
185. Re: [Amps] Arc distance (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 18:51:41 -0400; Most interesting is that everyone with direct experience in an engineering or working in a scientific environment, even people in widely different areas who do not know each other, agree to the smal; /archives//html/Amps/2006-07/msg01259.html (7,632 bytes)
186. Re: [Amps] Arc distance and plasma (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 21:00:45 -0400; That's almost certainly just phosphoresce in the glass. It's not rare to glass do that in HV tubes. 73 Tom _______________________________________________ Amps mailing list Amps@contesting.com http:; /archives//html/Amps/2006-07/msg01261.html (7,930 bytes)
187. Re: [Amps] Arc distance and plasma (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Fri, 28 Jul 2006 23:20:37 -0400; What Steve described is virtually always phospherense in the glass, not gas. It isn't the least bit harmful. 73 Tom _______________________________________________ Amps mailing list Amps@contesting.; /archives//html/Amps/2006-07/msg01270.html (9,405 bytes)
188. Re: [Amps] Ameritron Amps (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 15:12:08 -0400; The capacitors were initially 600 volt foil, and they were required to have a certain leakage at 525 volts at a specified temperature in a test at the manufacturer. That's one of the things you can; /archives//html/Amps/2006-07/msg01314.html (13,181 bytes)
189. Re: [Amps] plexiglas isolation in coils (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 18:48:37 -0400; The reason RTTY isn't on 160 is it doesn't work very well on 160. Multipath kills it. 73 Tom _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contes; /archives//html/Amps/2006-07/msg01330.html (8,755 bytes)
190. Re: [Amps] Arc distance (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 19:01:10 -0400; The 3-500 Zirconium getter works because the anode operates at widely varying temperatures, with the lower edges much hotter than upper areas. You'll never degass a 3-500Z unless the anode shows col; /archives//html/Amps/2006-07/msg01331.html (10,215 bytes)
191. Re: [Amps] plexiglas isolation in coils (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 21:37:39 -0400; -- REPLY SEPARATOR -- It's been a lot of years but I recall it being either 12 or 14. Bill, W6WRT>> Ya gotta just love the wild guesses on this reflector. Now a certain someone run off for twenty ye; /archives//html/Amps/2006-07/msg01342.html (9,518 bytes)
192. Re: [Amps] Ameritron Amps (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 23:05:13 -0400; Mike, I'm not posting this to pick at you, but just to show how we can leap to very wrong conclusions that sound very authorative. If people were paying $50K per amplifer and using them with navy ge; /archives//html/Amps/2006-07/msg01350.html (13,868 bytes)
193. Re: [Amps] plexiglas isolation in coils (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sat, 29 Jul 2006 23:15:02 -0400; Are you sure the early production - the one I had - used Absolutely. From number 001. Perhaps it was changed to #10 in later production based on (bad) experience?> Not a chance. Never was number 12.; /archives//html/Amps/2006-07/msg01351.html (9,926 bytes)
194. Re: [Amps] plexiglas isolation in coils (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sun, 30 Jul 2006 05:44:16 -0400; Ok, I'll take your word. So the next question is why did the plastic supports melt when operated within the advertised ratings, not once but twice? Was #10 wire adequate?>> I don't even know the S/N; /archives//html/Amps/2006-07/msg01357.html (11,332 bytes)
195. Re: [Amps] 160m RTTY (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sun, 30 Jul 2006 10:22:48 -0400; Multipath is the cause of selective fading on AM also. The low frequency plus the common multipath propagation all aggravated LORAN A, RTTY, and even skywave AM operation. RTTY was banned on 160 (as; /archives//html/Amps/2006-07/msg01379.html (8,158 bytes)
196. Re: [Amps] Ameritron Amps (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sun, 30 Jul 2006 11:18:53 -0400; When the Chinese were making 3-500Z tubes with regular glass and holes were sucking in the sides, Rich concluded it was a VHF parasitic that couldn't be seen or measured. This VHF oscillation suppos; /archives//html/Amps/2006-07/msg01384.html (8,651 bytes)
197. [Amps] Tube Prices (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sun, 30 Jul 2006 12:49:09 -0400; Actually a good bit of the blame falls on Richardson's Electronics and their policy of absorbing all the small manufacturers and dealers, and the poor decision by Eimac to allow a outright competito; /archives//html/Amps/2006-07/msg01390.html (8,864 bytes)
198. Re: [Amps] Ameritron Amps (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Sun, 30 Jul 2006 16:24:37 -0400; Steve, The Chinese tube problem was NOT VHF heating as Rich claimed. The Chinese used regular glass and the tubes melted even with no RF applied. What I said was Rich **concluded** it was a parasiti; /archives//html/Amps/2006-07/msg01403.html (9,522 bytes)
199. Re: [Amps] Ameritron Amps (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Mon, 31 Jul 2006 05:41:34 -0400; We can read it, but we should be aware it isn't correct. I'm not sure if MFJ is buying 2000 hour MTBF caps or not, but the 2000 hour number is NOT the expected mean time hours before failure in oper; /archives//html/Amps/2006-07/msg01421.html (13,936 bytes)
200. Re: [Amps] Pre-heating of tubes (score: 1): Author: "Tom W8JI" <w8ji@w8ji.com>; Date: Mon, 31 Jul 2006 05:56:57 -0400; Tempering and Heat treatment, Tubal Cain, Nexus Special interests, ISBN 0 85242 837 5) in a dim natural light, 700 deg C is dull red, 740 blood red, 800 cherry red, 825 bright cherry red, 850 red, 9; /archives//html/Amps/2006-07/msg01422.html (8,570 bytes)

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