- 41. [Amps] ALPHA 77 SX UPDATE (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 22 Aug 2002 08:34:12 +0100
- "Reputation for squirreliness"? Right, so you're looking for a real in-depth technical analysis here... If we've learned one thing on this list, it is that there's a huge range of variability between
- /archives//html/Amps/2002-08/msg00190.html (10,472 bytes)
- 42. [Amps] 3-500Z parasitic wows (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 22 Aug 2002 08:37:34 +0100
- Coming back to this "rules of evidence" thing: how do you *know* it was a parasitic, from the evidence it left behind? -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/
- /archives//html/Amps/2002-08/msg00191.html (8,406 bytes)
- 43. [Amps] pictures (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 22 Aug 2002 10:33:44 +0100
- Digital cameras are like computers - obsolete before you even buy them. You just have to learn not to worry about it. When we were buying a camera, about a year ago, there were several excellent in-d
- /archives//html/Amps/2002-08/msg00192.html (11,415 bytes)
- 44. [Amps] pictures (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 22 Aug 2002 13:50:35 +0100
- Yes, that's true - but you pay heavily for the SLR feature. In digital cameras, SLR tends to be associated with a range of other 'professional' features which kick the whole camera up into a much hig
- /archives//html/Amps/2002-08/msg00196.html (8,440 bytes)
- 45. [Amps] 3-500Z parasitic wows (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Fri, 23 Aug 2002 10:09:14 +0100
- Well, so much for RCA then! And so much for the G-E Research Labs, and all the R&D work that went into their book on 'Vacuum Arcs'; and Gossling's work with the UK General Electric Company (no relati
- /archives//html/Amps/2002-08/msg00219.html (8,835 bytes)
- 46. [Amps] 3-500Z parasitic wows (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Fri, 23 Aug 2002 16:56:00 +0100
- THE WHOLE POINT is that there's more than one possible explanation! Sometimes it's parasitic oscillations, sometimes it's vacuum arcs, sometimes it's arcs outside the tube, and so on... it very hard
- /archives//html/Amps/2002-08/msg00224.html (12,053 bytes)
- 47. [Amps] 3-500Z parasitic wows (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Fri, 23 Aug 2002 19:03:42 +0100
- Sorry, they had dropped off the site - they're back now. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek
- /archives//html/Amps/2002-08/msg00230.html (8,228 bytes)
- 48. [Amps] Re: diode and glitch resistor (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Sun, 25 Aug 2002 10:55:25 +0100
- In the Europe the "best buy" are the 14W Welwyn series, as shown in http://www.farnell.com/datasheets/909.pdf 10-ohm resistors of this type are very comfortable at <1A intermittent service - but they
- /archives//html/Amps/2002-08/msg00262.html (8,666 bytes)
- 49. [Amps] 2 x 4cx1500b Tube matching? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Tue, 16 Jul 2002 09:39:38 +0100
- When I was designing the boards, I looked very carefully at the possibility of dual independent screen and/or grid supplies to handle un-matched tubes... and decided it would be pointless. It is a m
- /archives//html/Amps/2002-07/msg00215.html (10,687 bytes)
- 50. [Amps] Bias Zener Diodes In Parallel ? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Wed, 17 Jul 2002 10:09:19 +0100
- The design in the databooks can oscillate with capacitive loads (which are what we have in am amp, due to the RF bypass capacitors). Adding an R-C at the base of the PNP power transistor will fix tha
- /archives//html/Amps/2002-07/msg00239.html (9,694 bytes)
- 51. [Amps] Bias Zener Diodes In Parallel ? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Fri, 19 Jul 2002 17:08:27 +0100
- Paul and I favor the TL431-TIP147 bias circuit because we supply our different control boards for a large range of tubes, so we need a 'one circuit fits all' solution. Maybe that makes us biased? How
- /archives//html/Amps/2002-07/msg00324.html (10,596 bytes)
- 52. [Amps] Bias Zener Diodes In Parallel ? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Fri, 19 Jul 2002 20:13:13 +0100
- Both circuits can make equally valid claims of simplicity, low cost and glitch resistance. They just get there in different ways. -- 73 from Ian G3SEK www.ifwtech.co.uk/g3sek
- /archives//html/Amps/2002-07/msg00334.html (9,738 bytes)
- 53. [Amps] Bias Zener Diodes In Parallel ? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Sat, 20 Jul 2002 08:50:34 +0100
- You can have it in green stamps: under $5. For that, you get: adjustable voltage from 5V to 40V, all the current capability you need, better regulation than you'd ever need, and EBS capability. The s
- /archives//html/Amps/2002-07/msg00350.html (11,296 bytes)
- 54. [Amps] Bias Zener Diodes In Parallel ? (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Sat, 20 Jul 2002 22:55:02 +0100
- And I do the same with my transistor using large varistors (as shown on the web page). In all out installations, the maximum possible current is also limited by the glitch resistor in the B+, so we h
- /archives//html/Amps/2002-07/msg00366.html (8,654 bytes)
- 55. [Amps] Muffin Fans and hot exhaust (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Tue, 23 Jul 2002 07:24:40 +0100
- Expanding on some of Tom's very sensible comments: So the question is: does your amp have significant back-pressure? If it has a ceramic tube where all the air has to be forced through the restrictio
- /archives//html/Amps/2002-07/msg00414.html (12,693 bytes)
- 56. [Amps] Muffin Fans and hot exhaust/3 (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Tue, 23 Jul 2002 15:43:42 +0100
- I still prefer the old North Carolina analog version: "Ain't got the brains Gawd promised a rag dawll." -- 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB)
- /archives//html/Amps/2002-07/msg00434.html (9,169 bytes)
- 57. [Amps] Muffin Fan on Swan Mark 1 (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Wed, 24 Jul 2002 22:16:21 +0100
- I've used the indicating strips to check the temperatures on a 3-500Z in a SB-1000, with quite interesting results. As most of you will know, the SB-1K has a large muffin-type fan in the center parti
- /archives//html/Amps/2002-07/msg00465.html (10,689 bytes)
- 58. [Amps] Muffin Fan on Swan Mark 1 (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 25 Jul 2002 07:45:25 +0100
- That is much more tricky, because the temperature-sensitive labels are way too big. It would either require dots of temperature-sensitive paint (and I only have 200C and 250C, which wouldn't be enoug
- /archives//html/Amps/2002-07/msg00473.html (9,558 bytes)
- 59. [Amps] Ceramic coil formers etc. (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 25 Jul 2002 13:56:35 +0100
- It's certainly very interesting - he has made some very nice plug-in ceramic coil formers of the good old-fashioned kind. However, it would be nice to see some results from the microwave-oven test, i
- /archives//html/Amps/2002-07/msg00479.html (8,395 bytes)
- 60. [Amps] Muffin Fan on Swan Mark 1 (score: 1)
- Author: Ian White, G3SEK" <g3sek@ifwtech.co.uk (Ian White, G3SEK)
- Date: Thu, 25 Jul 2002 20:04:28 +0100
- I can quite believe that, having been in the air/gas flow business back when such programs were in their infancy (Lord, that makes me feel old...) Failing which, you can do wonderful things with trac
- /archives//html/Amps/2002-07/msg00482.html (10,071 bytes)
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