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Total 614 documents matching your query.

61. Re: [Amps] Bandwidth tests (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 4 Jul 2006 06:10:34 -0400
Too high to pump ALC and too high frequency to work the electrolytics. Too close to resolve IM products on most test gear. It has to be something that is well below the lowest audio frequency and rep
/archives//html/Amps/2006-07/msg00167.html (7,697 bytes)

62. Re: [Amps] How to tune an FL-2100B (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 4 Jul 2006 08:08:59 -0400
Maybe. Maybe not. Since the PEP for normal 100% sine-wave modulated AM is 4 times the carrier power, and the FT101 can distort the audio and make it eight times or more the carrier, it easily could
/archives//html/Amps/2006-07/msg00172.html (9,102 bytes)

63. Re: [Amps] Maximum RF output in practical application: 4-250A (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 4 Jul 2006 09:52:19 -0400
I do all the time, and when there is significant noise and QRM **LESS** bandwidth improves copy provided that bandwidth is properly centered. If you listen to widefi AM guys, those with the deepest
/archives//html/Amps/2006-07/msg00183.html (10,807 bytes)

64. Re: [Amps] How to tune an FL-2100B (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 4 Jul 2006 10:39:57 -0400
25 watts carrier? That's 100 watts PEP if you watch the peak envelope power and use the controls properly to maintain that peak level. You'd need a good PEP reading meter. The Ameritron PEP meter is
/archives//html/Amps/2006-07/msg00186.html (9,329 bytes)

65. Re: [Amps] QEX Innovative Tube Linear? (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Fri, 7 Jul 2006 17:52:01 -0400
Do you actually have an application sheet for these tubes in linear amplifier service Will? 73 Tom _______________________________________________ Amps mailing list Amps@contesting.com http://lists.
/archives//html/Amps/2006-07/msg00256.html (8,229 bytes)

66. Re: [Amps] QEX Innovative Tube Linear? (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Fri, 7 Jul 2006 20:39:41 -0400
Will, I'm a little puzzled, and this may be confusing other people also. As I recall you stated quite emphatically everyone should follow the letter of a spec sheet regardless of what factory engine
/archives//html/Amps/2006-07/msg00263.html (10,570 bytes)

67. Re: [Amps] QEX Innovative Tube Linear? (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Sat, 8 Jul 2006 00:31:19 -0400
Hi Will, I'm still not sure I understand fully. I'll try one last time. Will replied: As I understand your answer, because the sweep tubes have no warranty it doesn't really matter how you run them e
/archives//html/Amps/2006-07/msg00267.html (13,048 bytes)

68. Re: [Amps] Question about glowing 3-400z's (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Mon, 10 Jul 2006 01:26:04 -0400
Ron, Some anode color is required to keep the tubes gas-free. The gettering agent is the gray powdery coating on the anodes. If the tubes never showed anode color they would go bad. The color is rat
/archives//html/Amps/2006-07/msg00303.html (8,086 bytes)

69. Re: [Amps] Mica cap substitute \ alternative (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Mon, 10 Jul 2006 12:38:25 -0400
How much RF current flows through the capacitor? Voltage is the easy part. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/l
/archives//html/Amps/2006-07/msg00310.html (6,948 bytes)

70. Re: [Amps] Silly question - interim report on results. (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 11 Jul 2006 06:34:55 -0400
Why? Q of one small part of a complex system doesn't determine anything by itself. If it did, we'd never be able to build a R/C oscillator circuit now would we? Many of these resistor swamped grid d
/archives//html/Amps/2006-07/msg00324.html (8,039 bytes)

71. Re: [Amps] Silly question - interim report on results. (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 11 Jul 2006 08:27:23 -0400
Phase shift of the feedback is an issue in any oscillator. The point is things can oscillate with almost any Q if phase is correct and feedback level is high enough. The biggest worry with paper amp
/archives//html/Amps/2006-07/msg00326.html (8,479 bytes)

72. Re: [Amps] Silly question - interim report on results. (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 11 Jul 2006 09:20:56 -0400
That's because the choke, at the lowest order series resonant point, acts like two back-to-back L networks with very high L and low C. Since the impedance step up and step down closely match, the th
/archives//html/Amps/2006-07/msg00329.html (9,221 bytes)

73. Re: [Amps] FL2100B (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Tue, 11 Jul 2006 21:25:52 -0400
The FL2100 series is notorious for the various mica capacitors being bad. I looked at one that appears to be a record a few months ago. It had about 8 bad mica caps in the tuned input. They also used
/archives//html/Amps/2006-07/msg00338.html (7,276 bytes)

74. Re: [Amps] Mica cap substitute \ alternative (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Wed, 12 Jul 2006 09:00:06 -0400
Mica isn't bad at a "certain frequency", and the dissipation of one type of mica cannot be directly applied to the complex workings of a component. There are many mica caps that are quite good to 1G
/archives//html/Amps/2006-07/msg00345.html (9,319 bytes)

75. Re: [Amps] Mica cap substitute \ alternative (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Wed, 12 Jul 2006 19:09:20 -0400
Ian replied: Ian is correct. A short answer to this question sounds clear and definitive, but is almost always misleading. Like the mica statement, the answer depends heavily on the application AND
/archives//html/Amps/2006-07/msg00357.html (8,980 bytes)

76. Re: [Amps] Mica cap substitute \ alternative (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Thu, 13 Jul 2006 07:13:05 -0400
So we are told that some manufacturers derate some mica caps above 5MHz. Others have caps that in slightly different applications have ratings that are high. Some mica caps can handle high currents i
/archives//html/Amps/2006-07/msg00362.html (9,187 bytes)

77. Re: [Amps] FL-2100B (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Thu, 13 Jul 2006 08:39:25 -0400
David, It isn't unusual to find a few bad input circuit capacitors along with some failed output circuit caps. I've never noticed any other amplifier series that had so many small cap failures as th
/archives//html/Amps/2006-07/msg00365.html (7,369 bytes)

78. Re: [Amps] high frequency filament excitation TSPA (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Thu, 13 Jul 2006 15:10:26 -0400
Another problem people commonly miss is voltage drop in the filament choke. A normal properly sized filament choke has a few tenths of a volt AC drop across the windings from filament current. This i
/archives//html/Amps/2006-07/msg00375.html (7,985 bytes)

79. Re: [Amps] Switching Power Supplies (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Fri, 14 Jul 2006 13:52:16 -0400
The ICOM 751A generates FM trash when the internal switching supply is used. The problem is the VCO coil is next to the transformer in the switching supply module, and the magnetic flux changes perme
/archives//html/Amps/2006-07/msg00382.html (8,868 bytes)

80. Re: [Amps] Switching Power Supplies (score: 1)
Author: "Tom W8JI" <w8ji@w8ji.com>
Date: Fri, 14 Jul 2006 17:23:58 -0400
Filament or emission life is virtually never an issue for amateur service. All the worry comes from commercial applications, where the tube runs 24/ 7/ 52 weeks a year. In amateur service the primar
/archives//html/Amps/2006-07/msg00395.html (9,472 bytes)


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