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81. Re: [Amps] nylons (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 15 Mar 2005 19:52:09 +0000; Sorry, two hydrogen ones. BTW, here's a joke someone told me recently, which that comment reminded me of. There are two hydrogens atoms in a water molecule. One hydrogen atom says to the other "I hav; /archives//html/Amps/2005-03/msg00344.html (17,088 bytes)
82. Re: [Amps] nylons (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 15 Mar 2005 20:06:37 +0000; One other thing I forgot to add is that I have here some Ross HyperSPARC CPUs, which were from a Sun workstation. (Sun did not make this CPU, but a 3rd party did). I know this particular machine had; /archives//html/Amps/2005-03/msg00345.html (9,216 bytes)
83. Re: [Amps] re. nylons (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Thu, 17 Mar 2005 15:48:48 +0000; Is that the stuff RS sell - if so it is very expensive, although I know RS is not the cheapest place to get bits from, I rather suspect the cost will be far more than buying ceramic insulators. Of co; /archives//html/Amps/2005-03/msg00390.html (7,474 bytes)
84. Re: [Amps] 4CX1000A for SSB?? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 19 Mar 2005 00:28:14 +0000; How about trying to use RF negative feedback, where some of the output is coupled back to the input in anti-phase? Negative feedback will generally improve the linearity. I've not tried it myself, bu; /archives//html/Amps/2005-03/msg00400.html (9,852 bytes)
85. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 19 Mar 2005 16:57:58 +0000; I used to work in the MOD as part of my sandwich degree. I checked the calibration of Bird elements and few were within the +/- 5% of FSD spec. Militrary groups would send the units in for cal, with; /archives//html/Amps/2005-03/msg00418.html (9,111 bytes)
86. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sun, 20 Mar 2005 17:21:31 +0000; It is simply not achievable on Bird 43's - at least not on a regular basis. My new element was out of spec the day I got it. I don't know what 'Type Approving' equipment is, but RF power can be measu; /archives//html/Amps/2005-03/msg00435.html (9,179 bytes)
87. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Mon, 21 Mar 2005 00:51:33 +0000; Of course, what it is marketed for would determine how accurate you need that instrument to be, and I would guess the tracability of the lab approving it. Surely an expensive Aligent VNA would need t; /archives//html/Amps/2005-03/msg00440.html (10,714 bytes)
88. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 22 Mar 2005 01:06:50 +0000; That is simply not true, and I doubt Bird would claim that either. Whether there is a more accurate "field" type instrument I do not know, but there are more accurate lab instruments around, but thes; /archives//html/Amps/2005-03/msg00474.html (8,743 bytes)
89. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 22 Mar 2005 02:20:35 +0000; No idea. I have no direct experience of using Calorimetric methods, but I know they were (25 years ago, and probably still are), the most accurate method for measuring high powers. Whether that is by; /archives//html/Amps/2005-03/msg00476.html (10,171 bytes)
90. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 22 Mar 2005 02:42:41 +0000; Agreed. Do you have any evidence to back that up? I don't have any to say whether you are right or wrong, but just wondering how you conclude that. Any idea how accurate? Yes, and a pretty good set o; /archives//html/Amps/2005-03/msg00477.html (10,346 bytes)
91. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Tue, 22 Mar 2005 02:56:34 +0000; But they do not meet the +/- 5% of FSD on anything like a regular basis. So the errors are not 125W on any part of the scale, but more like +/- 250W. I think they are pretty good right at the bottom; /archives//html/Amps/2005-03/msg00478.html (9,559 bytes)
92. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Wed, 23 Mar 2005 23:07:46 +0000; Peter, I might have an answer to that one. In the book "Principles of Microwave Measurements" by GH Bryant, IEE (1998). It mentions several variants of the Caliormeter for high power measurements, bu; /archives//html/Amps/2005-03/msg00538.html (11,855 bytes)
93. Re: [Amps] Bird Element Calibration? (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Fri, 25 Mar 2005 10:48:53 +0000; Peter, you are agreeing with *all* the comments I have put here. So there seems to be little (if any) disagreement between us. 1) In response to Gary Smith I said " I suspect Bird use Calorimeters fo; /archives//html/Amps/2005-03/msg00549.html (12,384 bytes)
94. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Fri, 25 Mar 2005 22:00:37 +0000; Rich, I think you are wrong. Here's my reasoning - I may well be wrong, as maths never was a good point of mine. You need to understand calculus to properly work out the RMS of an arbitrary waveform,; /archives//html/Amps/2005-03/msg00557.html (12,125 bytes)
95. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 00:26:43 +0000; Now I think you are wrong to disagree with K4FMX. I don;'t believe a simple multiple of the RMS values of voltage and current gives the rms power. If you have 1V peak across 1 Ohm you have an RMS vol; /archives//html/Amps/2005-03/msg00559.html (12,513 bytes)
96. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 00:37:49 +0000; PS, the average power of a 1V peak sine wave across 1 Ohms is 1/2 W, as we all know. You can demonstrate mathematically. Just integrate the shape of the power waveform (which is sin^2) over some inte; /archives//html/Amps/2005-03/msg00560.html (10,180 bytes)
97. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 01:36:19 +0000; I agree with you Gary (not specifically that its a common misconception), but that RMS power is not the same as average power for a sinusoidal voltage applies to a resistor. For 1V peak voltage and 1; /archives//html/Amps/2005-03/msg00563.html (10,543 bytes)
98. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 02:12:50 +0000; Rich, You have in the past gone to great lengths to try to back up your views on parasitic oscillations - is it asking too much to ask you to substantiate something as simple as power in a resistor?; /archives//html/Amps/2005-03/msg00564.html (10,616 bytes)
99. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 02:18:16 +0000; question when nothing is not defined properly. I mean nothing (P, I or E) are defined properly of course. But don't bother defining them for now - substantiate what you are saying. -- Dr. David Kirk; /archives//html/Amps/2005-03/msg00565.html (9,867 bytes)
100. Re: [Amps] Measuring RF Power (score: 1): Author: David Kirkby <david.kirkby@onetel.net>; Date: Sat, 26 Mar 2005 12:44:50 +0000; Interpreting the unintentional double-negative correctly, it means everything is defined properly. But I did correct myself when I said in a short post "I mean nothing (P, I or E) are defined properl; /archives//html/Amps/2005-03/msg00575.html (13,061 bytes)

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