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References: [ +from:johnf@futurenet.co.za: 121 ]

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81. [AMPS] Operating comments using the Emtron DX-2a (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 31 Jan 1999 18:48:30 +0200; Sounds good to me - but at 3 months salary a little steep!! Oh well I guess you have to pay for good quality rf items these days. John ZS5JF -- To: <amps@contesting.com> properly? ago, and AB1.I pref; /archives//html/Amps/1999-01/msg00653.html (23,312 bytes)
82. [AMPS] Silver mica's (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 9 Dec 1998 18:48:53 +0200; What capacity and voltage do you need? Most manufacturers who used to make silver mica caps have ceased production due to the world shortage of mica (the main mine was in India and became exhausted).; /archives//html/Amps/1998-12/msg00170.html (8,507 bytes)
83. Fw: [AMPS] tuning capacitor & insulator (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 18 Dec 1998 09:01:30 +0200; Eimac short form catalog gives typical operation in AB1 as 300W o/p with 2000Va and 400Vg2. Seems to me (and I have used a lot of 4CX250 types) that 600W from a pair is all you can really expect and; /archives//html/Amps/1998-12/msg00250.html (11,881 bytes)
84. Fw: [AMPS] A few questions (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 18 Dec 1998 09:10:57 +0200; Hi Martin - most probably you will find that the amp has a decoupling capacitor (about 0.01uf) from the line and neutral terminals to ground (chassis) to bypass any rf on the mains lead. This will de; /archives//html/Amps/1998-12/msg00251.html (9,639 bytes)
85. [AMPS] tuning capacitor & insulator (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 18 Dec 1998 10:52:10 +0200; According to my Eimac shortform the 4CX250R and the 7580W are the same tube. BTW the R stands for "ruggedised" it can withstand a lot more vibration and shock than a standard 250. However the plate,; /archives//html/Amps/1998-12/msg00254.html (12,574 bytes)
86. Fw: [AMPS] tuning capacitor & insulator (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 19 Dec 1998 08:51:08 +0200; Please explain why varying the VSWR on the driver "causes grief"? John ZS5JF -- <amps@contesting.com> To: <amps@contesting.com> linearity. tubes that -- FAQ on WWW: http://www.contesting.com/ampfaq.h; /archives//html/Amps/1998-12/msg00274.html (10,938 bytes)
87. Fw: [AMPS] tuning capacitor & insulator (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 19 Dec 1998 13:15:40 +0200; But what about the transceiver that uses tubes for the output - like the many hf rigs which use a pair of 6146's or similar? Surely if a tube or, for that matter, a transistor/power module is tuned t; /archives//html/Amps/1998-12/msg00276.html (14,026 bytes)
88. Fw: [AMPS] Anode load line calculations. (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 20 Dec 1998 13:07:06 +0200; In response to various comments made on my original posting. I think that some hams misunderstand the basic principles of of rf amplifiers! The load impedance of a tube is defined by the anode voltag; /archives//html/Amps/1998-12/msg00297.html (11,258 bytes)
89. Fw: [AMPS] Anode load line calculations. (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 21 Dec 1998 13:40:12 +0200; But Rich you misunderstand what I am trying to tell you and the others!!!! The anode voltage swing WILL be the 80% or so of the dc supply voltage - but it is now developed across a much higher impeda; /archives//html/Amps/1998-12/msg00307.html (12,211 bytes)
90. Fw: [AMPS] Anode load line calculations. (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 21 Dec 1998 16:10:03 +0200; Both - but what's the difference? An amplifier set up to give 100W using a 2000V supply or a 1kW amp using the same ht have the same requirement. The point I was trying to make, and which you are con; /archives//html/Amps/1998-12/msg00311.html (10,116 bytes)
91. Fw: [AMPS] Anode load line calculations. (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 22 Dec 1998 17:07:10 +0200; We seem to have lost the thread somewhere along the line. The original question I posed was to do with the possibility of making an output network which ALWAYS provided the correct match to the tube,; /archives//html/Amps/1998-12/msg00325.html (12,682 bytes)
92. [AMPS] Message subjects again (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 22 Dec 1998 17:28:31 +0200; Which is why I changed the subject to "Anode Load Line Calculations" John ZS5JF -- To: <amps@contesting.com> an hit rest to -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@cont; /archives//html/Amps/1998-12/msg00326.html (10,910 bytes)
93. [AMPS] 50:75 ohm matching (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 24 Dec 1998 18:58:37 +0200; On the subject let me recount a tale from days gone by! Many years ago when I lived in the UK, I ordered 4 antennas from Jaybeam for 432 MHz. I arranged to drive down to Northampton to collect them a; /archives//html/Amps/1998-12/msg00375.html (11,451 bytes)
94. [AMPS] Line input wiring (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 27 Dec 1998 10:37:18 +0200; In this country (RSA), the UK and many others, the "earth" wire is connected to the neutral (centre) point at the step-down transformer. (The transformer is usually a "star" type with 3 phases for th; /archives//html/Amps/1998-12/msg00421.html (14,775 bytes)
95. [AMPS] restoring/replating (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 28 Dec 1998 09:11:21 +0200; Correct - I used to work for Wingrove and Rogers in the UK, the leading tuning capacitor manufacturer (eventually went bust and bought by Jacksons). I learnt from their industrial chemist that decora; /archives//html/Amps/1998-12/msg00437.html (9,085 bytes)
96. [AMPS] Ultimate amplifier - follow up (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 1 Nov 1998 18:15:27 +0200; This is a multi-part message in MIME format. --=_NextPart_000_01BE05C3.9A0A9920 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Thanks to all who responded with informati; /archives//html/Amps/1998-11/msg00018.html (7,541 bytes)
97. [AMPS] Re: SV: G2DAF (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 1 Nov 1998 11:34:47 +0200; This is a multi-part message in MIME format. --=_NextPart_000_01BE058B.A13EE800 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Run some unbiased tests! Good way to kill; /archives//html/Amps/1998-11/msg00019.html (26,304 bytes)
98. [AMPS] Power rating of semi-rigid coax (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 3 Nov 1998 18:30:41 +0200; This is a multi-part message in MIME format. --=_NextPart_000_01BE0758.0FE47720 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Thanks to all who replied to my query. I h; /archives//html/Amps/1998-11/msg00060.html (7,958 bytes)
99. [AMPS] Screen regulator circuit needed (score: 1): Author: John Fielding" <johnf@futurenet.co.za (John Fielding); Date: Sun, 15 Nov 1998 14:34:32 +0200; Hi Bill - try using high voltage scan transistors from tv's. These are rated at 1500V or more for Vceo. Should be available pretty cheaply, I paid about $1 a piece a little while back. Use a smallish; /archives//html/Amps/1998-11/msg00198.html (10,292 bytes)
100. [AMPS] Pi-L networks (score: 1): Author: John Fielding" <johnf@futurenet.co.za (John Fielding); Date: Sun, 15 Nov 1998 14:23:14 +0200; Hi Carl - I am currently designing my "ultimate amplifier" using a Pi-L network. Like you I struggled to calculate the necessary values, that is until I used the ARRL Radio Designer software! I desig; /archives//html/Amps/1998-11/msg00199.html (11,353 bytes)

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