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21. [AMPS] RE: 4cx10000 (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 10 Jul 1999 18:16:43 +0200; I think that it is not "if" but "when" in Toms first statement. Most moving coil meters wouldn't even start to react to a minor grid current spike. What is needed is the drive being backed off to the; /archives//html/Amps/1999-07/msg00182.html (11,026 bytes)
22. [AMPS] DAF Amp (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 13 Jul 1999 18:33:58 +0200; As I recall we had this same discussion about 12 months ago and it finally peetered out because nobody had an amplifier which they would lend so that a full IMD investigation could be done. John ZS5J; /archives//html/Amps/1999-07/msg00247.html (8,515 bytes)
23. [AMPS] S units (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 13 Jul 1999 18:33:47 +0200; If i remember correctly (Peter G3RZP will probably corect me anyway) it was Roly Shears G8KW - who founded KW Electronics -that proposed that S9 be set at 50uV and that each S unit would be 6dB. For; /archives//html/Amps/1999-07/msg00248.html (9,387 bytes)
24. [AMPS] DAF Amp (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 13 Jul 1999 18:45:19 +0200; Hi all - the original G2DAF amplifier (notice I didn't say Linear!) used a pair of QY3-125. John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: a; /archives//html/Amps/1999-07/msg00249.html (9,296 bytes)
25. [AMPS] The DAF Amp (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 13 Jul 1999 22:54:25 +0200; The original G2DAF was a grid driven amp with a swamping resistor to define 50 ohms. John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@con; /archives//html/Amps/1999-07/msg00255.html (10,125 bytes)
26. [AMPS] G2DAF (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 15 Jul 1999 21:54:09 +0200; -- To: <amps@contesting.com> output impedance or a very high one, depending on the configuration of the circuit". John ZS5JF -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@con; /archives//html/Amps/1999-07/msg00307.html (9,672 bytes)
27. [AMPS] Impedance of amplifiers (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 16 Jul 1999 17:11:22 +0200; Absolutely correct Tom. We choose to use 50 ohms as a convenience because transmission lines are usually 50 ohms today. However consider a high power audio amplifier driving a load of 4 ohms. The out; /archives//html/Amps/1999-07/msg00323.html (11,195 bytes)
28. [AMPS] Impedance of amplifiers (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 17 Jul 1999 16:29:16 +0200; I think essentially we are talking along the same lines Tom. I said that the output Z of a tube amplifier is "highish" which implies several kohms. From the measurements we have all seen when loading; /archives//html/Amps/1999-07/msg00333.html (15,741 bytes)
29. [AMPS] blocking cap current (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 21 Jul 1999 20:12:34 +0200; -- <Peter_Chadwick@mitel.com> To: <amps@contesting.com> "Now you see me, now you don't " Lord Lucan John ZS5JF -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Ad; /archives//html/Amps/1999-07/msg00396.html (8,836 bytes)
30. [AMPS] blocking cap current (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 21 Jul 1999 20:13:45 +0200; You just lost me! John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Pr; /archives//html/Amps/1999-07/msg00397.html (9,625 bytes)
31. [AMPS] revisited duty cycle... (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 24 Jul 1999 12:53:17 +0200; Methinks something funny with that meter!! John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-; /archives//html/Amps/1999-07/msg00438.html (8,687 bytes)
32. [AMPS] revisited duty cycle... (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 24 Jul 1999 16:12:39 +0200; Hi Rich - on second thoughts there are two possibilities why this could happen, no make that 3. 1. The ht sags less during ssb than full key down. 2. The inertia of the meter is a bit low, allowing s; /archives//html/Amps/1999-07/msg00441.html (10,222 bytes)
33. [AMPS] 572-B Input impedance?? (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 26 Jul 1999 18:15:27 +0200; Hi all - I downloaded the Svetlana data sheet on the 572B so I could study it. Some interesting facts came to light. grid to plate = 6.0pF grid to filament = 5.9pF Plate to filament = 0.8pF I guess i; /archives//html/Amps/1999-07/msg00470.html (10,370 bytes)
34. [AMPS] online tube data (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 26 Jul 1999 22:28:51 +0200; Hi Ron - try these www.svetlana.com www.eimac.com www.tubes.ru df6na.mayn.de John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.; /archives//html/Amps/1999-07/msg00480.html (7,461 bytes)
35. [AMPS] 572-B Input impedance?? (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 27 Jul 1999 18:34:05 +0200; Amem Tom - clearly a "bum choice" for 6m! John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-R; /archives//html/Amps/1999-07/msg00536.html (8,798 bytes)
36. [AMPS] 572-B Input impedance?? (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 27 Jul 1999 18:44:32 +0200; Hi Peter - I noticed that no one responded to my Lord Lucan pun! John ZS5JF -- From: Rich Measures <measures@vc.net> To: Peter Chadwick <Peter_Chadwick@mitel.com>; John Fielding <johnf@futurenet.co.z; /archives//html/Amps/1999-07/msg00537.html (9,063 bytes)
37. [AMPS] Finally - a real amp (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 11 Jun 1999 20:53:58 +0200; Try using an old glass type 2C39 in a cavity amp for 23cms and you get similar results when pushed hard. A nice clean hole with no apparent other damage. John ZS5JF -- To: <amps@contesting.com> -- FA; /archives//html/Amps/1999-06/msg00398.html (13,388 bytes)
38. [AMPS] amp (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 14 Jun 1999 13:21:55 +0200; IMO a capacitor that small is a no-no! The predominant factor for reducing the output ripple to a point where it will not cause anode modulation is the ESR of the capacitor. For a ripple voltage that; /archives//html/Amps/1999-06/msg00425.html (9,908 bytes)
39. [AMPS] 7289's and other uWave tubes (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 12 May 1999 18:35:45 +0200; Hi all - a slightly off-topic question. I am updating my 23cm station for eme and converting the various tubes to water cooling. A question regarding the thread which is used to attach the air-finned; /archives//html/Amps/1999-05/msg00149.html (7,969 bytes)
40. [AMPS] 7289 screw threads (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 21 May 1999 16:36:07 +0200; A little while back I asked for some clarification on the screw thread used to attach the air cooler to these tubes. It appeared to be 3/8" x 16 Whitworth. I have now obtained the Eimac data sheet an; /archives//html/Amps/1999-05/msg00261.html (7,297 bytes)

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