- 21. Re: [Amps] COLLINS GANG BOOK (score: 1)
- Author: "Mark Marsden" <MM@plextek.co.uk>
- Date: Thu, 21 Apr 2005 09:21:12 +0100
- Hi John I recently bought a second-hand copy of "Single Sideband Principles and Circuits. by Pappenfus, E. W. , Warren B. Bruene And E. O. Schoenike". from http://www.alibris.com/home.cfm You may fin
- /archives//html/Amps/2005-04/msg00422.html (8,724 bytes)
- 22. Re: [Amps] 4CX1000A for SSB?? (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Tue, 3 May 2005 10:05:39 +0100
- Hi Bill & Amps reflectees I've remeasured the intermodulation characteristics of my 4CX1000A amplifier, more thoroughly, using two transmitters and a Wilkinson combiner. These results, and also measu
- /archives//html/Amps/2005-05/msg00015.html (8,629 bytes)
- 23. Re: [Amps] 4CX1000A for SSB?? (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Tue, 3 May 2005 10:23:20 +0100
- Hi Peter No it doesn't use any feedback. The schematics are in pdf form on the website, just a tad out of date now that I've changed the pi tank. 73 Mark G4AXX ________________________________ I've r
- /archives//html/Amps/2005-05/msg00017.html (7,714 bytes)
- 24. Re: [Amps] Dummy Load (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Wed, 25 May 2005 13:47:20 +0100
- Hi Stefan & Will That's very interesting to me. I'm looking at a possible 50R 40dB attenuator based on the new thick-film-on-steel planar resistors by TT-electronics/Welwyn. They aimed at the automot
- /archives//html/Amps/2005-05/msg00283.html (9,378 bytes)
- 25. Re: [Amps] Dummy Load (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Thu, 26 May 2005 11:25:57 +0100
- Hi Bert, Ian, David, et al I had a look at the datasheet, 3uH is unfortunate. Other resistors, for a 30dB T then, are Vishay parts, 47R 500W (FEC 306-8043), then 3R3 to deck, three 50W 10R in paralle
- /archives//html/Amps/2005-05/msg00300.html (7,380 bytes)
- 26. Re: [Amps] Dummy Load (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 27 Jun 2005 10:00:34 +0100
- I have now built a 30dB attenuator using non-iductive Vishay parts. It's documented on http://granta.digital-crocus.com/Attenuator.php3 73, Mark G4AXX --Original Message-- 30dB seems to be a "magic n
- /archives//html/Amps/2005-06/msg00259.html (7,926 bytes)
- 27. Re: [Amps] Tetrodes (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 11 Jul 2005 16:56:44 +0100
- That's one way but it certainly isn't the safest. For tubes without handles check out the Tetrode Boards on http://www.ifwtech.co.uk/g3sek/boards/tetrode/tetrode-1.htm 73 Mark G4AXX What is "small"?
- /archives//html/Amps/2005-07/msg00085.html (7,655 bytes)
- 28. [Amps] HF Baluns (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 18 Jul 2005 13:19:03 +0100
- Hi Amp'ers This weekend I documented some measurements on homebrew bifilar and coaxial 4:1 HF baluns. FYI, have a look at http://granta.digital-crocus.com/Balun.php3 <http://granta.digital-crocus.com
- /archives//html/Amps/2005-07/msg00198.html (6,571 bytes)
- 29. [Amps] Shorted turns reduce harmonics? (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Fri, 22 Jul 2005 10:41:31 +0100
- Hi Amp'ers The harmonics from my homebrew amplifier, on some bands, are much lower than expected, and I've been wondering why. The output Pi tank coil is made up of 3 orthogonal coils for 10-12m, 15-
- /archives//html/Amps/2005-07/msg00250.html (7,801 bytes)
- 30. Re: [Amps] Shorted turns reduce harmonics? (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Fri, 22 Jul 2005 16:06:24 +0100
- Steve Thanks for that. You're quite right it's not acting like a pure inductor. I think the inter-winding capacitance of the shorted turns, of parts of the 15-80m coil and the 160m coil, with a short
- /archives//html/Amps/2005-07/msg00259.html (7,554 bytes)
- 31. Re: [Amps] Shorted turns reduce harmonics? (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 25 Jul 2005 09:47:53 +0100
- HI Amp'ers I measured the response of pi-tank with a VNA this weekend. Thanks to Steve G8GSQ, Jos ON4KJ & Hank WV7U for the advice. There is a parasitic notch that is tuneable by the load control, wh
- /archives//html/Amps/2005-07/msg00306.html (7,303 bytes)
- 32. Re: [Amps] SB-220 Submerged (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Thu, 4 Aug 2005 10:15:58 +0100
- FYI for ultrasonic cleaning here at work we use Electrolube Super Safe Wash 2000, the chemical name is 2-Aminoethanol (MELA). It's diluted to 2% with 98% deionised water (as used in batteries & steam
- /archives//html/Amps/2005-08/msg00086.html (8,652 bytes)
- 33. [Amps] Ribbon Beam Amplifiers (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 15 Aug 2005 12:01:22 +0100
- An interesting press cutting appeared on the tea-point notice board here at work last week. It's about a new vacuum tube device called "Ribbon Beam Amplifier (RBA)" developed by MIT for 3G base stati
- /archives//html/Amps/2005-08/msg00515.html (6,452 bytes)
- 34. Re: [Amps] Ribbon Beam Amplifiers (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Mon, 15 Aug 2005 16:06:29 +0100
- Hi Jeff 60dB, that's quite a spec! Is that open loop, or with cartesian correction, or feed-forward? Current technology to do that (in the backed-off 10's of watts level) is rather complex. Mark I me
- /archives//html/Amps/2005-08/msg00529.html (8,172 bytes)
- 35. Re: [Amps] plate choke (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Fri, 26 Aug 2005 17:10:22 +0100
- Hi Amp'ers When I was building my amp I spent a long time investigating plate chokes or feeding DC in from the antenna end. I made 5 chokes, and bought one from a UK manufacturer, but could never get
- /archives//html/Amps/2005-08/msg00700.html (8,685 bytes)
- 36. Re: [Amps] Drake L-4B PSU burned resistor (score: 1)
- Author: "Mark Marsden" <mm@plextek.co.uk>
- Date: Wed, 2 Nov 2005 13:28:39 -0000
- I use the 50R 100W version, it's pictured at the bottom right hand corner on http://granta.digital-crocus.com/linear/Mvc-049x.jpg 73, Mark G4AXX --Original Message-- Vishay do a 'bolt down' 50W resis
- /archives//html/Amps/2005-11/msg00026.html (7,687 bytes)
This search system is powered by
Namazu