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References: [ +from:alan@g3xaq.net: 27 ]

Total 27 documents matching your query.

1. Re: [Amps] Labeling panels (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 20 Aug 2010 13:50:30 +0100
I've used the Front Panel Designer free software package for creating panel labels. http://www.frontpanelexpress.com/download/front-panel-designer/index.html Radial tick marks for rotary controls can
/archives//html/Amps/2010-08/msg00336.html (8,160 bytes)

2. [Amps] 8171/4CX10000D negative screen current? (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sat, 01 Oct 2011 15:16:52 +0100
Does the 8171 or other tubes with handles exhibit negative screen grid current like their much smaller 4CX250B brothers? The constant current curves on the data sheet suggests the 8171 doesn't suffer
/archives//html/Amps/2011-10/msg00000.html (6,047 bytes)

3. Re: [Amps] 8171/4CX10000D negative screen current? (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sun, 02 Oct 2011 13:34:06 +0100
Thanks to several people who replied to me off-list. I was wrong to call negative screen current an anomaly, it is an expected consequence of some tube geometries. I have been told that in practice t
/archives//html/Amps/2011-10/msg00004.html (7,094 bytes)

4. [Amps] SPICE models for tubes with handles (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sun, 29 Apr 2012 13:51:12 +0100
What's the collective opinion on here about the usefulness or otherwise of simulating valve RF linear amplifiers with the likes of SPICE? The specific application I'm thinking about is an 8171 model
/archives//html/Amps/2012-04/msg00254.html (6,787 bytes)

5. [Amps] Coupling a blower to an air system socket (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 15 Mar 2013 20:58:34 +0000
For minimum airflow resistance for a forced air cooled amplifier it would seem the blower needs to discharge in a straight line directly into the underside of the valve socket. This leads to a fairly
/archives//html/Amps/2013-03/msg00213.html (7,568 bytes)

6. Re: [Amps] Advice needed for SS amp (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Thu, 06 Jun 2013 22:53:15 +0100
Antenna baluns usually don't have galvanic insulation between input and output, so you can't use them in an amplifier powered directly off-line. But using the core of such a balun, and rewinding it
/archives//html/Amps/2013-06/msg00133.html (10,403 bytes)

7. [Amps] High current RF decoupling capacitors (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 03 Jan 2014 23:14:53 +0000
I'm working on a high power amplifier design using high voltage switching MOSFETs. It all looks fine in LTspice (doesn't it always?) until I look at the PSU decoupling requirements. I need something
/archives//html/Amps/2014-01/msg00022.html (6,666 bytes)

8. Re: [Amps] High current RF decoupling capacitors (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sun, 05 Jan 2014 17:59:04 +0000
Thanks, John. Baruch/4Z4RB just suggested the same thing. They look better for high frequencies than the leaded disc ceramics that Ian/GM3SEK pointed me towards. However, there doesn't seem to be a U
/archives//html/Amps/2014-01/msg00030.html (8,630 bytes)

9. [Amps] 381LR Cornell Dubilier date codes? (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Tue, 21 Jan 2014 14:21:00 +0000
I got some CDM 381LR 470uF/450v electrolytics off eBay. I'm wondering when they were made and/or if they are genuine. The only numeric marking on them is 821804. Is that a date code? Anyone know how
/archives//html/Amps/2014-01/msg00205.html (6,441 bytes)

10. Re: [Amps] 381LR Cornell Dubilier date codes? (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Tue, 21 Jan 2014 16:59:14 +0000
I can't find a press release from CDE and there's no date on their catalogue page but FWIW Digikey didn't begin carrying them until 2011 http://www.digikey.com/us/en/press-release/cornell_dubilier.ht
/archives//html/Amps/2014-01/msg00211.html (8,738 bytes)

11. [Amps] Force cooled heatsink aerodynamics (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 14 Feb 2014 16:32:12 +0000
I'm planning on using one of these in my solid sate PA project http://www.farnell.com/datasheets/17645.pdf and I'm curious to know what is inside the box between the fan and the cooler matrix in the
/archives//html/Amps/2014-02/msg00117.html (7,406 bytes)

12. Re: [Amps] Force cooled heatsink aerodynamics (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sat, 15 Feb 2014 17:04:01 +0000
http://www.farnell.com/datasheets/17645.pdf REPLY: That is interesting. Do you know what the prices are and where to order from? I am paying just over 100 each, say $160, including the fan. Farnell
/archives//html/Amps/2014-02/msg00129.html (9,219 bytes)

13. [Amps] QEX May/June 2014 amplifier article (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sat, 17 May 2014 15:38:58 +0100
May I timidly ask if anyone here can fathom the purpose of the article on page 14 of the current ARRL QEX magazine? It describes an amplifier using a high voltage IGBT which is operated for 600 cycle
/archives//html/Amps/2014-05/msg00098.html (7,432 bytes)

14. [Amps] Test versus working voltage for oil filled capacitor (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Tue, 14 Apr 2015 21:14:15 +0100
I have a pair of jumbo oil filled capacitors. They are each 6 x 6 x 12 inches and weigh about 10 pounds. I wish to use them at 3KV off load and with a 2A ripple current under full load. The only mark
/archives//html/Amps/2015-04/msg00103.html (7,533 bytes)

15. Re: [Amps] Test versus working voltage for oil filled capacitor (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Thu, 16 Apr 2015 19:28:03 +0100
My original post had a misleading typo: my capacitors weigh 10Kg not 10lb each. Sorry. They sound very similar to the CDE ones from Henry that Jim describes. I have tested each unit for temperature r
/archives//html/Amps/2015-04/msg00114.html (9,434 bytes)

16. [Amps] 8877 heater inrush (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Sun, 24 Apr 2016 16:01:53 +0100
I am collecting parts together to build a rugged but low weight amplifier for solo DXpeditions. I have an 8877 tube that I want to use. A 5V switchmode PSU instead of a mains transformer for the heat
/archives//html/Amps/2016-04/msg00042.html (7,917 bytes)

17. Re: [Amps] Thinking out loud 3-500Z and the like gettering (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Thu, 16 Jun 2016 17:11:38 +0100
It looks to me like they won't heat the graphite anodes in the modern day 3-500Z and similar tubes. They would have to be the metal type anodes for the induction heater to work. This video suggests d
/archives//html/Amps/2016-06/msg00063.html (7,396 bytes)

18. [Amps] Comet vacuum variable capacitor data (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Wed, 25 Jan 2017 20:01:57 +0000
There is a Comet vac variable on fleabay with the part number CV05-2000G/5. I think it's pretty old. OK, so it is 5KV test and 2000pF max capacitance. But can anyone identify it further? Specifically
/archives//html/Amps/2017-01/msg00288.html (6,693 bytes)

19. Re: [Amps] Comet vacuum variable capacitor data (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 27 Jan 2017 10:40:34 +0000
Hello Marv. Thanks very much for looking up the details. It looked good until you mentioned it is direct pull. That would require some head scratching and time in the workshop which makes the eBay it
/archives//html/Amps/2017-01/msg00291.html (8,540 bytes)

20. Re: [Amps] SS amps watercooling - was PowerGenius XL (score: 1)
Author: Alan Ibbetson <alan@g3xaq.net>
Date: Fri, 17 Feb 2017 22:44:09 +0000
cooling works on the premise that the water is brought up to a boil. And thats with normal sea level pressure. Put the system loop under pressure, and the boiling point will rise by a bunch. Will a
/archives//html/Amps/2017-02/msg00133.html (8,653 bytes)


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