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References: [ +from:d.cutter@ntlworld.com: 156 ]

Total 156 documents matching your query.

21. Re: [Amps] 50 Ohm Loads (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Tue, 13 Nov 2007 8:31:51 +0000
So far no-one has mentioned non-inductive winding technique. I think Caddock use a method of winding in one direction, then half way along reverse the direction to complete the winding. David G3UNA -
/archives//html/Amps/2007-11/msg00186.html (7,926 bytes)

22. [Amps] ROHS side effects (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Mon, 19 Nov 2007 10:09:29 -0000
A lot of soldering irons will come onto the amateur market. My very small firm gave away around 30 high spec irons to whoever wanted them, plus solder: I caught 2, one for me and on for my club, so m
/archives//html/Amps/2007-11/msg00272.html (8,292 bytes)

23. Re: [Amps] Very Off topic : AM without sidebands ?? :-) ++ (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Thu, 29 Nov 2007 19:21:46 -0000
I've often wondered how people in places like Droitwich (198kHz) get on with the BBC coming thro their teeth fillings etc... ( : o { Now we have plastic teeth fillings and plastic gutters and plastic
/archives//html/Amps/2007-11/msg00399.html (7,438 bytes)

24. Re: [Amps] Tranformer Suppliers (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sat, 8 Dec 2007 08:29:40 -0000
You may well have the ability or just learn on the job and good luck to you, BUT, since the transformer is the main barrier to mains electricity supply this is the major safety element. You can buy o
/archives//html/Amps/2007-12/msg00059.html (9,314 bytes)

25. Re: [Amps] expensive mistakes (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Fri, 21 Dec 2007 21:32:29 -0000
I've been making and breaking circuits from my earliest memories and learn something new each time but I don't always take proper notes. Someone once said "RF transistors are the fastest fuses on 3 l
/archives//html/Amps/2007-12/msg00190.html (8,067 bytes)

26. [Amps] FET bias (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Mon, 24 Dec 2007 13:02:13 -0000
I have seen FET gate bias in parallel schemes isolated by a diode to each FET. This would introduce a temperature gradient seemingly counter productive to stability. Can anyone explain it? David G3UN
/archives//html/Amps/2007-12/msg00229.html (6,637 bytes)

27. Re: [Amps] FET bias (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Wed, 26 Dec 2007 22:49:17 -0000
But the 723 allows an easy way to introduce temperature dependent bias voltage. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesti
/archives//html/Amps/2007-12/msg00259.html (7,936 bytes)

28. Re: [Amps] My HV supply design. (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 1 Jan 2008 13:11:55 -0000
Patrick I would be very wary of using the 4N33 in the high voltage supply line. I know the spec says it isolates to lots of kV, but, if you plan to put the device into a pcb or Vero, the distance bet
/archives//html/Amps/2008-01/msg00002.html (9,189 bytes)

29. Re: [Amps] My HV supply design. (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 1 Jan 2008 20:39:01 -0000
You might also look at this website for more information on safe distances: http://www.ce-mag.com/ce-mag.com/archive/01/03/ProductSafety.html in this one, the author re-states the old code of 10kV pe
/archives//html/Amps/2008-01/msg00013.html (7,971 bytes)

30. Re: [Amps] HV Supplies and Diodes (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Thu, 3 Jan 2008 12:51:32 +0000
It's the safety issues that worry me most of all. Having been through the mill of UL, CSA, CE etc when designing products for sale, I know it is a complex subject and common sense does not always lea
/archives//html/Amps/2008-01/msg00025.html (12,612 bytes)

31. Re: [Amps] HV Diodes + Hi Pot (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Fri, 4 Jan 2008 06:47:54 -0000
Why don't the guys with hi pot testers take a bunch of diodes and measure them individually and in a string? Try them hot and cold. Post the results here. David G3UNA ________________________________
/archives//html/Amps/2008-01/msg00055.html (7,788 bytes)

32. Re: [Amps] tuning bandpass filters (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Mon, 21 Jan 2008 19:27:41 -0000
It's also interesting to investigate what happens to harmonics when presented with a real multi-band antenna, say a multiband yagi on the other side of various filter types. David G3UNA _____________
/archives//html/Amps/2008-01/msg00133.html (9,202 bytes)

33. Re: [Amps] Step start (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 3 Feb 2008 13:22:54 -0000
Well over-priced compared to a relay and hand full of parts. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/list
/archives//html/Amps/2008-02/msg00009.html (7,867 bytes)

34. Re: [Amps] Step start (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Sun, 3 Feb 2008 13:41:29 -0000
I have a 240V 15A variac which would consistently blow a 13A plug fuse at switch on, unloaded. The spec for these plug fuses states they must blow in 30s with 2.1 x nominal current applied, ie >27A:
/archives//html/Amps/2008-02/msg00010.html (8,244 bytes)

35. Re: [Amps] Amps Digest, Vol 62, Issue 3 (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Mon, 4 Feb 2008 12:57:36 +0000
The relay will hold until about 20% or so of its nominal coil voltage. After that it will take 10 to 20ms to drop out, perhaps longer, so, it depends on the brown out you expect. Define "moment" Davi
/archives//html/Amps/2008-02/msg00021.html (9,324 bytes)

36. Re: [Amps] Silver (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 12 Feb 2008 13:57:52 -0500
2.5L will cost you about GBP13 from www.reagent.co.uk, but I doubt if you need that much. A proprietary cleaner and cotton bud would be easier. David G3UNA ___________________________________________
/archives//html/Amps/2008-02/msg00061.html (8,546 bytes)

37. Re: [Amps] Silver (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 12 Feb 2008 17:26:29 -0500
I did this 50 years ago with grandma's silver spoons David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amp
/archives//html/Amps/2008-02/msg00067.html (8,863 bytes)

38. Re: [Amps] Silver (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Tue, 12 Feb 2008 18:23:06 -0500
A jewellery shop may offer a silver cleaning service. They will probably use an ultrasonic cleaning bath to speed up the operation which will dig deep into crevices. David G3UNA _____________________
/archives//html/Amps/2008-02/msg00069.html (9,475 bytes)

39. Re: [Amps] Silver oxide is an insulator (score: 1)
Author: "David Cutter" <d.cutter@ntlworld.com>
Date: Wed, 13 Feb 2008 02:01:28 -0500
Some would say that silver plating is a bad thing in a multi-band amplifier because it encourages vhf parasitics. David G3UNA snip _______________________________________________ Amps mailing list Am
/archives//html/Amps/2008-02/msg00074.html (6,823 bytes)

40. Re: [Amps] filament supply D.C or A.C (score: 1)
Author: <d.cutter@ntlworld.com>
Date: Wed, 13 Feb 2008 13:08:37 +0000
This might give you a clue, but not the full answer: a lamp manufacturer published a treatise on this subject and concluded that ac was better for life expectancy. Something to do with migration of e
/archives//html/Amps/2008-02/msg00077.html (8,606 bytes)

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