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References: [ +from:gm3sek@ifwtech.co.uk: 471 ]

Total 471 documents matching your query.

21. Re: [Amps] One PS, many amps (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 10 Oct 2005 07:16:15 +0100
But only at the risk of RF instability in each amp. I think it can be done by leaving each amp as-is, and adding a series diode from each Ia meter to the common B-minus return. If you trace the curre
/archives//html/Amps/2005-10/msg00237.html (8,862 bytes)

22. Re: [Amps] Drake L-4B PSU burned resistor (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 2 Nov 2005 14:15:41 +0000
The voltage rating on these components is a continuous rating. The green Welwyn 14W resistors will handle higher voltages for a short time in glitch resistor service. Three of these 10 or 15 ohm resi
/archives//html/Amps/2005-11/msg00027.html (9,210 bytes)

23. Re: [Amps] Drake L-4B PSU burned resistor (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 2 Nov 2005 15:46:36 +0000
The metal-clad resistors have a very poor voltage rating, either end-to-end or to ground, and they seem to get worse with heat and ageing. They are totally unsuitable as glitch resistors. Also they a
/archives//html/Amps/2005-11/msg00032.html (9,432 bytes)

24. Re: [Amps] Meaning of "conduction cooled" (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Thu, 3 Nov 2005 19:25:54 +0000
Not in the normal usage of those terms... but it also depends on whom you ask. A fluid dynamicist would describe any kind of heat transfer by a moving fluid as "convection". An engineer would divide
/archives//html/Amps/2005-11/msg00055.html (10,345 bytes)

25. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 7 Nov 2005 07:52:44 +0000
There are two separate issues here: RF grounding, and power supplies. The RF grounding issue is thoroughly discussed in the description of a 4CX1000 amp for 2m that was in the ARRL Handbooks for seve
/archives//html/Amps/2005-11/msg00083.html (9,619 bytes)

26. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 7 Nov 2005 12:57:31 +0000
That's news to me, so I'd be happy to learn more. -- 73 from Ian G/GM3SEK http://www.ifwtech.co.uk/g3sek _______________________________________________ Amps mailing list Amps@contesting.com http://l
/archives//html/Amps/2005-11/msg00089.html (8,152 bytes)

27. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 7 Nov 2005 14:43:00 +0000
The 30S-1 is cathode driven (I'm looking at the schematic now). G1 is mostly grounded to RF by a 220pF capacitor, but RF negative feedback is also applied at this point by a 5pF cap from the anode. G
/archives//html/Amps/2005-11/msg00094.html (9,182 bytes)

28. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 7 Nov 2005 16:38:28 +0000
It is cathode-driven because the RF input is connected to the cathode - and nothing else (still looking at the schematic here). Yes... The control grid and cathode are not connected in the 30S-1. G1
/archives//html/Amps/2005-11/msg00096.html (8,990 bytes)

29. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 7 Nov 2005 22:30:46 +0000
Because G1 receives a small fraction of the anode voltage as negative feedback, it moves in the same direction as the instantaneous RF cathode voltage, but I think that "virtually no" signal potentia
/archives//html/Amps/2005-11/msg00102.html (9,176 bytes)

30. Re: [Amps] Grounded Screen 4CX1500B (score: 1)
Author: Ian White G/GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 8 Nov 2005 07:43:37 +0000
The problem is that everything about the 30S-1 is more weird than you think it's going to be. It's a fascinating design, full of complexities caused by the decision to cathode-drive a tetrode. You ha
/archives//html/Amps/2005-11/msg00107.html (9,828 bytes)

31. Re: [Amps] gs35b on hf problem . (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Fri, 11 Nov 2005 07:53:41 +0000
Sorry, I would say the exact opposite. Wirewound resistor CAN handle high-voltage surges, if they are the vitreous (glass) enameled type with a long body and terminals at opposite ends. But normal wi
/archives//html/Amps/2005-11/msg00150.html (9,680 bytes)

32. Re: [Amps] 220V wiring: Was Question about safety ground connection (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Thu, 17 Nov 2005 18:47:59 +0000
You mean the USA is building homes without glitch resistors? -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/m
/archives//html/Amps/2005-11/msg00279.html (8,745 bytes)

33. Re: [Amps] -48 Volt Switching Power Supplies (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 22 Nov 2005 07:59:00 +0000
But in other jurisdictions they can be bought for peanuts, with the magic smoke still inside. Part of the reason for the low price is that they often don't seem to be working... but see below. Oh goo
/archives//html/Amps/2005-11/msg00426.html (8,962 bytes)

34. Re: [Amps] Is This 4CX1600B Still Good? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 22 Nov 2005 21:51:30 +0000
Hello Mike Please can you let me have more specifics about which components had failed? -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contesting.com htt
/archives//html/Amps/2005-11/msg00448.html (8,727 bytes)

35. Re: [Amps] G3SEK complet kit for sale (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 23 Nov 2005 18:16:49 +0000
People's plans change, and that's fine by me. Whoever buys it, the "lifetime" support comes with the kit, so please e-mail to let me know. -- 73 from Ian GM3SEK ______________________________________
/archives//html/Amps/2005-11/msg00463.html (7,593 bytes)

36. Re: [Amps] G3SEK complet kit for sale (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 23 Nov 2005 20:02:29 +0000
For full terms and conditions of our beyond-the-grave product support plan, please touch B+ now. -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contestin
/archives//html/Amps/2005-11/msg00469.html (8,541 bytes)

37. Re: [Amps] G3SEK complet kit for sale (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 23 Nov 2005 21:07:03 +0000
Scottish law requires the standard four-and-twenty. -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/lis
/archives//html/Amps/2005-11/msg00474.html (7,897 bytes)

38. Re: [Amps] Why preference for 3CPX800A7? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Thu, 1 Dec 2005 08:11:21 +0000
There are definite advantages in using the 3CPX at 432MHz, as identified by K1FO: http://home.cshore.com/lunarlink/etubes/800e.html However, most of these factors apply *only* at UHF where gain and e
/archives//html/Amps/2005-12/msg00000.html (7,737 bytes)

39. Re: [Amps] Pop (arc) noise in Alpha 99 (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Thu, 1 Dec 2005 08:20:58 +0000
Have you cleaned it out? If not, you can have a situation where the same bits of dust and debris stay inside the grid compartment and the chimney, and occasionally are blow upward to bridge the ceram
/archives//html/Amps/2005-12/msg00001.html (7,274 bytes)

40. Re: [Amps] *** SPAM *** Re: Antenna traps (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Fri, 16 Dec 2005 09:31:29 +0000
I think Rich is more right than Peter on this one. We all agree that the network should have the lowest possible working Q, in order to achieve the lowest possible internal losses and the highest pos
/archives//html/Amps/2005-12/msg00198.html (9,665 bytes)

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