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Total 211 documents matching your query.

21. Re: [Amps] Advice (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Fri, 04 Dec 2009 03:08:16 +0000
If operated in push pull (double ended) the second harmonic (and other even) is canceled and if pushed into distortion it can mean more power before distorting out of specs. -- Ron KA4INM - The only
/archives//html/Amps/2009-12/msg00102.html (8,875 bytes)

22. Re: [Amps] GI-7B (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 01:58:07 +0000
/*snip*/ Increasing the plate Voltage allows a tube/s to produce more RF power, (once you reach the current limit of the tube) within limits. My experience with high power transmitting tubes (IOT-D2
/archives//html/Amps/2009-12/msg00139.html (8,207 bytes)

23. Re: [Amps] Advice (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 02:07:38 +0000
< There is a broadcast station that has kept a set of finals in stand bye, running at mildly reduced filament voltage, not dark heat, for something like 30,000 or 40,000 hours... Had the tubes tested
/archives//html/Amps/2009-12/msg00140.html (7,748 bytes)

24. Re: [Amps] Help With Command Technologies HF2500 (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 02:12:52 +0000
A grid can sag causing an internal short that will be gone after the tube is powered down. -- Ron KA4INM - The only real problem is death is so final. _______________________________________________
/archives//html/Amps/2009-12/msg00141.html (7,445 bytes)

25. Re: [Amps] Advice (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 02:22:54 +0000
I assume these values are at the maximum power dissipation, running a tube at reduced power dissipation allows operating at reduced cooling effort, so two tubes splitting a given amount of dissipati
/archives//html/Amps/2009-12/msg00142.html (8,321 bytes)

26. Re: [Amps] Step-start and 3-500Z filament life (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 04:25:48 +0000
I think of "step-start" as applying to the plate supply, to minimize the initial capacitor charging current and preventing a hV over shoot, and inrush limiting to be applied to initial filament heat
/archives//html/Amps/2009-12/msg00144.html (8,035 bytes)

27. Re: [Amps] Advice (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 06 Dec 2009 14:02:59 +0000
Not at all unusual at all, it takes is airborne lint to accumulate in the fins of the blower to reduce air flow, a few broadcast engineers have been known to log manometer readings down to the solde
/archives//html/Amps/2009-12/msg00153.html (8,990 bytes)

28. Re: [Amps] FW: Decent HF directional coupler for RF power meas. (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Mon, 07 Dec 2009 08:54:57 -0500
The cable and attenuator errors can be known without error, all he has to do is pay a cal laboratory to characterize each at the test frequencies. -- Ron KA4INM - I'm proud to be Chuck's pop! ______
/archives//html/Amps/2009-12/msg00188.html (7,714 bytes)

29. Re: [Amps] OM power power supply design (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Wed, 09 Dec 2009 09:40:25 -0500
This design (old) has the advantages of using 1 kW diodes and 300 Volt capacitors and if a diode shorts and blows it's fuse, the remainder of the power supply keeps operating at the reduced Voltage.
/archives//html/Amps/2009-12/msg00245.html (7,739 bytes)

30. Re: [Amps] OM power power supply design (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Thu, 10 Dec 2009 09:37:56 -0500
I don't understand how bleeder resistors are no longer needed. (which can also serve as the P.S. Volt meter multiplier) Many HP amplifiers use stacked low voltage capacitors so I don't see a differe
/archives//html/Amps/2009-12/msg00263.html (8,677 bytes)

31. Re: [Amps] Chinese DIN connectors (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Fri, 11 Dec 2009 01:21:28 +0000
It seems to me we are talking about two different kind of DIN connectors, one kind of DIN is a coaxial connector, the other is the round audio connectors used on some imported audio equipment. (and
/archives//html/Amps/2009-12/msg00289.html (8,817 bytes)

32. Re: [Amps] Chinese DIN connectors (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sat, 12 Dec 2009 02:06:03 +0000
Actually he said: "I need to get some 7-16 DIN connectors, and most of what I'm seeing is coming out of China." Perhaps the "7-16 DIN" instead of the correct "7/16 DIN" caused the confusion? -- Ron
/archives//html/Amps/2009-12/msg00304.html (8,917 bytes)

33. Re: [Amps] Excessive Plate Voltage Henry 2KD-5 (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 13 Dec 2009 01:17:26 +0000
A good safety idea is to calculate (and mark down next to them) the total bleeder resistance and measure the entire string as a part of any work on the amplifier. -- Ron KA4INM - Of what you see in
/archives//html/Amps/2009-12/msg00309.html (7,433 bytes)

34. Re: [Amps] Russian Power Tubes (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Wed, 16 Dec 2009 12:32:37 +0000
The oldest habits are the hardest to break. and As the old woman said as she hissed her cow: "Everyone to their own fetish." We also discus repairing old units, frequently with non-standard parts. -
/archives//html/Amps/2009-12/msg00371.html (9,587 bytes)

35. Re: [Amps] Alternative cooling strategies for SB-220? (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Fri, 18 Dec 2009 00:54:31 +0000
If all else fails look in the back of the December issues, at the annual index then you have only 10 issues to search. -- Ron KA4INM - Of what you see in books, believe 75%. Of newspapers, believe 5
/archives//html/Amps/2009-12/msg00405.html (8,521 bytes)

36. Re: [Amps] water cooling (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Fri, 18 Dec 2009 23:31:30 +0000
I operated a transmitter long ago that had a pair of 1.5" loops of "saran" tubing to the plates of dual tetrode tubes operating at 3 kV with no problems. I think the material is more important than
/archives//html/Amps/2009-12/msg00465.html (8,617 bytes)

37. Re: [Amps] water cooling (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sat, 19 Dec 2009 13:20:10 +0000
If they use Teflon tubing a foot might be sufficient. Different brands are cooled differently so it may depend on the arrangement. -- Ron KA4INM - Of what you see in books, believe 75%. Of newspaper
/archives//html/Amps/2009-12/msg00488.html (8,568 bytes)

38. Re: [Amps] Re GS-35B hours.. (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Sun, 20 Dec 2009 02:56:00 +0000
Filament power management. Good for indirectly heated cathodes. -- Ron KA4INM - Of what you see in books, believe 75%. Of newspapers, believe 50%. And of TV news, believe 25% -- make that 5% if the
/archives//html/Amps/2009-12/msg00503.html (8,017 bytes)

39. Re: [Amps] water cooling (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Wed, 23 Dec 2009 01:39:55 +0000
Pure deionized water is an insulator, like any other insulator it can be broken down with enough pressure (Voltage) the length of the path determines how much pressure it takes to break down. The tu
/archives//html/Amps/2009-12/msg00526.html (9,322 bytes)

40. Re: [Amps] Variac repairs (score: 1)
Author: Ron Youvan <ka4inm@tampabay.rr.com>
Date: Tue, 29 Dec 2009 15:24:56 +0000
I had one "powerstat" go bad at one spot (and seen many more over the years) out of 10 in use for over 20 years. The normal variable transformer has a carbon brush that constantly touches more than
/archives//html/Amps/2009-12/msg00556.html (8,585 bytes)


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