- 81. Re: [Amps] Fw: "Tubes 201" - How Vacuum Tubes Really Work (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 25 Jul 2006 21:15:54 +0200
- Will, the RF drive in GG is developed directly at the cathode. The cathode choke forms a RF resistor in parallel to the tubes input impedance from cathode to ground. The positive going cycle develops
- /archives//html/Amps/2006-07/msg01110.html (13,126 bytes)
- 82. Re: [Amps] Fw: "Tubes 201" - How Vacuum Tubes Really Work (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 25 Jul 2006 21:24:35 +0200
- Hi Will, Yes, the grid must always keep its DC connection to ground not to turn into a runaway condition by a positive charged grid, it does not matter whether it is grounded grid or grounded cathode
- /archives//html/Amps/2006-07/msg01111.html (13,710 bytes)
- 83. Re: [Amps] Fw: "Tubes 201" - How Vacuum Tubes Really Work (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 25 Jul 2006 22:21:29 +0200
- Will, It is also mentioned in my Siemens handbook of transmitting tubes together with the other safety measures on almost two pages. It is interesting to read that those measures were mandatory for c
- /archives//html/Amps/2006-07/msg01115.html (16,404 bytes)
- 84. Re: [Amps] Fw: "Tubes 201" - How Vacuum Tubes Really Work (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 25 Jul 2006 23:33:35 +0200
- Hi Will and the group, OK, I will scan it as it is and load it up tomorrow. You will have a hard time to find the book, it is called bei Siemens "Sende- und Genaratorröhren Hochspannungsgleichri
- /archives//html/Amps/2006-07/msg01126.html (12,931 bytes)
- 85. Re: [Amps] setting the grid adrift (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 00:06:56 +0200
- It's the same as swapping switching diodes in transceivers to pin-diodes without checking/correcting their current. Thousands did. Every day another fool awakes, one just hast to find him... 73 Peter
- /archives//html/Amps/2006-07/msg01127.html (8,720 bytes)
- 86. Re: [Amps] setting the grid adrift (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 01:06:01 +0200
- Will, Again, electrode voltages of tubes are ALWAYS referenced to the cathode of a tube, not to ground. I hope you agree that a 3-500Z draws about 100mA grid-current under normal conditions. If you l
- /archives//html/Amps/2006-07/msg01132.html (9,369 bytes)
- 87. Re: [Amps] PIN diode mods (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 13:27:06 +0200
- 73 Peter Then FT-1000D is a low end radio! 2nd order IMD improves over 20 dB when doing PIN diode mod. By the same time IMDDR3 2 kHz spaceing improves approx 15 dB. Voodoo....yeah right! 73 SM2EKM --
- /archives//html/Amps/2006-07/msg01158.html (9,531 bytes)
- 88. Re: [Amps] Fw: "Tubes 201" - How Vacuum Tubes Really Work (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 13:33:47 +0200
- All R&S TV transmitters using the THxxx family of tubes have the thyristor crowbar and glitch resistor installed in their power supplies 73 Peter Preferences of individual design teams seem to govern
- /archives//html/Amps/2006-07/msg01160.html (10,410 bytes)
- 89. Re: [Amps] plexiglas isolation in coils (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 22:34:17 +0200
- Hi Dick, Any material I wish to use as an insulator I test in a microwave oven before. When you run high power with coils of 2,5mm wire diameter, I am pretty sure that acryl will deform by the heat g
- /archives//html/Amps/2006-07/msg01188.html (7,768 bytes)
- 90. Re: [Amps] TL-922 question (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 22:42:31 +0200
- Vic, indeed the weak point is the transformer which I guess is not better then 0,8-1KVA CCS. The lower ZSAC will not change much. You have to improve the cooling dramatically, which is not sufficient
- /archives//html/Amps/2006-07/msg01189.html (7,942 bytes)
- 91. Re: [Amps] plexiglas isolation in coils (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 26 Jul 2006 23:47:24 +0200
- Hi Tom, I always found the micro wave oven test helpful in advance when I had materials to be crafted by someone else on a lathe or mill. Is there any material which would pass that test but fail on
- /archives//html/Amps/2006-07/msg01195.html (8,463 bytes)
- 92. Re: [Amps] plexiglas isolation in coils (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Fri, 28 Jul 2006 19:19:37 +0200
- Running any Heathkit at the same power level as the AL1200 on RTTY will blow off the Heathkit very quickly. Repaired a lot of SB-220 with melted band switches and HV transformers. Anyway, both are to
- /archives//html/Amps/2006-07/msg01245.html (9,483 bytes)
- 93. Re: [Amps] plexiglas isolation in coils (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Fri, 28 Jul 2006 21:32:51 +0200
- Not at all, I prefer large glass tubes ;-)) http://www.pbase.com/df3kv/image/21834772 http://www.pbase.com/df3kv/image/33238173/large 73 Peter My opinion on noisy fans is-- if they are a problem you
- /archives//html/Amps/2006-07/msg01255.html (9,207 bytes)
- 94. Re: [Amps] AL811, AL811H or AL572 mods to 6m (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Wed, 2 Aug 2006 18:12:24 +0200
- What do you mean by "needed impedance transformation"? The needed impedances transformation is always the same when other parameters are not changed by the conversion to 6m. Original anode capacitors
- /archives//html/Amps/2006-08/msg00049.html (8,472 bytes)
- 95. Re: [Amps] band decoders for 1.5kw low pass filters (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Sun, 6 Aug 2006 00:55:13 +0200
- Probably you are using the low power filters 73 Peter The W3NQN filters from Array can handle 200 watt SSB only, barely enough for QRP. I use them for my multi TRX Winlink station, they perform very
- /archives//html/Amps/2006-08/msg00196.html (7,079 bytes)
- 96. Re: [Amps] State of the Amp (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 22 Aug 2006 16:26:45 +0200
- I wonder if the factory price of the GS-35b is also less then that of a 3-500Z. No commercial amp factory would buy their GS-35b through eBay or dark channels without warranty I guess. The plate diss
- /archives//html/Amps/2006-08/msg00592.html (8,708 bytes)
- 97. Re: [Amps] State of the Amp (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Tue, 22 Aug 2006 18:50:13 +0200
- Never, especially not with the same drive at 4KV. When >2500W are claimed on that website, I claim 1000W for a 3-500Z or similar tube. Tony is using factory data when comparing the 8877 with the GS-3
- /archives//html/Amps/2006-08/msg00599.html (8,366 bytes)
- 98. Re: [Amps] Parasitics & Filament Sag (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Sun, 27 Aug 2006 17:55:38 +0200
- Perhaps the reason is that manufactures of amateur amplifiers are almost always hams and just duplicate amplifier layouts from the past. Commercial amplifier manufactures used suppressors wound of re
- /archives//html/Amps/2006-08/msg00698.html (9,897 bytes)
- 99. Re: [Amps] US source for TRIODE board (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Fri, 22 Sep 2006 01:23:54 +0200
- WD7S is doing triode boards in the US as well http://home.earthlink.net/~wd7s/triode_control.htm 73 Peter John, whatever you do, if KA0RYT contacts you after this message to say he has a triode board
- /archives//html/Amps/2006-09/msg00275.html (7,817 bytes)
- 100. Re: [Amps] Bad tubes from Ebay (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Thu, 28 Sep 2006 23:31:12 +0200
- Hi Larry, The seller who sold you the GU74 is a very bad example. I also had problems with him. Good experience is with "qro-stuff" and "alex550-2". vacuum switches, all items new in their original b
- /archives//html/Amps/2006-09/msg00344.html (8,251 bytes)
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