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Total 109 documents matching your query.

1. [Amps] Stainless (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sat Mar 1 07:26:12 2003; The fact stainless is "magnetic" or not isn't important at radio frequencies. Eddy currents and skin effect keep the magnetic properties out of the picture. If you add a solid steel slug core in a co; /archives//html/Amps/2003-03/msg00002.html (7,277 bytes)
2. [Amps] Stainless Steel (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sat Mar 1 13:37:22 2003; problem material any rule Apply it by considering the current density, or the total current flowing in a given cross-section of material. Contrary to all the notions about magnetic and non-magnetic,; /archives//html/Amps/2003-03/msg00011.html (10,838 bytes)
3. [Amps] AL-80B questions (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 06:48:15 2003; Parasitics, even assuming they would occur, can't cause tube failures unless you see some solid evidence of excessive current on meters. I don't know what time period you are talking about, but I've; /archives//html/Amps/2003-03/msg00017.html (10,207 bytes)
4. [Amps] AL-80B questions (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 08:33:05 2003; unless Rich, maybe you can put aside all the innuendo and diversion and explain how a parasitic can mechanically displace a filament, while thermal cycling or material problems are not likely to do; /archives//html/Amps/2003-03/msg00020.html (8,171 bytes)
5. [Amps] bending filaments (was al80B) (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 11:54:38 2003; Eimac states that as a general rule, and it is very conservative. The problem arises when the tube has poor materials, or is improperly manufactured. The AL80 series has a very long history with goo; /archives//html/Amps/2003-03/msg00022.html (11,503 bytes)
6. [Amps] AL-80B questions (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 12:28:50 2003; It isn't that bad Conrad. This is like engineering triage. We should help those who aren't terminal, and can still be helped. Sometimes we have to accomplish that by pointing out fatal mistakes by t; /archives//html/Amps/2003-03/msg00024.html (8,692 bytes)
7. [Amps] 8877 failures and GE Medical (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 19:06:02 2003; Rich made an incorrect statement that ETO was to blame for 8877 failures. The 8877 failures with GE medical were well known to be a manufacturing problem with the tubes. Eimac fought that problem for; /archives//html/Amps/2003-03/msg00033.html (8,025 bytes)
8. [Amps] Re: THANKS re the 8877 failures and GE Medical (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Sun Mar 2 20:01:34 2003; fiasco--but fault. The military had similar problems. It was not, as Rich tries to claim, a problem with specific amplifers. with low on full Ameritron was having the same problem during the same ti; /archives//html/Amps/2003-03/msg00036.html (8,650 bytes)
9. [Amps] AL-80B questions (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 06:07:23 2003; it The tape would certainly allow RF to leak out of the case and cause TVI, but the amp is unconditionally stable with or without a cover. Folks in Mississippi, like folks all over the world, are ge; /archives//html/Amps/2003-03/msg00044.html (9,607 bytes)
10. [Amps] Toroidal Tank Coils (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 07:49:08 2003; Not quite. The normal properly-tuned peak voltage of a near-class B amplifier (class AB approaching B) is about 80-90% of anode voltage in each direction, which would translate to 3kV or more across; /archives//html/Amps/2003-03/msg00047.html (10,057 bytes)
11. [Amps] hear hear about the toobs (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 10:15:28 2003; The unfortunate thing is the mass public has been hoodwinked into thinking tubes are nearly perfect, and little things like tape on cabinets or other unimportant (from a reliability standpoint) thin; /archives//html/Amps/2003-03/msg00052.html (8,878 bytes)
12. [Amps] Toroidal Tank Coils (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 10:42:17 2003; Your normal diversion is to lift things out of context. The rest of my answer explains the difference. the You thought wrong. Phase shift depends on reactance and circuit impedances. A series induct; /archives//html/Amps/2003-03/msg00053.html (10,968 bytes)
13. [Amps] hear hear about the toobs (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 12:20:31 2003; Yes, except I believe nearly all Russian tubes are old stock. That's 4CX1600's are tough to find now, and why 572B's were not correctable. (Since they were not being manufactured, Svetlana couldn't; /archives//html/Amps/2003-03/msg00056.html (8,472 bytes)
14. [Amps] Why hasn't solid state replaced tubes? (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 12:22:01 2003; It would be easy to build a solid state amp capable of 3-4Kw, and baby it at 1500 watts. The price wouldn't be any different than people pay now for autotune amps. You'd have to use decent FET like; /archives//html/Amps/2003-03/msg00057.html (9,335 bytes)
15. [Amps] Toroidal Tank Coils (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 12:30:33 2003; across inductor end, termination a behaves system. Either phase not currents is two fault protect of energy; /archives//html/Amps/2003-03/msg00058.html (13,576 bytes)
16. [Amps] Toroidal Tank Coils (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 13:09:22 2003; ie: No, phase shift is NOT the relationship between voltage and current in this case, nor is it normally considered except when you are looking at things like reactance or SWR. Phase shift is the re; /archives//html/Amps/2003-03/msg00062.html (8,961 bytes)
17. [Amps] Tank Circuit (was toroid) model (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 14:57:37 2003; I put a model of a tank up for anyone interested in tank Q, phase shift, and the inductor voltage. http://www.w8ji.com/tank_circuit.htm This shows how phase shift is related to Q, and how inductor vo; /archives//html/Amps/2003-03/msg00068.html (6,702 bytes)
18. [Amps] Why hasn't solid state replaced tubes? (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 15:10:18 2003; It is less expensive and more reliable to use multiple MRF150's. First, heat is spread out over a larger area. Second, the RF layout would be better Third, cost goes down because component quantitie; /archives//html/Amps/2003-03/msg00070.html (8,202 bytes)
19. [Amps] Why hasn't solid state replaced tubes? (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 15:13:16 2003; But those are not good amps at all! They are dirty low-voltage bipolar amps and the devices are pushed pretty hard. They would never be acceptable for anything but low-power mobile, or FM or CW. Sam; /archives//html/Amps/2003-03/msg00071.html (8,754 bytes)
20. [Amps] Why hasn't solid state replaced tubes? (score: 131): Author: w8ji at contesting.com (Tom Rauch); Date: Mon Mar 3 18:46:29 2003; Some rigs get close on the worse bands (like the TS2000) but that still isn't any justification for adding to the problem by taking things down another notch. When used in a mobile with a small ante; /archives//html/Amps/2003-03/msg00077.html (8,722 bytes)

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