Mail Archive Search: <+from:w8jitom@postoffice.worldnet.att.net>

Results:

References: [ +from:w8jitom@postoffice.worldnet.att.net: 313 ]

Total 313 documents matching your query.

181. [AMPS] re:8877 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 22 Jul 1997 10:40:34 +0000; To: <amps@contesting.com> That's another interesting statement! Are you saying triodes can't be used in grid driven AB2 systems? What is the technical reason triodes can not be used in grid driven a; /archives//html/Amps/1997-07/msg00161.html (10,553 bytes)
182. [AMPS] re:4-250A (AB2 in grid-driven amplifiers) (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 22 Jul 1997 19:47:30 +0000; To: <amps@contesting.com> We can add ANY tube that can tolerate grid current to that list. Some tubes are better than others, but by careful design virtually all tubes that allow grid dissipation ca; /archives//html/Amps/1997-07/msg00170.html (10,358 bytes)
183. [AMPS] Temp of exhaust (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 23 Jul 1997 06:18:21 +0000; The exhaust temperature has nothing to do with the tube temperature Randy. The seals are rated at 250 degrees C maximum. That could occur with 0 degree air temp on the exhaust of a PA, or 500 degree; /archives//html/Amps/1997-07/msg00175.html (7,514 bytes)
184. [AMPS] Re: 2m legal limit amps (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 23 Jul 1997 06:18:21 +0000; To: <amps@contesting.com> Hi Carl, First let me say I agree with Ian. Screen regulation is important, as well as adding a little negative feedback via an unbypassed cathode resistor. You can do IMD; /archives//html/Amps/1997-07/msg00176.html (10,186 bytes)
185. [AMPS] Re: 2m legal limit amps (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 23 Jul 1997 22:17:37 +0000; To: <amps@contesting.com> OK, that would be understandable because of phase shift due to stray C. The IMD will be well above the phase noise level. The main problem is shielding and having an accurat; /archives//html/Amps/1997-07/msg00196.html (11,140 bytes)
186. [AMPS] IMD measurement scheme (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 24 Jul 1997 06:45:25 +0000; Hi George, I use a magic T combiner. Any combiner with input port to port isolation will work fine. A magic T is a tightly coupled center tapped winding, with a resistor twice the 3 dB port impedance; /archives//html/Amps/1997-07/msg00199.html (9,754 bytes)
187. [AMPS] Re: 8877 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 24 Jul 1997 09:52:56 +0000; I've seen plenty of 811A's and 812A's. I've seen 100TL's and 100TH's also, right up to 450 TH's and TL's. My very first SSB PA was a pair of 812's grid driven by a homebrew 6L6 phasing exciter. I lat; /archives//html/Amps/1997-07/msg00201.html (9,756 bytes)
188. [AMPS] IMD measurement scheme (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 24 Jul 1997 13:31:33 +0000; Try moving the lines over util the resistor and CT are centered over the coil. These text drawings sometimes don't work. CATV splitter are magic T's. Of course they won't handle the power and are the; /archives//html/Amps/1997-07/msg00203.html (8,382 bytes)
189. [AMPS] IMD measurement scheme (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 24 Jul 1997 13:31:33 +0000; To: <amps@contesting.com> Good to have someone who makes measurements on, instead of using over the air splatter reports....hi. With a class AB PA stage, such as in transceivers, and measuring the t; /archives//html/Amps/1997-07/msg00204.html (9,866 bytes)
190. [AMPS] Two tone combiner (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 24 Jul 1997 21:12:12 +0000; If anyone is going to build and use a combiner, of any type, be sure to test the transmitter ports for crosstalk before firing up. You want to be sure the combiner is constructed and terminated corre; /archives//html/Amps/1997-07/msg00207.html (7,057 bytes)
191. [AMPS] Re: 8877 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 25 Jul 1997 08:37:55 +0000; To: <amps@contesting.com> Of course youn forgot to mention when the tube is neutralized, the anode grid capacitance effectively goes to zero. Interesting you know the IMD level of amps from the 60's; /archives//html/Amps/1997-07/msg00209.html (10,044 bytes)
192. [AMPS] IMD measurement scheme (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 25 Jul 1997 08:37:55 +0000; To: <amps@contesting.com> That is what I observed on several radios. Another problem is the ALC overshoot. Bipolar transistors seem to have a certain amount of nearly constant level crossover distor; /archives//html/Amps/1997-07/msg00210.html (8,214 bytes)
193. [AMPS] Re: 8877 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sat, 26 Jul 1997 21:55:43 +0000; To: <amps@contesting.com> Rich, I have to question your motives. People ask for help, and you go on and on with home made non-sense. Take, for example, the poor guy who asked about an ALC system que; /archives//html/Amps/1997-07/msg00240.html (10,597 bytes)
194. [AMPS] Ameritron AL80B: Dynamic ALC? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sat, 26 Jul 1997 21:55:43 +0000; To: <amps@contesting.com> Hi Vince, How much improvement it really makes depends on the ALC response time of your rig, and how you run the rig. Here is what the circuit does. Instead of sampling RF v; /archives//html/Amps/1997-07/msg00241.html (9,520 bytes)
195. [AMPS] Re: 8877 (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Sun, 27 Jul 1997 12:53:17 +0000; To: <amps@contesting.com> Only Rich Measures is allowed to do that! 73, Tom W8JI -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-R; /archives//html/Amps/1997-07/msg00246.html (8,459 bytes)
196. [AMPS] Linear Amplifiers (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 28 Jul 1997 13:50:28 +0000; To: <amps@contesting.com> Not true, audio amplifiers can use any configuration. Most audio amplifiers are single ended, unless high power is needed. In that case they switch to AB class so the condu; /archives//html/Amps/1997-07/msg00261.html (10,315 bytes)
197. [AMPS] Viewstar PT-2000A Manual (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 28 Jul 1997 13:50:28 +0000; To: <amps@contesting.com> I suspect what you have is a case of the METER circuit being incorrect, and drifting. It is quite common for defective HV multiplier resistors to change value with temperat; /archives//html/Amps/1997-07/msg00262.html (8,364 bytes)
198. [AMPS] linear amplifiers (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 29 Jul 1997 08:51:13 +0000; To: <amps@contesting.com> Earlier you defined coherent as a waveform with the same period, and indicated if the period changed the RF PA wouldn't amplify the signal. A square wave can have a constan; /archives//html/Amps/1997-07/msg00271.html (9,165 bytes)
199. [AMPS] Linear Amplifiers (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 29 Jul 1997 08:51:13 +0000; To: <amps@contesting.com> Once again, just because you don't find something in a certain book or spec sheet, it does not mean it does not exist. You have a strange definition of period. Is the perio; /archives//html/Amps/1997-07/msg00272.html (10,026 bytes)
200. [AMPS] Two 4PR1000's or ? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 29 Jul 1997 08:51:13 +0000; To: <amps@contesting.com> Hi Dave, The gain of a grounded grid PA is greatly determined by the ratio of cathode impedance to anode impedance. I'm afraid there is no cathode driven (grounded grid) co; /archives//html/Amps/1997-07/msg00273.html (8,251 bytes)

Current List: 181 - 200
Page: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16]