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Total 562 documents matching your query.

201. Re: [Amps] Electron HOLE flow (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 03:54:29 -0400
On 8/28/2013 2:59 AM, jim.linda@roadrunner.com wrote: When I first went to school to study electronics they taught the theory called Hole Flow. Lets start with the idea that there may be more than on
/archives//html/Amps/2013-08/msg00141.html (8,327 bytes)

202. Re: [Amps] AL-1200 and RTTY - JUST A SIMPLE ANSWER PLEASE! (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 12:26:54 -0400
On 8/28/2013 8:30 AM, David Jordan wrote: ... and doesn't running the legal limit in RTTY mode defeat the purpose of the mode, which is that with RTTY you can work the world with as little as 100 wat
/archives//html/Amps/2013-08/msg00153.html (9,396 bytes)

203. Re: [Amps] Hole Flow (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 16:48:48 -0400
On 8/28/2013 1:20 PM, Fuqua, Bill L wrote: Holes can not be used to explain the physics behind operation of vacuum tubes. As an example you have to some how make a hot filament a absorber of holes an
/archives//html/Amps/2013-08/msg00163.html (7,751 bytes)

204. Re: [Amps] Electron HOLE flow (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 17:56:07 -0400
On 8/28/2013 2:05 PM, Mike Waters wrote: Absolutely it is an illusion. IIRC, that was erroneously introduced into textbooks around 1970 the same time as the "electricity flows from positive to negati
/archives//html/Amps/2013-08/msg00164.html (9,556 bytes)

205. Re: [Amps] Electron HOLE flow (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 18:06:09 -0400
Scroggie's 1960 book "Principles of Semiconductors" talks of 'holes', and the idea was old then. I always found it confusing, especially when we got into majority and minority conductors in transisto
/archives//html/Amps/2013-08/msg00165.html (11,538 bytes)

206. Re: [Amps] Electron HOLE flow (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 28 Aug 2013 20:04:03 -0400
On 8/28/2013 6:36 PM, Fuqua, Bill L wrote: In a workshop I teach, I explain to young students how current flows thru conductors. I put them all in a circle and insert myself into the circle. Then I t
/archives//html/Amps/2013-08/msg00169.html (13,240 bytes)

207. Re: [Amps] New air system socket for 8877 needed (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 30 Aug 2013 14:49:32 -0400
On 8/30/2013 1:55 PM, John Farber wrote: I'm looking for an air system ceramic socket for an 8877 as part of my cleanup redesign of HB 6 m HF amp conversion project that is nearing completion. If you
/archives//html/Amps/2013-08/msg00185.html (8,680 bytes)

208. Re: [Amps] Quiet from Amps lately (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Tue, 10 Sep 2013 16:56:40 -0400
I don't know what's changed, but most of the stuff coming from contesting.com and Yahoo groups is ending up in the trash even though I have rules to copy them to specific folders.. 73 Roger (K8RI) __
/archives//html/Amps/2013-09/msg00014.html (7,772 bytes)

209. Re: [Amps] Future of RF AMPS (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Tue, 10 Sep 2013 23:35:53 -0400
Larry, the RF power MOSFETS to which I refer here are the VRF2933 devices from Microsemi. Sometimes one can find surplus and NOS ST Micro SD2933 FETS on eBay at low prices. I've worked with semicondu
/archives//html/Amps/2013-09/msg00029.html (10,111 bytes)

210. Re: [Amps] design approach for QRO solid state (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Thu, 12 Sep 2013 08:41:50 -0400
This may not be germane to the building of the amplifier and it is by necessity an over simplification, but it is the temperature problem explanation for those not familiar to transistor failure and
/archives//html/Amps/2013-09/msg00067.html (15,920 bytes)

211. Re: [Amps] S/S Amp's (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Thu, 12 Sep 2013 20:14:54 -0400
There are many valid reasons for that. We tune to make the audio sound normal. For me, if a station adjusts their audio to add 200 Hz on the low side, I will tune almost exactly 200 Hz high. Two time
/archives//html/Amps/2013-09/msg00096.html (11,066 bytes)

212. Re: [Amps] S/S Amp's (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 13 Sep 2013 02:12:17 -0400
Modify the BFO for variable injection level and connect to the last IF thereby maintaining AGC. Its almost as good as a sync detector for selective fading and its easier to follow a slightly drifting
/archives//html/Amps/2013-09/msg00102.html (9,307 bytes)

213. Re: [Amps] Workshop Danger (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 13 Sep 2013 15:52:13 -0400
I have a machine shop. ALL machine tools are dangerous. The less knowledgeable and experienced the operator, the more dangerous. However, because of its characteristics, I would rate the fly cutter a
/archives//html/Amps/2013-09/msg00137.html (12,768 bytes)

214. Re: [Amps] Making holes for amps (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 13 Sep 2013 15:59:30 -0400
I had an old Sears X-Y drill press attachment and made a small fixture to hold a Dremel tool which held a 1/8" milling bit. I then placed this on the surface of the area that needed to be slotted and
/archives//html/Amps/2013-09/msg00138.html (10,313 bytes)

215. Re: [Amps] Workshop Danger (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 13 Sep 2013 20:13:59 -0400
OTOH the lowly drill press is really danger in disguise. When drilling steel or Aluminum that long curl of metal that indicates a sharp bit doing its job will happily remove a finger(s) just by tryi
/archives//html/Amps/2013-09/msg00151.html (14,161 bytes)

216. Re: [Amps] Workshop Danger (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Sat, 14 Sep 2013 04:22:06 -0400
I like your point of view! What do you use grinding wheels for, when they are worn down almost to the hub? I have quite a few of them, and I hate throwing them away...! And the last two centimeters o
/archives//html/Amps/2013-09/msg00157.html (12,432 bytes)

217. Re: [Amps] Future of RF AMPS (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Mon, 16 Sep 2013 18:18:10 -0400
I have to believe that M2 knows what they are doing with these Amps. They offer a 12 month limited warranty on them. So where do I find out about this amp. I never heard of M12. Force 12 and M^2, bu
/archives//html/Amps/2013-09/msg00204.html (8,468 bytes)

218. Re: [Amps] Re Direct rectification of AC mains to derive the amp, VDD, supply (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 18 Sep 2013 17:50:52 -0400
I think that the reluctance of some people to accept line-connected electronics stems only from gut feeling, and not from a cool-headed analysis of the advantages and disadvantages. My reluctance co
/archives//html/Amps/2013-09/msg00221.html (9,346 bytes)

219. Re: [Amps] Direct rectification of AC mains to derive the amp, VDD, supply (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Thu, 19 Sep 2013 15:14:54 -0400
the near electrocution you describe was due to several concurrent problems: The short circuit due to a poor solder job, lack of a ground I know what contributed to the problem, but much of the techno
/archives//html/Amps/2013-09/msg00247.html (11,055 bytes)

220. Re: [Amps] Direct rectification of AC mains to derive the amp, VDD, supply (score: 1)
Author: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Fri, 20 Sep 2013 03:13:30 -0400
I saw one of those demonstrated. The rep actually used two fingers to short 240 to ground. He said it's so quick he didn't even feel it. I'm not quite that trusting, but that's like the elrctronic b
/archives//html/Amps/2013-09/msg00261.html (12,139 bytes)

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