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#161
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On Wed, 26 May 2004 00:05:40 GMT, "Henry Kolesnik"
wrote: I used 450 ohm ladder line and a balun along with a cheap SWR meter. Hi Hank, Classic! Thanx. 73's Richard Clark, KB7QHC |
#162
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On Tue, 25 May 2004 19:01:31 -0500, Tom Ring
wrote: Boy, I'm gonna have to try and find my old EE5xx Non-Linear Transistor Design notebook. I doubt I could translate it into words for this section of the thread, but it is incredibly applicable. Hi Tom, It's not that difficult. Edison corrupted the Thevenin model demanding that there be a RESISTANCE equal to the load to accomplish this equivalency (a case of being overly literal for a market advantage). The Thevenin model only requires an IMPEDANCE, hence these allusions to 50% maximum efficiency (an imposed condition much like debate here) were an invention by Edison to detract investment away from AC power transmission and attract it back to his DC dynamos. The real pro's new how to dance with numbers and concepts too. This resolves how the common Ham rig can present 50 Ohms Impedance and still offer more than 50% efficiency - although, a simple examination of the power in vs. the power out reveals it isn't nearly as good as 50% for ANY mode. Such is the gulf between reality and theory - some folk's mileage may vary. ;-) 73's Richard Clark, KB7QHC |
#163
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Richard Clark wrote:
Hi Tom, It's not that difficult. Edison corrupted the Thevenin model demanding that there be a RESISTANCE equal to the load to accomplish this equivalency (a case of being overly literal for a market advantage). The Thevenin model only requires an IMPEDANCE, hence these allusions to 50% maximum efficiency (an imposed condition much like debate here) were an invention by Edison to detract investment away from AC power transmission and attract it back to his DC dynamos. The real pro's new how to dance with numbers and concepts too. This resolves how the common Ham rig can present 50 Ohms Impedance and still offer more than 50% efficiency - although, a simple examination of the power in vs. the power out reveals it isn't nearly as good as 50% for ANY mode. Such is the gulf between reality and theory - some folk's mileage may vary. ;-) 73's Richard Clark, KB7QHC Understood. I still want to find it. Been about 30 years since I wrote it all down in 4 colors. I took serious notes. tom K0TAR |
#164
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Jim Kelley wrote:
Electromagnetic waves can cancel, but rocks can't. However, two EM waves have to exist before they can cancel. If they exist, they posses both energy and momentum. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#165
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This is absolutely the best thread I've seen in years. It's
educational, thought provoking, entertaining, and revealing about the human psyche. The thread reminds of some of those that I monitor from time to time regarding aeronautics and fluid dynamics on the topic of how an airplane wing generates lift. Believe or not, there is still no consensus after 100+ years. It's interesting in that it parallels this thread in many ways -- attempting to interpret various abstract mathmatical definitions of a physical process in a way that it "makes sense." We're fortunate in that such things don't actually have to make sense to work. Al |
#166
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On Tue, 25 May 2004 19:43:42 GMT, "Henry Kolesnik"
wrote: They continued to work well and I always thought this was from overdriving but now I'm not so sure because it ran at the same high swr as the 30S-1. Hi Hank, I gave this some more thought from my Collins period. If I recall, overdriving an amplifier brings damage to the grid, which has its own dissipation limit. The usual failure mode is that it melts or sags and causes a grid-cathode short. This is especially true in lighthouse style tubes. 73's Richard Clark, KB7QHC |
#167
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Richard Clark wrote:
"The Thevenin model only requires an IMPEDANCE." Yes, but "To secure maximum power output from a generator whose emf and whose internal impedance are constant, the load must have an impedance equal to the conjugate of the generator`s internal impedance." (page 43, "Transmission Lines, Antennas, and Wave Guides", King, Mimno, and Wing) Best regards, Richard Harrison, KB5WZI |
#168
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![]() "Richard Clark" wrote in message ... On Mon, 24 May 2004 13:19:41 -0500, Cecil Moore wrote: Well Richard, here's your chance. Please enlighten us on J.C. What was the original question? [accredited stock response] It's clear that R.C. loves tweeking Cecil. Steve |
#169
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![]() "Dave Shrader" wrote in message news ![]() Cecil Moore wrote: snip For what it is worth, I believe that the first homo sapien originated about a quarter of a million years ago and was a female with dominant genes. -- 73, Cecil http://www.qsl.net/w5dxp My wife has me convinced that ALL women have the dominant genes!!!! Deacon Dave There's a guy claiming that the male gene (is it the X?) will dissapear in several hundred years because it is on the decline now... Steve |
#170
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![]() "Tdonaly" wrote in message ... Richard Clark wrote, On Mon, 24 May 2004 15:28:40 -0500, Cecil Moore wrote: I am sure that our solar system and homo sapiens didn't exist when the original question was asked. So the question is which came first, the homo or the solar system? Homos before Helios, or Helios before homos? That's a profound question which I'll have to think about over my after-dinner port. On the surface it looks about as meaningful as "turkeys from Turlock," but first impressions are sometimes deceiving. 73, Tom Donaly, KA6RUH Hey! I know it HAD to be a PREGNANT Chicken that came first... |
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