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#191
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I have not followed the whole thread, but at the bottom line, the impact
of a complex Zo on power is an attenuation factor. It can be shown as follows. The general equations a Vf = [[(R+jwL)/(G+jwC)]^0.5]*If Vr = [[(R+1wL)/(G+jwC)]^0.5]*Ir. A numerical example for typical 50 ohm cable at 30 MHZ follows: Assume C = 30E-12 F/ft. Therefore L = 0.075E-6 H/ft [50 ohm lossless]. Assume 1/R [G] 1E-8 [100 megohms][lossy dielectric] Finally, assume R = 10 ohm [moderate rf resistance]. The resulting Zo for the assumed conditions is [[(10+jw7.5E-8)/(1E-8+jw30E-12)]^0.5] ohms. |Zo| = [[(10+j14.137)/(1E-8+j0.00565)]^0.5] = 55.360 ohms. Determine the relative phase shift as follows: atan[10+j14.137] = 54.7257 degrees. atan[1E-8+j0.00565] = 89.99989859 degrees [approximately 90]. The relative phase shift for the assumed complex Zo at 30 MHZ is 54.7257 - 89.99989 degrees [35.274 degrees]. Result: Zo = 55.360 ohms @ 35.274 degrees. Therefore Vf = If*[55.360 degrees] Therefore Pf(load) = Vf(source)*If(source)*cos(35.274) = 81.63% of maximum. The transmission line does not care if the signal is left to right or right to left; or forward and reflected. The effect is to introduce a mirror image to both the Vr and Ir terms. I hope I have not been redundant to other posts on this thread! Deacon Dave, W1MCE |
#192
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"Richard Clark" wrote in message ...
| | Hi Fellows, | | Such intense interest and no comments to SV7DMC for his work to this | matter? | Dear Mr. Richard Clark, Thank you very much for your kind interest! You have absolutely right. It's a pity indeed but unfortunately there are but very few comments for our point of view. However at least, all of them which are centered on the heard of the matter, I have a feeling that, are rather positive. I hope. Perhaps we have to put the blame on this damned language barrier. Who knows? Too much silence... Sincerely yours, pez SV7BAX P.S. Permit me please to correct you on that: It is not "his work" but "her work". |
#193
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Dear Mr. Richard Clark,
Here it is, once again! I do my best but it happens constantly. As I just told you for the Language Barrier, now it is "The heart of the matter", not "The heard of the matter". But I keep try... Sincerely yours, pez SV7BAX |
#194
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Dr. Slick wrote:
Cecil Moore wrote: Yes, the pair that satisfies the conservation of energy principle including source power and losses in the feedline. For instance, if a load is accepting 100 watts when the power reflection coefficient is 0.25, Pfwd(0.75) = 100W, so Pfwd = 133.33W, Pref = 33.33W. From Pozar: For a lossless 2-port network, [s11]**2 + [s21]**2 = 1 0.25 + 0.75 = 1 So hopefully this would be a lossless, passive network. Yes, the above is from an earlier lossless Z0-matched example. If any heat was generated in this passive network (NOT the load, the network itself), then the sum of the power reflection coefficient and the power transmission coefficient would be less than one. My example was the impedance discontinuity point between 50 ohm feedline and 150 ohm feedline. Not much room for losses in 0.1" of copper. -- 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! =----- |
#195
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On Mon, 8 Sep 2003 08:16:34 +0300, "pez" wrote:
P.S. Permit me please to correct you on that: It is not "his work" but "her work". Hi, I am at a loss for the equivalent to OM in your regard, and initials do mask you further. I should have been able to surmise this essential difference from your listing on Buckmaster. Another essential difference is that you performed the work that others simply meander around in the hopes of being mistaken as workers. Myself, I cannot task myself to publish complete derivations for two reasons. One, very few here are here to resolve anything but a sagging ego - hence the lack of standards in maintaining a progressive dialog. Two, I abide by a maxim that if one cannot express the key argument to the limited confines of one screen, then that argument lacks focus. I hope you do not take this as a diminution of your work, but more as a statement of stylistic variation. Keep up your effort, you are doing well. 73's Richard Clark, KB7QHC |
#196
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pez, your English is no barrier. It's better than many Americans posting
on this and other newsgroups. The "language" of the "language barrier" here is the language of mathematics. Some of the posters who have been the most verbal and insistent don't seem to able to deal with the math necessary to understand the concepts involved, so they're reduced to arguments which can't be mathematically demonstrated. Roy Lewallen, W7EL pez wrote: "Richard Clark" wrote in message ... | | Hi Fellows, | | Such intense interest and no comments to SV7DMC for his work to this | matter? | Dear Mr. Richard Clark, Thank you very much for your kind interest! You have absolutely right. It's a pity indeed but unfortunately there are but very few comments for our point of view. However at least, all of them which are centered on the heard of the matter, I have a feeling that, are rather positive. I hope. Perhaps we have to put the blame on this damned language barrier. Who knows? Too much silence... Sincerely yours, pez SV7BAX P.S. Permit me please to correct you on that: It is not "his work" but "her work". |
#197
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On Thu, 11 Sep 2003 12:13:44 +0300, "pez" wrote:
Dear Mr. Richard Clark, Thank you for the encouragement and your kind words. but I am not so sure that we deserve them (*). Hello, Your manners are superlative, and far better than my own manners (according to others, and that's fine as this is a characteristic of my aggressive style). Yes, you have absolute right about the initials, etc. But this became the motivation to discover, with a great deal of surprise I admit, that someone has given a bunch of inaccurate details to this site. We do not have something to hide You offer your call sign, that is far more unique than any signature that may be applied (like Dr. Slick). We have (as I am sure your part of the world does also) a history of pseudonyms or nom-de-plume for writers who wish to obscure their identity. I take care to write everything such that I can accept responsibility - or take responsibility. Many here do so too. Others do not, but in this day and age, anonymity is not guaranteed (again, taking the example of our same Dr. Slick) nor is it an affront if the writer commits to dialog and not simply slander or attack. Such occurrences of attack are rare here, and generally ignored. therefore we certainly do not belong to those with an extremely sensitive interest on private data. But I have to wonder: is there any responsibility by the site owner to guard the amateurs' personal data from anybody's will? Well, if by "site owner" you mean this newsgroup, then there is no "owner." There are nearly 40000 newsgroups that simply exist by nature of a combination of news-servers that are interconnected and sharing a protocol called NNTP. This protocol has been around since the beginning of the Internet (long before the WWW). It is like the public square where people meet to talk and listen and as in that square, if you are recognized, others will call you by name and perhaps comment about your ancestors. Such is privacy. Just as anything may be written here for free, anything written here has no intrinsic value. Value comes through association to the writer and that writer's continuity of thought and logic. You are already establishing a very good continuity and achieving a good association - to those who care! Finally, I do share your point of view for the length of a message and I try to keep them as short as possible but anyhow, take a look please on their rejection (*) in the related thread of our lengthy, indeed, derivations... do;^) Sincerely yours, pez SV7BAX Rejection is the forge of ideas. It does not condemn your work, it merely marks the critic by the nature of their criticism. If that criticism is weak, so is the critic. If that criticism is strong (not abuse, not refusal), then your argument is weak. Being technically and mathematically correct is not necessarily strength in an argument. You may be quite accurate, but the message is obscured by the bulk of presentation. A Canadian social scientist, Marshall McCluhan, demonstrated that identical material presented through different media become different messages. For instance, if you were to present you material to a class, they would accept it and work through it for understanding. If you were to present it to that same group of students in the public square, some might scoff, others might wander off with indifference. If you were to present it on TV, you probably wouldn't even make it to the first commercial. If you presented it on radio, you might have a highly interested audience. Same material, different venues, different responses. The same goes here. The nature of newsgroups is with dialog and hopefully you exchange correspondence with those who will allow you to develop your idea and stick with you to the end. If you attempt to make one presentation that answers all questions in one place, it violates a social contract that excludes them - except for them to accept or reject your work. They are not here to submit. This means you have to allow a style that is dialog in nature that allows their questions along the way to the end, where you do not find yourself wandering down the wrong path. (Think of the Socratic or Platonic methods of argument.) Unfortunately there are those who will manipulate discussion to the wrong path, or confusion. Dialog over time will reveal these individuals. This is why "lurking" is advised to newcomers so that they recognize personality with the signatures. One last point. Nothing is done once here. Nothing is solved. Nothing is fixed. The message will need repeating if only because new participants have not read the first message. The message may need repeating because you did not convince your critics, but they have had more time to ponder. This means that you sometimes have to vary your style and presentation so that repeating is not ignored. If you absolutely need the lengthy, mathematical treatment, then publish it at a web site and make a reference to it in your discussion. Offering the complete mathematical treatment each time you write here automatically limits you and reduces your audience. The craft of writing is knowing what to throw away. I generally discard 3/4ths of what I write before I hit the send button (some may groan not enough was thrown away here ;-) 73's Richard Clark, KB7QHC |
#198
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Dear Mr. Richard Clark,
What can I say? This is the fourth time, I have to call on my inadequate English to justify a misunderstanding. And this time it is related to the Buckmaster site mentioned by you and that's all. As for the rest three quarters of your message, I don't feel that I am in position to make any comment since they are looking to me as advises to successful advertisers. But, there is one point which, remarkably enough, is referenced by you in both of your letters and about the bottom line of them. It has to do with the matter of "maths" publication. Noticeably, you show about this matter a strong predilection to web site publication and a rejection of any inclusion into newsgroup messages. Although for the moment is seems that the right is on your side, at the same time, a recall to the need for direct communication surpasses any other argument. After all this is the deepest reason for newsgroups existence, I believe. Anyway. Thank you very much for your time. Sincerely yours, pez SV7BAX "Richard Clark" wrote in message ... | On Thu, 11 Sep 2003 12:13:44 +0300, "pez" wrote: | | Dear Mr. Richard Clark, | | Thank you for the encouragement and your kind words. | but I am not so sure that we deserve them (*). | | Hello, | | Your manners are superlative, and far better than my own manners | (according to others, and that's fine as this is a characteristic of | my aggressive style). | | Yes, you have absolute right about the initials, etc. | But this became the motivation | to discover, with a great deal of surprise I admit, | that someone has given a bunch | of inaccurate details to this site. | We do not have something to hide | | You offer your call sign, that is far more unique than any signature | that may be applied (like Dr. Slick). We have (as I am sure your part | of the world does also) a history of pseudonyms or nom-de-plume for | writers who wish to obscure their identity. I take care to write | everything such that I can accept responsibility - or take | responsibility. Many here do so too. Others do not, but in this day | and age, anonymity is not guaranteed (again, taking the example of our | same Dr. Slick) nor is it an affront if the writer commits to dialog | and not simply slander or attack. Such occurrences of attack are rare | here, and generally ignored. | | therefore we certainly do not belong to those | with an extremely sensitive interest | on private data. | But I have to wonder: | is there any responsibility | by the site owner | to guard the amateurs' personal data | from anybody's will? | | Well, if by "site owner" you mean this newsgroup, then there is no | "owner." There are nearly 40000 newsgroups that simply exist by | nature of a combination of news-servers that are interconnected and | sharing a protocol called NNTP. This protocol has been around since | the beginning of the Internet (long before the WWW). It is like the | public square where people meet to talk and listen and as in that | square, if you are recognized, others will call you by name and | perhaps comment about your ancestors. Such is privacy. | | Just as anything may be written here for free, anything written here | has no intrinsic value. Value comes through association to the writer | and that writer's continuity of thought and logic. | | You are already establishing a very good continuity and achieving a | good association - to those who care! | | Finally, | I do share your point of view for the length of a message | and I try to keep them as short as possible | but anyhow, | take a look please | on their rejection (*) | in the related thread | of our lengthy, indeed, derivations... | | do;^) | | Sincerely yours, | | pez | SV7BAX | | Rejection is the forge of ideas. It does not condemn your work, it | merely marks the critic by the nature of their criticism. If that | criticism is weak, so is the critic. If that criticism is strong (not | abuse, not refusal), then your argument is weak. Being technically | and mathematically correct is not necessarily strength in an argument. | You may be quite accurate, but the message is obscured by the bulk of | presentation. | | A Canadian social scientist, Marshall McCluhan, demonstrated that | identical material presented through different media become different | messages. For instance, if you were to present you material to a | class, they would accept it and work through it for understanding. If | you were to present it to that same group of students in the public | square, some might scoff, others might wander off with indifference. | If you were to present it on TV, you probably wouldn't even make it to | the first commercial. If you presented it on radio, you might have a | highly interested audience. Same material, different venues, | different responses. | | The same goes here. The nature of newsgroups is with dialog and | hopefully you exchange correspondence with those who will allow you to | develop your idea and stick with you to the end. If you attempt to | make one presentation that answers all questions in one place, it | violates a social contract that excludes them - except for them to | accept or reject your work. They are not here to submit. This means | you have to allow a style that is dialog in nature that allows their | questions along the way to the end, where you do not find yourself | wandering down the wrong path. (Think of the Socratic or Platonic | methods of argument.) Unfortunately there are those who will | manipulate discussion to the wrong path, or confusion. Dialog over | time will reveal these individuals. This is why "lurking" is advised | to newcomers so that they recognize personality with the signatures. | | One last point. Nothing is done once here. Nothing is solved. | Nothing is fixed. The message will need repeating if only because new | participants have not read the first message. The message may need | repeating because you did not convince your critics, but they have had | more time to ponder. This means that you sometimes have to vary your | style and presentation so that repeating is not ignored. If you | absolutely need the lengthy, mathematical treatment, then publish it | at a web site and make a reference to it in your discussion. Offering | the complete mathematical treatment each time you write here | automatically limits you and reduces your audience. The craft of | writing is knowing what to throw away. I generally discard 3/4ths of | what I write before I hit the send button (some may groan not enough | was thrown away here ;-) | | 73's | Richard Clark, KB7QHC |
#199
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On Fri, 12 Sep 2003 17:37:26 +0300, "pez" wrote:
And this time it is related to the Buckmaster site mentioned by you and that's all. Hello, Buckmaster makes available information that is already part of the public record. That is the point of licensing so that your activities are not shrouded in secrecy; but it also confirms you have certain rights to engage in activities others would not be allowed to do. This, of course, has nothing to do with posting to a newsgroup, but it was also your choice to declare your call sign which is related to the activities here, but it is not necessary to reveal to participate. 73's Richard Clark, KB7QHC |
#200
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On Fri, 12 Sep 2003 22:11:59 +0300, "pez" wrote:
Dear Mr. Richard Clark, Do you realize that, this site is unguarded and open to anyone who would like to modify your personal data, even if it is "only" for 48 hours at most, as it claims? That is the point. All of the rest are redundant. Sincerely yours, pez SV7BAX Hello, Well that is news, yes. Perhaps you should write them (Buckmaster) to suggest that they track the IP of the persons responsible for making those changes. This is a trivial, technical modification to their server software (I've written such software for Web servers - probably no more than 5 lines of code and a database call). Then ask them for that IP number so that you can register formal complaints against that individual. There are any number of simple and effective methods to prevent what you describe, nothing is technically difficult nor impossible. 48 Hours is not defensible with today's attention growing against identity theft. 73's Richard Clark, KB7QHC |
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