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Baluns?
Cecil Moore wrote:
... Please prove that the "Holy Spirit" exists outside of the human mind. Remember, "Holy" and "Grain" both have the same name. Most likely come from the same lineage; they might even be brothers! Some ancient text from the bible I once read, if I remember correctly, said something akin to, " ... take a little wine for the spirit ..." Obviously a toast to one, or both, of those brothers! Regards, JS |
Baluns?
John Smith wrote:
What am I missing? Even if an omnipotent being is not omniscient, he is.:-) -- 73, Cecil http://www.w5dxp.com |
Baluns?
Cecil Moore wrote:
... Even if an omnipotent being is not omniscient, he is.:-) As soon as I "cement" what can happen in my mind, or the realm of possibilities, I also change what will happen ... How can I limit a God (aliens, etc.) I cannot even begin to fathom, indeed, how can anyone? Perhaps time is like an infinite building of rooms, the past is but a series of rooms in one direction from the "present room", the future an endless series of rooms stretching the other direction. And, perhaps God walks these rooms with the ease I do my own home ... I hate to even do this speculation, as I begin to place limits which may divert me away from envisioning other possibilities ... when we know more about time, we will finally be able to make far better guesstimates. When something is truly "unknown", it is truly unknown ... Regards, JS |
Baluns?
John Smith wrote:
When something is truly "unknown", it is truly unknown ... Unfortunately, with an omniscient God, the future is known and cannot be changed by your "free will". -- 73, Cecil http://www.w5dxp.com |
Baluns?
On Sep 1, 3:31*pm, Cecil Moore wrote:
wrote: A common mode choke is used in RF applications, very true, but it serves a filtering purpose, not a conversion of unbalanced to balanced energy transfer or vice versa. A common mode choke that operates well will turn unwanted RF into heat or cause it to dissipate in its core or a resistor etc.. The common "W2DU balun" works well as both choke and balun function. -- 73, Cecil *http://www.w5dxp.com Yes and I have to partially take back what I said; a balun CAN double as a CM "choke" and a CM choke can double as a balun. If one wishes to balance an unbalanced line with a CM choke, then the impedance of the CM choke must match the source and the load, which makes the CM choke a balun and no longer a choke :-) |
Baluns?
On Sep 1, 3:25*pm, Cecil Moore wrote:
wrote: I use an ugly balun with an attic GRrV and do not suffer significant back-RFI to my transceiver in the regular frequency ranges. I think that by chosing 1Kohm that may be a bit conservative. In (old) engineering school, we tended to use an order of magnitude (X10) as our highly arbitrary :) cut-off point for impedances that have a significant effect. You are doing that too but by using 1000 ohms, you are using (X10 times 2) as your arbitrary cutoff point. Since the filter is an exponential curve, if you chose 500 ohms instead of 1000 ohms, you might even get a 4 or 5 to 1 frequency range. In my case I use two different turns chokes so that is why I think I am covered pretty well. Your information is very interesting; good to see people are actually measuring things! Actually, 1000 ohms is pretty liberal. For instance, on 15m, the G5RV coax sees 36+j230 ohms or about 233 ohms. The balun needs to be 10x that value or 2330 ohms. -- 73, Cecil *http://www.w5dxp.com Why not 500 ohms, assuming a 50 ohm source and transmission line? |
Baluns?
Cecil Moore wrote:
John Smith wrote: When something is truly "unknown", it is truly unknown ... Unfortunately, with an omniscient God, the future is known and cannot be changed by your "free will". Well, we are now focused on the crux of the matter, alright. However, I see him/her/it/the-aliens only being able to view the after effects of my free will ... in my speculation(s) of how-this-all-works, of course. I see the mind of God as having similarities to my own (man created in Gods' image--it is most difficult for me to see it any other way.) He would not conduct an "experiment" in which he controlled all action; the reason? Too boring. The variable is my freewill which provides the seed-of-chaos, however, one piece of equipment in "his laboratory" allows him to view the final outcome(s), and ahead of me experiencing the same. But then, I have nothing to argue against the way you would envision it .... can we agree to wonder until some point in the future offers a proof worth extrapolating from? Or, in other words, the only horse I have in the race is curiosity of "the truth." Regards, JS |
Baluns?
wrote:
... Yes and I have to partially take back what I said; a balun CAN double as a CM "choke" and a CM choke can double as a balun. If one wishes to balance an unbalanced line with a CM choke, then the impedance of the CM choke must match the source and the load, which makes the CM choke a balun and no longer a choke :-) Although this URL: http://www.radioelectronicschool.net.../ocfdipole.pdf deals with a Windom Antenna, his text on the design, construction, function and implementation of baluns is well worth the read. Regards, JS |
Baluns?
"John Smith" wrote in message ... wrote: ... Yes and I have to partially take back what I said; a balun CAN double as a CM "choke" and a CM choke can double as a balun. If one wishes to balance an unbalanced line with a CM choke, then the impedance of the CM choke must match the source and the load, which makes the CM choke a balun and no longer a choke :-) Although this URL: http://www.radioelectronicschool.net.../ocfdipole.pdf deals with a Windom Antenna, his text on the design, construction, function and implementation of baluns is well worth the read. Regards, JS It's a trivial point, I agree, but there is one error in the url JS provided above that needs correcting. The VK author tells us that the Windom antenna was invented by Loren G. Windom. Tain't so. It was invented (developed) by William Everitt, then the Dean of the EE Dept at Ohio State U. Everitt was doing the grunt work and taking measurements along with another OSU professor. However. Loren Windom was a student of Everitt's, and was tagging along and observing. Then, later on he wrote up the experiment and had it published in QST sometime in 1929, and as well as I can remember, he failed to give Everitt any credit for having done the actual work. Consequently, readers of QST assumed it was Windom's invention, while it actually was not. Walt, W2DU |
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