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#1
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Cecil, W5DXP wrote:
"I`m assuming that the "relative phase velocity" is the same thing as the VF of the coil." Back a couple of pages on 251, Kraus defines v/c as equal to "relative phase velocity of the wave propagating along the helical conductor, v being the phase velocity along the helical conductor and c being the velocity of light in free space." Repetition of "along the helical conductor" implies to me, thal like Terman, Kraus says the signal follows the actual wire, not sprinting across the coil as if it were a straight rod. Best regards, Richard Harrison, KB5WZI |
#2
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Richard Harrison wrote:
Repetition of "along the helical conductor" implies to me, thal like Terman, Kraus says the signal follows the actual wire, not sprinting across the coil as if it were a straight rod. Yes, I believe you are right about that. -- 73, Cecil, w5dxp.com |
#3
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![]() Richard Harrison wrote: Repetition of "along the helical conductor" implies to me, thal like Terman, Kraus says the signal follows the actual wire, not sprinting across the coil as if it were a straight rod. It seems to me there is more than just one way to use a wire to convey a signal. In fact it can be difficult to prevent a wire from using more than just one, especially when there are other wires nearby. 73, Jim AC6XG |
#4
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Jim Kelley wrote:
It seems to me there is more than just one way to use a wire to convey a signal. In fact it can be difficult to prevent a wire from using more than just one, especially when there are other wires nearby. Yep, I'm afraid that Kraus was wrong to a certain degree. Of course, he didn't have NEC in 1950. If we double Kraus' calculated relative phase velocity for loading coils, we will be closer to the results predicted by EZNEC. -- 73, Cecil http://www.w5dxp.com |
#5
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![]() Cecil Moore wrote: Yep, I'm afraid that Kraus was wrong to a certain degree. Ordinarily I'd be inclined to call it the other way to be honest, Cecil. What equations are you using for both cases? Perhaps you wouldn't mind showing your work. 73, Jim AC6XG |
#6
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Jim Kelley wrote:
Ordinarily I'd be inclined to call it the other way to be honest, Cecil. What equations are you using for both cases? Perhaps you wouldn't mind showing your work. I have explained it multiple times before, Jim, over the past few years. Please forgive me for getting tired of explaining the basics of physics to people with less than average IQs. Maybe I will be in a better mood tomorrow. -- 73, Cecil http://www.w5dxp.com |
#7
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Jim Kelley wrote:
Perhaps you wouldn't mind showing your work. I have added some new material to my web page concerning this subject. http://www.w5dxp.com/current2.htm -- 73, Cecil http://www.w5dxp.com |
#8
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On May 11, 6:33 am, Cecil Moore wrote:
Jim Kelley wrote: Perhaps you wouldn't mind showing your work. I have added some new material to my web page concerning this subject. http://www.w5dxp.com/current2.htm -- 73, Cecil http://www.w5dxp.com You'll forgive me if I'm not in a mood to be generous. You might consider adding some ordinates to your phase plots. Also, some credit to Roy for making all of the calculations for you might be appropriate as well. (You might ask him how he does it.) We still haven't seen any of your work. By work I mean calculations, not typing i.e. assumptions, deductions, inferences, and proclamations. Assuming there are actual values, it would be good to know, for example, what calculations were made in order to arrive at the phase angles in the plots. The only equations you provide are for instantaneous amplitude as a function of phase angle for a standing wave. Obviously that isn't suffiencient for obtaining the data in your plots. It's very poorly done. D+ ac6xg |
#9
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Jim Kelley wrote:
You'll forgive me if I'm not in a mood to be generous. You might consider adding some ordinates to your phase plots. Here's the definition of "ordinate": "The y-coordinate on an (x,y) graph" I'm not sure what you are asking for. The graphs were generated by Excel. What exactly are you saying? Do you want me to add the dots for the data points? Also, some credit to Roy for making all of the calculations for you might be appropriate as well. (You might ask him how he does it.) How he interfaces to NEC? I'm not sure what you are asking for. EZNEC is a great piece of software but the calculating engine is NEC. I doubt that even Roy knows the NEC equations. We still haven't seen any of your work. By work I mean calculations, not typing i.e. assumptions, deductions, inferences, and proclamations. Assuming there are actual values, it would be good to know, for example, what calculations were made in order to arrive at the phase angles in the plots. I don't know what "work" you are asking for. All I did was run EZNEC simulations and report the results. The phase angles are calculated and reported by the NEC calculating engine. I don't know what equations they use, but probably the method of moments equations. I believe Balanis has a chapter on MOM equations. The only equations you provide are for instantaneous amplitude as a function of phase angle for a standing wave. Obviously that isn't suffiencient for obtaining the data in your plots. It's very poorly done. D+ All the data is directly from EZNEC, Jim. Download coil505.EZ and run it yourself. It is NEC that is doing the calculations. The data reported by EZNEC was entered into coil505.xls and Excel produced the graphs. Your objections seem really strange and petty. -- 73, Cecil, w5dxp.com |
#10
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Jim Kelley wrote:
You'll forgive me if I'm not in a mood to be generous. You might consider adding some ordinates to your phase plots. Also, some credit to Roy for making all of the calculations for you might be appropriate as well. (You might ask him how he does it.) We still haven't seen any of your work. By work I mean calculations, not typing i.e. assumptions, deductions, inferences, and proclamations. Assuming there are actual values, it would be good to know, for example, what calculations were made in order to arrive at the phase angles in the plots. The only equations you provide are for instantaneous amplitude as a function of phase angle for a standing wave. Obviously that isn't suffiencient for obtaining the data in your plots. It's very poorly done. D+ EZNEC uses NEC-2 for calculations and produces results essentially identical to those from NEC-2. The method is well documented in the NEC-2 manual, available on the web. Like NEC-2, EZNEC reports the magnitude and phase of current at each segment of the model. It calculates these from fundamental electromagnetic principles. No attempt is made by NEC-2 or EZNEC to consider the antenna as a transmission line or calculate any supposed traveling waves. Decomposition of the verifiable NEC/EZNEC results into traveling waves or anything else is strictly Cecil's doing, and any conclusions he reaches from it are also his only. Roy Lewallen, W7EL |
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