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Trying to find out what Ferrite material this is.
Jim Kelley wrote:
It's ridiculous to assert that someone "thinks EM waves can't be reflected" based on the fact that they might happen to take issue with one or more of your speculations on the laundry list shown above. You obviously have not been following the arguments. -- 73, Cecil http://www.w5dxp.com |
Trying to find out what Ferrite material this is.
Cecil Moore wrote:
Jim Kelley wrote: It's ridiculous to assert that someone "thinks EM waves can't be reflected" based on the fact that they might happen to take issue with one or more of your speculations on the laundry list shown above. You obviously have not been following the arguments. Neither have you, Cecil. 73, Tom Donaly, KA6RUH |
Trying to find out what Ferrite material this is.
Tom Donaly wrote:
Cecil Moore wrote: You obviously have not been following the arguments. Neither have you, Cecil. Tom, please inquire about reflected energy just "sloshing" around rather than traveling end to end at a VF(c) speed. -- 73, Cecil, w5dxp.com |
Trying to find out what Ferrite material this is.
On Jun 5, 11:40 am, Cecil Moore wrote:
On Jun 4, 5:39 pm, "Tom Donaly" wrote: Maybe you'll tell me who you think thinks waves of any sort can't be reflected. I haven't run into anyone who thinks EM waves can't be reflected, refracted, etc. Maybe there's a misunderstanding somewhere. I don't want to get personal but if you have followed the reflected wave arguments, you know who they are. Some simple true/false questions will highlight the argument. 1. Do reflected EM waves actually exist in reality? 2. Is the reflected EM wave a traveling wave? 3. Does a reflected EM wave obey the rules for traveling waves? 4. Do reflected EM waves contain ExB joules/second? 5. Do reflected EM waves have any effect on forward waves in a constant Z0 environment? 6. Do standing EM waves superceed and obsolete the component traveling waves? 7. Does reflected EM energy violate the laws of physics by standing still within the standing wave? 8. Does reflected EM energy violate the laws of physics by just "sloshing" around? 9. Does reflected EM energy travel in the reverse direction at VF(c) until it encounters an impedance discontinuity? 10. Is it valid to consider the forward EM traveling wave and the reflected EM traveling wave separately and then superpose the resulting fields (voltages, currents)? 11. Are the decades-old EM wave intensity equations from the field of optics valid for an RF EM wave analysis? 12. Can standing wave current be used to determine the delay through a 75m mobile loading coil? 13. Is the current "drop" through that loading coil just an illusion caused by superposition of forward and reflected currents? 14. Would the delay be different if only a forward traveling wave was used for measurement purposes? -- 73, Cecil, w5dxp.com An excellent list of questions, but you left out a few: 15. Can superposition be used in the analysis of linear time invariant circuits? 16. Does P equal E times I? 17. Can source (or output) impedance be used to compute the reflection occuring at the generator? 18. Does a directional wattmeter MEASURE power? 19. Do reflections occur at places other than physical impedance discontinuities? ....Keith |
Trying to find out what Ferrite material this is.
Owen Duffy wrote in
: Owen Duffy wrote in : ... Search Jaycar's site for a LO1238. If that is what you have, you could ask them for data. I should have added that I think it is similar to the L8 material described in their data sheets. I have a vague recollection of measuring the inductance of a winding on the material, and I think the ui was around 1500 which suggests it is low loss up to a few hundred kHz, perhaps to 1MHz or so. I am back at home and dug out my measurments for LO1238. I make ui around 1100 at 10kHz (Al ~145nH), so it is a little lower than the L8 material, probably goes to slighly higher frequency before loss sets in. Owen |
Trying to find out what Ferrite material this is.
On Saturday, June 2, 2007 at 1:54:28 AM UTC+10, wrote:
I came across two ferrite toroids with the measurements of 35mm diameter, the hole in the middle is 21mm and it is 13mm thick. On the packet it says that the ferrite material is L15. Does anybody know if L15 is equivalent to 43 or 61 ferrite material? I have searched the net but have been unable to find any information. Any information would be appreciated. Cheers. Owen was was right saying 259 can't measure inductors with impedance over j500, say j4788. With small VNA you get accurate scan over entire HF. Roy seems to be using 259 for everything, including making pizzas. I know only one way for 259 to be accurate with high impedance inductor. Add capacitor and 50 ohms in series with inductor, and 259 becomes very accurate around resonant frequency. I doubt there is another way to do it properly. Tino VK3EGN |
Trying to find out what Ferrite material this is.
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Trying to find out what Ferrite material this is.
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