Quote from: DrBagelBites on 06/29/2015 03:10 amQuote from: rfmwguy on 06/29/2015 03:04 amHow to waste precious time on the build - spent 4hrs trying to get the cheap 100mw exciter to fire up...junk from china without an online manual. Its not the ten bucks, its the time wasted. Moral of story, get a well documented board or module. Forget troubleshooting, surface mount components, electronics hardware is throw away stuff now, which I just did Sorry to hear that, rfmwguy.I'm awaiting to see if I will soon be in the same boat with the stuff I ordered as well.I don't know when I'll learn that you can't afford to go cheap. Funny thing is the cheapest module caused the problem. No big deal, 2.4ghz stuff is in every store and easy to obtain which is a big plus. Let u know what I substitute in there...probably a teardown of a wifi cam. Most all are 100mw.
Quote from: rfmwguy on 06/29/2015 03:04 amHow to waste precious time on the build - spent 4hrs trying to get the cheap 100mw exciter to fire up...junk from china without an online manual. Its not the ten bucks, its the time wasted. Moral of story, get a well documented board or module. Forget troubleshooting, surface mount components, electronics hardware is throw away stuff now, which I just did Sorry to hear that, rfmwguy.I'm awaiting to see if I will soon be in the same boat with the stuff I ordered as well.I don't know when I'll learn that you can't afford to go cheap.
How to waste precious time on the build - spent 4hrs trying to get the cheap 100mw exciter to fire up...junk from china without an online manual. Its not the ten bucks, its the time wasted. Moral of story, get a well documented board or module. Forget troubleshooting, surface mount components, electronics hardware is throw away stuff now, which I just did
I know how you feel, but I just found out that the surface resistance of copper at 2.4GHz is supposedly,RS = 0.013 Ohms. From this, you can get the power losses as the integral over the internal surface area,P_loss = ∮S(RS*|H|2)*dS, Basically Ohm's law.That's a pretty high resistance, so a 100mW source will hardly overcome the copper losses. Based on the heating reported, the losses are in the "watts" range at high Q. I'm sure you will need a stronger source. Todd
Those pointing up Shawyer's outlay as compared to those attempting to replicate his experiments might want to note this: Shawyer did it first.In many areas of research, there is definitely a first-mover disadvantage. It's the first person on the path that chases down blind alleys, deals with cobbled together instrumentation, and makes do with custom-machined components. All of these things tend to be much simpler for those who come after. The availability of high-quality measurement devices in consumer-grade equipment has also greatly affected costs over the last few years. I've seen people expend many millions hardwiring experimental gear, that just a few years later could be bettered with an iPad and off the shelf components. All this is just to say—everyone is now trying to reproduce what appears to be Shawyer's best design. I doubt we have the full catalog of his failures.
And what the heck, just stack them all up at once.
...We need NUMBERS to quantify this, there is no other way around it. Without numbers one cannot compare.At least now we have everything scaled to the same Max Min numbers, unfortunately we don't know the numbers.Can you tell aero how to output NUMBERS in Meep?
Quote from: VAXHeadroom on 06/29/2015 03:50 amAnd what the heck, just stack them all up at once. Wow, that's almost too much at once! I needed to stare at it for the longest time to see patterns of relationships. Nice work. Thanks!Shell
I just read Mr. Traveller claim on reddit that the vibration increase the thrust of the EmDrive. May I ask you folks if there was already a debate about it here? I would be glad to read about it bit more. Did anybody here tried to increase the vibration in order to increase thrust? I would be glad to check that as well .Quote:Vibration is everywhere.Vibratory movement causing small end to big end movement will be opposed by the EMDrive.Vobratory movement causing Big end to small end movement will be supported by the EMDrive.Please understand what Roger Shawyer has said:"A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.UK flight thruster measurements employ this principle to calibrate the background noise on the force balance prior to carrying out force measurements."So eliminate all external forces and you have NO THRUST.Just maybe EagleWorks did too good a job in the elimination of vibration. GOOD for their Warp Field work but BAD for their EMDrive tests.Link is here. The claim is in lower half of the thread.https://www.reddit.com/r/EmDrive/comments/3ah1ta/using_thetravellers_excel_emdrive_calculator/Thank you
Quote from: SeeShells on 06/29/2015 06:09 amQuote from: VAXHeadroom on 06/29/2015 03:50 amAnd what the heck, just stack them all up at once. Wow, that's almost too much at once! I needed to stare at it for the longest time to see patterns of relationships. Nice work. Thanks!ShellIf you can see/think another useful way to try to visualize these I'll see what I can do! I don't understand really what I'm looking at, just processing the pictures Are these different cross sections (I think they are)? I could build a semi-transparent 3d animated cross section (I think I can anyway!)...
I think the traveller will like this article when he feels better:Direct determination of the resonance properties of metallic conical nanoantennashttp://www.researchgate.net/profile/Carlo_Liberale/publication/260040081_Direct_determination_of_the_resonance_properties_of_metallic_conical_nanoantennas/links/5476ccbd0cf2778985b08312.pdf"A cone can be envisioned as a continuous sequence of coaxial cylinders with decreasing radii. Under the localmode concept, valid for slowly varying structures [21], within local domains the plasmonic cylinder modes aregood approximations to the solutions of the Maxwell’s equations."
Quote from: Chrochne on 06/29/2015 09:12 amI just read Mr. Traveller claim on reddit that the vibration increase the thrust of the EmDrive. May I ask you folks if there was already a debate about it here? I would be glad to read about it bit more. Did anybody here tried to increase the vibration in order to increase thrust? I would be glad to check that as well .Quote:Vibration is everywhere.Vibratory movement causing small end to big end movement will be opposed by the EMDrive.Vobratory movement causing Big end to small end movement will be supported by the EMDrive.Please understand what Roger Shawyer has said:"A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.UK flight thruster measurements employ this principle to calibrate the background noise on the force balance prior to carrying out force measurements."So eliminate all external forces and you have NO THRUST.Just maybe EagleWorks did too good a job in the elimination of vibration. GOOD for their Warp Field work but BAD for their EMDrive tests.Link is here. The claim is in lower half of the thread.https://www.reddit.com/r/EmDrive/comments/3ah1ta/using_thetravellers_excel_emdrive_calculator/Thank you A claim is made based solely on what supposedly Shawyer said.The magnitude and frequency of the vibration that facilitates the measurement of the EM Drive is never addressed.Is the EM Drive an equal opportunity friend of all magnitudes and frequencies of vibration? This is implied, but it leads to absurd nonsense: is nanometer amplitude vibration enough ? How about picometer amplitude vibration? At what level the boundary between vibration in continuum mechanics and quantum mechanics uncertainty is breached ?How about frequency? Is 100 Hz sufficient? How about 0.0000000001 Hz? How about 10^100 Hz?What is noteworthy is that Shawyer is quoted as " in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured" which, if anything, shows that even Shawyer measures no force from the EM Drive when "background forces" are reduced to an unspecified level (for sure Shawyer does not have the ability to have measured picoNewton forces).The statement is self-contradictory with TT's statement that "Vibration is everywhere." Yes, vibration, at all kinds of magnitudes is present everywhere, so how was Shawyer then able to measure no force from the EM Drive when "background forces" where reduced to an unspecified level? Vibrations did not dissappear.This is the kind of unspecified, unscientific nonsense that makes scientists and engineers to cringe in disbelief.If anything, the statement " in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured"means that either the EM Drive is an experimental artifact or if it involves something that can be used for Space Propulsion, Roger Shawyer does not understand what physics are behind it, he doesn't understand how to engineer its development and most clearly he is not able to explain it in scientific and engineering language.Statements like this serve to explain the controversy surrounding the EM Drive, and why it has made so little progress (despite the extravagant claims) in the 27 years (almost 3 decades) since Shawyer's 1988 patent application. A scientific approach is needed instead. Hopefully we will hear more news from NASA soon or get independent experimental data from well-constructed tests from the people in this thread.
Quote from: Rodal on 06/29/2015 12:01 am... I estimate (but I maybe wrong) that TM114's frequency is 0.8% higher than TE013, TE114 is 3.9% higher frequency, TM212 is 6.5% lower and TE213 is 9.2% lower. frequency. Using those estimates, Meep should have picked up TM114 (except I was exciting TE modes) and maybe TE114. Probably not TM212 or TE213. I guess we'll see in the fields, if someone can get some numbers somehow....
... I estimate (but I maybe wrong) that TM114's frequency is 0.8% higher than TE013, TE114 is 3.9% higher frequency, TM212 is 6.5% lower and TE213 is 9.2% lower. frequency.
Quote from: rfmwguy on 06/29/2015 03:28 amQuote from: DrBagelBites on 06/29/2015 03:10 amQuote from: rfmwguy on 06/29/2015 03:04 am...Sorry to hear that, rfmwguy.I'm awaiting to see if I will soon be in the same boat with the stuff I ordered as well.I don't know when I'll learn that you can't afford to go cheap. Funny thing is the cheapest module caused the problem. No big deal, 2.4ghz stuff is in every store and easy to obtain which is a big plus. Let u know what I substitute in there...probably a teardown of a wifi cam. Most all are 100mw.I know how you feel, but I just found out that the surface resistance of copper at 2.4GHz is supposedly,RS = 0.013 Ohms. From this, you can get the power losses as the integral over the internal surface area,P_loss = ∮S(RS*|H|2)*dS, Basically Ohm's law.That's a pretty high resistance, so a 100mW source will hardly overcome the copper losses. Based on the heating reported, the losses are in the "watts" range at high Q. I'm sure you will need a stronger source. Todd
Quote from: DrBagelBites on 06/29/2015 03:10 amQuote from: rfmwguy on 06/29/2015 03:04 am...Sorry to hear that, rfmwguy.I'm awaiting to see if I will soon be in the same boat with the stuff I ordered as well.I don't know when I'll learn that you can't afford to go cheap. Funny thing is the cheapest module caused the problem. No big deal, 2.4ghz stuff is in every store and easy to obtain which is a big plus. Let u know what I substitute in there...probably a teardown of a wifi cam. Most all are 100mw.
Quote from: rfmwguy on 06/29/2015 03:04 am...Sorry to hear that, rfmwguy.I'm awaiting to see if I will soon be in the same boat with the stuff I ordered as well.I don't know when I'll learn that you can't afford to go cheap.
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