Quote from: Rodal on 08/01/2015 04:50 PMThe difference between the two geometries is completely negligible compared to the difference between the geometry in the EM Drive wikiCompared to the geometry in the EM Drive wiki, the two drawings you show line up excellent !Could you please superpose the geometry of the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results ), which has a cone half angle of 6 degrees to make that clear ?If you do that you will see how utterly different is the geometry in the EM Drive wiki for Yang, and that the estimate in the EM Drive Wiki is unreasonable.Blue outline is the Wiki version of Yang...As you said... it's way off..Could it be that the composite shape of a cylinder and frustum, like we see in the more "technical" drawing, altered the data in such a way that reverse calculation gives a length value that is way off?

The difference between the two geometries is completely negligible compared to the difference between the geometry in the EM Drive wikiCompared to the geometry in the EM Drive wiki, the two drawings you show line up excellent !Could you please superpose the geometry of the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results ), which has a cone half angle of 6 degrees to make that clear ?If you do that you will see how utterly different is the geometry in the EM Drive wiki for Yang, and that the estimate in the EM Drive Wiki is unreasonable.

Quote from: Flyby on 08/01/2015 05:07 PMQuote from: Rodal on 08/01/2015 04:50 PMThe difference between the two geometries is completely negligible compared to the difference between the geometry in the EM Drive wikiCompared to the geometry in the EM Drive wiki, the two drawings you show line up excellent !Could you please superpose the geometry of the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results ), which has a cone half angle of 6 degrees to make that clear ?If you do that you will see how utterly different is the geometry in the EM Drive wiki for Yang, and that the estimate in the EM Drive Wiki is unreasonable.Blue outline is the Wiki version of Yang...As you said... it's way off..Could it be that the composite shape of a cylinder and frustum, like we see in the more "technical" drawing, altered the data in such a way that reverse calculation gives a value that is way off?No. I am the one and only one person that came up with the dimensions that are in the Wiki EM Drive wiki. I know how I came up with those dimensions. Either my interpretation of the tables or something else in her paper is off or she has a mistake in her paper. Something is OFF by a huge amount.There is NO basis on which to pretend that the dimensions in the EM Drive wiki represent Yang's geometry on the contrary. All the evidence is to the contraryTo start with, the all important cone half-angle is around 15 degrees instead of 6 degrees.Yang's angle is close to NASA.I look forward to Shell's test with a cone half-angle of only 6 degrees to prove this Experiments have a way to settle things...To make it simple:Geometry close to a cylinder ===> badGeometry close to Shawyer and NASA ===> good

Quote from: Rodal on 08/01/2015 04:50 PMThe difference between the two geometries is completely negligible compared to the difference between the geometry in the EM Drive wikiCompared to the geometry in the EM Drive wiki, the two drawings you show line up excellent !Could you please superpose the geometry of the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results ), which has a cone half angle of 6 degrees to make that clear ?If you do that you will see how utterly different is the geometry in the EM Drive wiki for Yang, and that the estimate in the EM Drive Wiki is unreasonable.Blue outline is the Wiki version of Yang...As you said... it's way off..Could it be that the composite shape of a cylinder and frustum, like we see in the more "technical" drawing, altered the data in such a way that reverse calculation gives a value that is way off?

Great Internet collaboration!We are getting there !

knowing that 1) L=24 cm

Quote from: Rodal on 08/01/2015 05:51 PMknowing that 1) L=24 cmHem… taking the longer length L1 = 43.34 mm for the coupling window, according to latest Yang's drawing I get a cavity internal height of 14,87 cm The size of the coupling window may be wrong.

Quote from: deltaMass on 08/01/2015 03:31 AMActually I got the impression from the vid that the heat capacity of the magnetron is quite low - it lost heat very rapidly after turn off. Oddly perhaps, the same could not be said of the frustum. Or perhaps these observations are due to vid editing messing with the observed timeline?It was about 1 minute clipped out as I took the cam off the tripod. Next time, I'll just let it run...you are correct, that is the best way.

Actually I got the impression from the vid that the heat capacity of the magnetron is quite low - it lost heat very rapidly after turn off. Oddly perhaps, the same could not be said of the frustum. Or perhaps these observations are due to vid editing messing with the observed timeline?

Quote from: deltaMass on 08/01/2015 05:54 AMQuote from: WarpTech on 08/01/2015 05:42 AMQuote from: deltaMass on 08/01/2015 05:14 AMQuote from: WarpTech on 08/01/2015 04:44 AMQuote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. ToddI take issue with your use of the arithmetic division operator.Nick picking again... ^{o}C/W. Not that - that you say you need "about a dozen" 400 mW transistors to get 400 Watts.Oops! 4W each, not 400mW. Off by a decimal. It was a long day.Todd

Quote from: WarpTech on 08/01/2015 05:42 AMQuote from: deltaMass on 08/01/2015 05:14 AMQuote from: WarpTech on 08/01/2015 04:44 AMQuote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. ToddI take issue with your use of the arithmetic division operator.Nick picking again... ^{o}C/W. Not that - that you say you need "about a dozen" 400 mW transistors to get 400 Watts.

Quote from: deltaMass on 08/01/2015 05:14 AMQuote from: WarpTech on 08/01/2015 04:44 AMQuote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. ToddI take issue with your use of the arithmetic division operator.Nick picking again... ^{o}C/W.

Quote from: WarpTech on 08/01/2015 04:44 AMQuote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. ToddI take issue with your use of the arithmetic division operator.

Quote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. Todd

rfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37

Quote from: flux_capacitor on 08/01/2015 06:16 PMQuote from: Rodal on 08/01/2015 05:51 PMknowing that 1) L=24 cmHem… taking the longer length L1 = 43.34 mm for the coupling window, according to latest Yang's drawing I get a cavity internal height of 14,87 cm The size of the coupling window may be wrong.She has two lengths for TE012 in page 811, Table 1 http://www.emdrive.com/NWPU2010paper.pdf. 24 cm is the longer length, associated with a slightly higher Q and frequencyshe also has a length of 17.5 cm . This length of 17.5 cm agrees better with the 14,87 cmHowever in her Table 2 this shorter length is associated with a much lower thrust level and much lower measured Q

NSF-1701 random thoughts on thermal management. As someone else pointed out, and empty microwave oven will cause a magnetron to overheat. This will also apply with a frustum. Can't help but think that Yang adressed the issue correctly with a circulator on the waveguide, which redirects reflected energy into a load. Another option seemed to be EW using a dielectric, and I propose it was a non-conductive "heat sink" as opposed to an electrical match (whether they realized it or not).So, off for some more testing this weekend. I'll make a tear-down and inspection video next.

Quote from: WarpTech on 08/01/2015 03:26 PMQuote from: deltaMass on 08/01/2015 05:54 AMQuote from: WarpTech on 08/01/2015 05:42 AMQuote from: deltaMass on 08/01/2015 05:14 AMQuote from: WarpTech on 08/01/2015 04:44 AMQuote from: Silversheep2011 on 08/01/2015 03:37 AMrfmwguy.I'm thinking replace the magnetron [see attachment below looks the same] with a RF transistor as used herehttp://www.zdnet.com/article/freescales-radio-frequency-oven-the-end-of-the-microwave/maybe it runs with less heat loss?and runs cleaner r.f. waveshttp://www.freescale.com/webapp/video_vault/videoSummary.sp?code=RF-SAGE-VIDEO see 2.37They still require a heat sink. 3.7 deg. C/Watt is a lot of heat. These are also only good for about 200 to 400 mW per transistor, if you've got a good heat sink. If you want to get back up to 400W, you will need to parallel about a dozen of them on a well designed PC board, that is thermally conductive to the heatsink. At these frequencies, I have no idea how you would do that, or what proper design criteria are necessary for a microwave amplifier of sufficient power. ToddI take issue with your use of the arithmetic division operator.Nick picking again... ^{o}C/W. Not that - that you say you need "about a dozen" 400 mW transistors to get 400 Watts.Oops! 4W each, not 400mW. Off by a decimal. It was a long day.ToddStill a long day I think? 400/4 is not equal to 1 dozen

The only dimension given by Yang in her paper is the Length (also called height) measured perpendicular to the bases. It is 0.240 meters.Look at page 811, Table 1 http://www.emdrive.com/NWPU2010paper.pdfHence it would be best if you superpose all the images so that they all have the same length: 0.240 metersThen one has to use this image:knowing that 1) L=24 cm2) f = 2.45 GHz3) D = (Dbig + Dsmall)/24) TE012 line should be used

Here is attached a high definition clean version of Yang's 2014 cavity drawing, so we can start guessing the correct dimensions and ratios from the length L of the coupling window (with the value of L1 or L2 provided by Flyby).

Quote from: Flyby on 08/01/2015 05:07 PMQuote from: Rodal on 08/01/2015 04:50 PMThe difference between the two geometries is completely negligible compared to the difference between the geometry in the EM Drive wikiCompared to the geometry in the EM Drive wiki, the two drawings you show line up excellent !Could you please superpose the geometry of the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results ), which has a cone half angle of 6 degrees to make that clear ?If you do that you will see how utterly different is the geometry in the EM Drive wiki for Yang, and that the estimate in the EM Drive Wiki is unreasonable.Blue outline is the Wiki version of Yang...As you said... it's way off..Could it be that the composite shape of a cylinder and frustum, like we see in the more "technical" drawing, altered the data in such a way that reverse calculation gives a length value that is way off?The only dimension given by Yang in her paper is the Length (also called height) measured perpendicular to the bases. It is 0.240 meters.Look at page 811, Table 1 http://www.emdrive.com/NWPU2010paper.pdfHence it would be best if you superpose all the images so that they all have the same length: 0.240 metersThen one has to use this image:knowing that 1) L=24 cm2) f = 2.45 GHz3) D = (Dbig + Dsmall)/24) TE012 line should be used

OK, using the above and Cone half-angle = 15 degrees I proceed as follows:TE012 Equation (from Yang's graph): y = 13.5 + 8.5 xwhere y = ((f D) ^2)*10^(-20)x = (D/L)^2replacing L=24 cmf=2.45*10^9 Hzand solving the quadratic equation for D, I getD=17.26915 cmand since(Db - Ds)/2 = (24 cm)* tan (15 degrees)and(Db + Ds)/2 =D = 17.26915 cmand solving these coupled equations for Db and Ds, we finally getDb = 23.69993 cm ~ 23.70 cmDs = 10.83836 cm ~ 10.84 cmL = 24 cmNeed to calculate whether these numbers give a natural frequency for TE012 of 2.45 GHzif not, need to modify the diameters in order to get TE012 @ 2.45 GHzThe main imprecision comes from the coefficients of the equation y = 13.5 + 8.5 xObviously, there is a whole family of solutions that satisfy the equation for TE012 in Yang's graph, for different values of the cone angle. The larger the cone angle, the more different are the values of Db and Ds, all we know is their average D.

Quote from: Rodal on 08/01/2015 08:39 PMOK, using the above and Cone half-angle = 15 degrees I proceed as follows:TE012 Equation (from Yang's graph): y = 13.5 + 8.5 xwhere y = ((f D) ^2)*10^(-20)x = (D/L)^2replacing L=24 cmf=2.45*10^9 Hzand solving the quadratic equation for D, I getD=17.26915 cmand since(Db - Ds)/2 = (24 cm)* tan (15 degrees)and(Db + Ds)/2 =D = 17.26915 cmand solving these coupled equations for Db and Ds, we finally getDb = 23.69993 cm ~ 23.70 cmDs = 10.83836 cm ~ 10.84 cmL = 24 cmNeed to calculate whether these numbers give a natural frequency for TE012 of 2.45 GHzif not, need to modify the diameters in order to get TE012 @ 2.45 GHzThe main imprecision comes from the coefficients of the equation y = 13.5 + 8.5 xObviously, there is a whole family of solutions that satisfy the equation for TE012 in Yang's graph, for different values of the cone angle. The larger the cone angle, the more different are the values of Db and Ds, all we know is their average D.With these values, Yang went from the largest k*r values to the smallest, and is now utilizing a much larger differential position along the impedance curve.Todd