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#1860 by Greg Pecchia on 12 Sep, 2015 19:15
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Long time lurker, first time poster here.
I have an idea way out in left field: could microwave phase conjugation using antenna arrays be implemented to create resonance at any desired input frequencies?
Some reference.
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=734509&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel4%2F22%2F15815%2F00734509.pdf%3Farnumber%3D734509
http://www.hindawi.com/journals/ijap/2010/564357/ -
#1861 by sghill on 12 Sep, 2015 21:12
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Long time lurker, first time poster here.
I have an idea way out in left field: could microwave phase conjugation using antenna arrays be implemented to create resonance at any desired input frequencies?
Some reference.
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=734509&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel4%2F22%2F15815%2F00734509.pdf%3Farnumber%3D734509
http://www.hindawi.com/journals/ijap/2010/564357/
And as someone who has worked with many phased array designs, I've wondered if steerable beams could be used to manage the sweet spot within the frustum.
It's hard (but not impossible) with a waveguide, and impossible (IMHO) with loop antennas, but we haven't explored patch antennas attached to the interior of a frustum. The D/A chipset is the magic here, and you need sensors within the frustum to tell the D/A chip where to steer the beam if there are differences between each device.
If each device is calculated separately (the approach this NSF group has been taking) beforehand, that's fine, but this new approach could work with any new device without exact pre-calculations. -
#1862 by Stormbringer on 12 Sep, 2015 21:39
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along those lines i think you would need a scanning type radar to get beam steering -or could you use the radars from an auto with collision avoidance radar (can you get those from an auto dealer, parts store or junk yard?) or a cannibalized polaroid camera?
the power though is likely too tiny from those types of gear. -
#1863 by TheTraveller on 13 Sep, 2015 07:44
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2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.
Great to see you back!!
This is a very interesting insight into how Shawyer may now see this phenomena working. It is almost like striking a bell! Very, very interesting. Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer. Hm.
Would that explain the long duration drop off after the power is turned off?
No.
Have to agree with Rodal. From a microwave perspective you are looking probably at nanoseconds (femtoseconds?) unless I am missing something. Same thing would be true as far as I know for any ionized gasses rattling around. Couldn't speak to how long a superconducting EM bell would ring on its own but it would likely still be much shorter than say a millisecond, if that.
The insight for me is that the EM Drive could possibly be best driven by a pulsed power source and not a continuous one.
That said, that long duration drop off is one of those signals that makes this such a tar patch. It shows up in different experiments, usually explained away as either thermals or stiction in the measuring apparatus.
Thing is, while thrust does not require new physics, this duration thing would if it is not just an experimental artifact...
Resonant cavities have a TC (Time Constant) which defines the rate of energy increase or decrease. Is defined as
TC = (2 QL) / ( 2 Pi Freq).
For a SC cavity with a unloaded Q0 of 5,000,0000 and a loaded QL of 1,000,000 due to an antenna coupling factor of 0.20. QL = Q0 * antenna coupling factor, the excitation period TC is then 130us and the post excitation TC (no phase distortion from the excitation antenna's EM waves on the internal resonant wave) climbs to 650us. All at 2.45GHz.
Which would suggest the cavity can maintain the pure, non phase distorted, resonant EM waves for quite some period alter the excitation, cavity fill EM pulse is stopped.
Also suggests the antenna coupling factor is not as important as is getting an ideal impedance match to drop the frustum VSWR to as close to as 1:1 as possible.
I would again point out the use of a feed slit on the frustum side wall. To me this suggests a desire for an excitation method that will have minimal effect on the post excitation non loaded Q. Sort of how to have a RF in feed capability but not upset the frustum mechanics, smooth side wall, to obtain max non loaded Q post the excitation period.
Using the side wall slit and doing short 20% of 1 TC RF excitation pulses is a clever way to eliminate antenna coupling factor dequeuing the frustum post excitation Q and to eliminate the excitation antenna being a permanent feature inside the cavity.
At 900MHz the above 1 TC times lengthen to
Excited TC = 354us
Nonexcited TC = 1.77ms
Attached drawing shows the 20% of 1 TC excitation RF period that Shawyer mentions in his patent.
Also is attached data from his peer reviewed paper, showing the time of the pulse, and how the Force generated declines as the mainly TC driven resonant EM standing waves inside the cavity decline in strength.
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#1864 by rfmwguy on 13 Sep, 2015 22:27
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Uh-oh...LDS display that was supposed to be working was not...bummer
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#1865 by TheUberOverLord on 13 Sep, 2015 22:48
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Uh-oh...LDS display that was supposed to be working was not...bummer
Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.
You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.
Don -
#1866 by rfmwguy on 14 Sep, 2015 02:08
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I downloaded the manual and discovered the error code was a "Memory Error". It said to plug it in several times to see if it goes away. It did not. Also tried Reset and Zero signalllls without success. Good news is laser displacement sensor seems to be fine, just a problem with the display. Sent the seller a note and I'm sure they will help. Just hate delays.Uh-oh...LDS display that was supposed to be working was not...bummer
Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.
You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.
Don -
#1867 by zen-in on 14 Sep, 2015 04:01
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I downloaded the manual and discovered the error code was a "Memory Error". It said to plug it in several times to see if it goes away. It did not. Also tried Reset and Zero signalllls without success. Good news is laser displacement sensor seems to be fine, just a problem with the display. Sent the seller a note and I'm sure they will help. Just hate delays.Uh-oh...LDS display that was supposed to be working was not...bummer
Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.
You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.
Don
There may be some configuration tables that need to be initialized. It looks like one of those problems that turns out to be trivial once you find the solution. deja-vous all over again.
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#1868 by CW on 14 Sep, 2015 11:24
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[..]
Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?
I'd rather say, your mind is going too fast for other people your age.
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#1869 by SeeShells on 14 Sep, 2015 13:38
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I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.[..]
Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?
I'd rather say, your mind is going too fast for other people your age.
Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different. http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum, about 5 meters from the laser to the paper.
Shell
Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine. -
#1870 by D_Dom on 14 Sep, 2015 16:59
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SteamPunkt!
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#1871 by VAXHeadroom on 14 Sep, 2015 18:03
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I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.[..]
Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?
I'd rather say, your mind is going too fast for other people your age.
Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different. http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum, about 5 meters from the laser to the paper.
Shell
Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine.
I have a 5mw HeNe laser I can loan you...
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#1872 by SeeShells on 14 Sep, 2015 18:34
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I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.[..]
Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?
I'd rather say, your mind is going too fast for other people your age.
Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different. http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum, about 5 meters from the laser to the paper.
Shell
Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine.
I have a 5mw HeNe laser I can loan you...
Thanks! Let's see what I can get out of these one I ordered, if it turns out unusable then I might take you up on it.
Sorry for not posting as much but my time is being spent on trying to get my mom's estate closed out and .... families are.... sigh, well families. Plus, I want to get this build finished.
Thanks again!
Shell
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#1873 by CraigPichach on 14 Sep, 2015 18:56
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Hmm, so 10us is too short but 200us shots might actually be better than continuous at 900MHz?
Well, 20% 70us.... so 10us you might actually see something??2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.
Great to see you back!!
This is a very interesting insight into how Shawyer may now see this phenomena working. It is almost like striking a bell! Very, very interesting. Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer. Hm.
Would that explain the long duration drop off after the power is turned off?
No.
Have to agree with Rodal. From a microwave perspective you are looking probably at nanoseconds (femtoseconds?) unless I am missing something. Same thing would be true as far as I know for any ionized gasses rattling around. Couldn't speak to how long a superconducting EM bell would ring on its own but it would likely still be much shorter than say a millisecond, if that.
The insight for me is that the EM Drive could possibly be best driven by a pulsed power source and not a continuous one.
That said, that long duration drop off is one of those signals that makes this such a tar patch. It shows up in different experiments, usually explained away as either thermals or stiction in the measuring apparatus.
Thing is, while thrust does not require new physics, this duration thing would if it is not just an experimental artifact...
Resonant cavities have a TC (Time Constant) which defines the rate of energy increase or decrease. Is defined as
TC = (2 QL) / ( 2 Pi Freq).
For a SC cavity with a unloaded Q0 of 5,000,0000 and a loaded QL of 1,000,000 due to an antenna coupling factor of 0.20. QL = Q0 * antenna coupling factor, the excitation period TC is then 130us and the post excitation TC (no phase distortion from the excitation antenna's EM waves on the internal resonant wave) climbs to 650us. All at 2.45GHz.
Which would suggest the cavity can maintain the pure, non phase distorted, resonant EM waves for quite some period alter the excitation, cavity fill EM pulse is stopped.
Also suggests the antenna coupling factor is not as important as is getting an ideal impedance match to drop the frustum VSWR to as close to as 1:1 as possible.
I would again point out the use of a feed slit on the frustum side wall. To me this suggests a desire for an excitation method that will have minimal effect on the post excitation non loaded Q. Sort of how to have a RF in feed capability but not upset the frustum mechanics, smooth side wall, to obtain max non loaded Q post the excitation period.
Using the side wall slit and doing short 20% of 1 TC RF excitation pulses is a clever way to eliminate antenna coupling factor dequeuing the frustum post excitation Q and to eliminate the excitation antenna being a permanent feature inside the cavity.
At 900MHz the above 1 TC times lengthen to
Excited TC = 354us
Nonexcited TC = 1.77ms
Attached drawing shows the 20% of 1 TC excitation RF period that Shawyer mentions in his patent.
Also is attached data from his peer reviewed paper, showing the time of the pulse, and how the Force generated declines as the mainly TC driven resonant EM standing waves inside the cavity decline in strength. -
#1874 by Rodal on 14 Sep, 2015 19:01
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Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects: https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/
Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects). -
#1875 by rfmwguy on 14 Sep, 2015 19:48
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Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects: https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/
We are getting there, Doc...slow but sure. It takes time on a home budget, but my personal goal of adding to the data will be accomplished soon. Proving or disproving, its all the same to me...I've enjoyed the build and commaraderie to date.
Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
p.s. Good Canadian seller of (defective) K3NX LDS display controller. Immediately issued refund and didn't bother with asking me to return it. -
#1876 by SeeShells on 14 Sep, 2015 20:17
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Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects: https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/
And you wonder why I'm being picky?
Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
Shell -
#1877 by SteveD on 14 Sep, 2015 21:20
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Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects: https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/
l
Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information. -
#1878 by rfmwguy on 14 Sep, 2015 22:42
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Sorry for late notice...I'll be back on Mr Hoagland's Other Side of Midnight show this evening at 12 Midnight Pacific Daylight Time.
The first hour will be a status review of the NSF-1701 project and we will be taking callers at 1 AM.
Everyone is invited to call in, believers and skeptics: http://othersideofmidnight.com -
#1879 by Rodal on 14 Sep, 2015 22:59
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Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects: https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/
l
Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information.
On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.
