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#860 by SeeShells on 22 Aug, 2015 14:22
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Asked by a dear friend lurker to look this up. I had no idea this happened.
https://en.wikipedia.org/wiki/SNAP-10A -
#861 by rfmwguy on 22 Aug, 2015 14:46
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Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first
You have me excited rfmwguy! It will be interesting to compare the two tests as we eneded up with similar setups.
Did I mention to you that you could make a tiny pinhole in a plastic business card with a hot pin (cheap and dirty pinhole lens) and put it in front of the laser to clean up the beam to get you a very small dot? I was surprised at how well this old school pinhole lens worked.
Shell
Full steam ahead rfmwguy! -
#862 by Rodal on 22 Aug, 2015 14:50
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...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test? Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case) -
#863 by Ricvil on 22 Aug, 2015 15:40
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http://ir.hfcas.ac.cn/bitstream/334002/12022/1/
Mode%20converters%20for%20generating%20the
%20HE%2011%20%28gaussian%20like%29%20mode
%20from%20TE%2001%20in%20a%20circular%20waveguide.pdf
In the above article, the mode coupling theory shows how a bended circular waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half lenght and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode? -
#864 by Mr. Peter on 22 Aug, 2015 17:01
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For those of you who want to measure in the microgram/nanonewton range . A small microbalance, might come in handy.
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#865 by SteveD on 22 Aug, 2015 17:21
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NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first
Can you post pictures of your device and rig? -
#866 by SeeShells on 22 Aug, 2015 17:24
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I like this article a lot! Has some info that I suspected could happen and have been looking for.
In the above article, the mode coupling theory shows how a bended circular
waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half lenght and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?
Big Thanks!
Shell -
#867 by Rodal on 22 Aug, 2015 18:43
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TE012 excitation
For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.
This is for flat ends. Do you plan flat or spherical ends?External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?
Shell, my understanding from numerous posts is that you are looking at getting TE012 resonance with this design. Please notice that you are NOT going to get TE012 resonance with your proposed dimensions. Flux Capacitor gets TE013 resonance instead. I don't get TE012 resonance at 2.45 GHz either, far away from it
Using:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
I get this cone half-angle:
theta=14.69 degrees
and these resonances:
TE012 =2.033 GHz
TE013 =2.418 GHz with a Q = 83,300
Note:
a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away.
b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz.
c) using the extension, extending the length, will make it even more difficult to resonate in TE013. Remember than longer length lower the natural frequencies of given mode shapes
d) you have to make the EM Drive shorter
////////////////////////////////////////////
Decreasing the length to 0.163 meters results in:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends
I get this cone half-angle:
theta = 22.50 degrees
and these resonances:
TE012 = 2.450 GHz Q = 73,800
TE013 = 3.152 GHz Q= 70,000
Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension.
Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
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#868 by SeeShells on 22 Aug, 2015 19:01
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TE012 excitation
For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.
This is for flat ends. Do you plan flat or spherical ends?External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?
Shell, my understanding from numerous posts is that you are looking at getting TE012 resonance with this design. Please notice that you are NOT going to get TE012 resonance with your proposed dimensions. Flux Capacitor gets TE013 resonance instead. I don't get TE012 resonance at 2.45 GHz either, far away from it
Using:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
I get this cone half-angle:
theta=14.69 degrees
and these resonances:
TE012 =2.033 GHz
TE013 =2.418 GHz with a Q = 83,300
Note:
a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away.
b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz.
c) using the extension, extending the length, will make it even more difficult to resonate in TE013. Remember than longer length lower the natural frequencies of given mode shapes
d) you have to make the EM Drive shorter
////////////////////////////////////////////
Decreasing the length to 0.163 meters results in:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends
I get this cone half-angle:
theta = 22.50 degrees
and these resonances:
TE012 = 2.450 GHz Q = 73,800
TE013 = 3.152 GHz Q= 70,000
Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension.
Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
I just looked again and you're quite right, I mucked it up, a hard week spent running between the computer and the bathroom I guess. I'll recheck and see where I messed up as I want to know and will even use TT's and Shawyer's spread sheet to double check in the end.
Be back after a bit.
Shell
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#869 by aero on 22 Aug, 2015 19:04
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Meep does concur.
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#870 by Mulletron on 22 Aug, 2015 19:04
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@TheTraveller, what happened? Are you done now? Tell us about your discoveries!
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#871 by RERT on 22 Aug, 2015 19:04
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Dr. Rodal -
Thanks very much for you post #812, which explained much pertaining to out previous discussion.
Of your logic, the only remaining thing I don't understand is why the side wall force must always be a pressure in TE modes. If I'm understanding the pictures Aero has shared, for what I think was TE012, the magnetic field is unidirectional, and the electric field circulates in the frustrum in opposite directions in the small and big end (halves) respectively. The wall force direction looks to me opposite in each half, and why it should always integrate to a net pressure escapes me.
I don't seriously doubt that you are correct but I for one, and I would guess others, would really appreciate your insight into why this is so.
Regards and thanks in advance,
R. -
#872 by Rodal on 22 Aug, 2015 19:13
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Dr. Rodal -
Thanks very much for you post #812, which explained much pertaining to out previous discussion.
Of your logic, the only remaining thing I don't understand is why the side wall force must always be a pressure in TE modes. If I'm understanding the pictures Aero has shared, for what I think was TE012, the magnetic field is unidirectional, and the electric field circulates in the frustrum in opposite directions in the small and big end (halves) respectively. The wall force direction looks to me opposite in each half, and why it should always integrate to a net pressure escapes me.
I don't seriously doubt that you are correct but I for one, and I would guess others, would really appreciate your insight into why this is so.
Regards and thanks in advance,
R.
Dear RERT,
Please see the discussion by Greg Egan http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html, section "Energy, pressure and forces" who (although using a very different method than mine, as Egan does NOT compute the stress tensor components, which I do carefully), explains that:QuoteThe force distributions are plotted below, for the lowest n value and lowest three k values for the TE mode(s). This time there is no Coulomb tension, so the pressure is the only contribution to the force.
(bold added for emphasis, parenthesis (s) added for clarity)
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#873 by RERT on 22 Aug, 2015 19:20
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ref: Wolf of Wall Street and discussion of accounts.
You say there was no investment, I gather because no new shares were issued. Can you rule out sale of shares from treasury?
As regards 'Black' programs and DoD involvement: TT reported that SPR had refused his request to be a licensee because of concerns of the ?UK DoD (if I'm recall in correctly). There are a number of possibilities around who is lying to whom, so I wouldn't draw too much comfort from that. At best, were SPR a scam they would doubtless have found a way to take money from TT.
TT also reports (forgive my imperfect recall) "SPR have smart people working on the superconducting...". If that is not showing up as payroll costs (and isn't Shawyer!), it occurs that one way to fund SPR noiselessly would be to second staff to them who stay on someone else's payroll.
R. -
#874 by Mulletron on 22 Aug, 2015 19:20
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Anyone know where one can find performance such as this:
http://www.maxamps.com/proddetail.php?prod=Lipo-22000-74-Pack
....or better, but without such a hefty price?
I have the voltage regulators so I can go full DC now (and ditch the galinstan slipring). I just have to get as much battery bang as I can for my buck. Any suggestions? -
#875 by X_RaY on 22 Aug, 2015 19:21
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Yes right! I getTE012 excitation
For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.
This is for flat ends. Do you plan flat or spherical ends?External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?
Shell, my understanding from numerous posts is that you are looking at getting TE012 resonance with this design. Please notice that you are NOT going to get TE012 resonance with your proposed dimensions. Flux Capacitor gets TE013 resonance instead. I don't get TE012 resonance at 2.45 GHz either, far away from it
Using:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
I get this cone half-angle:
theta=14.69 degrees
and these resonances:
TE012 =2.033 GHz
TE013 =2.418 GHz with a Q = 83,300
Note:
a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away.
b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz.
c) using the extension, extending the length, will make it even more difficult to resonate in TE013. Remember than longer length lower the natural frequencies of given mode shapes
d) you have to make the EM Drive shorter
////////////////////////////////////////////
Decreasing the length to 0.163 meters results in:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends
I get this cone half-angle:
theta = 22.50 degrees
and these resonances:
TE012 = 2.450 GHz Q = 73,800
TE013 = 3.152 GHz Q= 70,000
Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension.
Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
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#876 by SteveD on 22 Aug, 2015 19:29
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Meep does concur.
How does that stack up with the known output of the magnetron? Is there a good reason to test in TE012 and not TE013? -
#877 by Rodal on 22 Aug, 2015 19:33
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You get the same results that I do?
Yes right! I getTE012 excitation
For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.
This is for flat ends. Do you plan flat or spherical ends?External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?
Shell, my understanding from numerous posts is that you are looking at getting TE012 resonance with this design. Please notice that you are NOT going to get TE012 resonance with your proposed dimensions. Flux Capacitor gets TE013 resonance instead. I don't get TE012 resonance at 2.45 GHz either, far away from it
Using:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
I get this cone half-angle:
theta=14.69 degrees
and these resonances:
TE012 =2.033 GHz
TE013 =2.418 GHz with a Q = 83,300
Note:
a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away.
b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz.
c) using the extension, extending the length, will make it even more difficult to resonate in TE013. Remember than longer length lower the natural frequencies of given mode shapes
d) you have to make the EM Drive shorter
////////////////////////////////////////////
Decreasing the length to 0.163 meters results in:
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends
I get this cone half-angle:
theta = 22.50 degrees
and these resonances:
TE012 = 2.450 GHz Q = 73,800
TE013 = 3.152 GHz Q= 70,000
Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension.
Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
and way different from TheTraveller's spreadsheet? -
#878 by rfmwguy on 22 Aug, 2015 19:36
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Location is almost identical to EW on small end....Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test? Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case) -
#879 by rfmwguy on 22 Aug, 2015 19:38
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I'll do a walkaround video within 24 hrs.NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first
Can you post pictures of your device and rig?
