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EM Drive Developments - related to space flight applications - Thread 10 by Chris Bergin on 19 May, 2017 23:29
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This is a thread - Thread 10 in the series - focused on objective analysis of whether the EM Drive (a cavity resonating at microwave frequencies) reported "thrust force" is an experimental artifact or whether it is a real propulsion effect that can be used for space applications, and if so, in discussing those possible space propulsion applications.
Objective skeptical inquiry is strongly welcome. Disagreements should be expressed politely, concentrating on the technical, engineering and scientific aspects, instead of focusing on people. As such, the use of experimental data, mathematics, physics, engineering, drawings, spreadsheets and computer simulations are strongly encouraged, while subjective wordy statements are discouraged. Peer-reviewed information from reputable journals is strongly encouraged. Please acknowledge the authors and respect copyrights.
Commercial advertisement is discouraged.
In order to minimize bandwidth and maximize information content, when quoting, one can use an ellipsis (...) to indicate the clipped material.
Only use the embed [img ]http://code when the image is small enough to fit within the page. Anything wider than the width of the page makes the page unreadable as it stretches it (we're working on auto reduction, but different browsers work different ways, etc.)
This link
http://math.typeit.org/
enables typing of mathematical symbols, including differentiation and integration, Greek letters, etc.
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Links to previous threads:
Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=29276.0
Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36313.0
Thread 3:
http://forum.nasaspaceflight.com/index.php?topic=37642.0
Thread 4:
http://forum.nasaspaceflight.com/index.php?topic=38203.0
Thread 5:
http://forum.nasaspaceflight.com/index.php?topic=38577.0
Thread 6:
http://forum.nasaspaceflight.com/index.php?topic=39004.0
Thread 7:
http://forum.nasaspaceflight.com/index.php?topic=39772.0
Thread 8:
http://forum.nasaspaceflight.com/index.php?topic=40959.0
Thread 9:
https://forum.nasaspaceflight.com/index.php?topic=41732.0
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Entry level thread:
http://forum.nasaspaceflight.com/index.php?topic=37438.0
Baseline NSF Article:
http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/
This is the link to the EM Drive wiki that users are encouraged to contribute to, edit for accuracy, and build as a knowledge resource for the EM Drive:
http://emdrive.wiki
http://rfdriven.com
Chris note: Please note all posts need to be useful and worthwhile or they will be removed via moderation. This subject has large interest, with over 5 million thread reads and 900,000 article reads. Most people are reading and not posting, so when you post it is in front of a very large audience.
Also, and it should go without saying, amateur experiments are discouraged unless you have gained educated and/or professional advice for safety reasons. -
#1 by R.W. Keyes on 20 May, 2017 03:37
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Regarding Vector Network Analyzers; What are some affordable units that fit the bill for emdrive purposes at around 2.4 ghz? This http://www.ebay.com/sch/i.html?&_nkw=282376642705 seems inexpensive but my Chinese language skills are non-existent. Or would some big heavy Agilent 8753 series be better? I saw the post on the http://www.megiq.com/products/vna-0440 but I don't want to buy more than I'd need.
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#2 by Monomorphic on 20 May, 2017 11:56
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Regarding Vector Network Analyzers; What are some affordable units that fit the bill for emdrive purposes at around 2.4 ghz? This http://www.ebay.com/sch/i.html?&_nkw=282376642705 seems inexpensive but my Chinese language skills are non-existent. Or would some big heavy Agilent 8753 series be better? I saw the post on the http://www.megiq.com/products/vna-0440 but I don't want to buy more than I'd need.
The miniVNA Tiny works very well for return loss sweeps. It also has a smith chart for impedance matching the antenna. http://miniradiosolutions.com/54-2/
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#3 by ThatOtherGuy on 20 May, 2017 12:55
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Uh... not the windfreak synthnv ? Why?
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#4 by Monomorphic on 20 May, 2017 13:09
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Uh... not the windfreak synthnv ? Why?
I use the windfreak as a signal generator and RF power detector. Then I use the miniTiny VNA for VNA and impedance tuning. The miniTinyVNA is not permanently attached to the torsional pendulum. -
#5 by ThatOtherGuy on 20 May, 2017 13:13
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Oh I see now, I wasn't aware of that setup, thanks for the clarification !
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#6 by rfmwguy on 20 May, 2017 13:41
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#7 by R.W. Keyes on 20 May, 2017 15:52
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According to the referenced website, production of this unit ended in December 2014 and no new products seem to be available from the company. While some may be available used, it's disconcerting that it's been discontinued. But then again, the HP 8753 I mentioned is discontinued and over thirty years old. However I have a great trust in classic HP equipment.
EDIT: I did find a knock-off of this unit available from China, but I wonder how good it is and true to the original. It sure is cheap in comparison to other units ($330) https://www.aliexpress.com/store/product/3G-miniVNA-Tiny-Vector-Network-Analyzer-Frequency-1-3000-Mhz-RF-Antenna-Analyzer-VNA-Signal-Generator/1939783_32717858518.htmlRegarding Vector Network Analyzers; What are some affordable units that fit the bill for emdrive purposes at around 2.4 ghz? This http://www.ebay.com/sch/i.html?&_nkw=282376642705 seems inexpensive but my Chinese language skills are non-existent. Or would some big heavy Agilent 8753 series be better? I saw the post on the http://www.megiq.com/products/vna-0440 but I don't want to buy more than I'd need.
The miniVNA Tiny works very well for return loss sweeps. It also has a smith chart for impedance matching the antenna. http://miniradiosolutions.com/54-2/ -
#8 by R.W. Keyes on 20 May, 2017 16:37
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Uh... not the windfreak synthnv ? Why?
For those needs I will be using the LimeSDR, two of which are supposed to be arriving next week (after almost a year wait). -
#9 by xyzzy on 20 May, 2017 17:43
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Regarding Vector Network Analyzers; What are some affordable units that fit the bill for emdrive purposes at around 2.4 ghz? This http://www.ebay.com/sch/i.html?&_nkw=282376642705 seems inexpensive but my Chinese language skills are non-existent. ...
What you found there is the KC901S, one of a series of handheld network analyzers that are becoming very popular in the amateur radio community around the world. The previous models have been available in China for a couple of years now and people were already buying them directly from China through Taobao agents when the manufacturer did not have official overseas distributors.
The series initially became popular around 2014 with the KC901H model, followed by the slightly updated KC901E. Both were scalar-only instruments, now discontinued predecessors of the model you saw.
Then they released the KC901S and also began to more actively market it overseas. The KC901S was redesigned for higher battery capacity (4 instead of 2 cells) and for the first time it included some basic vector network analysis functions (S11 was vector, but S21 scalar only).
The newest model is now the KC901V. It works to 6.8 GHz (compared to 3 GHz for the -S model), goes down to 9 kHz, performs vector measurements for both S11 and S21. They also redesigned the amplitude detector to a digital design, resulting in noise floor improvements and the more options for resolution bandwidths in spectrum analysis mode. They call it an "RF Multimeter" because it includes the functions of a network analyzer, a spectrum analyzer, two signal generator configurations for RF and LF, and a frequency selective RF level meter (like a basic measurement receiver).
You can find a summary here: http://www.deepace.net/kc901v-6-8ghz-handheld-network-analyzer-rf-multimeter/
A datasheet in English is available (https://drive.google.com/file/d/0B_sPOt4-zQd8RWlVbGZLUld4bDQ/view) and it also includes a block diagram with a short description of the instrument's measurement principles.
Some people have reviewed various models from the "KC901" series and posted their reviews on the net. Here you can find a very detailed review of the latest -V model:
P.S. Both the -S and the -V models are currently sold. Since I own neither one myself, I don't have direct experience with them. From the published specs and from what radio enthusiasts have posted in public forums, the newer -V one appears to be clearly superior in its abilities and technical characteristics, but of course it is also more expensive. When compared to "traditional" RF instruments however, both seem to have relatively benign price tags.
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#10 by Monomorphic on 20 May, 2017 19:10
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According to the referenced website, production of this unit ended in December 2014 and no new products seem to be available from the company.
Where does it say the miniVNA Tiny has been discontinued? I see a new unit available from Ham Radio Outlet now. I think you are mistaking, "The production of the "EXTENDER" ended in December 2014" - which is another product: http://miniradiosolutions.com/extender/ -
#11 by ThatOtherGuy on 21 May, 2017 08:18
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You may even build your VNA
http://hforsten.com/cheap-homemade-30-mhz-6-ghz-vector-network-analyzer.html#
The site carries full infos, pcb blueprints and cad files and full sw on github
[edit]
The problem with DIY is mainly calibration and stability; while the first one may be solved, the second one mainly depends from circuit and pcb design and could be critical since when it comes to measurements, once the VNA is calibrated, you should have always the same error/deviation, but sometimes this may not be the case, components stability (also due to heat) may cause variations and while this may be ok for some amateur radio or similar applications, I doubt it may be suitable for a test rig trying to measure and understand an experimental device like the EMdrive; in such a case one usually wants some good (enough) and stable measurement system, otherwise, well, one won't even know what gets measured, be it a signal, noise or some measurement device error. Not saying that one must pick professional and costly devices (at least not as a start), but having some commercial one, whose problems have already been solved, will for sure be of help
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#12 by R.W. Keyes on 21 May, 2017 10:45
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You are correct. I misread. My humble apologies. I believe that is the responsibility of every scientist to read closely, and in this case, I gave it no more than a simple cursory scan before reporting its discontinuance. I could blame too much caffeine,which may be a cause, but not an excuse.
According to the referenced website, production of this unit ended in December 2014 and no new products seem to be available from the company.
Where does it say the miniVNA Tiny has been discontinued? I see a new unit available from Ham Radio Outlet now. I think you are mistaking, "The production of the "EXTENDER" ended in December 2014" - which is another product: http://miniradiosolutions.com/extender/ -
#13 by R.W. Keyes on 21 May, 2017 11:44
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There are so many options to choose from. I just discovered that I can use the LimeSDR itself as a VNA, though it may still have some rough edges at this point.
I am trying to figure out the best price/performance point. I know this is subjective based upon my budget for building n EMdrive, which is currently not very well defined but I am giving priority to an adequate testing and verification rig, as well as a time budget for documentation to enable others to reproduce any encouraging design. -
#14 by spupeng7 on 22 May, 2017 02:30
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Is that magnetic charge physical or not… Is an electron really made of "two magnetic charges" or is the magnetic field just a description of the electrodynamic interaction of two charged particles in motion relatively to each other, due to their spin?
Physically speaking, it depends of how you answer the question what is the magnetic field.
Simplistic view: when you cut a magnet in half, you don't get two separate North pole and South pole, you get two dipole magnets. You can cut the magnet again and again and again down to the atomic level: finally you'll reach the electron which is still a magnetic dipole. It's like saying you want to slice a window glass so thin because you want a window with only one side.
So according to this view, the magnetic field is something that comes out from an electric flow (current) and not the other way around, and it is always a dipole. And the magnetic monopole cannot exist.
But is an electron made of two magnetic charges? When explaining the origin of mass and inertia, some people including the media tell it is due to a particle, the Higgs boson. Although they omit to say it is just a hypothesis, and others hypotheses for the origin of inertia do exist, like the Mach-Einstein-Sciama-Woodward hypothesis, or quantized inertia (MiHsC). But at this point choosing between them is rather a matter of belief.
Dirac's equations plead in favor of the existence of discrete magnetic charges and magnetic monopoles. Observation does not. What is reality?
My understanding of the magnetic field is incomplete, since there is no electric charge in movement in the propagation of an electromagnetic wave in a vacuum, although there is a magnetic and electric fields associated with the wave. I admit I don't understand the physical meaning of an EM wave, I have always seen this as a mathematical trick and not a true description of reality, especially as there is no æther as a medium for the propagation of the wave and its EM field. Except EM waves are really propagating in vacuum, so… I'll stop there, because I can't add more to the debate. But you get the idea.
Thank you flux_capacitor,
this is exactly why I have developed a conceptual explanation for 'action at a distance' which allows a moment of complex time to be that place where quantum exchange requires no intermediary particle and no fields. The electric field is, in my opinion, a broken description of how electrical force acts upon a charge which is separated from an emission by light speed. The magnetic field is a broken description of how combinations of positive and negative electric fields act upon remote charges. All electromagnetic action being completely absorbed. Inertia and gravity being similar interactions partially absorbed by all charges.
This must sound like broken record but if it did not make more sense to me than collapsing fields at an absorption, I would happily shut up and go away. -
#15 by ThereIWas3 on 22 May, 2017 03:40
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I always considered magnetic and electrical "waves" to be distortions in the space-time continuum, much like gravity, not as something physical that moves through space. Clearly it is a different sort of distortion, but the ways in which electrical and magnetic fields interact with solid objects are not entirely different from the way gravitation interacts with mass. Somewhere in there lurks the Unified Field theory.
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#16 by ThatOtherGuy on 22 May, 2017 06:19
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ERASynth: something to check out
https://myriadrf.org/blog/tag/erasynth/
https://www.crowdsupply.com/era-instruments/erasynth
A quite interesting signal generator
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#17 by ThatOtherGuy on 22 May, 2017 07:36
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Magnetic monopoles
I thought I already posted this, but probably I didn't
http://www.sciencealert.com/our-quest-to-find-the-truest-north-in-the-universe-just-took-an-unexpected-turn
given the latest discussions about monopoles, I suppose the above (and the original paper linked at bottom) may be of interest
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#18 by Stormbringer on 22 May, 2017 07:49
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Magnetic monopoles
I think what happened is a lot of people were posting stuff in the old thread after Mr Bergin posted the closing and requesting all further posts to be in the new thread. thus a few monopole related posts got banished into the aether -a shame because they were good though they were tangential to the topic.
I thought I already posted this, but probably I didn't
http://www.sciencealert.com/our-quest-to-find-the-truest-north-in-the-universe-just-took-an-unexpected-turn
given the latest discussions about monopoles, I suppose the above (and the original paper linked at bottom) may be of interest -
#19 by meberbs on 22 May, 2017 07:54
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Magnetic monopoles
That is another article based on the same research that started the recent discussions.
I thought I already posted this, but probably I didn't
http://www.sciencealert.com/our-quest-to-find-the-truest-north-in-the-universe-just-took-an-unexpected-turn
given the latest discussions about monopoles, I suppose the above (and the original paper linked at bottom) may be of interest
It has some good information in it including a description of the 2 types of pseudo-monopoles. Neither is an actual monopole, and I don't think this direction of research can lead to a real monopole, which would be a new particle and discovered at the LHC or some similar experiment. It still is interesting, and could lead to something useful in the future.Quote"Whereas the Dirac monopole experiment simulates the motion of a charged particle in the vicinity of a monopolar magnetic field, the quantum monopole has a point-like structure in its own field resembling that of the magnetic monopole particle itself."
