...
Both statements say the Chinese are testing EmDrives in space. I expect IBT would have checked with other sources. It may be that the Chinese are doing BOTH experiments.
Oyzw also reported Prof Yang had retired and the Chinese were no longer funding EmDrive research? My sources suggest Prof Yang never retired and is engaged in EmDrive research, which with 2 reports of Chinese EmDrives would suggest Oyzw's earlier comments were not correct.
Likewise the US maybe testing EmDrives along with Ion drives.
I recall that you were the first one to post at NSF the rumor about the Chinese testing the EM Drive in orbit.
According to your source in China, approximately when was the EM Drive launched into orbit by the Chinese?
Thank you.
Don't have that info. Was just informed it had happened, which would be before I posted the info.
For the record, you posted this information on October 23, 2016:
http://forum.nasaspaceflight.com/index.php?topic=40959.msg1602565#msg1602565
So the Chinese launch was some time earlier.
This is very similar information to what the IBTimes is now printing...did the IBTimes get this information from you?
I'm not their source. I have also heard this from several sources, plus you now have Oyzw telling you of other EmDrive launches and that Prof Yang did not retire. Seems he was fed false info to spread on NSF.
This is very similar information to what the IBTimes is now printing...did the IBTimes get this information from you?
I'm not their source. I have also heard this from several sources.
Everybody noticing the increase in EmDrive related News events hitting the circuits?
I expect Universal Propulsion (the SPR & Gilo) JV is getting ready to do a product release plus both the US and the Chinese are making it certain that the press knows they also have EmDrives.
Should be interesting.
Oh BTW my frustum fabricators knew straight away what my plans were. Was told many EmDrives are being built in China. They even suggested a few antenna tweaks.
My sources also say the Indians have an active EmDrive research program.
Roger claims 7 countries have EmDrive programs, in addition to those on his list.
Interesting times. If these things scale, the strategic concept of continental separation may as well not exist.
Most of you are discussing advanced topics, but I am still more or less in the 'plumbing phase'. Fortunately, according to Paul March, I don't have to get skilled in silver soldering but can use ordinary lead/tin solder as well to make a reasonable microwave cavity. That will save some time. 
Best,
Peter
from thread 5
« on: 10/18/2015 04:45 AM »
The manufacturing tolerances for building these EMDrive based room-temp copper frustums does not have to be very good to get Q-factor results that are quite usable in obtaining interesting thruster performance. Our unloaded, (-7dB down from the VNA S11 amplitude reference plane assuming near optimal antenna coupling using a magnetic loop antenna), with no dielectric discs, the TE012 resonance at 2,167 MHz per our 2014 AIAA/JPC paper's copper frustum came out to be ~54,000. Considering our garage construction crew used a civil war vintage bending mill to form the copper sheet into a cone, which was then lead/tin soldered together with two half inch wide exterior flanges butted together, and pulled together using 0.050" thick by 1/2 inch wide copper hoops that I hand routered out of copper sheets, which were then lead/tin soldered to the cone, should tell you that great precision for your first frustum prototypes is not required. And since I also just used semi-flat 1/16" thick FR4 printed circuit boards with one side plated with 1.0 oz (34.8 microns thick) copper with the copper side towards the inside of the cavity, super parallel surfaces on the end caps is not required either.
BTW, since the wave-length of ~2.0 GHz RF is 5.906" (0.1500m), keeping within 1/100th of a wavelength (0.0591") tolerance of your design in your first build as the telescope builders do, one should just use moderate (0.03") shop tolerances for your first prototype builds and go from there.
Best, Paul March
Looking at the pictures in the leaked document, I see they are still using the same frustum.
Interesting times. If these things scale, the strategic concept of continental separation may as well not exist.
They scale and your suggestion is of course a very major military security issue.
Just remember Roger told us he was working with a unnamed Uk aerospace company on a wing and prop less drone, which most of you totally ignored. Now we know he is working and has a JV with Gilo Industries which supplies their engine to drone manufacturers and have a VERY STRONG desire to build a flying car.
So what many thought was Roger just talking, has turned out to be factual. I suggest it would be very foolish to ignore what IBT and Roger are doing, creating a credibility enhancement program, with what one would suspect to be a product launch some time in 2017. BTW Roger did say he would demo a EmDrive propulsed drone in 2017.
Tick Tock.
It is all happening.
Most of you are discussing advanced topics, but I am still more or less in the 'plumbing phase'. Fortunately, according to Paul March, I don't have to get skilled in silver soldering but can use ordinary lead/tin solder as well to make a reasonable microwave cavity. That will save some time.
Best,
Peter
Trust me Peter the frustum needs flanges that allow the end plates to be removed. By exciting in TE013 mode, you eliminate eddy currents crossing from end plate to side wall, If you excite in some other mode and if the joint is not good you may get arching across the joint. With TE013 all you need is a good compression fitting between frustum flange and end plate.
The SPR Flight Thruster is a very good example of how to build a TE013 frustum.
I'm happy to share and help you with the dimensions and build suggestions.
Reading this thread is like following Alice further down the rabbit hole.
Everyday seems more and more unbelievable...yet the more I read...
With an eye towards the ISM bands, what kind of dimensions would you want for a 902 to 928 Mhz frustum?
Supplementary question, is it better to target a narrow bandwidth, or to target the full, allotted spectrum at 915 +/- 13 MHz?
I can not say too much, Professor Yang's team improved thruster, R & D team completed a ground thrust measurement, is likely to have been sent into space, a few days ago.
Nice to learn Prof Yang did not retire and received additional funding to continue her EmDrive work.
With an eye towards the ISM bands, what kind of dimensions would you want for a 902 to 928 Mhz frustum?
Supplementary question, is it better to target a narrow bandwidth, or to target the full, allotted spectrum at 915 +/- 13 MHz?
Need a single freq to design to. Doesn't matter to the frustum design or excited mode what it is. Does matter to the Rf amp that is has enough bandwidth to trace resonance / reflected power changes as the frustum gets warm and moves. So maybe pick the centre of the Rf amp bandwidth and design for that frequency.
With an eye towards the ISM bands, what kind of dimensions would you want for a 902 to 928 Mhz frustum?
Supplementary question, is it better to target a narrow bandwidth, or to target the full, allotted spectrum at 915 +/- 13 MHz?
Need a single freq to design to. Doesn't matter to the frustum design or excited mode what it is. Does matter to the Rf amp that is has enough bandwidth to trace resonance / reflected power changes as the frustum gets warm and moves. So maybe pick the centre of the Rf amp bandwidth and design for that frequency.
This raises an engineering first principles question, then; do you design the frustum around the RF system, or the RF system around the frustum? It sounds like you strongly prefer the former.
Reading this thread is like following Alice further down the rabbit hole. Everyday seems more and more unbelievable...but the more I read...
Boeing took the EmDrive black as did the Chinese with that BS final paper of Prof Yang. Any experienced EmDrive builder would know it was BS, which I think was her intent to send a signal.
So governments have lied as have many individuals.
Bottom line is the EmDrive has worked since Roger invented it. His theory has been through several academic and industry groups, so it is also correct.
It has taken some time for the penny to drop that the EmDrive works as Roger claims. Might take a bit more time until the theory penny drops but it will happen.
With an eye towards the ISM bands, what kind of dimensions would you want for a 902 to 928 Mhz frustum?
Supplementary question, is it better to target a narrow bandwidth, or to target the full, allotted spectrum at 915 +/- 13 MHz?
Need a single freq to design to. Doesn't matter to the frustum design or excited mode what it is. Does matter to the Rf amp that is has enough bandwidth to trace resonance / reflected power changes as the frustum gets warm and moves. So maybe pick the centre of the Rf amp bandwidth and design for that frequency.
This raises an engineering first principles question, then; do you design the frustum around the RF system, or the RF system around the frustum? It sounds like you strongly prefer the former.
You select the freq, understanding Q is larger with a large / lower freq frustum but not that much. Then you need to look at price and availability of Rf amps for the desired freq. Ideally those Rf amps will have inbuilt attenuator and forward/reverse power monitoring so you only need a variable freq source and a way to auto adjust freq to lowest reflected power. Plus you need a low cost S11 VNA to map the frustums resonant modes and do a rough calc on Q / VSWR.
Once you have the Rf system, then you design the frustum.
Attached is how I track the freq.
There is no overwhelming reason I know of to test the EM Drive in the X-37B, and there are many reasons why it would not be a good use of the X-37B.
Pardon? Where does that line of logic come from as it makes no sense?
The X-37B has a big cargo hold. An EmDrive is not very big or massive plus the ship has the required cryo to cool a high thrust cryo drive down.
Space race revealed: US and China test futuristic EmDrive on Tiangong-2 and mysterious X-37B plane
http://www.ibtimes.co.uk/space-race-revealed-us-china-test-futuristic-emdrive-tiangong-2-mysterious-x-37b-plane-1590289
I really question the veracity that the US AirForce is testing the EM Drive in the X-37B: we know that they are testing instead a conventional Hall Thruster using Xenon propellant.
There are good scientific and technical reasons to test the Hall Thruster in the X-37B (they have to do with examining the damage experienced by certain components in the Hall Thruster upon long-duration exposure in Low Earth Orbit, and hence why it is advantageous to recover the Hall Thruster and examine it when the X-37B returns). There is no overwhelming reason I know of to test the EM Drive in the X-37B, and there are many reasons why it would not be a good use of the X-37B.
So I take all this (particularly the IBTimes article about the X-37B testing the EM Drive) with a very skeptical grain of salt.
The Hall thrusters on the current flight use an electric field to accelerate xenon propellant, producing a small but steady thrust that’s useful for many types of spacecraft, including military communications satellites already in orbit. Brian Weeden, technical adviser for the Secure World Foundation, thinks the Air Force might also be testing the thrusters with an eye toward placing reconnaissance satellites in lower orbits, so that imaging sensors could take higher-resolution pictures of targets on the ground.
“I think the clue is how low an orbit [the X-37B] is in,” says Weeden. The spaceplane is orbiting at an altitude of about 320 kilometers (a little under 200 miles), which is lower than the International Space Station. Low orbits require more maneuvering, and therefore more fuel, to maintain. And fuel adds weight. “One of the reasons that the traditional exquisite imaging satellites are so hard to launch is because they’re big and they’re heavy,” says Weeden. Hall thrusters could enable lighter, cheaper reconnaissance satellites to be orbited.
Read more: http://www.airspacemag.com/space/spaceplane-x-37-180957777/#kvQUiMsrqOBDCRjv.99
Well there was something odd about it as unlike the other launches no pictures at all were released leading to speculation that something has been added to its outside that the USAF didn't want seen. I do wonder if we will even see any landing videos this time.
Everybody noticing the increase in EmDrive related News events hitting the circuits?
You sound so proud about breaching the trust of Paul March. You should be embarrassed and at the very least apologetic.
Most of you are discussing advanced topics, but I am still more or less in the 'plumbing phase'. Fortunately, according to Paul March, I don't have to get skilled in silver soldering but can use ordinary lead/tin solder as well to make a reasonable microwave cavity. That will save some time.
Best,
Peter
Trust me Peter the frustum needs flanges that allow the end plates to be removed. By exciting in TE013 mode, you eliminate eddy currents crossing from end plate to side wall, If you excite in some other mode and if the joint is not good you may get arching across the joint. With TE013 all you need is a good compression fitting between frustum flange and end plate.
The SPR Flight Thruster is a very good example of how to build a TE013 frustum.
I'm happy to share and help you with the dimensions and build suggestions.
Yes, I plan to build one with flanges. The frustum on the picture looks a bit massive, though. For my torsion balance, it would be nice if the mass does not exceed 2 kg too much. At most 3 kg.
That means using 0.5 mm copper plate and flanges not thicker than 5 mm.
I appreciate your help. Would you recommend other dimensions than given by Brady et al.?
Peter
Someone asked earlier what size a 900Mhz emdrive would be. Here is an image showing the different scales. All three cavities are designed to resonate at mode TE013 but at specific frequencies. The smallest is C-band at 5.8Ghz, the next is S-band at 2.4Ghz, and the largest is at the requested 900Mhz. All dims are in cm. So a 900Mhz TE013 emdrive has a major plate diameter of 44cm or 17.3 inches and would be ~38cm or ~15 inches in height.
How much does it hurt to have three decimals of precision (+/- .001) in a 900 MHz cavity instead of five?
Different question - how much does a given cavity's resonance change with tolerance? Are we looking at a few kilohertz for every hundredth of a millimeter? Every thousandth?
Reading this thread is like following Alice further down the rabbit hole. Everyday seems more and more unbelievable...but the more I read...
Boeing took the EmDrive black as did the Chinese with that BS final paper of Prof Yang. Any experienced EmDrive builder would know it was BS, which I think was her intent to send a signal.
So governments have lied as have many individuals.
Bottom line is the EmDrive has worked since Roger invented it. His theory has been through several academic and industry groups, so it is also correct.
It has taken some time for the penny to drop that the EmDrive works as Roger claims. Might take a bit more time until the theory penny drops but it will happen.
As repeated many times before, the "Boeing took the emDrive black" is just a conspiracy theory, and there is evidence against it since they still would have needed further SPR contracts to use the data.
Your claim that Yang's paper was somehow a secret signal, is just silly, and makes you guilty of ignoring experimental data, like you like to accuse others of. 3rd hand anonymous sources do not somehow override published data.
All of the recent statements about X-37B and Chinese experiments are based on pure speculation and "sources" that appear to be 3rd hand or more. Most likely these may involve mis-translations, or misunderstandings of taking "electric propulsion" to mean emDrive rather than ion drive.
"His theory has been through several academic and industry groups" No evidence has ever been provided that it has, and his theory is internally inconsistent, and I know of no way to rescue it. Some other theories around here that have been proposed are at least plausible, but his is not.
Can we all calm down a little bit, take a few steps back and separate out the facts from the speculation, hyperbole, and crystal ball like statements about future events?
How much does it hurt to have three decimals of precision (+/- .001) in a 900 MHz cavity instead of five?
Different question - how much does a given cavity's resonance change with tolerance? Are we looking at a few kilohertz for every hundredth of a millimeter? Every thousandth?
Frustum size scales linearly with the frequency, so it's really easy to figure that out. I've not done that, but i have confirmed in FEKO that it scales linearly.
Everyday seems more and more unbelievable...yet the more I read...