tokamac wrote:That could be better for several reasons, mainly because the cavity is heated and quickly becomes hard to keep in resonance if the operating frequency bandwidth is too short.
If keeping the microwave source tuned to the resonant load is important, the resonant load needs to be part of the tuning network for the microwave source.
As a side benefit, building magnetron and cavity into a single unit to mount on the thrust balance, minimal microwave plumbing between components, fed with filtered DC, eliminates some suspects for false readings.
The daylight is uncomfortably bright for eyes so long in the dark.
tokamac wrote:That could be better for several reasons, mainly because the cavity is heated and quickly becomes hard to keep in resonance if the operating frequency bandwidth is too short.
If keeping the microwave source tuned to the resonant load is important, the resonant load needs to be part of the tuning network for the microwave source.
As a side benefit, building magnetron and cavity into a single unit to mount on the thrust balance, minimal microwave plumbing between components, fed with filtered DC, eliminates some suspects for false readings.
Eagleworks at JSC already uses filters and a Phase Locked Loop (PLL) to automatically lock onto the current resonate frequency of the cavity, and already mounts the power amps and equipment as a whole onto their thrust balance.
As for Roger Shawyer he has also developed a dynamic system based on piezoelectric actuators that slightly modifies the length of the cavity hence its operating frequency, to follow and match any change in the resonance. This helps fighting the natural tendency of the cavity to "detune".
Keep in mind another point, according to White's QFV conjecture, there is another use for the noisy, wide-band magnetrons, as Paul March said:
"These time rate to change of energy modulations increase the Q-V density in our model."
I think there are 2 different events occurring at the moment. The first is the experiment-based community discussion, which I'm fine with because I think it's the best way to confront criticisms in the work and experimentation. The second is Dr. White's theory, which it appears several with in the discussion are struggling to reconcile. This comes as no surprise to me as I personally believe his theory has little to no value. It appears to me that Dr. White is attempting to fit the (square) results of the experiments into his (round hole) theory. If an effect is confirmed, I have strong doubts that the proper theory that will explain the effect will be Dr. White's.
ScottL wrote:I think there are 2 different events occurring at the moment. The first is the experiment-based community discussion, which I'm fine with because I think it's the best way to confront criticisms in the work and experimentation. The second is Dr. White's theory, which it appears several with in the discussion are struggling to reconcile. This comes as no surprise to me as I personally believe his theory has little to no value. It appears to me that Dr. White is attempting to fit the (square) results of the experiments into his (round hole) theory. If an effect is confirmed, I have strong doubts that the proper theory that will explain the effect will be Dr. White's.
Concur. We may have an anomalous experimental result here. That needs to be examined and verified or refuted far more than theory needs to be applied at this point. Theory can come later.
ScottL wrote:I think there are 2 different events occurring at the moment. The first is the experiment-based community discussion, which I'm fine with because I think it's the best way to confront criticisms in the work and experimentation. The second is Dr. White's theory, which it appears several with in the discussion are struggling to reconcile. This comes as no surprise to me as I personally believe his theory has little to no value. It appears to me that Dr. White is attempting to fit the (square) results of the experiments into his (round hole) theory. If an effect is confirmed, I have strong doubts that the proper theory that will explain the effect will be Dr. White's.
Concur. We may have an anomalous experimental result here. That needs to be examined and verified or refuted far more than theory needs to be applied at this point. Theory can come later.
I second your opinion.
Unfortunately, everytime there is a news blast about this experiment. Everyone latches on to the theoretical ramifications and forgets that the only thing that is really known is that we have some anomalous force being generated by the experiment. Personally I consider DR. White's theory as just a working hypothesis. Everyone should be in favor of EagleWorks working to increase repeatability and increase thrust level, as each of those things will make it much easier to figure out if this is something real or wierd experimental artifact.
Scientists Confirm 'Impossible' EM Drive Propulsion
Later today, July 27, German scientists will present new experimental results on the controversial, "impossible" EM Drive, at the American Institute for Aeronautics and Astronautics' Propulsion and Energy Forum in Orlando. The presentation is titled "Direct Thrust Measurements of an EmDrive and Evaluation of Possible Side-Effects."
...White and Tajmar have impeccable credentials that put them beyond cheap dismissal and scorn.
Nobody jumping on Sonny White's veracity yet? That said, I do trust Paul and, in our number of conversations, he has never given me any reason to doubt him or the work he has done.
In any event, this looks interesting, and the paper to go with should be illuminating.
I have to wonder if curving the chamber side walls (cone) and rear face to tune it to the RF wavefronts would improve Q.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
Well, big surprise, I clicked on the link, which is to hacked.com, and McAfee popped up its big red "Whoa, are you sure you want to go there?" warning.
A shame. I'd love to be illuminated, although I expect the scientific world will need a lot of mental recalibration to truly illuminate this topic.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)
Places I try not to get my science news: The Register, The Huffington Post, and The Telegraph.
Self-respecting Boffins just don't go there. 'Cause they'll blow up your claim of microNewtons into a HEADLINE about getting to the MOON in FOUR HOURS. Shocking.
Figure 2c shows a microwave oven magnetron, 2.44 GHz.
They're not the cleanest, most frequency-controlled things out there (maybe why the modest Q on this device), but cost effective, for sure. Gotta lose the label in a vacuum. They've got some stray magnetic field around them from the pair of ceramic donut magnets they contain, which calls for some caution regarding stray forces.
Noting the liquid metal contacts for the power, I'm recalling some of the amusing effects I observed while doing some Marinov Motor experiments. There are forces apparent at these contacts.
Tom Ligon wrote:Places I try not to get my science news: The Register, The Huffington Post, and The Telegraph.
Self-respecting Boffins just don't go there. 'Cause they'll blow up your claim of microNewtons into a HEADLINE about getting to the MOON in FOUR HOURS. Shocking.
Yes, that is obviously bullsh*t produced by someone who doesn't understand acceleration and deceleration or "microNewtons", but my normal practice is to post the headline of a story I link to just as it comes. One some websites that I participate on, it is a requirement. You aren't allowed to change the headline.
Did it not have that bit about Shawyer in it, I would have simply not bothered to post it, but I considered that bit significant enough to warrant it. I hadn't seen that anywhere else.
‘What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.’
— Lord Melbourne —