-
#3780 by Monomorphic on 12 Jul, 2016 15:50
-
I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
-
#3781 by Monomorphic on 12 Jul, 2016 16:00
-
Test 07 for comparison.
-
#3782 by SeeShells on 12 Jul, 2016 16:12
-
I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
Can you explain what the 2.45 and 2.46GHz means in this graph and how it relates to the drive?
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Shell -
#3783 by Monomorphic on 12 Jul, 2016 16:37
-
I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
Can you explain what the 2.45 and 2.46GHz means in this graph and how it relates to the drive?
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Shell
I watched the spectrum analyser in real-time and as the frequency drifted due to magnetron heating, I clicked when center frequency was 2.46Ghz and then again at 2.45Ghz. This gives me vertical lines on another channel that represent separate events.
Here is a video of the spectrum analyser. This is from an earlier run though. https://www.youtube.com/watch?v=sKsV3qTStyE?t=168 -
#3784 by Rodal on 12 Jul, 2016 16:52
-
From your FEKO runs, are there well-defined mode shapes associated with the flat (constant force) portions of the response curve during power on?I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
Can you explain what the 2.45 and 2.46GHz means in this graph and how it relates to the drive?
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Shell
I watched the spectrum analyser in real-time and as the frequency drifted due to magnetron heating, I clicked when center frequency was 2.46Ghz and then again at 2.45Ghz. This gives me vertical lines on another channel that represent separate events.
Here is a video of the spectrum analyser. This is from an earlier run though. https://www.youtube.com/watch?v=sKsV3qTStyE?t=168
Particularly just before it went below 2.45 GHz ? (long portion of flat response) -
#3785 by Monomorphic on 12 Jul, 2016 17:00
-
From your FEKO runs, are there well-defined mode shapes associated with the flat (constant force) portions of the response curve during power on?I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
Can you explain what the 2.45 and 2.46GHz means in this graph and how it relates to the drive?
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Shell
I watched the spectrum analyser in real-time and as the frequency drifted due to magnetron heating, I clicked when center frequency was 2.46Ghz and then again at 2.45Ghz. This gives me vertical lines on another channel that represent separate events.
Here is a video of the spectrum analyser. This is from an earlier run though. https://www.youtube.com/watch?v=sKsV3qTStyE?t=168
Particularly just before it went below 2.45 GHz ? (long portion of flat response)
I will need to run a sweep of the frustum with dialectic insert to answer you. I already have the geometry constructed, just need the processing time. Working on that now. -
#3786 by Monomorphic on 12 Jul, 2016 17:03
-
Particularly just before it went below 2.45 GHz ? (long portion of flat response)
Just to be clear, the flat portions represent no movement of the beam. Time is horizontal, displacement is vertical. When the graph line drops, the frustum is moving in reverse direction (large end leading), when the graph line goes up, it is moving in forward direction (small end leading). So it would seem the the portions where the beam moved down quickly are the most interesting. -
#3787 by Monomorphic on 12 Jul, 2016 17:45
-
I've superimposed the rate of change in beam displacement.
-
#3788 by venir on 12 Jul, 2016 17:51
-
...
The power was going into the wire harness instead of going into RF thus producing a thermal effect on the wire. Similar to what Prof Yang experienced prior to nullifying her tests by running with a battery.
Sigh...there was not 900 watts, it was a null test on a magnetron without rf output. The temp rise on both the mag and the harness was minimal. That experimenter probably knows what they are observing.
The long time delay to coming back to the original position being due to the wire taking a long time coming back to its original length (due to the long time constant involved in thermal diffusion).
Thus from this mistake (the experimenter at the time thought that he was running the magnetron: he only realized that the magnetron was broken after the fact) one can learn a valuable lesson as how to identify such an effect.
Suffice it to say that at the time that this experimental artifact was being presented here it was being argued by some as being the real thing. It wasn't. We can learn from experimental mistakes such as this how to distinguish such an experimental artifact from the real thing.
ADDENDUM: The experimenter (rfmwguy) proposes elsewhereQuote from: rfmwguy-EMDrive Builder an hour agowas actually a slow dissipation of a magnetic charge, not of the frustum cavity, but of the wires themselves
...
Pardon if this question has been answered, but it appears that rfmwguy has been able to isolate a source of experimental artifacts due to the thermal effects on the wire harness attached to the beam. Now that he has cleared this up and verified with a null test in the reconfigured setup, does this also alleviate concerns about additional thermal effects on the magnetron itself? Prior to this, a lot of the discussion around thermal artifacts seemed focused on the heating of the magnetron and not just the supply wires. Does this new null test point to this as no longer being a concern? -
#3789 by WarpTech on 12 Jul, 2016 17:53
-
I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Why doesn't it return to it's starting place? Is the test rig sticky now or is there some heating/thermal effect that is causing the offset to persist after RF is off?
-
#3790 by Monomorphic on 12 Jul, 2016 18:02
-
I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Why doesn't it return to it's starting place? Is the test rig sticky now or is there some heating/thermal effect that is causing the offset to persist after RF is off?
We are dealing with a much smaller force than the tap test so it takes much longer to return to center. I've truncated the data to be centered on the RF portion. I also agree that it may be a little sticky at this level and there are probably thermal effects too. I'm looking into that now.
Edit: I might try the 3 inch dampening paddle again. -
#3791 by SeeShells on 12 Jul, 2016 18:23
-
Have you thought about centering your oil damper to the center of the beam like Dave did. As the beam tries to move back to zero it will cause the beam to tip a little dragging in the oil, giving you asymmetrical movements from the drag. This also could show up in how your measurement records beam movements.I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Why doesn't it return to it's starting place? Is the test rig sticky now or is there some heating/thermal effect that is causing the offset to persist after RF is off?
We are dealing with a much smaller force than the tap test so it takes much longer to return to center. I've truncated the data to be centered on the RF portion. I also agree that it may be a little sticky at this level and there are probably thermal effects too. I'm looking into that now.
Edit: I might try the 3 inch dampening paddle again.
Shell -
#3792 by Monomorphic on 12 Jul, 2016 18:28
-
Have you thought about centering your oil damper to the center of the beam like Dave did. As the beam tries to move back to zero it will cause the beam to tip a little dragging in the oil, giving you asymmetrical movements from the drag. This also could show up in how your measurement records beam movements.I did two more powered runs this morning. Test 09 is very similar to the results from test 07. Unfortunately test 10 was corrupted. I can see the data, I just can't export it to excel. It looks very similar to test 09 from what I can tell. I may need to shield the dataq to prevent corruption in the future.
As before, by monitoring the spectrum analyser, I could send events to be recorded. This time I captured not only RF on/off, but also 2.46Ghz and 2.45Ghz.
Why doesn't it return to it's starting place? Is the test rig sticky now or is there some heating/thermal effect that is causing the offset to persist after RF is off?
We are dealing with a much smaller force than the tap test so it takes much longer to return to center. I've truncated the data to be centered on the RF portion. I also agree that it may be a little sticky at this level and there are probably thermal effects too. I'm looking into that now.
Edit: I might try the 3 inch dampening paddle again.
Shell
Yes. In fact, I spent three hours on Sunday making that change. Dampening was TERRIBLE with the oil moved to center - even with a paddle twice the size. This is because there is less movement in the center to dampen. I spent the next hour moving it back to its current location. Fortunately, my build keeps the counterweight very close to the dampening. This greatly reduces the asymmetrical movements from the drag (twisting, etc).
-
#3793 by Rodal on 12 Jul, 2016 18:34
-
I disagree.Particularly just before it went below 2.45 GHz ? (long portion of flat response)
Just to be clear, the flat portions represent no movement of the beam. Time is horizontal, displacement is vertical. When the graph line drops, the frustum is moving in reverse direction (large end leading), when the graph line goes up, it is moving in forward direction (small end leading). So it would seem the the portions where the beam moved down quickly are the most interesting.
The figure of merit in all discussions about the EM Drive has been force/InputPower.
With constant input power, you should get a constant force on the torsional pendulum: it should settle down to a flat line. Constant input power = constant rotation of the torsional pendulum. Flat.
As we discussed several times, even this, if larger than thrust/inputPower of a photon rocket leads to a problem with conservation of energy.
Having increasing force with constant input power can trivially be shown to be a free-energy machine.
I doubt that the strongest advocate for the EM Drive as a source of space propulsion would seriously advocate for the EM Drive to result in increasing force at constant power. That would be a runaway free-energy machine.
Hence increasing force at constant power is clearly a transient or an artifact.
NASA Eagleworks plots were showing fairly good looking pulses with the force settling down at constant power. Not increasing force at constant power. That is a no-no.
It must be related to the fact that you are doing frequency sweeps and therefore the mode shapes are changing.
It must be due to the fact that they are transients and not steady-state.
If you want to understand what is going on, you better go for the simpler things: the steady-state.
Transients are always more complicated.
Transients for mechanical oscillations are more complicated than the steady-state solution: for example a mechanical system excited with a mechanical force oscillating harmonically will display a transient with a damped frequency different from the excitation frequency, and the shape of the transient will very much depend on the amount of damping and the shape of the transient excitation including initial conditions.
Therefore you should be looking for flat portions of the curve at constant power at constant frequency.
The worst thing to have, which was shown to be an experimental artifact is something like this, with the measured force increasing, apparently without bounds, at on/off pulsing of constant power in each on segment:
-
#3794 by Monomorphic on 12 Jul, 2016 18:55
-
I disagree.Particularly just before it went below 2.45 GHz ? (long portion of flat response)
Just to be clear, the flat portions represent no movement of the beam. Time is horizontal, displacement is vertical. When the graph line drops, the frustum is moving in reverse direction (large end leading), when the graph line goes up, it is moving in forward direction (small end leading). So it would seem the the portions where the beam moved down quickly are the most interesting.
The figure of merit in all discussions about the EM Drive have been force/InputPower.
With constant input power, you should get a constant force on the torsional pendulum: it should settle down to a flat line. Constant input power = constant rotation of the torsional pendulum. Flat.
As we discussed several times, even this, if larger than thrust/inputPower of a photon rocket leads to a problem with conservation of energy.
Having increasing force with constant input power can trivially be shown to be a free-energy machine.
I doubt that the strongest advocate for the EM Drive as a source of space propulsion would seriously advocate for the EM Drive to result in increasing force at constant power. That would be a runaway free-energy machine.
Hence increasing force at constant power is clearly a transient or an artifact.
NASA Eagleworks plots were showing fairly good looking pulses with the force settling down at constant power. Not increasing force at constant power. That is a no-no.
It must be related to the fact that you are doing frequency sweeps and therefore the mode shapes are changing.
It must be due to the fact that they are transients and not steady-state.
If you want to understand what is going on, you better go for the simpler things: the steady-state.
Transients are always more complicated.
Transients for mechanical oscillations are more complicated than the steady-state solution: for example a mechanical system excited with a mechanical force oscillating harmonically will display a transient with a damped frequency different from the excitation frequency, and the shape of the transient will very much depend on the amount of damping and the shape of the transient excitation including initial conditions.
Therefore you should be looking for flat portions of the curve at constant power at constant frequency.
The worst thing to have, which was shown to be an experimental artifact is something like this, with the measured force increasing, apparently without bounds, at on/off pulsing of constant power in each on segment:
Ah okay, I see what you're talking about and that does make sense. Thank you!
I have almost everything I need to go solid state and that is next on the list. Solid state will also be vastly easier to run on batteries.
-
#3795 by Space Ghost 1962 on 12 Jul, 2016 19:00
-
Sorry to briefly "butt in".
Different points of view here between experimenter, enthusiast, engineer, and academic.
An academic evaluates, tracking down where all the energy is deposited, to get it to add up to 100% (or 99.9%). That is to account for error and to bound the "new science", so you can assign to likelihood of given theory.
An enthusiast attempts to intuit a partial experiments results into how they think it works. They cling to the hints, and ignore the noise, because they are looking to tweak to get more of hints (signal) vs noise, which then they can characterize the noise after the fact with.
An engineer mixes parts of both of these knowing pragmatics of what they can/can't get, using experience as a guide, and "gut feel" as to what to go on.
An experimenter validates or invalidates, and tries to not intrude much.
All get fooled in different ways. All get slighted by each other because they don't always see eye to eye, or communicate well. Its hard to be objective when you invest yourself in things too far.
Right now on the LHC, the "bump" in the statistics from last years run has vanished because of a longer, higher intensity run has caused it to go away. The "new physics" wasn't there. How annoying.
And they have enormous resources and talent. Finding something unusual is not easy at all. -
#3796 by RotoSequence on 12 Jul, 2016 19:01
-
I've superimposed the rate of change in beam displacement.
That increase in beam displacement after the power turns off always stands out to me in these tests. Where does it come from? -
#3797 by tchernik on 12 Jul, 2016 19:36
-
...
Ah okay, I see what you're talking about and that does make sense. Thank you!
I have almost everything I need to go solid state and that is next on the list. Solid state will also be vastly easier to run on batteries.
Wow
If you run this experiment on batteries you will be making history.
Only Prof. Yang, and if my memory is correct our esteemed DIY at NSF, RFPlumber, run the EM Drive with batteries, both with null results.
Nobody else...
Yep, we are maybe close to a very important point for all this Emdrive affair. Either it shows something or it shows nothing with the DIYer tests, now with batteries and with the biggest sources of noise removed, and that's where things either break or break through.
If the tests show nothing with batteries, it's almost certainly game over. We can get a bit upset or sad, or laugh about all the fuss and move on.
Personally, it has been a fun ride since the beginning, because even as a spectator I have learned a lot about these topics of anomalous thrust, EM theory and the scientific method in general, thanks to some terrific smrt people I had the chance to read on these discussions.
But if it still shows something... then this can indeed be a historical moment. All from the hands of a very few curious minds, refusing to let it go.
Either way thanks for the ride and best of luck! -
#3798 by jaydurst on 12 Jul, 2016 20:06
-
Warning, layman thoughts below:
Based on the graph and Rodal’s statement concerning the constant input power = constant force, it seems plausible, to me anyway, that the general downward direction is likely caused by the increasing temperature of the cavity skin, as the skin continues to heat as the magnetron runs, increasing the force. The flat segments, where we seem to see a constant force for input power is working against the thermal displacement, seemingly cancelling the increasing thermal force.
What I find interesting/strange is that this mode was supposed to generate a “reverse thrust” (downward displacement on the graph). I would have expected the displacement to suddenly drop and then continue on its thermal downward drift. If my layman’s interpretation makes any sense, it seems the drive operated in a “forward thrust” direction.
End layman's musings.
-
#3799 by Tellmeagain on 12 Jul, 2016 21:00
-
One thing that always bothers me is that a thin-wall frustum that consumes 900W power will be red hot in seconds. If it does not become red hot, it is hard to believe that much power is consumed rather than reflected. If it does not look like the picture below, then we should ask: how much power is consumed? A 900W power source does not mean 900W is delivered to the frustum. So those reported mN/kW numbers are questionable. I think future experiments should show how much power is consumed by the frustum, and how it is measured.
