Author Topic: EM Drive Developments - related to space flight applications - Thread 9  (Read 1800725 times)

Offline Bob012345

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ARW, since you are new to posting in this forum, I do not know how much of the history of these threads you have gone through, but assuming it is not much there is some context you should be aware of. The Traveller has given you a lot of advice and much of it is good, but many of the things he says have nothing to back them up. For example, in the post quoted below he dismisses the actual, high quality experiments by EW as "not representative of reality". He instead quotes figures from Shawyer, when no other emDrive builder has gotten results close to Shawyer's, and Shawyers results are suspect due to insufficient data released for replication, known issues with the data that has been released, and the fact that Shawyer has demonstrated an inability to do a simple force balance.

Some of what TheTraveller posts is based on sound RF engineering, but other things are rules of thumb he got from Shawyer, when there is no evidence Shawyer has actually done the types of tests that would be required to determine them.

TT will inevitably respond to this saying to not listen to me, because I'm not a builder and therefore I don't know anything. My goal is just to give you context not advice. (If I did give advice it would largely mirror PotomacNeuron's advice above for minimizing error sources) As some additional context, TT's experience with building an emDrive is building a single one, which he has only provided hand sketches of and not a single picture. His explanation involves his RF equipment burning out during testing (a common occurrence here due to the nature of these experiments), but I still haven't figured out how that prevents him from taking a picture of the frustum. He supposedly is working on his second one now.

Please review the attached document.

I doubt that your cavity will have E field above 50Mv/m. More likely a lot lower. Max E field increases as the sqrt of the incressed power. So increase pwr 9x, E field increases 3x and H field increases 3x.

Why do you want to use 10kW? 100W should be fine. Please don't take the NASA 1.2mN/kW as being representative. SPR'S Flight Thruster at 326mN/kW is closer to reality and that was with spherical end plates and a Q of 60,000.
http://www.emdrive.com/flightprogramme.html

I don't currently have that frustum.  It was a quick build, was gravity stacked & didn't have flanges on the side wall. It was sent to my S band thruster fabricators to have flanges put on and to be machined so the end plates are parallel and orthanagal to the Z axis.

Plus I was very sick recovering from the after effects of 5 hours of cancerous prostate removal,  then 40 days of radiation treatment as attached. Dark area is cancerous tissue removed and the white line are where the radiation was applied. Plus several visits to hospital to deal with a superbug infection & cancer related bowel shortening.  Currently undergoing further cancer treatment with dual hormonal & chemo treatment as the cancer came back. The result of all that took many, many months in bed and not working in my workshop. This is not new to NSF. Have reported it before.

Do have 5 professionally fabricated thrusters and 4 Rf amps due to ship this month. $60k worth of gear.

Have promised my wife & family to not engage with them until my current treatment is completed and New Year is well over.

My next experimental programs will be extensively documented,  with a YouTube channel any can watch.

If I don't make it, all my frustums, test rigs, amps, freq trackers,  etc go to Paul March. Is in my Will.

BTW I've built several frustums. The Rf amp didn't burn out. The variable attenuator failed to deliver an output signal.

We all want to see you do those tests yourself as soon as you are up to it!

Offline mwvp

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"4 meter long photons"  ;D

https://www.sciencedaily.com/releases/2016/12/161202074852.htm


Really messes with your head, doesn't it? Tempts me to expound on dark solitons, vacuum energy, et.

You might enjoy Macken's book at: http://www.onlyspacetime.com/

I read it last month, and still chewing and digesting. Perhaps his property of "unity" and superluminal propagation of Plank-scale longitudinal waves could be accounted for by time symmetry mentioned in the spacedaily article; the Plank scale vacuum waves travel forward and reverse in time.

But the first chapter speaks on energy sloshing around in a waveguide accounting for particle motion.

Offline M.LeBel

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The uncertainty principle; revisited?

First off, position and velocity (for momentum) are two contradictory aspects. Movement is a blur on position. But the problem is not there.

Consider an oil tanker coming into harbor. We can determine its position by GPS to the centimeter precision. But, the oil tanker is 500 meters long and, it is “all tanker” from one end to the other. See me coming? The precision on the position of the oil tanker can NEVER be more precise than the actual size of the tanker! This is what you get when you work with “point” like particles without considering that things that exist must have an actual size. Furthermore, the wake, or the Broglie associated wave is an integral part of the moving particle making its operational size bigger than the actual particle. The moving particle is somewhere inside its associated wave...

Associated wave ....Wass that? The particle replaces by logical substitution some of the local (explosive) time process, which creates a local explosive deficit of the time process, i.e. a slower time field a.k.a. its gravitational field.  The gravitational field is the signature of the existence of the particle. What is existence? Anything that somehow-anyhow makes a difference... exists! So, the particle exists via this time process substitution, a difference. When the particle moves, the signature of its existence is distorted. How far the distortion goes (wavelength) depends on the velocity of the particle. (all absolute velocities wrt c). A slow particle allows more time (at c) for the change in signature to travel; equals a long De Broglie wavelength. A very fast particle gives little time for the change in signature to travel away; equal a short De Broglie wavelength. Very near c, no more change in signature may travel away and/and make a difference. Then, no more change in signature can happen as well. In summary, existence is about making a difference, somehow. Near c, no more change in signature difference may travel away. Therefore, no more change is possible. IMO, at this point, the time process substitution is maximum and so is its relative mass....   

Now, because this existence is about replacing a dynamical process, “to exist” is also a dynamical process, not a steady state. In other words, how long an object stays in one place, the “time of residence”, determines how far away its gravitational signature will travel. The time of residence is inversely proportional to velocity.. This is also to be considered in macroscopic situations.... like planets.

Consider the probability of finding a planet anywhere on its complete orbit around the Sun. (Assuming here a closed loop, not a slinky..) The integrated probability of finding a planet somewhere on its complete orbit within a complete period is equal to 1; it is there, somewhere. But, the “time of residence” is not the same in all parts of the orbit as the planet speeds up or slows down in various places of the orbit. From a large distance, the influence of its existence is blurred accordingly and would appear to be (averaged out) at the long foci. IMO, Keppler’s first law is about the computation of the relative existence (time of residence) of the celestial body along its orbit.

Now, I believe, IMO, that one day we will teach in say, 7th grade, how logical and simple the universe DOES what it does by itself. If one want to DO something WITH the universe in our reality, he will get 12th grade physics and later, engineering. Sounds to me like, this emDrive adventure is like a 12th grade project without the 7th grade knowledge....

(headaches anyone ??? )

Food for thought
some of these things like the fact than an electron is not actually a point particle are only recently experimentally observed/verified. I digress...

Most if not all of the EM drive DIYers *here* are certainly not lacking in education. :)

... Education?.. No, of course not. But take PhD for example. Says “Doctor of Philosophy”. This last word is important. All the great scientists of the last century had some classical education including Greek philosophy, middle age and renaissance philosophies...  Philosophy is a system of opinion, not a truth system. Yet, forming proper opinions and questions is what gets us through all other truth systems. Theoretical physics requires more philosophy as forming and weighing assumptions, looking at the big picture etc. Engineering squeezes the equations and parameters to their limits to get results, here and now. The emDrive is an exploration both experimental and theoretical. But, IMO, there is nothing wrong about stepping  back, from time to time, and asking yourself; How does what I am doing compare to what I am trying to achieve?

Food for thought..

Offline SeeShells

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As for why EW would do this, it is explained in their paper - EW was looking to verify that a thrust exists and so were satisfied with a mode that they could well control, while TheTraveler and SPR are beyond the point of existence and are looking for increased thrust. (correct me if I'm wrong, but I don't think so.)

You're right, but strong critics of the Eagleworks peer-reviewed paper focus on the fact the very tiny anomalous force recorded is inferior to the thermal signature, which leads to a method trying to separate the real anomalous force from the normal thermal force. An anomalous force well above thermal would have not triggered such criticism.

Concerning your prior post http://forum.nasaspaceflight.com/index.php?topic=40959.msg1613822#msg1613822

I am periodically updating drafts of my article on Mach Effect Propulsion, a chapter in the proceedings of the 2016 Advanced Propulsion Workshop at Estes Park Colorado, to be published in the near future.

If you like, you can download my report from here:

https://www.researchgate.net/project/Mach-effect-propulsion

Best regards
Dr. Rodal,

Very well done. There is a tremendous amount of great information in this paper. It's going to take me several days to digest it.

Thank you for posting this.

Shell

Offline WarpTech

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Thank you for your feedback. Over the weekend we will be having few meetings to discuss and finalize all the details so I could start working on getting necessary equipment. Feel free to add any other remarks.

Another question I have is how to proceed with end plates, is there a need for any kind of seal or simply bolt 2 pieces together?

Also could you recommend RF generator to match my design vision of up to 10kw.

Dude has a vision and good money to spend to crank 10kw into a frustrum, and everyone is saying 100w is better. I for one really want to see what happens! Surely if that's a narrow band source then it's a very useful set of data? Especially if it's adjustable, so it can be measured at 100w, 1kw, 10kw. Maybe that's where the signal really leaves the noise.

I think if you put 10kW RF into a frustum with no idea how much reflected power and power dissipation it will have, you're just asking for trouble. 10kW is a LOT of power to be dissipated by a thin walled copper can. It's going to need some serious mass and cooling. Not a quick or easy design. A lot of thought needs to be given to this.

I'm working on an experiment to try driving resonance with a spark gap. It's battery powered, only about 5W DC input at 12VDC, but it will provide an ~1 ns pulse at ~350kW, provided it works that is! It should have an adjustable repetition rate from low Hz to maybe 14kHz. I just ordered components to test it on one of my ice buckets. Now I just need to save up to buy a VNA, so I have something to measure with.

Note: I don't know how long the spark gap will last at this repetition rate, but they're dirt cheap and the system is easily scaleable to much higher pulsed power, or faster repetition rates by upgrading the power supply. This one was $14.

Any thoughts or comments on this cheap experiment would be helpful. Thank you.



Edit: In this image, L and C2 are the frustum. The antenna is just a small loop of wire in series with the spark gap. It will provide an enormous H-field impulse through the loop. I'm assuming it can be tuned by the length of the antenna loop.



« Last Edit: 12/03/2016 06:47 pm by WarpTech »

Offline WarpTech

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Went through my notes and created a spreadsheet of the result as attached. Was very careful to make each measurement sequence procedure as identical as the others. Did quite some practice to get the process to work well.

I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Please note that each test run was hand tuned to the lowest reflected power. Test setup was very KISS as attached.

I know all you guys are going to beat me up as no photos but I was in the heat of the measurements and I didn't have my phone handy. BTW my phone is a Samsung Note 10.1, so it doesn't fit in my pocket and I don't normally carry it with me.

Then the Rf amp died and I was sucked back into hospital so it all stopped.

Will not happen the next time. Will be heaps of videos and pics.

What is the frequency for each run?
What is the mode?
What are the dimensions of the frustum?

These should be added to this post and archived TT, as a vital part of the data.

Thanks!

Offline WarpTech

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I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

Maybe not so weird. When the small end is down, it is resting on a copper clad PC board, which gives it a bit of a heat-sink effect that might reduce the losses at that end. This board might also be reflecting some of the escaping flux (momentum), that is not reflected when the small end is up. Thereby pushing the PC board down on the scale.

TT also said there were no flanges, everything was held together by gravity, I assume he means at both ends. In which case there were plenty of leaks for hot air to escape. Maybe buoyancy in this case is negligible? Probably a good thing.



Offline meberbs

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Any thoughts or comments on this cheap experiment would be helpful. Thank you.
I think you have likened this previously to "ringing a bell," but there are some key differences, which is why I don't think this will work the way you are thinking.

When you ring a bell, you transfer energy to it by hitting it, but then you pull the hammer back, so the energy is trapped in the bell. Also, generally the hit is much faster than the frequencies you are trying to excite.

For your setup, a 1 ns pulse corresponds to a 1 GHz primary frequency, and some additional higher order frequencies depending on what actual rise/fall times you can achieve. Also, I would expect most of the energy to simply be reflected back due to mismatched frequency.

I have some concerns about the potential to do bad things to the power supply when most of the energy feeds back into the battery, but I'll let someone with experience working with spark gaps determine if that is a real concern.

Offline WarpTech

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Any thoughts or comments on this cheap experiment would be helpful. Thank you.
I think you have likened this previously to "ringing a bell," but there are some key differences, which is why I don't think this will work the way you are thinking.

When you ring a bell, you transfer energy to it by hitting it, but then you pull the hammer back, so the energy is trapped in the bell. Also, generally the hit is much faster than the frequencies you are trying to excite.

For your setup, a 1 ns pulse corresponds to a 1 GHz primary frequency, and some additional higher order frequencies depending on what actual rise/fall times you can achieve. Also, I would expect most of the energy to simply be reflected back due to mismatched frequency.

I have some concerns about the potential to do bad things to the power supply when most of the energy feeds back into the battery, but I'll let someone with experience working with spark gaps determine if that is a real concern.

Thank you. I have a lot of experience working with spark gaps for power protection circuits. I wish I had all the ancient test equipment I used to work with in the 80's.

In this case, you are right. I'm not sure how fast a rise time I can get, but there are ways to increase it by overdriving a lower voltage spark gap with a higher voltage spark gap. It's a very inexpensive test, except for the VNA.

As for feedback. The power supply is a DC/DC converter with an isolated 1.5kV output. The spark gap will close when the voltage across the gap exceeds 840V. The gap will open as soon as the current goes to zero, or typically within the first few cycles. This, and the fact there is a 1nf capacitor on the other side, makes sure that once that happens, the power supply is well decoupled from the ringing. (I hope.)

Look at it this way. A 100W RF input is only going to provide 1.4A at 70V into 50 Ohms, or about 30 nV-s of magnetic flux per pulse. My spark gap should provide 840 nV-s of magnetic flux. If it can't cross back over the gap, it has to go somewhere, and dissipation is what makes it go. We shall see.




Offline InterestedEngineer

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"4 meter long photons"  ;D

https://www.sciencedaily.com/releases/2016/12/161202074852.htm

synopsis:  the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not.

Com'on; it's related to what we are discussing here... you know it is :)

how photons interact with matter and that photons and their interactions can be even weirder than we knew.

The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail.

So there's an asymmetry in excitation. Is it possible to build a device where one side preferentially absorbs and another side preferentially reflects photons of a standing wave?  You'd get a net thrust in the direction towards absorption.  Until we can figure out the mechanism of the asymmetry, you'd have an apparent CoM  violation.. but basically you are getting the difference between the force of absorption and reflection of a light sail, times Q.

Alas, the article didn't detail the mechanism behind the asymmetry.

Sounds kinda familiar.  Add this one to the list of theories?


Offline Stormbringer

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"4 meter long photons"  ;D

https://www.sciencedaily.com/releases/2016/12/161202074852.htm

synopsis:  the "shape" of a photon and the shape of the matter it interacts with determines whether it will be absorbed or not.

Com'on; it's related to what we are discussing here... you know it is :)

how photons interact with matter and that photons and their interactions can be even weirder than we knew.

The researchers found that if the photon arrived dimly, from the atom's point of view, then ended brightly, the peak probability of excitation was just over 50% higher than when the photon arrived bright and had a long, fading tail.

So there's an asymmetry in excitation. Is it possible to build a device where one side preferentially absorbs and another side preferentially reflects photons of a standing wave?  You'd get a net thrust in the direction towards absorption.  Until we can figure out the mechanism of the asymmetry, you'd have an apparent CoM  violation.. but basically you are getting the difference between the force of absorption and reflection of a light sail, times Q.

Alas, the article didn't detail the mechanism behind the asymmetry.

Sounds kinda familiar.  Add this one to the list of theories?
Only the guys and girls with the scientific experience could tell. I just brought it here because it looked like it might be of interest and might be helpful.
 
The only 4 meter photons I am familiar with were the ones launched in the Star Trek reboot. :D
When antigravity is outlawed only outlaws will have antigravity.

Offline TheTraveller

IAC, Adelaide, Australia, Sept, 2017

Hi Guys,

I'm very seriously considering setting up an exhibit booth, so to demo my non cryo S band thruster happily spinning and accelerating on a rotary test rig during the conference.

Will any of you guys be going and/or will any of you have a product in the market by then?

All the best,
Phil
of course assuming my health will support that plan

My intention from day one has been to manufacture and sell EmDrive based thrusters that are at least 5x more thrust efficient than the best Ion drives. Any reader here should know that.

Believe my latest design will deliver on that goal with a min 600mn/kW rating.

Intention in going to IAC 2017 will be to demo the thruster operating / accelerating on a rotary test rig and to fill my order book.

It is my understanding that my potential clients will have little interest in CofM nor CofE discussions but instead their interest will be on how much energy X they need to supply the thruster to deliver a deltaV of Y to mass Z.

The rotary test rig experiments I'll be doing are designed to provide that answer, ie what is the power supply load characterists during long term acceleration of mass X at acceleration Y?
It Is Time For The EmDrive To Come Out Of The Shadows

Offline TheTraveller

I can't explain the difference between up and down weight changes. Roger also measured the same effect.

Surprisingly you recorded a greater force downwards, yet heated uprise airflow and thermal buoyancy (if thermal effects sufficiently present, maybe they were quite low in your tests) should have added to the upwards force. Moreover Shawyer had the same stronger force downwards than upwards?! Weird.

Glad to see more tests are coming because you need to quantify EMI with the electronic scale as well as any electrostatic, magnetic, Lorentz and thermal effects on the cables attached to the frustum.

I expect the weight change difference may be hysteresis in the strain gauges.

The scale is designed to be zeroed out and weight added. When the weight reduces, that may not be an optimised measurement situation.
It Is Time For The EmDrive To Come Out Of The Shadows

Offline Monomorphic

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Paul March was kind enough to invite me to tour the NASA Eagleworks lab as I was passing through Houston in September to visit family. I agreed at the time to delay posting about the tour until the AIAA paper had been released since I was given free reign to look around and take pictures.

The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around.  ;D

Here are a few of my favorite pictures.

« Last Edit: 12/04/2016 12:31 am by Monomorphic »

Offline otlski

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Paul March was kind enough to invite me to tour the NASA Eagleworks lab as I was passing through Houston in September to visit family. I agreed at the time to delay posting about the tour until the AIAA paper had been released since I was given free reign to look around and take pictures.

The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around.  ;D

Here are a few of my favorite pictures.


Very cool pictures.  In the shot with the air bearing.  The stator looks white in color.  Is is made from Delrin or other plastic?

Offline M.LeBel

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"Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. Here is why, with an example. One tera-joule dissipated by a dripping faucet over eons will make a hole in the sink. The same tera-joule dissipated in a nanosecond ... and goodbye the sink and part of the neighborhood. Do you see a difference? I, for one, see a real difference. Real events out there happen in time and energy alone means nothing in the real world without time. In a universe with a background of running time, how quickly something happen does matter.

The blue photon (short period) delivers its h content much faster than the red photon (long period). In a universe sizzling with time, power is the real money, not energy. We “collapse” the wave, which means forgetting about the delivery time and integrating the work done i.e. calling it energy. Was this written for a better understanding or for a better “doing?”

The takeaway: “Think sink”

"Negligible".... : The theoretical physicists (and the philosopher) trying to understand will be uncompromising on all aspects of his investigation. But, “physics”, for one, is demonstrated by physical experimental proof, in our reality. We notice then, that the discourse of the theorist will slowly shift from the will to understand.... to the need to prove. Leaving the absolutes of the theorist he engages now into the shaving off of those elements deemed “negligible” in preparation to present, not an understandable theory, but for a doable experiment. His final equation will not show necessarily that he understands, but rather that he can do. And doing something with the universe, controlling it, is how we define “understanding”.  A doable experiment shows first hand the utility of the equation found and speeds up its technological extension. The equation does not describe our understanding of the universe but our ability to do something with it. So, do we understand the universe? Nope! We learn more and more how to do something with the universe. We don’t necessarily learn more about a) what the universe is made of or b) how it does what it does by itself. IMO, the need to prove physically some theory in our reality (conventional space and time) is a prejudice preventing physics answering these two questions.

Food for thought...

Offline Bob Woods

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The visit to Eagleworks and touring the lab and meeting Paul was the highlight of my Texas trip. Thanks to Paul for taking three hours of his time and showing me around.  ;D

Here are a few of my favorite pictures.


Jealous, Mono... VERY jealous.  ;D

Offline meberbs

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"Potential Energy" ...: “energy” is a nice paper concept for sentient beings. Alone, it means nothing in this universe. ...
Your argument that energy doesn't really exist because power is a thing is completely wrong. It is like saying that water in a reservoir doesn't exist because it only matters when it is falling over a cliff in a waterfall.

Remember that mass and energy are equivalent. If you want to see evidence that energy is a real thing, just try picking up (or pushing) a light and a heavy object.

Offline Peter Lauwer

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I did tests in 4 locations and rotated the thin & flexible 0.5m coax in different orientations to Earth's mag field. Even so no way can a 0.5m long coax with 100W of 2.45GHz can generate any significant Lorentz force to alter the frustums weight.

I was thinking more of mechanical forces. I guess the dielectric inside the cable heats up with supply of 100 W.

Also consider that when the frustum was reversed on the scale and nothing else changed, other than the weigh gain changed to weight loss.

That certainly is a good point. Well... the angle of the cable must have been changed (acc to your drawing).

When the frustum was flipped / reversed / rotated 180 deg, the height and alignment of the Rf amp and frustum SMA connectors were adjusted so they were level, pointing at each other and the same distance apart. Which is what it says on the drawing.

While the cable may stiffen,  never noticed that happening, there is a 2cm dip in the centre of the cable. Any expansion of the cable is not going to at one time generate a 0.9g down force and then generate a 0.7g up force when the frustum is flipped.

In that case, I would say it is quite an interesting result.
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.   — Richard Feynman

Offline Peter Lauwer

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From what I know,  the EW frustum's antenna was designed to excite TM modes strongly.

As such, I don't believe it is a good design to excite TE modes. My antenna is very different.


You mean TM modes in the last sentence?
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.   — Richard Feynman

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