Author Topic: EM Drive Developments - related to space flight applications - Thread 7  (Read 1678030 times)

Offline rfmwguy

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

« Last Edit: 03/17/2016 09:31 pm by rfmwguy »

Offline rq3

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.



Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

Offline rfmwguy

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.


Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.

Offline spupeng7

This is the Horizon episode on the BBC 23/03/16 featuring EM drive.

http://www.bbc.co.uk/programmes/b0752f85

I must say EmDrive will probably hit news again.

Also the conversation here really started to get very interesting lately! Thanks in part of Monomorphic landing in this thread :-). There is also that paper from University of Helsinky. I think that it was Dr. Rodal that stated that there are many groups we do not know about that dig into the research of the EmDrive. I did not believe that. I am glad I was wrong.
It is also interesting to see the development of the Baby-Emdrive. I just do not fully understand that each report of the positive thrust is hit with the tsunami of pessimism.

Mod: Added the last sentence.


Chrochne,

that pessimism is a direct consequence of standards of proof not being met. Results not statistically analysed, graphical axes unlabelled and lack of methodological detail, all conspire to make the emdrive look like Science Fiction. Even the most successful emdrive builders suffer from these flaws which can only be cured by properly funded experimentation conducted by established research institutions.

Meantime this, this is the crucial moment for amateur builders. This is when love and desire for interplanetary travel can raise the unemployed technician or the inspired misfit to the top of what may yet prove to be the biggest game in town. El Gordo has nothing on this. Attempting to build an emdrive, which proves itself, is a bid to reinvent the meaning and purpose and security of humanity. Pessimism comes of disbelief and the only proper answer to that is the scientific method.

Take your dream, analyse what you must do to realise it, theorise how that can be achieved, predict the consequences and then test for success. If you fail, repeat the cycle till you succeed. That is optimism and to an optimist other people’s pessimism is a compliment.
Optimism equals opportunity.

Offline meberbs

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...
My understanding is the prototype Flight Thruster was actually working and showing a weight reduction on the scale. Note the spring above the Flight Thruster and then read Roger's notes on Force Measurement.

By Roger's notes on force measurement, do you mean that pdf you posted a couple pages ago?

The only thing that paper should convince anyone of is that the author of that paper should not be trusted with making force measurements.

Both me and dustinthewind posted issues we saw with that document. The fact there are issues with the document should be obvious to anyone who has taken high school physics. Could you please respond confirming that you understand this? If you don't see the issues with that paper, then I (and other posters) can help explain, and any understanding you gain may help you improve your emDrive setup.

Offline SteveD

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I believe it is very important to compare the anomalous force resuts of these different frustums to make a valid comparison.

As I have measured ~8mN with my 1st non dielectric build, dielectrics are of no interest to me. I believe they are a waste of time. I know of NO build that has shown above multiple SnowFlake level of force generation using dielectrics other than Roger's Experimental EmDrive, after which he abandoned using dielectrics.

Dr. Rodal did have a point about builds with dielectrics seemingly having a higher force generation in vacuum.  Unfortunately these test are a bit suspect as they're not at near same mode and near same frequency with simular equipment. 

Offline Monomorphic

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Antenna Magus can export ready made antennas to FEKO. These are all the antennas available. Some look very promising.

http://www.antennamagus.com/antennas.php?page=antennas

Offline zen-in

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.



Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.

Offline rfmwguy

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.



Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.
Yes, it is a passive circuit designed for maximum thermal dissipation. bias and filtering are simple adds. My experience on this is designing for hi-reliability, meaning even heat distribution throughout the assembly and using transmission line material that has great thermal & mw properties, such as ceramic. I have seen non-ceramic boards burn, warp and peel, lifting above ground and inducing failure on passive and active devices.
Ceramic carriers are rather common and the expansion coefficients are very compatible with metals, especially when using indium solder. Yes, I did hi-rel stuff, but if we think about what an emdrive will have to do on long missions, it doesn't hurt to think about using the good stuff, even on observational tests.

Of course, this is only my opinion and Jamie has the freedom to pick and choose humble suggestions like everyone else building. Thought I'd pass along my experience. Specifically it was on 1.5kW passive attenuators and loads rated to 2.4 GHz. I was product manager for this device (note 7/16 DIN) used in Digital Broadcast transmitters:
http://www.birdrf.com/Products/Terminations_Loads/Coaxial-Terminations/1-5kW/1500-CT_1-5-kW-Conduction-Cooled-Dry-Termination.aspx#.VuwCi8v2ZxA



Edit - In a form factor like this, feedthrus would supply the bias voltage from a centered, perpendicular (thin) side (compared to the connector axis). Jamie could get creative and have a monopole extend downward from a center point on the assembly directly into a frustum. The opposite side could be the finned heatsink or coolant carrier. Lots of choices...
« Last Edit: 03/18/2016 12:51 pm by rfmwguy »

Offline meberbs

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(Mod alert - NSF staff deleted linked posts per a user request...I'll delete this to limit discussion on deleted posts.)
« Last Edit: 03/18/2016 12:50 pm by rfmwguy »

Offline rfmwguy

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Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf

I'm not eligible, just doing this as something different and giving a little back to the outstanding readership/users here. In case of a tie, I'll read those posts and select one to break it. In the meantime, I will not be posting LIKEs myself so as not to influence the outcome.

Could it be that experimental result post wins? A breakthrough theory is presented? Cool pics of in-process builds or models? The first to point out some breaking EMDrive news? YOU decide. Go! Clock is ticking.




Offline mwvp

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Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!

Offline rfmwguy

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Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)

Offline mwvp

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Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)

Beat? I prefer exploit or hack. It's what technology and innovation are about.

Speaking of which, perhaps you don't need 7 watts to drive that solid state S band amp, if you use a "bootstrap"; i.e. turn it into a (power) oscillator. That would complicate things a bit, but perhaps result in a cheaper tradeoff.

One of my favorite hacks is using digital CMOS hex inverter gates as analog amplifiers, or in a ring-oscillator configuration. By varying the chip's supply voltage/current, it can function as a sine-wave VCO over a 20:1 range, or with distortion, greater than 100:1. Alas, the high-speed devices (74HCT4069) can only hit 200MHz.

Offline rfmwguy

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Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)

Beat? I prefer exploit or hack. It's what technology and innovation are about.

Speaking of which, perhaps you don't need 7 watts to drive that solid state S band amp, if you use a "bootstrap"; i.e. turn it into a (power) oscillator. That would complicate things a bit, but perhaps result in a cheaper tradeoff.

One of my favorite hacks is using digital CMOS hex inverter gates as analog amplifiers, or in a ring-oscillator configuration. By varying the chip's supply voltage/current, it can function as a sine-wave VCO over a 20:1 range, or with distortion, greater than 100:1. Alas, the high-speed devices (74HCT4069) can only hit 200MHz.
Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

http://www.ebay.com/itm/like/281686883954?lpid=82&chn=ps&ul_noapp=true

Offline Monomorphic

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Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

The MHT1003 can operate at three frequencies. 2.4Ghz is one of them. I would need to adjust my frustum dims to match 2.4 as they are optimized for TE311 @2.45.

So I can have something to experiment with while working on the RF amp, I did order a 600W microwave from Amazon. It's supposed to get here today but traffic is terrible. This unit has all mechanical dials, so it should be easy to make work with the flip of a switch. I hope to use it in concert with my infrared camera to verify resonance patterns predicted by FEKO, specifically TE311, like NASA/Eagleworks did in their experiments. 
« Last Edit: 03/18/2016 07:57 pm by Monomorphic »

Offline X_RaY

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I think I had post this sometime in the past but think it's quite interesting to follow the video lessons of Susskind Lectures at Stanford university.
The pic below shows one of the most important formulas and it may be the source of some confusion(regarding to Shawyers theory) because it illustrates that momentum ρ of a wave function ψ depends on the wavenumber κ which changes along the central axis of the frustum (beside of his red/blue shift postulate in relation to the unclear reference frame problems  :o  ).
Since we are dealing with very complex problems in this case the lectures can be very helpful to learn and refresh the already known basics.
I think is it possible that we running into the problems of the uncertainty principle using such approximations*!
Would be nice to know the other side of the coin. ::)


*For sure it delivers a true quantity of energy.



I know about the particle interpretation ;) (as nicely created by Monomorphic) but I mean the explicit reason why there should be thrust at all.
« Last Edit: 03/19/2016 09:08 pm by X_RaY »

Offline rq3

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.


Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.

Dave, I'm thinking you didn't even take a cursory glance at the manufacturer provided artwork? It has rectangular cutouts, ground vias, mounting holes, cap/ind tuning stubs, impedance transistion strips, etc. Not trivial in ceramic. The last item I had made in alumina of similar size and complexity cost ~$5K.

Telling monomorphic to basically buy some pre-printed 50 ohm stripline on alumina (with the stripline being WAY too thin anyway), tack it to a heatsink with indium solder, and Bob's your uncle is a bit...weird.

Offline rq3

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Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

The MHT1003 can operate at three frequencies. 2.4Ghz is one of them. I would need to adjust my frustum dims to match 2.4 as they are optimized for TE311 @2.45.

So I can have something to experiment with while working on the RF amp, I did order a 600W microwave from Amazon. It's supposed to get here today but traffic is terrible. This unit has all mechanical dials, so it should be easy to make work with the flip of a switch. I hope to use it in concert with my infrared camera to verify resonance patterns predicted by FEKO, specifically TE311, like NASA/Eagleworks did in their experiments.

No, the MHT1003 can operate at an infinite number of frequencies, they just happen to be fairly close together. It's design was centered at the middle of the ISM 2.4GHz microwave band, and it's a fairly narrow band amplifier.

Offline rq3

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Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.



Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.

Nor is the RF board in the pic ceramic. I'm unclear why Dave thought it necessary to gainsay the manufacturer of the device and recommend a very expensive alternative to the material actually recommended by the device manufacturer. His reasoning got so circular it was a waste of time trying to follow it. Good luck, monomorphic!

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