Quote from: Notsosureofit on 03/22/2015 02:06 pmCan you use your analyser in a reflectometer configuration ?Um, no I don't think it can do that. I have an Agilent E4443A, and also an 8562A and 8562EC to use. I can't take test equipment home from work anyway. So all I can do is test at work to get data, then use the data at home. I've had to work all weekend, so that's why I'm in test mode instead of building things and trying to find a lathe to use.....
Can you use your analyser in a reflectometer configuration ?
@ Star-Drive"EDIT 4: @Star-Drive: up-thread the participants were trying to get your attention on the reverse thrust condition."-from StormbringerThanks
Quote from: Notsosureofit on 03/22/2015 12:17 pm@ Star-Drive"EDIT 4: @Star-Drive: up-thread the participants were trying to get your attention on the reverse thrust condition."-from StormbringerThanksNotsosureofit:The reverse thrust signals for the 1937.15MHz thrust signals are not the negative going mirror images of the forward or positive going thrust signatures as one would have liked. I'm still trying to understand why this is so, but I think it means that the force measurement system is not symmetric in its response to left and right going force inputs at the low thrust magnitudes we are currently having to put up with, since I've already shown that the frustum produces similar thrust values both inside and outside the stainless steel vacuum chamber. I've appended two slides to this post that show the forward and reverse signals in-air on one slide at 50W and then just the reverse thrust signal in-vacuum at 35W. I've also appended the frustum out of the vacuum chamber thrust run, noisy as it is for your inspection. Bottom line to all this is we need more thrust to work with and from our current COMSOL/QV-Plasma Code runs now for the TM010 mode at 942 MHz, its becomes very apparent we really need to increase our power levels into the 1.0-to-10kW-rf range or even higher. And yes they may validate the magnitude of thrust data that Shawyer's and Chinese's reported even without dielectrics in the cavity. Of course one data point is only suggestive, but it sure points us to where we have to go to truly validate these conjectures. However that course of action requires resources that are at present not available to the Eagleworks lab... BTW, these COMSOL/QV-Plasma Code thrust predictions may be reporting up to an order of magnitude low from what the real test article will generate at the noted power levels as shown in the last appended slide.Best, Paul M.
@ Star-DriveHave there been any experimental runs that show force towards the big end ??
Quote from: Notsosureofit on 03/22/2015 04:26 pm@ Star-DriveHave there been any experimental runs that show force towards the big end ??All:1. For my post of earlier today reversed thrust means physically reversing the frustum test article 180 degrees from its previous "forward" position. 2. I've also observed several test setups that generated reversed thrust signatures without physically turning the thruster around 180 degrees in its mount. One of these instances was with the current copper frustum and the others were with my two Mach Lorentz Thrusters (MLT) as reported in my STAIF-2006 paper. Thrust reversal was obtained in those test setups by reversing the E-field & B-field drive polarities via relay control.Best, Paul M.
Mulletron:In regards to your sense antenna port on the copper frustum, when not being used for taking VNA S21 frequency sweep plots I either leave our sense antenna as an open circuit, AKA in a high-Z state, or use it as a feedback control signal for our phase locked loop (PLL) circuit. If the latter, I still have to make the E-field sense antenna in the frustum very small, (like just the solder cup on an SMA bulkhead connector), so as to not overload the PLL's mixer input. Even with this small of an antenna, I still have to add at least 40 dB of 2W each 5-to-10 dB attenuator pads to the sense antenna's output to keep the PLL's mixer circuit from overloading. And the higher the Q-factor of the mode under study, the more sense antenna padding isolation that is required.Best, Paul M.
Quote from: Star-Drive on 03/22/2015 05:11 pmQuote from: Notsosureofit on 03/22/2015 04:26 pm@ Star-DriveHave there been any experimental runs that show force towards the big end ??All:1. For my post of earlier today reversed thrust means physically reversing the frustum test article 180 degrees from its previous "forward" position. 2. I've also observed several test setups that generated reversed thrust signatures without physically turning the thruster around 180 degrees in its mount. One of these instances was with the current copper frustum and the others were with my two Mach Lorentz Thrusters (MLT) as reported in my STAIF-2006 paper. Thrust reversal was obtained in those test setups by reversing the E-field & B-field drive polarities via relay control.Best, Paul M.The bell just tolled: my understanding of what "reverse" meant in your plots was thereby defenestrated corrected Is there a position vs. time plot of the "One of these instances ... with the current copper frustum" with the force directed towards the big end? If so, can you make that plot available?What was the frequency, mode shape, thrust force, Q, input power and testing environment corresponding to the case exhibiting a thrust force pointed towards the big base?It is very important to report this case because it defenestrates nullifies mechanistic theories proposed to explain the NASA Eagleworks measurements as an experimental mechanical artifact having no application whatsoever for spaceflight applications.
Dr. Rodal:The copper frustum thrust reversal due to only its dielectric placement came when I was experimenting with the TM010 mode, when I cut back the HDPE disc count to one, while the copper frustum was mounted in its little OD pointed to the right or forward position.
I then removed the HDPE disc ...
... and replaced it with one 5.13" OD by 1.06" thick PTFE discs that was mounted at the large OD end of the copper frustum with the frustum still mounted in the same direction as the first TM010 test, i.e., with its small OD end pointed toward the right in the vacuum chamber.
The attached slides summarizes these two test series at 954MHz (1 HDPE Disc at which OD end ?) and 901 MHz (1 Teflon Discs at Large OD end).
http://www.dtic.mil/dtic/tr/fulltext/u2/a564120.pdf?"Demonstration of a wingless electromagnetic air vehicle"Pretty much proof-of-concept, goes into lots more detail than I have endurance to read.