Paul March is providing more information about the NASA EMDrive Experiments

How High RF issues are being managed

Please note that the entire RF system including its voltage controlled oscillator, phased locked loop, RF amplifier, RF coupler and coaxial transmission lines are hard mounted on the moving torque pendlum arm with the test artricle as it would be in flight. The only power lines that comes across the liquid metal contacts (LMC) are the +5.0Vdc control and +28.0Vdc and their associated ground power lines for each circuit. The Maxwell stress forces created in the LMC pots due to these dc power currects are calculated to be in the nano-Newton range and just act to restore the LMC metal pins to the center of the LMC pots that hold the Galanstan. In otherwords these Maxwell centering stress forces just increase the effective C-flex spring constants by less than a tenth of a percent even when drawing ten amps through the plus and minus 28Vdc bus wires. And yes, all these power wires are twisted and and shielded throughout their runs to cancel out most of B-fields associated with the RF amplifer and control power feeds. Even with all that though, we appeared to still have a small residual interaction between these stray power line shield B-fields interacting with the stray B-fields from the magnetic damper, so we’ve already upgraded the magnetic damper design to further reduce this problem. Here are some pictures with the new magnetic damper design and buildup pictures.

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