I will be at home today writing up the results from yesterday, i.e. null. The good news is that the new cable, for test runs under 2 minutes, just gets warm and there was no arcing, smoke or twisting. As we figured out in the lab, what smoked was not the dielectric but the injected plastic which held the probe in place:
After taking the probe assembly apart it was apparent that the probe was held in place by plastic injected through holes (not shown) in the side of the metal mount, through the dielectric and around the probe top. The plastic was then allowed to harden. For our latest test runs, we just flipped the dielectric around, attached the coax and made sure the probe was pushed in far enough to seat on the N-type connector and then bolted the probe assembly into the cavity.
With the cable and probe problems solved, we can now iterate through a bunch of cavity designs to find one that moves.
Below is a picture of the video camera hooked up to an external monitor. The camera is connected to the monitor with a $75 mini HDMI to DVI cable although the feed resolution is low, only 720×480, even though the camera is HD(??) With the camera’s IR remote, we can start and stop the recording from outside the Faraday cage, which means we can close the cage, watch until the pendulum stops moving and then start the experiment. We don’t have to enter the cage, except for temperature measurements.
The money on the table was part of an “asymmetrical bet” I made with Kevin and Gary – if the cavity moved I would pay them $60, but if it did not, they owed me 50c. I made 50 cents!