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Expedition 397T officially started got underway at 10h18 on September 12 and ended at 08h00 on October 11. Expedition 397T occupied two new sites from Exp391: U1584 U1585.
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- I was in contact with Nolan Pretty at Knudsen. He wanted us to perform some tests using the EchoSIM.
- The first figure is from the impendence tests in Transducer Test Mode. The orange traces are from Exp397T and the blue traces are from Dec 2020 when we were also troubleshooting. The left plot is from the Thyrig Room junction box to the dome. The right plot is from the amp to the dome.
- Both cables measure continuity. The 12 kHz is 0.9 ohm and the 3.5 kHz is 2 ohms.
- The next figure is from the Simulator Mode. Nolan wanted to confirm that the amp is working correctly, and the test confirmed. You set the EchoSIM software to a certain depth and then check if the EchoControl software receives the same values. A nice test. Just remember to use the internal impedance of 50 ohms using the EchoSIM cable.
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- We opened the hull hatch . We took this opportunity to replace the 3.5 cable to the O'Brien connection. It was suggested to replace for a couple of years now. All the pins on the O'Brien connection were measured going to the sonar dome. All five pins gave approximately the same ohm value. This is an indication that the cable down to the junction box or even the junction box itself is compromised; or worse case both.
- A - B : 1 ohm
- A - C : 1.1 ohm
- A - D : 1 ohm
- A - E : 0.9 ohm
- The MRU heave data is coming through a new comm port over previous configuration but could not be tested as the Balck Box and RS232 convertor was not temporarily relocated to the gym locker. The need is not urgent.
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