| | Current setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50. |
| | Overnight: Taking background data. Last flash at 7:31. Tower temp stable between flashes. |
| 0915 | Fill LN2 cold trap full. |
| 0930 | Tower/MC(H35)/MC sensor/Cold Plate = 30.9/25.3/40.7/158 mK, Still = 1.31 K / 0.11 mbar, G1/G2 = 150/140 mbar, 1K Pot = 1.72 K / 20 mbar, Main bath = 74.8% |
| | Overnight, DIB1pB had problems. Around 11 pm the test signal pattern appeared in it. Then at around 4am it railed. |
| 1100 | After MIDAS tests finished, unrailed DIB1pB. No pulses, jagged noise. Fiddling with cable-to-DCRC connection brought them back, but not for long. These connections should be better secured… |
| 1145 | Removed all screws from the connector chain to DCRC55 (cable Dsub, gender changer, filter, DCRC Dsub) and ran zip ties through the holes to tighten the connections. Had to file down the width of the zip ties so they would fit through the holes. |
| 1205 | Repower DCRC55 and zap SQUIDs |
| 1215 | DIB1pB dead, jagged noise. Fiddling with now-tighter connections has no effect. Knocking DCRC around has no effect. |
| 1300 | Try using DCRCX instead of DCRC55. Apply SQUID and QET settings that we used for DCRC55 just to see if we can see pulses. DIB1 pA, pC, and pD show pulses with DCRCX, but DIB1 pB is still showing jagged noise and does not respond to changes in QET bias. |
| 1320 | Remove DCRCX and connect DIB1 to the Break Out Box using the same shielded cable we've been using to connect to the DCRCs. All 4 QET B to QET B Return connections are open. |
| 1325 | Switch shielded cable with regular Break Out Box cable. QET B to QET B Return connections are now closed connections, so it appears to be an issue with the shielded cable. |
| 1335 | Reconnect the shielded cable to the Break Out Box and EBox. QET B to QET B Return connections are open again. It's definitely the cable or the gender swap connector. Attempt jiggling the cable to cause connections to close, but didn't notice anything with the voltmeter. |
| 1400 | Perform continuity check on shielded cable. All connections are closed, so turn our attention to the gender swapper. |
| 1420 | Check pin 49, which should be QET B. It connects through. Notice that pins 35, 36, and 37 are loose-ish on one side. Check continuity, and find all three to be open circuits. Pins 36 & 37 are QET B Return lines and Pin 35 is FET TSense +. |
| 1500 | Swap the “good” gender swapper from DIB3 to DIB1, and repower DCRC55 on DIB1. All channels show up fine. |
| 1530 | Plug in “suspected” gender swapper that was on DIB1 to DIB3 and power on DCRC50. All channels show up, though pA shows up upside down and noisy pulses. Suspect the gender changer is responsible, though not sure why/how. |
| 1550 | Put gender swappers back on the DIBs they were originally on. Power on DCRC50 on DIB3 - all traces show up fine (pA no longer upside down), though noisy w/ some shelving. Squeeze together filter/gender changer/cable assembly and noise gets better (specifically on pC). Start touching wire between cable-connector shield and DCRC-connector shield, and noise/shelving goes away. Connect wire through filter/gender changer/cable assembly in hopes of reducing noise. |
| 1600 | Put “suspect” gender swapper back on DIB1 and power up DCRC55. Now DIB1 pA is showing upside down pulses so they seem to follow the “suspect” gender swapper. |
| 1615 | Flip around “suspect” gender swapper. Side that was up will be called Side I, so flip it around so that Side II faces up. Power on DCRC55. After applying SQUID settings, not only is pA still showing upside down pulses, but now pB is dead and showing the jagged noise and not responding to QET bias changes. Whoah whoah. Order two new gender swappers for overnight delivery. |
| 1650 | Dissect the “suspect” gender swapper. When taking off the shell on the side of the loose pins, the three loose pins (35,36,37) actually fell out because their solder joints had become broken. At the base of the pins are little fins that connected them to the rest of the connector. These fins could have been rotating and contacting nearby fins and causing strange shorts… |
| 1655 | Put Cf source in shield near detector for overnight activation. |
| 1700 | Fill LN2 cold trap full. |
| 1720 | Remove broken pins and reassemble “suspect” gender swapper. Attach to cable/filter/DCRC assembly with Side I facing up. Power on DCRC55. After applying settings, pA is still showing upside down pulses, and pB is still unresponsive to QET bias changes. Remove “suspect” gender swapper, flip over so that Side II faces up, and reattach. Power on DCRC55. |
| 1735 | After applying settings, pA is still showing upside down pulses, and pB is still unresponsive to QET bias changes. So yup… it's just a bad gender swapper. Lower source back down to near detector for overnight activation. |