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2012/03/15

1420	Fill N2 cold trap full. Pressure in dump is quite high at 740 mbar: signs of contamination. Start cryocleaning mixture through nitrogen cold traps 1 & 2.
2230	Finish constructing tower.
	The reason for no signal from Qo flexible in Run 24 is unknown: solder joints looks good; everything passes electrical checks with flying colours; and capacitance of “suspect” capacitor is no different from what is expected at room temperature. Just in case, capacitor was replaced. New capacitor checked at room temperature: looks fine.
	Piezo speaker (Projects Unlimited APS2714S-R) taped to bottom (Soudan orientation) lid. Kapton tape behind it provides insulation from chassis, kapton tape on face provides insulation from detector capacitors, copper tape on perimeter ensures kapton tape will stay in place. Positive terminal connected to QET B and negative terminal connected to QET B Return, both on rigid side coax. Please see Fig. 1 for photograph.
	Flexible Side Coax SCAB v1 connected to SCHUBA with low noise copper coaxial cables. Please see Fig. 2.

Figure 1: Wiring for Piezo Speaker in Detector Housing.

Figure 2: Assembled Flexible Side Coax v2.

Table 1: Tower Level Continuity Checks.
Side Coax	ZB1-1-9	Flexible v1
Tower Face	5	2
Qi Feedback-Qi Gate	26 nS	25 nS
Qi Feedback-Qi Bias	<0.1 nS	<0.1 nS
Qi Bias-Qi (at DIB)	*	25 nS
Qo Feedback-Qo Gate	26 nS	25 nS
Qo Feedback-Qo Bias	<0.1 nS	<0.1 nS
Qo Bias-Qo (at DIB)	*	25 nS
No shorts to ground!

* didn't check

2305	Fill N2 cold trap full.