DATE	MAINTENANCE
10 Dec 2006	cold head stopped? Lenze problem?
03 Mar 2008	removed from C14 at Cedar Flat
13 Mar 2008	opened refrig, cleaned cylinder and displacers; changed stage3 seal, worn through in 1 spot; reused seals for stage 1 and 2
31 Mar 2008	removed 3mm mixer xx, installed HIA-185 ; removed 1mm mixer 31-015-2, found its SIS device had fallen to bottom of slot; rebuilt with mixer 31-015-1, WBA13 amp with bias tee annex to shorten distance from mixer to amp replaced 200 ohm heater resistors on stage3 with 600 ohm resistors in lab tests running at 47/11/3.5/3.7/3.7 K
09 Apr 2008	installed on C15 at Cedar Flat cooled to 45/12/3.7/3.8/3.9 K
10 Sep 2009	removed from C15 at Cedar Flat
17 Sep 2009	cleaned displacers and cylinder