From: John R. Gunther <johng@prospero.uoregon.edu>
  To  : John Toedt <toedt@carb.nist.gov>
  Date: Fri, 19 Nov 1999 10:02:29 -0800

Re: SPIKES

Dear John Toedt,
    Regarding your spike problem, and wavelength shift of the mono, a possible fix is
lube the wavelength drive shaft O-ring.  This O-ring provides a seal between the
chamber and the atm room pressure where the drive pin enters the chamber.  If you have
a service manual it is pictured on page 5-12 item # 108 upper left-hand corner.
Description O-ring buna n 1/4". As the wavelength is changed this shaft moves in and
out (the very same one you can see in the chamber that goes into the mono).  If the
O-ring or shaft is dirty it can be sticky and not move correctly or move when it's not
suppose to.
    Use silicone vacuum grease to properly lube it.  I believe the grating motor will
have to be removed to accomplish this properly.  This is what my service rep did to
correct wavelength shift problem, and the spikes went away at the same time.

Spike less in Eugene

John Gunther
University of Oregon
Institute of Molecular Biology
Dr Pete von Hippel's XLI, GUI 4.5, Win 98.