User`s manual

A-Chain Alignment Procedures
Notes
4-15
b. Optical Preamplifier Adjustments
x x
Not enough light
on one channel
Uneven light on cell
Thread and play the pink noise on the Cat. No. 69 film (emulsion away from
screen). Connect the RTA to the left test point L on the Cat. No. 510.
Switch the oscilloscope to the X/Y mode and adjust the azimuth of the projector
optics for the narrowest diagonal trace. (Blooming at the ends of the trace may
be caused by improper lighting of the edges of the optical tracks. If necessary,
repeat the cell alignment steps or the exciter lamp position step to reduce such
blooming to a minimum.)
While observing the trace on the RTA, adjust the focus of the sound track lens for
the best high frequency response. The trace shown in the example is ideal;
merely attempt to obtain the best response. The azimuth and focus adjustments
interact so you must repeat Steps 12 and 13 until no further adjustments are
required.