Advertisement
G l : O P T I C A L
S O U N D
F O C U S I N G
PROCEDURE
A. Description
Models NST-O, NT-0, NST-I and NT-l are optical
sound pfayback onfy. Models NST-2 & NT-? are
both optical and magnetic playback and NST-3 &
NT-3 are optical playback *ith magnetic playback
and record. The optical pick-up $ystem resembles a
small preijector within a projector, consisting of a
light source, a lens, an image, and a screen or targgt.
Frs. #1O7
EXGITER LAMP {BRK}
The light from the exciter lamp is focused through
the sound track imaged onto the {target} :olar cell
where varied light intensity is converted into
minute electrical voltage changes that are amplified
and cqnvert€d into acoustical variation or sound
which directly relate to the photographic variation
reeorded on the film.
B. Sound Focus Al_igrl1ryI1-lrylg{g5!
b. Sound lens adiustment tool (Tool No. 320-
02T. Fig. #.|08, See note below)
c. $MPTE sound focus test film 7000H2
d- SMPTE buzztrack test film
e. AC VTVM {audio range} and or
f. Oscillosccpe
g. I ohm 30 watt dummy load resistor
h. External speaker {frant cover}
6 6
Fas- #109
2. Set-up.Pracedure
a. Open the lamp house door and remove the
exciter lamp cover.
b. Remove the lamp house door with frame cast-
ing to obtain access to the sound lens,
Fig. #l0g
EXCITER
-__-
ut|HP
c. Insert the tool No. 3?0-02T onts the larger
barrel of the ssund lens and tighten the set
screw on the tool.
Fb. #110
320-{t2T
srlt r\lD LENS
AA'USTME{TIT TOOL
SOUND LETIIS SARREL
NOTE: This adiustment may also be pcrformed
by adiusting the *lnd
lens with your
fingers, if the tool is not available.
3. Sound Focusing Adiustment Procedure
a. Connect the dummy load resistor to the
speaker output jack.
b. Thread the 700OHz SMPTE test film loop
with the emulsion side towards the film shoe.
c. Connect either an AC VTVM {?0 volt range}
or an Oscilloscope across the dummy load
resistor. {Fig. #t 13}
NOTE: When using instruments with agrounded
shield input, avoid a ground loop con-
ditian by not connecting the slrield at
the load resistor.
d. Turn the projectors function switch t$ &rr-
ward-
_ LETGHOLDEB
1: Tsols and Eq*ipment Reguired
a. Screw driver set {lso}
$OUND LENS A&IUSTMENT TOOL
- 6 1 -
Advertisement
