Specifications
3. 
Utmost reliability 
because...
The  sound 
proiectors 
5-211  and 
5-221
show  infinite 
care in 
every 
component, 
the
observance 
of  microscopic 
tolerances 
and
a carefully 
planned 
design  down 
to 
the
minutest 
detail. 
Materials 
of  chosen 
qua-
lity 
guarantee 
heavy 
duty 
performance. 
The
main 
components 
are 
permanently 
adjust-
ed. 
All 
projectors 
have 
to 
pass 
exhaustive
tests 
during 
and 
after 
assembly.
Here are three  specific,  significant 
exam-
ptes 
of  care 
in 
production 
and main 
parts
control:
The film 
gate 
and 
pressure 
plate 
have 
to be cor-
rected, machined, 
polished 
and mounted with the
highest degree of accuracy 
justified 
by the limited
depth of focus of fast 
projection 
lenses.
The claw 
is 
made from extra-hard 
chrome-plated
tempered 
steel. 
lts 
cam 
is 
milled to a tolerance 
of
0.0002" or one twelfth ol the diameter 
of a hair.
The claw is tested 
in 
the 
"life 
test" laboratorv
during a 1,000 hour test run at24 f.p.s. 
represent-
ing 
almost 90 million claw movements. 
Examina-
tion 
must not reveal any trace.of wear.
Even 
greater precision, 
of an order of 0.00004"
or one 
sixtieth o{ 
the 
diameter of  a  hair, is
observed 
for 
certain 
parts 
of 
the 
magnetic 
sound
head. All heads have to undergo 
final electronical
testing 
of high standards.
'€:l,t:;i:''::''1t
fi
7e,&
ft''.f.'&
Assembly of  l
the sound heads.










