The silver state. [volume] (Winnemucca, Nev.) 1909-1925, 1923-05-17
HOW TO MAKE A SOUND INTENSlFIER

A.-Screws holding wooden block
and commutator shell together.
B.-Nipples OF spokes holding COM
mutator shell central with reflector.
C.-Spokes passing through reflec-
tor and commutator shell.
D.-Earpiece of telephone receiver.
E.-Plece of rubber bulb as sound
deneetor conveyor to reflector.
F.-Commutator shell.
G.-Wooden block fitted into COM
mutator shell. In which telephone Is
fitted.
H.-Adjusting screw to press re-
ceiver against rubber washer NJ.
J.-Holes for waves from telephone
receiver.
K.-Holding down clip for front Of
reflector.
L.-Brass standard screwed to base
and soldered to reflector.
M.-Rubber ring made from inner
tube of motor tire.
The arrangement for using the old
aluminium commutator shell for hold
ing the telephone receiver can also be
applied in different manner. II the
wooden block Is turned fiat II could
be screwed to the top Of the radio
cabinet and large horn fitted on the
small end of the commutator shell as
ampllfier. II number OF holes were
drilled In the side of the cone and the
holes tapped TO take a-inch brass pipe.
1t could then be fitted with rubber
tubes. which could be fitted with ear
pieces Of glass tubing and used by a
number o. persons.
Part of the brass knob taken from
a bed or door could be used instead
of rubber.
Procure telephone receiver. the d.
ameter of the cover of which Is less
than that of the inside of commu-
tator shell which Is two and thirteen
slxteenths inches. The depth from the
face of the earplece TO the back of
the telephone does not matter much.
as wooden case must now be made
to III inside OF the commutator she'll
In this wooden case, part IL turned out
10 hold the rest of the receiver. A rub
Der ring is put inside the commutator
shell and the earplece rests against II.
The wooden case Is then put In place
and with the commutator shell II In
held firmly by four screws. An adj
justing screw at the end Of the wood
en- case presses the earplece tight
ly against the rubber ring and makes
an alright joint. The connections can
be brought out through the wooden
case Of flexible cable. or otherwise, to
suit the maker. Diagrams OF each
part ARE shown, ms well as Of the as
sembled instrument. When all parts
are ready, proceed to assemble ms fol
lows: Take commutator shell reflector
and four spokes: pass a spoke from
the outside of the reflector into n hole
In the commutator shell and screw on
the nipple DO the same with the other
spokes. The shell Is then held In the
center of the reflector with the mar
row end pointing towards the polished
face of the reflector. Tighten up the
nipples evenly until the shell Is rigid.
with no wabble or shake. The piece
Of rubber horn bulb Is cut so that
there Is space between II and the
face OF the reflector when slipped over
the end of the commutator shell open
ing. The brass strip Is slipped on
the outside and fastened TO neat
wooden base. The edge Of the reflect
ha hau a.,A Ia
held down tight by screw and clip
When the reflector Is fixed on the bnse
the brass strip can be soldered to the
back of the reflector. When the tele-
phones are inserted. the block placed
In position. screwed tight and the back
adjusting screw frightened up. oil Is
then complete to connect up TO the
set.
| 10 Science and Invention and Radio News.)