Evening star. [volume] (Washington, D.C.) 1854-1972, 1938-08-07

" " this little metal DOX CnaC
causes strong men to pale
and gentle women and little children
to quaver, yet gives every one a lemme-
at-that-mike feeling SO that the world
may not lose the Allen-McNamee-
Crosby Mccarthy gift latent in each of
us? Well. basically the microphone
is an electrical generator, operating
on the principle everybody learned in
his high school days-that moving a
conductor in the field Of q magnet
creates an electrical current. In other
words, any sound within earshot of the
mike registers exactly in the form of
series of electrical impulses.
And therein lies tragedy. When
Dame Ellen Quack slips on the high
one she gets no help from the me-
chanical ear. Neither does it put over
the punch line OF Joe Outlaws joke
Nor will it sweeten the clans" of the
first trumpeter in Reynard Valentines
Midnight Blue Serenaders. playing for
you directly from the grill room of
Sans Chop House: but If you have
something people will listen to, it's a
mighty convenient way to put it over.
The standard type Of microphone
used in the studios Is the ribbon veloc-
ity. Essentially. it consists of a mar
row. corrugated ribbon Of aluminium
alloy. fastened at either end in such
q way as to permit it to vibrate freely
in the field Of q self-energizing mag
net. When Jack Benny sounds his
a." preparatory to beginning one Of
his famous unfinished coloe, the micro.
phones ribbon Tbrates in perfect
tune. In the studio, where other
strange noises can be controlled, the
ribbon velocity. Is an almost per-
feet instrument, from the engineers
point Of view It is the microphone
used in pick-ups Of the big variety
shows and most other studio "jobs."
This ribbon velocity microphone Is
bi-directional, which means that it
registers sounds from both front and
back OF its squirrel cage case. II
noises to the rear of the microphone
are considered undesirable. unidirec-
tional velocity can be used.
HE most democratic Of microphone
is the parabola mike, developed
IN the N. B. c. laboratories at Radio
City under the direction of o. B.
Hanson, vice president and chief engi-
neer. It has . large, scientifically
designed concave shell to reflect and
focus incoming sounds to the dia-
phragm Of an inductor microphone.
This Is . very satisfactory micro
phone from everybody's point of view.
It registers the voices of thousands,
balancing of the raucous against the
sweet, satisfies the announcer by pro-
viding a breathing spell, and gives
the engineer on the job no undue
trouble in picking up the thunderous
Yea, Squeedunk!" in the annua!
game against Springwater.
When the microphone goes afield it
is usually the "inductor" that comes
into use. This Is the round micro
phone, made familiar through pictures
Of such field broadcasts as those Of
World Series baseball games. speeches
of the President, descriptions of
championship prize fights and other
events outside the studio. The in
ductor microphone is considerably
more rugged than the velocity and is
not too sensitive to changes in tenn
perature, humidity and the like. It
has diaphragm, corrugated like the
ribbon, to which Is attached a single
conductor. Pressure of sound waves
causes the vibrating diaphragm to
move the conductor through a mag
netic field and thus set up electrical
impulses.
Engineers will tell you that this is a
fine microphone for announcers. It
seems that the engineers have trouble
keeping the announcers at the proper
distance-three feet-from the velocity
type Of microphone. In their en-
deavor to get over that last millivolt
of personality, according to the engl-
neers, announcers snuggle up close to
the microphone. In which case the
hardened engineer coldly supplies an
inductor and bids him be as intimate
with it as he likes.