Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-06-07

New, Powerful Tubes Reduc-
ina Static and TeIevision
Also to Be Features.
BY MARTIN CODEL.


CHICAGO, Ill, June 6.-What's new
In radio? Here. on the eve Of the
annual Radio Manufacturers Associa-
ton trade show, one hears much talk
of midgets, television, the variable-mu
and pentode tubes, new long-life bat
terry sets, the Stenode radiostat, home
talkieS and many other things.
All Of these developments IN radio
and its allied arts will be on display
during the Forthcoming week. Thou
sands of radio dealers are gathering
from all parts Of the country to pre-
view the latest the radio industry has
to offer-the offerings these same
dealers will be making to the buying
public from this time forth.
Follows Engineer Meeting.
The r. M. A. trade show Is following
close upon the annual convention here
Of the Institute of Radio Engineers.
meeting which this week brought the
engineering minds Of radio out OF
laboratory and factory for mutual
exchange of views and information.
These men: who discussed not only
what they have perfected for the en-
suing years market but that which may
be expected in the future, closed their
sessions today.
Doors of the radio exhibit halls are
not yet opened. but enough information
| has seeped out to give some general
| IDEAS OF the new development and
| trends.
Foremost, perhaps. Is the emphasis
being placed upon the production OF the
| small, compact low-priced receiving sets
generally called midgets. They will be
evident on all hands and for the most
part they, like the larger SETS are en-
ploying the superheterodyne circuit.
They are exceedingly light weight and
! in all shapes. They may or may not be
the product OF the demand for cheaper
radios, due to the depression, but the
fact remains that they now dominate
the market.
| Large Sets Continue.
| The larger sets, Of course, will con-
| tinue in great evidence, for much more
can be done with them in the way of
engineering true tone values. The super
heterodyne dominates all classes OF sets,
| hardly a major manufacturer today
ignoring that circuit. Then, too, with
wide market still prevailing for battery
sets. especially among the nonelectriied
rural regions, the new low-voltage bat
teries, one with a life Of about 1000
hours, will be considerably in evidence.
| The two new tubes, the variable mu
| and pentode are scheduled to be very
1 important features OF the Autumn and
Winter markets. The variable -mu is a
screen-grid which permits stronger
signals to be fed into the radio fire.
quency amplif1er without causing cross
talk and which eliminates Kissing back
ground noises and does away with the
| need for various controlling devices to
compensate for the different intensities
Of distant and local signals. It reduces
manufacturing costs and makes possible
more compact cabinet designs at lower
cost to the consumer.
| The ordinary radio receiver cannot
use the variable-mu. Neither can It use
the power pentode. which Is tube with
many times the usual anpliflcation Of
the power tube and. therefore, does the
work of two or three ordinary ampli-
hers. It takes special circuits for both
these tubes, and the special circuits are
incorporated in many of the sets being
offered TO the public this year.
TeIevision Foremost.
Television Is a foremost topic Of dis
cussion. and every shade of opinion pre-
walls about its imminency. This much
Is certain, that the television expert
mentors are a jealous lot who have at
tracted thousands Of experimentally-
minded persons 10 look-in with them on
| IlOH ONcI ~ VI IlOlC
stations east of the Mississippi. Com
merciaI television receivers are available
| today for those minded to dabble with
an art that Is just about ct the stage Of
perfection that ordinary radio was seven
or eight years ago.
| Advance reports have It that DR..
James Robinson'S stenode radiostat will
be q stellar attraction at the trade show
next week, with several manufacturers
showing models OF the British scientists
new system Of exceedingly sharp tuning.
The models to be displayed by several
manufacturers, 1t is said, will incorpo-
! rate the pentode and vsriablemu tubes.
The broad claims made for the stenode,
especially for its reduction of back
ground noises and static In receivers, as
we'll as its reputed potentially for mar
rowing the channels of radio transmits
sion and thus making more wave lengths
available, will merit considerable atten-
ton from the radio world.