LANE'S STATION W. L. T. S.
By Wm. F. Hawley
from Page 98-99, T H E LANE TECH PREP 'June
click picture for larger view
February saw a great change in our station. Tubes
disappeared, parts hung by one support and wires flew this way and that.
Our aerial was no more.
But now order emerges from the chaos. A new transmitter
and a new aerial appear. Trim and neat is the workmanship and sure is the
design. And why not? Haven't we the athletic
Mr. Sommers, the thoughtful Mr. Heinzelman, the
inventive Mr. Berlund and the wizard Mr. Pearne, to direct us to the
correct path. And besides, do not forget those who worked sometimes to
nine o'clock to see the set completed. They are as follows: William Loebel,
Harry Rowe Jr., William Hawley and John Kautzner.
Besides appearance our set has the ability to reach as
far as Wichert, Illinois, sixty miles away which heard us in day time. No mean accomplishment for
one hundred watts. And even many requests have been received from various
parts of the city.
click picture for larger view
Perhaps you should be interested in an explanation of
how the circuit works. Here it is;
When the tubes are lighted and the plate switched
closed let us say a positive potential is created on. the grids of the oscillator
tubes, (It works out the same if a negative potential is created.) This
causes an increase above the normal plate current in the plate circuits of
the tubes but the radio frequency choke in the plate circuit prevents the
increase from flowing into the plate battery. It therefore charges the
condenser plate to which it can flow, minus, producing a plus charge on
the other plate. This causes current to flow from the helix through the upper tap (which you way mark A
with your pencil) and into the coil through the filament tap (which you
may mark B.) This current produces a on increasing field of magnetism
which travels through the lower part of the helix, B to the lower or grid
tap (which you may mark C.) Since the magnetism increases it creates a difference in potential between
Band C. B is positive and C is negative. C being negative the condenser
plate to which it is connected becomes charged, charging the other plate
positive and making the grid negative through the well known law of
This negative charge lowers the plate current to a
greater degree than is was before increased since the tubes are
amplifiers. The radio frequency choke again stops the current, the
condenser is charged, a current flows in the coil, this time however from
A to B, produces magnetism, creates a negative potential at B and a
positive one at C, charges the condenser and produces a potential at B and
a positive one at C, charges the condenser and produces a positive charge
on the grids which produces an increase in plate current greater than is
was before decreased.
This keeps up till the current limit of the circuit is
reached when it remains constant.
Nothing has been said of the modulator circuit till now
but do not think it has been forgotten. The action of sound waves produces
an irregular pulsating current in the input primary. This pulsating
current produces an alternating current in the secondary.
When the grid terminal is positive to the filament
terminal, the negative grid bias is lessened, producing an increase in
plate current. Since the 30 Henery choke furnishes a constant current,
this increase must be robbed from the oscillator tubes which decreases the
amplitude of the radio frequency oscillations.
When the grid terminal is negative to the filament
terminal, the negative bias is increased lessening the plate current of
the modulator and allowing more current for the oscillators which promptly use it to increase the size of the
It should be noted that any sound interrupted by the
Mike does not change the frequency of the wave, it merely alter the
amplitude, preserving the general characteristics of the sound wave.
THE NEW WLTS
The Lane Technical High School broadcasting station, W
L T S, has been entirely rebuilt and remodeled, and the new station is
hitting the high spots in radio popularity. Letters of commendation from
all parts of Chicago and from outside the city have been received. The
average Lane Indian is already well-informed as to the station's
semi-weekly program but any student who is interested in knowing what the pro-. gram will be, should
look in any Tuesday or Friday newspaper and there it will be in black and
"Go, Lane, Go," that popular school song
which is emblematic of Lane in all its glory, is meeting with such acclaim
that hardly a program is put on the air without its being sung. The new
staff of W L T S is becoming very popular with the radio listeners,
especially George Burhop, tenor, who is getting special attention. One
listener described him as a future operatic star. Nate Collier's falsetto
solos are enjoyed by the men listeners who often mistake Nate for a coloratura soprano. "James Kessler at the Lyon and
Healy," is a popular phase with the radio audience, as Jimmy's
popular medleys are living up to their name.
Bennie Horwitz and his ukulele are there with bell on
too. Bill Lava, the classical-jass fellow, also has the job of telling the radio public that
"so-and-so" just sang the Needle Song from "Haystack"
by Findit. His classical piano numbers add a solemn touch to the otherwise
merry proceedings. Then of course, Earl Storm and his
harmless harmonica give quite a novelty to the trend of the program.
Manuel Kupferberg is there, once or twice with his sassy saxophone, and
Manny sure can handle the reed-box with vivacity.
Those, are some of the entertainers of WLTS, "Lane
Tech-Chicago!" Listen in if you are lucky enough to have the chance,
on any Tuesday or Friday between the hours of 1:00 and 2:30 P. M. on 258.5