Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1922-04-30
VACUUM TUBE CENTER
OF ACTION IN OUTFIT
Invention OF Tiny Bulb Responsible for Rapid Strides
in Wireless Fied-Tl,eory of Operation Not
Difficult to Understand

small grid charge has very strong
erect on tho plate current. In '"is
way small current in the antenna
IL caused too have n violent effect on
the plate current, and consequently
IL made very audible In the receivers
Tube Chops Wave in Two.
The wireless wave that impinges
upon the antcnna may be represent
cd by series OF spirals. the lower
haii. In the case of spark trans
mitters. OF which has 10 be cut off
to be audible. Through the action OF
the grid Just described this oppoyjte
mar OF the incoming current is not
only cut OF and rendered audible
but Is ampii!icd to sufficient intcn-
sity I" he heard. This is not the case
WIN inc crystal dctcctor. which only
rect'hcs. or chops off. the half wave.
40" this operation is concerned
with spark" waves only; that is
waves produced by some sort of in =
s'rumcnt similar to n Ford coil which
generates high frequency oscillations
tnat rapidly die out" and produce a
series Of very small waves. large nj
the beginning and small at the end
continuous wave transnittcrs such
az the Poulson arc. the Alexander
the vacuum tube transmit,er, are re-
ceiVcd In quite different manner.
shape OF Waves.
These waves are continuous Sc
ries Of oscillations. which NAV be
represented by a spiral OF uniform
size. unbrokcn and unvarying in In
tensity \ telegraph key inserted In
the circuit breaks the wave up into
dots and dashcs; a telephone trans
mitter modhlates the wave according
10 voice shapes. In case speech is
being transmitted
When these waves are caught on
the antcnna circuit II is necessary To
do two things. First, break the wave
into number of uniform pieces. and,
second. TO cut OF half of the wave.
AS In tho first case. The latter half
Is readily accomplished in the man
ner already described. The second
part OF the program is accomplished.
briefly. as follows: y coil Of wire
is connected In series with the plate
circui; and brought into close reIa
ton with the primary and tuned.
Thc effect Of this Is that the cur
rent already nowing In the coil. or
ticker" Imposes Itself upon the pr! 8.
mary. rc-cnters the circuit in a Ger
tain definite way and chops the wave.
Numbers OF different methods have
bccn discovered To obtain this result
only the most Fundamental method
study tho different circuits publishct!
III various books and magazines and.
with the knowledge indicated in this
article. obtain fairly good idea OF
their operation
In this study Of tho vacuum tube
rs detcctor IL was mentioned that
INC tube Is used as an ampliiicr and
as q generator of high frequency
oscillations The last-namcd use is
gaining popular favor with such in
creasing Intensity that other methods
"' transmission are threatened with
cNtinction. The plant installed In
Ihe Times Dispatch makes use OF
4 modern circuit. using two nfty-
watt tubes and one dvc-watt tube
ioF inns purpose. In another article
an attempt Will be made to make tn.
use Of the tube in the two la,,cr
capacities clear to the s.uden, n,
radio communication.