New-York tribune., 1922-10-30
Vacuum Tlll,eof.
Fifty Times Old
Power Invented
transmission Problems Are
/ Solved by New Million
L Watt Capacity, General
1 Electric Engineers Say
Output Near Maximum
Would illuminate l.5OO
u Average Homes if Adapt
ed TO Lighting Purposes

lli A one million watt vacuum tube, fifty
llItimes more powerful than any now in
lIuse, has been developed by J. II.
,lpsyns ir., In the laboratories of the
IGensraI Electric Company at Sehenec-
Hsady. It was announced yesterday. Mr..
Hpayns employed the discoveries Of DR..
Earing Langmufr and DR.. A. w. Hull
Ilsa naking the super-tube. which is in
lIlsenaed primarily for power transmits
sion
III Engineers have found that the major
IIy.ohlem Of tube development for radio
l'work has been solved so far as making
llaarger sizes Of tubes is concerned.
4 They have demonstrated that almost
II any size tube can be made for wire
tIess and operated successfully. Power
transmission, however, is more deli
este matter and there is still a great
Geld there for more powerful tubes.
Although It is not adapted for use
on lighting circuits the best concep-
Hen Of tho monster tubes output may
be gained by stating it's possibilities in
terms Of incandescent lamp require
ments. Il weighs sixty pounds but
will supply energy enough to light 40,-
600 26-watt incandescent bulbs, enough
for i,500 average homes. The tungsten
flament of the big tube cotnains
enough material to make filaments for
i75,o00 such lamps.
Solves Transmission Problem
One of the great problems of cleo
srical engineering in the past has
been that while it Is easy to generate
alternating current, it is difficult to
transmit it economically over great
distances. Direct current, on the
other hand, is harder to generate in
high voltages, but easy to transmit.
II is believed that the super-tube will
solve this. A high voltage alternating
current can be passed through it. and
on coming out is rectified or changed
TO direct current. 1t can then be sent
out on power lines.
In describing the new tube DR.. Lang
muir said:
This tubs consists essentially of a
water-cooled cylindrical anode 80
inches long and ~ inches in diane
ter. In the axis of the anode is a tWng-
sten filament four-tenths of an inch
in diameter and % inches long. This
flament is excited by current of 1900
amperes at 10000 cycles, the tilament
excitation requiring about 20 kiowatts.
"The magnetic field produced by this
large heating current is suficinet to
cut off the electric current from the
cathode to the anode during portion
Of each half cycle of the current pass
ing through the cathode, this action
Making the place of that of the grid in
'the three electrode tube. The electron
current to the cathode is thus inter-
rupted 10000 times per second. By
the use of properly tuned circuits this
can be used for the production of high
frequency power, radio or any other
purposes.
Efficiency 10 Per Cent
"This type of tube will supply 1000
Alowatts of 10000 cycle power at an
efficiency of 70 per cent, operating with
an anode voltage of 10000 volts direct
current, and a cathode voltage of
twenty volts and current of fifty am
peres, thus consuming about one kio-
watt. For radio purposes efficiencies
of seventy ana eighty per cent are en-
inently satisfactory, but for other en-
gineering purposes they are not as
high as would be generally desired.
"Another line of development is
therefore in progress. namely the pro-
duction of tubes of higher efficiency as
we'll as tubes of larger output The
progress in this direction is more diff
ficult and is art to be slower than in
the direction which thus far seemed
more important.
'These DEVELOPMENTS will come grad
ua}ly, for the practical construction of
powerful tubes giving thoroughly sat
isiactory operation requires great
deal of development work, 1t would be
rash, however, to predict the limitation
of the ultimate use of the vacuum
tub ~ 80 rovrer field"