Perth Amboy evening news., 1923-07-28
ANOTHER new TUBE

The heart of the radio set-for
transmitting and receiving-is still
to be raised to perfection.
That is, the tube itself.
In the last two years during which
radio has met with the greatest pop
ular response in it's history, the tube
has been subject to change about
as often as any other part of the
radio apparatus. In fact more so,
for scientists have realized that this
the most important part of the set,
was where they should go for i'm
Aprovement.
s Immediately upon expiration OF
Z the patent rights on one form OF
tube, the market began to be invad-
ed by other forms, some of which
still exist, while others have died a
quiet death. Various kinds of dry
battery tubes, gas tubes and vacuum
tubes now exist and each has its in
dividual hook-up by which it Is sup
posed to be most effective.
The latest form of tube Is what is
termed the "alkali vapor tube"
brought out by Hugh A. Brown, as
sociate of the department of electro
cal engineering, and harles T.
Knipp, head of the physics depart
ment of the University of Illinois.
It is a detector tube made so sensi-
tive as practically to obviate the ne
cessity of using simplifying tubes.
The injection of a potassium
sodium alloy into the tube during
the process of evacuation is said to
be the whole principle on which its
construction is based. 1t Is a COM
zo11AafnI aN1 1~f~ANo41rY In1f4akA
process, however, and is therefore
costly.
characteristics
According to its inventors, the
ties and advantages:
1. 1t acts as a sensitive detector
at any plate voltage up to go volts,
although 1t produces best results be-
tween s and 10 volts.
2. It is more than three times as
sensitive as the ordinary detector
tube.
8. Adjustment is less critical,
therefore much easier, than on an
ordinary tube.
4. Besides being more selective in
wave length, and steady, the tube is
said to give absolutely distortion
less reception" This has long been
n of the bugaboos of radio recep-
ton, the correction of which will be-
Hreceived with glee by every radio
Nan.
8. The voltage is higher than on
the ordinary tube, to raise the tenn
perature of the f1lament to a point
at which the potassium sodium alloy
vapor can become active.
Long Distance
When the new tube was tested in
the vicinity of Urbana and Cham
paign, ILL.,, the receiving fans who
used the tube in their sets reported
having heard Kansas City, Atlanta,
Schenectady and Pittsburgh on an
ordinary regenerative hook-up with
no ampliher. And with the antenna
~ feet above ground and 40 feet
long.
BY raising the antenna to a height
of 40 feet, broadcasting stations as
far way as Los Angeles could be
heard on this single tube. These
stations, the inventors report, could
be heard even without a "B'' battery
and with the plate circuit return
connected to the negative flament
lead.
Even this tube is not the final
word in perfection of the heart of
the radio set" for what radio fans
want is not only a highly sensitive
and efficient tube. but one that is
cheap and more durable.
After the interior of the tube has
been brought to the zenith of perfec-
ton, perhaps. inventors will seek to
produce methods by which it can be
produced in larger quantities, at low
er rates.