Evening star., 1925-04-12
SENDS OVERSEAS,
/ USING TWO WATTS
Arthur Lynch, With Tiny
Homemade Set, Estab-
fishes Record.
BY CARL II. BUTMAN.

r. some one suggested he could
transmit overseas with watts of
power and single receiving tube
you might laugh, and yet:
With a homemade Snort-wave trans
mitter, comprising Il single 201-A
tube. q 1S0-volt B battery on the
plate, a 6-volt A battery and a few
spare parts. Arthur Lynch CONNER
cial operator, has succeeded in COM
municating with operators in several
foreign countries and amateurs in all
nine United States radio districts. His
set, described as an exceedingly
homely affair, is portable and was
used with great success on a recent
trip by boat to the Bahamas.
Briefly, this transmitter. which is
scarcely larger or more bulky than
an ordinary single-tube receiver, con-
sists of one radiotron such as we
all use in reception, a 1S0-volt b
battery hooked up to the plate cir
cult, 6-volt A battery for lighting
the flament a few turns of bell wire
on an oatmeal box, a variable con
denSer like those found in many re-
ceiving sets and vacuum tube
socket. His sending key was con-
nected in the plate circuit, permis-
sible in this type of low powered
transmitter, although prohibited in
higher-powered transmitters as bad
practice.
Reached Continent.
He used straight CIV transmission
and held two-way communication, in
code, with operators in France, Eng
land, Belgium and in every United
States radio district on 75 meters at
night. The antenna used had a nat
ural period of 455 meters, but
shorter antenna having a natural
period of $50 meters was also used
with nearly as great success The
first antenna was actually $50 feet in
length and comprised four wires ap-
proXimately so feet above the earth
or water. The shorter antenna was
single wire, only 90 feet in length
and 80 feet high. OF course, Mr.
Lynch also carried a good radio re-
ceivinE set.
Explaining that the set was expert
mental and that a better and more
compact one was being planned at
the Garden City laboratory. where ex-
perlmentS are now in short wave work
going forward. Mr. Lynch said:
1t Is the aim of the radio broad
cast laboratory to establish a sort of
central office for explorers who go
into the field with short-wave sets.
Our radio experts plan to cooperate
with explorers such as Beebe, Rice
and Mcmillan, acting as sort of
radio clearing house for them. re-
ceiving and forwarding their traffic"
Sees Future in Field.
Mr. Lynch believes there is great
future in short-wave code work
around 20 meters, but has also ex-
perimented on shorter wave lengths.
The use of such low power, less
than watts. he points out. is al
most ridiculous when we realize that
an ordinary electric light bulb uses
20 watts at least.
Although his successful trans
missions were all conducted at night.
the laboratory at Garden City is plan
ming to operate in darkness and day
light, and TO this end a real set is
being constructed there. 1t will be of
approximately 10 watts in power
The portability OF his small set is
possible because of the small current
consumption used on the plate, making
large batteries unnecessary, thus
saving weight. The use of short
aerials is also possible because of the
short wave lengths employed, all of
which points to possible utilization
in field work. The Signal Corps of
the Army, it is known, has been work
= n
transmitter for the Infantry in the
field for some time.
Conferred with Squier.
During recent visit to Washing
ton, Mr.. Lynch conferred with Mai
Gen. George 0. Squier, formerly chief
signal officer of the Army, and DR.
James H. Rogers of Hyattsville, Md,
who is experimenting with short
wave underground radio transmits
sion and reception. Arthur lynch, it
will be recalled, handled the Amer
lean end of the direct trans-oceanic
broadcast reception tests last fall, CO.
operating with Hugh Pocock of the
British magazine Wireless World.
Some sort of warning should ac-
company this brief sketch of Mr..
Lynch's portable receiving trans
mitter, else lay experts" may get
into difficulties by building similar
sets and going on the air without au-
thority. To transmit, it is necessary
to hold an amateur or commercial op-
orators license, and furthermore, to
have station license, both types of
which are issued only upon exami-
nation by the Bureau of Navigation