Evening star., 1923-02-06
TWQ-WAY PA0N|NG
PROVES SUCCESS
Verbal Talks BY Radio
Transmitted Over 1900
Miles of Space.
BREAKS PRIOR RECORDS
Feat Performed hv Iarvext Co1Isvs
BREAKS PRIOR RECORDS
Feat Performed by Largest College
Broadoasting Station in World,
Located at Troy, N. z.
Special Dispa ten to The Star.

miles overland has been accomplished.
Ihis feat was performed at the In.
stance Of radiophons station wEAz,
the largest college broadcasting
station in the world conducted by the
Rensselaer, Polytechnic Institute at
troy. N. Y. The two-way communi-
cation was carried on with absolute
success and at the will OF the opera
tors with station CFcN at Calgary.
Alberta, Canada, a distance OF ap-
proximately 1000 miles airline, and
breaks all previous records for two
way overland radio telephone COM
munication by a wide margin. and IT
is not believed that this distance has
ever been exceeded even over water.
The new radio station at the Rens-
selaer Polytechnic Institute, although
established only at the opening Of
gift OF $4,000 from the Roeblings,
eng1neerfng graduates Of the insti-
tute' famous a s the builders OF the
BROOKLYN bridge, has already become
well as the widest in range and one
of the most efficient of the class B
installations in tho United States.
Unlike nearly all OF It's companion
high-power broadcasttng equipments,
station WHAz does not confine itself
to broadcasting, but enters into all
well.
Heard Over TIE Continent
OF course. the Troy Polytechnic
station, like many others, has been
| heard over considerably greater dis
tances than that OF the two-way test
In fact, station WHAZ announced
worlds record for long distance
broadcasting of concert programs,
/! clear reception of both music and
speech having been reported from
three communities, Hilo. Wailuku and
Haiku In the Hawaiian Islands, a dis
| tance Of approximately $500 miles.
! Its regular Monday evening concert
programs and its monthly interna-
tional midnight programs have been
| heard In France as well as through
out the North American continent
! from coast to coast and from Alaska
to Panama. 1t is not unusual for it's
| eroadcasts to be reported heard In
| all OF the forty-eight states Of the
| Union. In every province Of Canada, In
! Mexico. Cuba, Porto Rico and the
| Panama Canal Zone. Widely scattered
! instances of these reports have como
from northwest police ofiicer in
| Hodgson, Manitoba; a snowbound
! prospector in Alaska, a. sojourner in
the eternal summer Of Miami, Fla. ::
! cuban planter, a minister entertain
ing his little group OF parishioners
nigh up in the mountains of Lake
county, Calf: rancher in Montana,
|! a government official in Mexico CITY
and an engineer in Panama The
point is, however, that such listeners
nave no way of replying. except by
cable, telegraph or letter. This has
been true, heretofore, even of the
high-power, long-wave-length trans
mission experiments carried on with
England by the large commercial
companies.
Not All Equally Easy.
!, AS all radiophone listeners know. It
IS one matter to pick up" a program
DaiIas DrGaacast ss., from pm a station. say 1000
tirely different thing to receive"
from a particular station at that dis
tance. by design, at definite time
and regardless OF all kinds OF in
terference Yet that is what both
On the morning OF January l3 last,
a previous test, hastily arranged
and quite casually after the midniTht
ttffansGontinenta iran program from sta
Wondsv Mon whAI Ia ~. at Troy on the second
failure because Of interference from
other radlophones near Troy Work
was then hurried on q new suner.
selective receiving set, which had al
reaay been almost completed by the
selear POLYTECHNIC Institute, and a
more complete test was cheduled for
four days later. That time, in spite
OF every severe local electrical dis
tablished during the pre-arraneed
period and was maintained as long ss
desire cd. actually for more than an
hour hour The communications Of the
remote points. There was a heavy
snowstorm in progress in Troy at
the time and the static was az
tremely bad. Sparks were continu-
s series 'umptng eondegses acress sns the aatenna
sible to operate q small electro. static
motor by connecting 1t across the
antenna and ground wires
Receiving Set Described.
The radio engineers at the Rensse-
laer Tech describe the new receiving
set. which they used In this record.
breaking test. as a conventional type
Of superheterodyne, EMPLOYING a may
imum OF eleven vacuum tubes Eight
were used at the time Of the test with
Calgary. The 400-meter wave length
Of the incoming signal 10 first changed
amplified by a nve-stage radio fre-
quency amplifier and passed on to q
detector tube. Additional audio FIRE.
quency amplifiers are used when 1t
is desired to use loud speaker. Pa
cif1c coast stations were heard with
this receiver on the night it's con-
struction WAS completed. Varied ex-
periments arc being carried on now
by the institute engineers with other
sets Of this type which are less con-
ventional, and the institute is pro-
vidinE o large amount Of equipment
and measuring apparatus for radio
research.
ShOrt.fWave TeleGFaph.
short-wave telegraph experiments
Of all kinds are being conducted by
the radio star and station 2xAP, the
chief radio telegraph Installation Of
the institute, has been reported QSA
in Hawaii, France and England and
at all points between. This station
was one OF the frst successful con-
testants In the transatlantic tests last
December. A larger telegraph trans
mitter OF . newer type is now near
ing completion, and several small
sets are in operation for short -dis-
tance work. The two operators at
the institute station state that they
will be glad to use both 2xAP and
2CDC in intercollegiate communica-
tioR and in American Radio League
work as much as their rather limited
time permits.
From the foregoing II is apparent
that the Monday evening concert pro-
grams, with which the radio public
Of the country Is now SO familiar,
represent but q part Of the wireless
activities Of the Rensselaer, Polytech-
mic Institutes most versatile radio