Brownsville herald. [volume] (Brownsville, Tex.) 1910-current, 1929-06-09
Pan-American Radio
Station At Airport
Link In Huge Chain

America. Miami with Nassau. Ha-
vana, Camaguey, Santiago, Port-au-
Prince, San Juan and Mexico City.
Radio stations already have been in
stalled at various terminals along
the routes. About twenty-five
ground stations are already in OPP
Grafton and others are being placed
into commission at the rate Of one
every three days.
Apparatus Improved
When the airways were first
opened, last January. the radio ap-
paratus then in use was regarded as
experimental. but the equipment
has been developed to the point
where 1t is dependable and regarded
as Of utmost Importance 70 the safe
ty Of the planes flying the routes.
OF the fifty-four planes now in
service all are equipped with 100
watt telephone and telegraph trans
mitters.
From the minute a plane takes
off until the time its wheels touch
the ground II is in the hands of the
radio division Of the airways com
pany. A zoning system has been DC
veloped whereby a plane communl-
Gates with the two nearest stations
throughout the entire trip. IN
addition TO messages or ordinary
dispatch. weather reports and posi-
ton hearings are constantly trans
mitted 10 the plane. The location
OF each ship is known at all times
while en- route.
Use Direction Finder
In mapping out the air rortes. a
direct line has been plotted between
each radio station along the route.
Operators at the ground stations
maintaining communication with a
plane keep constant check Of the
ships bearing. and should the pilot
drift off the course more than
two and a half miles either side Of
the direct line. he is notified Of his
position. and advised which direc-
ton to steer, in order to regain his
correct route.
The Pan-AmerIcan Always are
constructing most Of their own radio
equipment for both ground and air
craft stations. Special permission
has been granted for the construc-
ton Of the apparatus without in
fringement.
Plans for the development OF the
radio facilities call for the erection
Of ground stations every 200 miles
along the routes throughout the
West Indies. Central America and
South America. Central ground sta
lions have already been installed at
San Juan. Porto Rico. Cristobal.
Canal Zone and Mexico City. In
5srmediate stations have been es
tablished at Key West. Havana.
Camaguey. Santiago, Cuba: Port
au Prince. Haiti: Santo Domingo
City, Cozumel Island. off the Yucca
tan coast and at Tela. Honduras.
Weigh SO Pounds
Present aircraft transmitters weigh
eighty-six pounds, including gener-
ator and accessory equipment. Wave
lengths of $40 and 1249 meters are
employed. However, some of the
ground stations are operating on
the regular marine channel Of 500
meters. Bearings are supplied
through direction finding apparatus
installed at each Of the ground sta
tons. When the pilot wants a
special bearing. the radio operator
transmits a series Of long dashes.
The ground stations record the di-
rection on an uni-directional receiv-
er and plot a straight line on a
marine chart. The point Of inter
section indicates the location Of the
plane at the time the signal was
transmitted. The operation re-
quires less than a minute and one
half after the operator aboard the
plane transmits the signal. Speed
is Of utmost Importance. it was
pointed out. because of the high
velocity planes travel. and because
Of the possible drift due to cross
winds.
In addition TO flashing weather
repo%s. bearings and messages of
dispatch, passengers can also trans
NIT and receive messages