Evening star., 1925-05-24

The deSlrabillty and practlca blllty or
using radio in exploration, particular
ly in the unmapped tropics, have just
been successfully demonstrated by the
Brazilian Amazonas and Venezuelan
Guayana expedition headed by DIR.
Hamilton Rice of New York. John w.
Swanson, radio inspector in the New
York district, returned May ], after
nearly a years leave spent in the
Brazilian wilds as DR.. Rice's radio
aide. According to Inspector Swanson,
who expects to take up his official
work for the Department of Commerce
soon, credit for this pioneer work in
tropical radio communication goes to
DR.. Rice. The recent trip was the third
radio-equipped expedition into south
ern jungles.
Exploration parties of the future
need never be out of touch with their
bases or the world centers, either, Mr..
Swanson insists, if they carry proper
equipment, plenty of spares and radio
experts. Although this party spent
several months in the heart of north
central Brazilian forests, amid wild
life and far from sources of supply,
they were constantly in touch with
their own base, or the Brazilian sta
ton at Manaos. and the outside world
by two-Way communication. Ordi-
narily communication with the States
the base station WIS at Boa Vista on
the Rio Branco, operated by Thomas
McCabe of Norfolk. However. Mr..
| Swanson also communicated directly
with many amateurs in the States by
means of his field equipment from
! deep within the unexplored northern
tributaries of the Amazon.
| Steaming up the Amazon to Manaos,
which is almost in the center of north
i -, IA
| disembarked early last Spring and
prepared their field equipment 1t in
! cluded a launch, a flying boat, several
canoes and their radio apparatus. 1t
! had to be assembled and tested before
| going up the Rio Branco to their base,
| Boa Vista. Here the main transmit
ter was set up. Its call was WIS
actually Mr.. Swanson's initials, with
! the j. and w. transposed, so as to
! conform with United States call sig
nails. This station, a 500-watt long
wave affair, maintained daily COM
munication with the Brazilian station
6QM at Manaos and many other dis
| tant stations, as well as the advance
party up the river. This was decidedly
| beneflclal, as mail came up river only
once in two months, whereas radio
| kept the station posted each day on
world events.
In was at Boa Vista that Mr. Swan
sons first difficulties appeared. He
| was told there We're plenty of tall
| trees in the neighborhood, but was un-
| able to secure anything suitable for
! the masts he planned to erect and had
| to explore the country, making a trip
! of four days before he found trees
suitable. However, he finally secured
several good specimens, which he
hauled to camp, and eventually, with
| considerable difficulty. working with
unSkllled natives, he erected two
| masts, one rs and the other so feet
high. In the field later on he fourd
no such handicaps; trees were too
| plentiful: in fact, he was forced az
| practically every camping place to cut
| down a number to make a clear space
| for stringing of his aerial, which was
always swung within the confines of
| surrounding verdure, and never above
the tree-tops.
| Even when setup within the fast
! ness OF the primeval forests, the field
radio equipment functioned perfectly,
although many difficulties had to be
surmounted. Static was terrific, but
was overcome; ants by the million
| found their way into one receiver and
had to be evicted: the sets all got
damp from the great tropical humid
| ity and had to be summed each day, in
dicating that extra insulation precau-
/ tions should be taken in making up
sets for tropical use. During the time
the party was afield, short wave COM
munication became popular. Hearing
| of this, Mr.. Swanson built himself a
two-tube, Short-Wave receiver out of
sugar tins, spare parts, and odds and
ends, receiving on his counterpoise.
| On this set he heard amateurs in
practically every United States State,
some of them more than 5000 miles
| distant. His transmitter, designated
as station LR, was designed to oper-
ate on 100 meters, primarily for com
| municating with WIS at Boa Vista,
! but finding shorter waves in vogue,
he redesigned it to operate on 60 to 20
meters with from Is to 25 watts power.
| WIS was also changed to transmit
on so meters. This was accomplished
accurately, for by building a wave
meter and checking it on the stand
ard wave lengths broadcast by WWV
at the Bureau of Standards, Washing
ton, Inspector Swanson was able to
calibrate his apparatus accurately.
WWV came in loud, being audible a
foot from the phones. he reports. Both
WIS and LR received time signals
daily, which in itself proved a great
boon to explorers. They tuned in to
KDKA'S Short-Wave broadcaStS at will,
receiving information and entertain
ment throughout the trip. A tiny
daily paper was typewritten tor the
benefit of those who had not lis
tened in.
The greatest value of the field set,
! however, was in keeping in touch
with the advance parties and the base
and for ordering supplies from down
the river.
Even from the worst possible loca-
tions and through fierce static Mr..
Swanson succeeded in working Amer
lean amateurs on short waves sue
cessfully. While communicating with
one surprised amateur, M. M. Burns,
owner of ADO, Atlanta, Ga, he sent
long radio message, which was re-
layed to his wife in New York.
Another time when he was trying to
get in touch with two amateur friends
in Yonkers, he heard one tell the
other in radio code that Swanson's
signals were coming in strong. These
Yonkers stations, 2AG and 2DD, oper-
ated by c. r. Runyon. ir.. and W. r:
.(2 : II =, =. sc aieut go miles III