Evening star., 1924-08-24

, Iohen transmission formula. Anna
teurs nave succeeded in bridging all
most unbelievable distances, using
Irequencies in the neighborhood Of
5000 kilocycles
The Westinghouse company has
with these frequencies and infornas
ton Is at hand that they have dis
covered that great distances can he
regularly bridged with yery small
amounts of power If the frequency is
nigh enough. They found. for in
| stance, working between Pittsburgh
and Cleveland, that at 5000 kilocycies
,,lansmlsslon tran. was possible by day
light, but better after dark. On the
other hand, at $500 kilocycles Iso
meters) the transmission was actual
Iy better by daylight than after dark.
!ney also found remarkable lesser
degree of fading and swinging of
signals on these high frequencies
than on those well known in the ANA
1eur range within $500 kilocycles.
Ihey further found very much less in
the way of atmospheric disturbances
tnus permitting very high amplifica-
tion In the receiver. They are actually
attempting regular broadcast sched-
ule between Pittsburgh and Hastings.
Nebr., on "a meters The Hastings sta
tlon Will relay these signals on a
| wave length suitable for the broad
| casting receivers. thus availing itself
OF the Pittsburgh programs
/ These experiments have been more
| or less borne out by the tests which
this laboratory has made on the intra
| meet transmitter. 1t has been COM
| paratively easy TO work as far west
as Detroit in the daytime and as far
| north as Connecticut. AS a matter Of
lact, q considerable number of sta
tlons within radius of several miles
| have been comfortably communicated
with both by daylight and after dark.
until recently the shortest wave
length which this transmitter reaches
was 1lo meters (2,726 kilocycles). On
| TINS frequency considerable fading
| had been observed both by daylight
and after dark, but it is not as pro-
| nounced as 1t, is on somewhat lower
| frequencies. This transmitter can
readily be modified to go down to
short waves or higher freuuencies.
and further experiments in this lab.
| oratory will be made. Successful tests
| with 81 meters have also been made.
| 1T Is well known that other coun-
| tries, particularly France and Eng
| land, are prosecuting such investiga-
tions very actively. 1t is reported
| that entirely satisfactory daylight
| transmission between Paris and Nice
mas Oeen OBTAINED on a wave length
of So meters, which is about $500
| kilocycles. 1t is we'll known that
Marconi has succeeded in bridging
| considerable distances in the neigh
| borhood of 100 miles by telephone at
wave length of Is meters, or a fire.
quency Of 10000 kil6cycles. This he
| did with the aid Of reflectors, which
brings up the point that if the wave is
short enough, or the frequencies high
enough it is possible to build a sort of
renectlng screen of parabolic shape
which is not too large and cumher-
some, and will confine the energy to
a considerably smaller beam. This
| obviously permits small power to be
used with remarkable efficiency.
THE 10o-meter transmitter Of the
| Westinghouse company at their
| Springfield works, is said to have
| been copied in Denver (telegraphic
| Transmission without the aid Of an.
| tenna or ground). The Navy intra.