The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1924-03-19


subject commanding much atten-
ton these days, is Interestingly
discussed by w. E. Duckwall, a
HillsborO, Ohio, fan, who has
given considerable study to the
subject.
Every radio listener has been
annoyed at times by fading and
unsteady reception, and, after a
very extensive investigation,
have learned that this trouble Is
due directly to barometric pres
sure" he writes.
IF we study carefully the
maps issued by the Government
weather bureaus at the same
time we are operating our re-
ceiving set, we notice that radio
behaves differently when there
are areas of either low or high
pressure between the receiving
set and the broadcasting station.
IF the pressure is low, the re-
ception is clear, steady and of
long range, but If there is high
pressure between the receiving
set and the broadcasting station,
tuning is hard, reception is I'M
even and markedly subject to
fading. Fading seldom is notice
able when you are within 100
miles of the sending station, but
is most pronounced at night.
In Ohio we frequently find
low barometrical pressure west of
us, extending 500 or 500 miles,
and high pressure east extending
over about the same amount of
space.
Then the Western stations
come in steady but those in the
East are received with q certain
amount Of fading. Then, again,
when the high is West and the
low is East, receiving conditions
are similarly reversed.
1T sometimes happens that
there is a sort of trough of low
pressure extending from the Gulf
of Mexico to the Lakes between
two highs. Then we have fad
ing from both Eastern and West
ern stations and good reception
from both North and South.
When these conditions exist, Ha-
vana comes in exceptionally clear.
AFFECTS THE VISION.
I'VE know the barometric pres
sure affects the vision. Those of
us who have more or less regular
use Of an astronomical telescope,
large or small, have noticed that
seeing is unsteady on the clear,
cold nights when pressure is high.
The air appears to boil around
the objects being viewed. Focus
ing is difficult. II the barometer
is low and the weather mild, see
ing is good and the object viewed
remains steady and we'll defined.
Everyone has noticed that the
stars twinkle more violently on
the cool, crisp nights than they
do on mild nights.
ct has been claimed that what
ever affects light waves will af-
feet electromagnetic waves Of
radio. and so we who have made
a study Of the suitation are Of
the belief that the same baro-
metric pressure that affects see
ing affects radio hearing.
The ionized layer theory seems
to account well enough for longer
range at night than at day and
AON Ia04H5g IOOs IL we assume IIdL
1t il broken up over the high
areas and remains unbroken over
the low.
Whatever the causes, weather
has well marked effects upon
radio transmission and reception.
Extensive areas of low barOmet-
ric pressure seem to favor steady
reception and long range recep-
ton, while pressure areas cause
uneven and unsteady reception
with pronounced fading"
SUBJECT INTERESTING.
The subject of fading, as dis
cussed by Mr.. Duckwall, is al
ways interesting. despite the fact
that more than twenty years
Of investigation has failed to re-
veal the exact cause. The Fed
eral Bureau Of Standards re-
Gently completed an exhaustive
survey along these lines, but
nothing was decided upon def