New-York tribune., 1922-06-25
,,,,rt Describes Ciuses Of
FADING and Explains Why
Radio Waves Sometimes
navel Further at Night
Radio Fog Is Tonized Air
ll.o Electrically Charged
Clouds Affect Passage
of the Wireless Waves
By a. F. Van Dyck
Radio Engineer. @. +.

...elves. However, my snswers and
r,,,,tions orc What are believed to
y mr,s, the truth.
,-. ly " consider what radio
.,,.inion - We know that radio
,,tr: station SENDS out from Us an
Il .., in ell directions disturbance
i = ,l~,rie forces. We cannot see or
,w ~ oher~ise observe with our
..v, iv,, ho~ this disturbance be
/ .v,, u We can With ligh; waves and
.,,s vsvss. We consider il quite
,,.r,l tia, stone wall stops the
"a, sesn from a sesrehlight or that
,ur, esil ear be heard much further
30, ssitf than through . forest, OF
.r rns.r certain air conditions on a
,,,,r N. nirAge phenomenon 10 OBJ
| yv,S. and 70 know what 20 expect m
,s, a, need oRly 20 remem Der that
4 a., thin, IN space will stop or re-
a. AZ perhaps absorb the travelling
~, v,y,, ,ust 80 some other things
mace s,op OF absorb or reject light
u,s, o. sound waves We must not
4 ,,.,s, .adio waves 20 trsvel out from
4 ,,rmnittirr I'stion over some enor-
rv, distance 20 receiving station
s,kou, eneountering some obstael"s
s-evhsYs - their path.
Ether Tef stops Waves
Subs,sne., which are obstruetions 20
/ ,it o. sound waves ere not neces
u,iy sucb 70 radio waves For cV-
rrls, We knsv that radio waves pass
arsgsh ths walls Of house with only
rgrt. loss Bv; there j. some sub
farst IN toe space around the esfih
ri,h does hsvs effect upon rsdio
4 y.v.s - .ubstsnce 10 not UNI
1 t,nly d.s,-ibuted throu~h space. but
vtsnt here and there, is eentin-
4 afg changing oeati5n and magnitude.
IA tersooucntly h-s very erTatic ef-
Il tt.i on the rassare ef radio waves.
70 esnditc c. is olite similar 20 tire
i .. Of 4 searehiifht N fog which
80 r. vhr, ing rapidly IN density
leauen OF both This radio fog
| unnor.y suppolyd 10 be made o
s'isn a. f'st .. air wnirh nv some
s,1n,t hss bscome a psrt'sl eonduc-
g. of elscsri,ity.
Mtturse this radio fox never STANDS
| rl ard Is changing from moment 10
rss,p. under the Influence o. the
1 a-, ,a,cd conditions 81 our stmos-
lyn.. and "a the radio wave ptssing
arsst inrce surely. has an adventur-
4 ~ journey because u meets eieetrl.
j rly thtr-ed clouds, patches OF ioniIea
ard nerhaps other obstseles OF
Md " snow nothing
tbt faet often observed that II -
4 s,tl. - wors rsdio communication
ser much greater distances al nirh'
,isa II ,h, DAYTIME. This may be eX-
ri.,r kv ,At effect - the sun upon
he an. vhieA causes ionitstion o. H.,
\ ans mes, ae,ive IN the daytime. and
Wsrie.ny absent Of night. The sun
ians 70 ne responsible without ques-
iten. in view OF the fact that very
1fat. results IN long distance rseep,
OF are Away, noticed ~ sunrise ano
Juris,
Why sirnals Fade
Wits the preceding statements IN
| sAs u sheuld be clear hat vnen one
y receiving over long distances sew
| tt. hundreds 81 miles n is rstura
| ~ d, waves - come through strong
q enc moment. and "a fade away con
tt,rssly TIE next menent, as some OBJ
rls,e 70 Fasio waves comes between the
trssn t,.r ard receiver This explains,
n., Why one tfAhtmitting station, of
W or rere which are being heard,
ny ttt weaker. While the others DO
~, Yer Example. suppose . receiving
rs,isn N Chicago ls receiving from
sv Yek tsd also from, sat Francisco.
4 ts,.s ~ radio fog might appear be
wen chiuso and Nsv York and weak
" the hsu York signals, while the
'r,t from San Frtneisco remained
us,N,srd
Il Nwwu IN reception over a con
nssrls distance one observes
r'atu ~ the intensity Of the tig.
W 70 nest likely due 20 so-esiled
Nts caused by some obstruetion TO
~ rsyslirf waves somewhere between
~ ist itstisAs. and not 10 any fault
E ", ,rsnsmittinE station fseli.
l'W sfttti ere much more frequent
ne sumner than in the winter sea
W ts,umtbly because Of the rieatel
a'ssss Of the sun on the esrth ano
- ,.ss,shsr. during that season.
.isnghsisly Hs way Of avoiding TINS
Sseiy 10 knsvn to-day.
10 trtnsoetsnie radio stations have
1 be equipped with high power sp-
Nale In order % work through the
- ftriods OF The day and year, al
nsfs a. certain times Of the year
~ Gay len powtF may be used, a'
y ..shsse b. the successful trans
A ~Mt uEnimbEioh by low power
-'sS stations during the Last winter
thu fsr Also Reflects Waves
'v The sake Of elearness we have
M described the Gauss Of fading
sssi as due 10 oostruetiens IN the
~ d the radio waves. Actually, the
.s eleuds sometimes reflect the
mu' nsss as mirror does light
g. sno - very secular reception
."u are somstimss noticed. Some
~ M signals are MADE stronger
e {" weaker. sometimes they
N lost sltogs,ser. a. the seysrs.
sssins 1
ne ,eS let Us consider for n mo.
H ts,t areh enemy of radio-Old
49, Static. when Nsreoni hrst be-
receive messages over distances
IL 'sv miles Ne notsd bssids, the
- p. vas listening fer noisss
@ hd nothing - DO with the
th ard every receiving operator
uas time has heard those same
tst and interfering noisss.
~" neisss have essn called strsys,
.ssrhsrie. er static. And the elm.
p.ss ef them 10 the most important
.,,m IN adis communicates TO-
liz n Intensity of this disturbance
r.a'srhs q, different ysrts Of the
surface. being pYegrsssivsly
Al" uen The temperate 10 the trer;-
H., esss The intensity ef static
t,,'" (tttly With the seasons ef the