The Filer record. (Filer, Idaho) 1919-1930, 1922-04-27


The high -frequency current Is known
as the carrier-wsve and It's function
Is 20 radiate into space la the form Of
electromagnetic waves aud By It's Va.
Ration in amplitude carry with II tho
variation In the tone al the transmit.
ting station.
! u Il the frequency OF the carrier.
wave that determines he ~s,e-lsngsh
on which radiophone slafi"n ls trans
mlffed. by experiment Il has been
found that electro magnetic waves
travel AZ the same velocity that ilglf
waves travel, that is. $4,000 miles per
second. Wavelensth IL the distance
between any two similar points on two
successive waves for example. the dis
lance from crest Ia crest OF any two
successive waves in the same direction.
measured In meters. unit OF length
equal approximately 10 one and QUE
tenth yards. Converting 49, 90 nIlss
To- meters, the equivalent l. 800 oooUO
meters. The length Of an el@ctro.msx-
netic wave Il equal then Ia s00.oooo 90
divided by the frequency. suppose .
station WAS transmitting on q ~svs.
length Of $50 meters The frequency
~ the carrierwave would be approx
mately $4,000 cycles.
Just as violini.t tunes his instru-
ment. that In. makes q certain string
emit note Of higher or lower pitch.
or, technically speaking, a sound wave
OF higher or lower frequency, by I'd
lusting the tension on the strins. %
may the electrical constants Of the
anienna circuit OF radIophons trsns
mlifer be changed In order to have
the station emit a carrier-wave VI
different frequency.
II tuning fork having a natural
period corresponding 10 middle Z be
placed nenr viollnist who il playing.
ne fork viii yibrate when the musi-
rian plays middle c. but all other tlmss
i viii remain quisseent. This phsnosp-
enon Of the tuning fork slba4 ting
whenever the musician plays the cor.
esponding note on the violin IL known
"a mechanical resonance. IN a radio
eceiNer be adjusted 50 that slecfricsily
n natural period OF vibration will be
$1,000 cycles 1880 meters wave
engfh) every time n station transmits
n wave length OF 800 meters. cur
ent VIII be set up la the receiver by
lectrieal resonance. stations trsns
lifting on any wave length other than
90 meters will not cause q currsat
} be set up In the receiver.
The portion OF radio receiver tia.
langes the rnvs-lebgfh At which IL
electrically resonant 10 called
iner. suppose that "A station trans
ITS on waye.iengfh OF 20 meters
Id "B' on wsve-lengih Of 80 ms-
~. BY adjusting the tuner until the
'nsianis Of the receiver make II cleo
ieally resonant TO go meter wsys
300 meter wave. either Of the two
ations can be picked ny. but both
ations cannot be picked up slEsslfsr
'ously This 10 the reason that mere
an one trsnsmitfsr csp be operating
one time and yet only one can be
ard on receiver without lsterfsx-
90 from the others.
The other necessary part Of q rsdss
''iftf ~ me oetecfor. The funcfi0s
this portion OF the receiver 10 ~
lie the small currents In the tuner
q are set ~ b, o Transmitting sta
o and make them sBaibls thresss
medium ~ q telephone receiver. II
feieph0ns recsiysr we're connected
ectiy 10 the tuner the high frssuse<y
rent would not operate the 4s-
-agm % the receiver and even n fhs
phrngm were set In motion IL would
too fast motion to be picked ay
the human ear
p simple receiver the dstseter rs
~ gsnsists Of two pieces " lsinsssl
.ontacf Or piece Of Dsissrsl In COO
with . metallic spring EltLss
ibinstioD IL known 40 crystal DE-
or. A defector ef this type IL moth
more thsn rectifsr that 10. whoa
current Ia applied Of the
ninsls the curresf IL allowed to
only In one direction