Wauwatosa news. [volume] (Wauwatosa, Wis.) 1900-1948, 1902-03-15

| is shown Mt A and the operators key
! at Il. These are connected with an in
/ ductlon coil IL, which intensiies the
lS11FEnllE A1lds SoI 4itaaistto- be- eelIj
ID d d y. The letter may be called the
transmitting circuit. II is broken at Il,
where series of sparks leaps across
from one brass halt 10 another. The
imperfect barrier presented here imnartS
to the oscillations in ID ID ID d an
enormous frequency. Another instru-
ment iii this circuit is a condenser n.
At G. is shown only the lower part of the
famous vertical wire. in which similar
oscillations are produced. and from which
radiate sideways into space the SO-called
Hertz waves. The frequency of the lat
ter depends on that of the former. A
few turns are made III the Vertlc2i wire
at l.. for n purpose about to be eX-
planned. The extreme lower end of the
wire CID is not attached to ANYTHING.
The oscillations get out of ID ID ID d
into q in the following manner: Two
distinct coils of wire q and k( are com
bined in such way that symplathe tlc
current is excited III the latter by the
former The coil l forms part of the
transmitting circuit while the upper end
of X can be adjusted so as to come IN
contact with any of the convolutlons of
G. Thus. X whose lower end is in the
earth at NJ, is practically a continuation
of the vertical wire. BY shifting the
point of contact between the upper end
Of X and the lower part of the vertical
wire the length of the combination may
he either increased or lessened. Since
the natural rate of oscillation depends on
length. the adjustment is made SO rs 10
make G and X together as long us ID ID
| ID u. The two then oScillate Ill mar
monv. Similar steps are taken at the
| receiving station. 1t should be added.
| however, that this plan represents only
| one of several methods of tuning, but
| it is perhaps the most lntelhgible.
| Mr., Marconi said that the exact IRE
ouencv of the oscillations in the Poldhu
! tranSmitter and the receiving instrument
| on the Philadelphia was millions sec
ond." but Just how many millions was
| n professional secret tie was not pre-
pared to say just how many tuned CIR
| rrits could be worked simultaneously IN
| the same neighborhood, nor precisely
how close one frequency could safely ap-
/ nronrh another without SacrlhclnG Sccre-
| cy. In addition to privacy and freedom
| from interruption there was another al
vantage in tuning the sending ana re-
| ceiving apparatus. greater ulstdut' {
could be covered thus than otherwise.
| The chief explanation Os his recent gam
in distance, however. was the greater
| mower employed to operate his transmit
! Tor He secured better results after he
| connected both sets of instruments with
the ground than he did at the outset
/ and he WAS now COhNiuCct NAidA tiiV a. 81
| was TO some extent conductor or me
waves. Concerning the exact combina-
ton of instruments at sending station
he was reticent. The diagram does not
show these with precision. 1t merely il
| lustretes the means of tuning Mr..
NIa~coni still uses the coherer for re-
ceiving instrument 70 some extent, but
not exclusively The other apparatus
for that purpose. however, he was not
ready to describe yet.