New-York tribune., 1922-03-26

velops.
zincite and hornte. The crystal de-
tector has the peculiar property Of act
ing as an electrical vslyc. The electro
magnetic waves used in radio work al
ternste at very high frcquencies. The
crystal detector permits only one-half
OF these alternations to pass through
che Telephones and stops the other half
In other words, it acts in just the same
manner as q valve in water pine svs-
tenn, which permits the water to how in
one direction, but closes up il there is
back Now.
Limit of Crystal Is Twenty ave Miles
NJ. G., Hopkinsville, Ky:
Q.-How far ought to get with an
aerial ESQ feet long, loose coupler tun-
ing $500 meters, variable condenser.
ga!ena dctectcr and 1000 ohm tele-
phones with stopping condenser
across $hem?
A.-For music you wiz not get any
further thxn twenty y-fye miles. and T
doubt whether there is broadcasti2g
station within that distance Of YOU.
For wireless telegraph stations every
thing vii! depend upon the power OF
the sending station You should get
very good distance results with them.
G. G., Greenwich Conn:
Q'-ls there any smsl! gap or other
device that 7 car use to ground nv
aerial and protect my Instruments and
the house from lightning instead o.
using single pole double throw
switch: Is there any device Of this
sort that VIII help elm nate static
effects?
Al. Yes, there are a number Of
devices OF this kind which have been
approved By The board Of Underwriters
9. Those which have been approved
Will protect the instruments yrom the
effects fstxtic, but of course VIII not
eliminate the interference caused b.
static
Soft Tube Is Critical
q. ?. A., Rdgewood y. J.:
Owl! you please explain the differ
ence between radio frequency trans
former and an aud;o Frequency trans.
former?
AIN genera. practice an open core
transformer is used for radio tre-
qrency and an ron core transformer
for audio frequency, An exception to
shis IS where resistance coupling is
used between tubes. This can be used
for both kinds OF frequency ampIih&
tion, but is best suited to long waves
only in radio frequency amplihca ion.
a s. n, New York;
Q.-Can substitute honeyconb
coils for The vario-coupler and tickler
coil in the regenerati7e set the dia-
gram OF which was published in sun
days Tribune?
Ayes. A primary and secondary
honeycopb coil in place Of the vario-
coupler, ard another honeycomb col!
ii place o. the tickler. You will have
to get mount for these coils, SO that
you can vary their relative positions to
each other. Otherwise the wiring will
be the same.
G. g., Hartford, Conn.
Q.-1s It possible for me 10 hear the
broadcasting station at Chicago? I
have all serial 175 feet lorg and 35 feet
high, Homemade honeycomb coils,
homemade variometer in the plate
circuit, audiotron detector and two-step
audio amplification. have heard the
following: NOF, KDKA, WIZ, WDY,
WBZ and WYCB. Alt would only be
guess on my part to say you could
get Chicago. think you are getting
very good results with your set as it is.
Q.-Y received TYCB with a horse
shoe magnet placed next to the detec-
tor. was unable to hear him without
it. It does not work on short waves.
A.-WYCB comes in fairly good on $50
and $50 meters under certain circum-
stances This Is due TO ths law GOV
erning haYmonics. In other words,
those waves are the oetaves below the
naturs! wave Of WYCB.