New-York tribune., 1922-03-26
First Aid to Radio Fans
Parts for Simple V. t. Set;
Beware of Loud Speaker ON Crystal;
Protective Cap for Aerial Wires

Il. c. R., East Orange, N. J.
VI have one vario- coupler, one as
plate condenser, one 200 V. { deteeto,
tube socket and rheostnt, one pair
phones. two telephone Jacks, one POI
'uoe' socket and rheostat and on~ am
pt'fying transformer. can operate
the detector with great success, bu. am
not able to use the ampliher.
A.-You have got the nepntiv. s,S.
OF your ampliiier B battery Joined TN
wrong, according to your diagram. 1t
thouid be connected to the positive Of
the detector B battery, and not to .h.
secondary o. your nmplifying trans.
former. The latter should have on.
side joined TO the grid Of YOUR amr,,.
Tying tube and the other side to the
negative terminal Of the amplif,er 6ia-
/ ment. If you will send me yeuy mama
l will return your diagram showin~
where it is wrong.
+. W, Augusta, Ga. ...
Q.-I live about nine hundred n,,.o
from New York. Could a s,2oo.meeer
wireless transformer ard & mineral do
tector be used at the distance 1.-Two
, from New York?
A'-ln the first place, the majority
! OF broadcasting stations operate or
66o-meter wave and the unused portion
Of the 3,2oo-meter oscillation trao,-
former would materially reduce results
through losses in the dead ends A
crystal detector is not good for the re-
ception Of music and speech over
greater distances than Twenty-Five
miles. 1t will be necessary. for you to
install = vacuum tube detector sct
using regenerative current, to get
music.
Ground Shield the Set
G. r. K, Brooklyn.
Cat times Srl troubled with the
capacity effect Of my body when re-
ceiving. Can get VINO very we'll at
times, but sometimes must keep nv
hands on the varionetor dial IN or
Ger to hear them. Is this simply be-
cause Of local conditions Of the atnos-
phere. or what? Is there sny way ot
eliminating this with shields?
A.-The condition is caused by the
capacity effect Of your body, and the
only way 90 eliminate it is to ground
shield TIE apparatus. You can DO this
by lining the cabinet with Thin copper
sheet, being careful to have holes
large enough in it for all the connec-
lions 20 pass through without touch
ing. The copper sheet should then be
so.dered TO YOUR ground connection.
s. f., New YORK City.
Q-How would you account for the
fact that have heard WYCB quite
plainly, although he was broadcasting
at I,45o meters, and yet my set is not
rated over 700 meters"
A.-This IS due TO the phenomenon
OF harmonica. WCYB has two per
Iectly good harmon;cs on 725 meters
and 36o meters. The harmoncs, OF
course, are not nearly SO strong as the
natural wave, but you are able te hear
them because you are SO near to him.
". ". Ramsey, n. J.
Q.-Please publish the parts needed
for making a simple vacuum tube set
A.-The simplest set Of this kind
&C crsists o. a vario coupler, loose coup
ler or vsriomcter for the oscillation
/ circuit, one vacuum tube with socket
and rheostat, one variable condenser
Of .005 MID capacity, one pair of 5000
"a" and %" batteries. The A battery
is six-volt storage battery and the
B battery should be OF 22N volts.
Crystal Won't Work Loud Speaker
Mrs. J. r. H, Plainfeld n. J.
{ Q.-Can q loud speaker be used with
crystal detector set? would rather
have q loud speaker than the teie-
phones, but I want to be sure Arst.
An answering this question it
cannot be too emph hatically stated that
it is absolutely impossible to operate a
loud speaker with crystal detector set
without the use Of at least two stages
! Of application. If you put In smpii-
| fcation it would be much better to use
vacuum tube as q detector. There
are some unscrupulous dealers demon
strating sets which apparently are op-
Grating loud speaker with e crystal
detcctor only. This is an out-and-out
fake, and if you see such 4 demonstra-
tion make the saleman trace the
wiring connections out for you and you
will discover hidden AmpiifeY some
where.
2. ", Youngstown, Ohio:
Q.-Nhat is crystal detectoP
made Of?
| A-Thers are several crystal de-
j tectors, but for music the ore mostly
used is galena. This Is crystal Of
lead ore. Another crystal used 10 the
/ element silicon. and still another IS