THE SUNDAY OREGONIAN, PORTLAND, JULY 9, , 1923
7
SgJT;E .'.V ML i.fc.:e-t I 1 -
LOOAli radio dealers are demon
strating successfully the use
of the House lighting; system
as an antenna for the reception of
the radio concerts by the addition
of a new device which has appeared
on the market. It is a simple ftttle
thing- and plugs into the nearest
light socket With the use of this
device the lighting wires can. be at
tached safely to the receiving set
and concerts received practically as
well as with the usual antenna.
Since the beginning of radio in
ventors and scientists have racked
their trains to find a suitable sub
stitute for the antenna. In order to
make radio absolutely practical the
unsightly outdoor antenna hanging
from the chimney tops or crude
poles must be eliminated.
When General Squlor, head of the
United States signal corps, an
RADIO QUERIES
Editor Radio Waves and Ripples; Will
you please describe to me in Sunday's
paper a set that I would be able to re
ceive aoo miles with? 1 want to make it
myself and would like to know what
Darts, etc., I would need to get, the best
results. , H. L. S., Portland, Or.
tOIt consistent radiophone recep
tion from 200 miles away and
farther you will need what is
known as a short-wave regenerative
receiver and a two-stage amplifier.
The parts for such a set are as fol
lows; For the short-wave receiver
you will need a vario-codpler. two
variometers, one vacuum tube hold
er, oue filament rheostat, one grid
leak and condenser, one variable
condenser, one deteccor tube and a
22 1-2-voIt B battery. For the am
plifier you will need two vacuum
tube holders, two filament rheostats,
two amplifying transformers, two
amplifier tubes and a 45-volt B bat
tery. A six-volt 100-ampere hour
storage battery will be required to
light the filaments of the three
tubes.
Editor Radio Waves and Ripples:
1. Where- is the best place to connect
a variable condenser in a set composed
of the following: Crystal detector, tuning
coil, fixed condenser across the phones
and a loading coil? Please publish hook
up. '2. Why is it that I can hear all the
. local stations plain but K. G. X. ?
3. Give information for making a
sending condenser. -
4. Is No. 28 wire all right for winding
a loading coil?
, - W. T., Portland, Or.
1. Place the variable condenses
in series with the aerial circuit or
in parallel by shunting it around
the tuning coil. This column is too
limited in space to publish any
, hook-upa. Send a stamped 'and ad
dressed envelope and will mail the
hook-up to you.
2. Station KGN is using very
small power at the present time.
3. The size of the condenser will
depend on the amount of power of
your coil or transformer. As you
do not state the power it will be im
possible to give you any data- for
the condenser. The data for the
construction of a sending condenser
will be furnished if you state the
power of your coil or transformer.
4. No. 26 will do, but would ad
Vise the use of a larger wire, say
about No. 22, as the smaller size has
too large a resistance to the oscil
latory currents.
Editor Radio Waves and Ripples:
1. Are the Brandea phones reliable?
2. Will No. 25 double cotton covered
copper wire do for the winding of the
variometer that you described in your
issue of June 11?
3. How far will an uiduotfon coil giv
ing a 0-inch spark send? How far, with
one giving a 10-inch spark? How far
with one giving a 1-meter spark?
V. T., Portland. Or.
1. The Brandes are one of the
reliable makes in use today.
2. Would not advise the use of
smaller wire in winding the de
scribed variometer. Smaller wire
has too great a resistance to the
oscillatory ' currents and would
thereby weaken the sigaals.
S. The distance certain coil
will carry is not measured by the
size of the spark. The modern
spark transmitting stations use but
a comparatively small voltage of
perhaps 10,00 to 15.00A volts with a
large current. The spark is small
in comparison to the induction coils
but, because of the large current,
travel much farther in the ether
than the high voltage and highly
damped spark of the Induction coiL
Editor Radio Waves and Ripples:
1. Which would he the best to use
witlt a crystal set, a varlo-coupler or a
variometer ?
2. Is it necessary to use a variable
condenser with either one?
. What would the capacity of the
variable condenser have to be, with such
set as described to take on a coming
trip in Sunday Oregonian of June 25?
Would- a CroBely variable condenser with
a capacity of .0005 or .0008 mfd. be
all right? It not, how many plates con
denser should I use?
A FAN, Portland, Or.
' 1. Either the variometer or vario
coupler in combination with a crys
tal detector will make an efficient
set for a short range of perhaps up
to 25 miles.
. 2. It is not necessary to use 'a
variable condenser with such set,
but. the addition of one will make
the tuning sharper and thereby add
10 ine general etticiency of the set.
3. For short-wava radiophone re
ception, the .0005 or .0008 mfd. will
do excellently. . ,
Editor Radio Wave and Ripples:
1. Is there any way I can make an
audion tube? If so, how?
2. I have an .aerial 30 feet high and
about 100 feet long of No. 2s bare wire.
Will this do to receive radiophone from
t miles awayr
3. Living 27 miles from Portland:
eould I hear The Oregonian with a crys
tal set. fixed condenser and a coll made
or s.o. D. (J. u. wire having six taps?
Will you please send me a hook-up for
such set?
4 Could you tell me the parts and
cost for an inexpensive audion set?
5.. What is the best kind of phones
10 user
. Can I use he ordinary telephone
receiver to hear The Oregonian, living 21
nines irom rortiand.
A RADIO. FAN, Forest Grove, Or.
1. It is not advisable for any
amateur to attempt making vacuum
tubes, as they require skillful work
and costly machinery in their con
struction. It will be much cheaper
to buy them.
1. Xo. it wirs la altogether too
nounced that he could use the light
ing system for an antenna in con
nection with his wired wireless"
he started a number of rabid radio
amateurs to experimenting along
dangerous paths. The house light
ing system carries a heavy current
of electricity in its circuits and is
not -a particularly &f e thing for
the ' person without the knowledge
of electrical Jaws to fopl with.
iDespite warnings from electrical
inspectors and engineers hundreds
of persons literally took their lives
in their" hands when they hooked up
their sets to the light wires hap
hazardly to see -what would happen
next.
Luckily no fatalities were re
ported. Outside of a blown fuse or
two and a burnt out tube nothing
else happened. The experiments
were not successful. If they had
studied the subject a little they
would have found that the light cir
cuit could not toe directly connected
to a grounded receiving set without
a display of fireworks.
The principle of the new device
tor connecting a set to the lighting
wires 1b 'based on a condenser which
Is placed -between the wires and the
rest of the set. The gondenser al
lows the high frequency oscillatory
radio currents to flow across into
the receiver, -but holds back the low
frequency current of the lighting
system.
In this manner the use of the
lighting wires as an antenna is
made safeand practical. It will be
but a short time before all outdoor
antenna will have been entirely
eliminated-and radio made 'wholly
practcially for all pirposes and un
der all conditions.
AND ANSWERS
small for an antenna. Do not use
anything smaller than No. 14. Also
raise the antenna at least 10 feet.
3. Under very favorable condi
tions you may hear the Portland, sta
tions with a crystal set, but as such
conditions are no permanent you
will need a vacuum tube detectpr
for regular work.
4. An inexpensive audion set 'can
be made of a loose-coupler, vacuum
tube receptacle, filament switch, de
tector tube, "B" battery. "A" battery,
fixed condenser, and paid of 2000T
ohm phones. A' hook-up of such set
will be mailed to you on the receipt
of a stamped and addressed en
velope. '
5. A pair of 204W to 3000-ohm re
ceivers is necessary for good recep
tion of radiophone.
6. No; you will not be able to
hear ny distant stations with the
ordinary telephone receiver.
Editor Radio Waves and Ripples:
1. Please mail me a regenerative
hook-up for a single "tube set using the
following: ttouble, slide tuning coll, one
varimeter, detector tube, grid condenser
and leak, A and B batteries.
2. How can I tell when the specific
gravity of my V'A" battery ia down 'to
1.1457- '
8. I have heard that the Bull. Run
water on account of its purity can be
used In place of distilled water. Is this
true ?
4. About how many hours will an
ordinary 22-volt B battery?
H. Portland, Or.
1. The hook-up has een mailed
to you. '
2. The specific gravity of the
battery electrolyte is found by the
use of the hydrometer.
3. Tes.
4. The average life of the B bat
tery is around 10O0 hours. They
usually, however, begin to4weaken
after about 700 hours of use.
Editor Radio Waves and Ripples: I am i
enclosing the diagram of my crystal set. J
iT.-Jv anmeLer uiea,in, rlB?i
Would I get better results If I took out
the double slide tuning coil and put the
variometer in its place? Could I receive
ooncerts from Seattle with this set?
M. 8.. Portland. Or.
Tou will get much better results
in receiving short waves such as are
used in radiophone broadcasting if
you take out entirely the double
sl'dv: tuning coil and use the vario
meter in its place alone. ,The rest
of the apparatus is connected- up
O. K. It is hardly possible to hear
long-distant stations with a crystal
set. - Now and then one hears of
such a "freak" happening, when ex
traordinary receiving conditions pre
vailed, but for regular work crystal
sets cannot be depended upon for
more than 26 miles at the most .
Editor Radio Waves and Ripples: I
have constructed the variometer de
scribed in The Oregonian of June 11.
Does the lead from the stator connect
to the aerial and the lead from the rotor
to the ground wire?
2. Will It be all right to place the
condenser directly beneath the vario
meter ?
3. Is It necessary to have the two
fiber tubes between the stator and the
rotor? 4. I have a galvanized iron wire
for revolving the rotor. Is this as good
( a copper wire? - ,
5. What is tbe range of wave-length
01 mis variometer?
6. How far should the cat whisker
post be placed from the crystal cup or
noiaer? . .
T. Does it make any difference which I
side of the crystal the eat whisker Is on.
between the crystal and the antenna orJ
between the crystal and the phones?
8. llow large a piece 01 copper .should
I use to make a lightning switch?
V. Could a resonance wave coil be
used with this variometer described in
The Oregonian of June 11? If se. please
give the dimensions and amount of wrie
to wind the same.
10. Will any body of iron as large as
an automobile serve as a around for a
crystal receiver?
AN OLD RAIL FAN, '
Timber, tr.
- 1. Tes.
2 Yes. . ' V .
3. They are placed between the
two coils in order to separate them
o that the rotor coil can easily re
volve in ana out or tns etator.
4. There will be UUle difference
noticed,
6. From 6 to. 600 meters.
6. Several Inches away" will do
very well. - "
7. No. - . f : y .
8. Maka the lightning switch as
large as possible,, with the blade at
least stl inches long and one inch
in width. A single-pole double
throw type with at least six Inches
of throw will make a good light
ning switch... .' ....
9. No otbe coll will fte necessary
to receive the short waves, as are
used for radiophone work. How
ever, if you desire to receive the
longer waves as are used'-in radio
telegraphy, you can plae a loading
coil in series, with the aerial circuit.
Such coil can easily be made by
winding 204 turns- of No. 22 double
cotton covered wire on a paper tube
for inches in diameter and t inches-
long. Every twentieth turn should
be tapped and brought to a multiple
point switch. Such coil will add- sev
eral thousand meteTS of wave length
to the aerial circuit.
10. The body of an' automobile will
act a a fair ground if it is desired
to install a set in the automobile.
However, for stationary radio work
it will be better to drive an iron
stake, to which the ground wire is
attached, Into damp earth.
Editor Radio Waves and Ripples:
1. Does it maka any difference how
far the aerial is located from the re
ceiving set?
2. would you please send me a hook-
U. S. RADIO EXPERT INVENTS AMPLIFIER
WHICH ELIMINATES USE QF BATTERIES
P. D. Powell, Employe of Bureau of Standards, Perfects New Device for Wireless, Enabling Operator
to Connect Up With-Ordinary Electric Light Socket and Simplify Apparatus.
P. D. Powell, radio expert with the
nected to the ordinary electric lamp socket, thereby eliminating,
A
RADIO receiver In which the
usual, batteries are eliminated
and connection made instead to
the ordinary electric lamp socket
has been developed by P. D. Powell
of the bureau of standards in the de
partment of. commerce. The appa
ratus is an amplifier, which consti
tutes a receiving set when connected
with a simple tuner. It may be
used with any kind of an antenna.
One of the drawbacks to the pres
ent type vacuum tube amplifier is
the unwieldy and awkward storage
battery which is necessary for the
lighting of the tube filaments. Mr.
Powell, recognizing this, began to
experiment along lines which would
abolish 'the storage battery in radio
use. The new- amplifier eliminates
both filament and plate batteries. J
The receiving set consists essen
up for a vacuum tube set capable of re
ceiving at least 250 miles?
3. Please show how a loud speaker
could be connected in later on.
4. Xoes your station use continuous
waves in sending?
t R. S., Nalpee, Wash.
1 For the best results the aerial
should be directl over the instru
ments. At any rate the antenna
should be located so that the an
tenna lead is as short as possibl,
not any more than 50 or 60 feet at
the most. '
2. The hookup has been mailed to
you.-
1 3. The loud speaker Is connected
In the cirduit in place of the tele-
phone receivers,
4. Yes. All radiophone stations
transmit continuous waves.
4Radio Notes.
FOREIGN trade news and dls
. patches by the radiophone will
be another means of informing the
American business man of develop
ments in foreign fields of industry
and commerce if the mnovation to
be made by the United States de
partment of commerce on July 11
and 12 is to be established as a
permanent practice.'
This is promised in a bulletin by
the department of commerce, .which
announces that on the above dates
while two large gatherings of busi
ness men will be held in Boston and
Baltimore and during the two con
ventions those present will be con
stantly informed by radio of news
of foreign markets and trade op
portunities received from abroad by
the department of commerce. The
news will be broadcast by the United
States navy radio station at Arling
ton, one of the most powerful in the
SIMPLE DEVICE AMPLIFIES
RECEPTION FOR RADIO SET
Little Transformer Example of Phenomena of Electricity Which
Takes Small-Voltage Currents and Develops Higher Power.
THAT little device known to the
radio fans as the "amplifying
transformer." which performs
no trifling function in strong re
production of radio muslo, is an1 ex
ample of ' the great phenomena of
electricity termed "induction." It is
nothing niore than a "step-up"
transformer, which takes electrical
currents of small voltage and turns
them into currents of higher volt
age. - The spark coil us.ed on the gas
engine is also fn amplifying transformer-which
rakes the six volts of
the storage battery and turns them
into a current of several thousand
volts, which will cause a spark to
Jump across the points of the epark
plugs and bo ignite the gas.
How. does a little bit of mechanism
perform such a marvel? Look at
the : diagram at the head- of this
article for a moment and- you can
get a general idea of how a trans
former works. The square frame
work is made of iron or steel.
Around each leg of the frame is
-wound, a coil, of wire both care
fully insulated from each other and
also the frame. '
t Liet us assume that we send an
alternating current of ten volts
through and around the turns of
coil No. 1. Each time, the current
swings from positive to negative, or
back, it sends through the frame,
or "core," a strong wave -of mag
netism. This magnetism " goes
around the core and cuts through
tho insulated wire of coil No. 2. A
queer thing about magnetism is
that, while electricity will not pass
thrnne-h certain substances" known
as insulators,, magnetism can and"
does flow through any substance we
know of. ' ... " '
As the magnetism cuts through
the insulation of coil No. 2 it causes
an actual current of electricity to
flow through the turns, of coil No. 2,
although this. wire has no electrical
connection with coil No. 2. We say
that this second, current has been
"induced" by the first, and the
CsW I1
(tsC5w
fcnrean of standards, demonstrating;
tially of an amplifier with minor
auxiliary parts. This is described In
a paper which haS been prepared
and will be published by the bureau
of standards about the fiTst of May
and sold et 5 cents a copy. A few
details of tho amplifier, which util
izes 60-cycle current supply for
both filaments and plates of the,
electron tubes, are as 'follows: This
amplifier has three radio-frequency
stages, and uses a crystal detector.
The 60-cycle current when used in
an ordinary amplifier circuit Intro-"
duces & strong 60-cycle note Which
offers serious interference. This
has been practically eliminated by
balancing resistances, grid con
densers and special grid leaks of
comparative low resistance; tele
phone transformer in the output
circuit, and crystal detector, instead
of election tube detector. In the
final form of the amplifier, there is
world, time of broadcasting wilr be
3 P. M.,' eastern time, on the two
days, making the time about mid
night in California. The wavelength
will be 2650 meters. '. .
' m
Although much has been said and
written about the remarkable filters
employed' by the telephone linea and
be advanced radio workers forep
separation of the telephone and
telegraph messages, it has re
mained for Dr. Frank B. Jew
ett, chief engineer of the Western
Electric company, to demonstrate
how the filter permits of transmit
ting' radio telephone and telegraph
messages simultaneously, and of
separating these messages at the re
ceiving end, at a recent meeting oft
the American Institute of Electrical
Engineers, the Scientifio American
says:- '- '
The present electrical filter is the
invention of Dr. G. A. Campbell, a
telephone engineer, and makes it
possible to separate the various fre
"quencies at which the individual
Ltelephone and telegraph messages
are carried. The detected electrical
'current in a radio receiving set is
passed through the filter which sep
arates the frequencies of the tele
graph message from those of tele
phone. 1-
The filter differs materially from
the ordinary tuned circuits familiar
to the radio enthusiasts, -since it
separates not single frequencies, but
bands of frequencies of any prede
termined width. The filter makes
it possible to separate the band ef
frequencies comprising the telephone
message from the band comprising
the telegraph message. It can also
separate one telephone message from
another. .
,
A dynamo, the revolving center of
which weighs several tons and spins
CO
Sketch of amplifying transformer,
giving rough Idea of how a cur.
rent of 10 volts la increased to
100 volts.
process is what we call "induction.'
If the number of turns in the sec
ond coil is the same as in the first
coil the second coil (will have ap
proximately the same voltage as the
first. If the second coil has twice
the number -of turns, the current
will have twice the (voltage of the
first, and so on.
- "
The amplifying transformer In
radio work have five orf six times
the number of turns in fhe second
coil as they have in the first. There
fore the output of the transformer
will be: in voltage five or six times
the input. However, as the voltage
is Increased in the transformer, soj
is the amperage or amount of cur
rent decreased in proportion. While
the voltage in the second coif of the
transformer is five or six times that
of the first, the amount of current
will be one-fifth or one-sixth of
that in the first.
As voltage is what la required
mainly, in order to' actuate the
hdiaphgrams of a telephone receiver.
this loss of chrrent in stepping up
the. voltage is eX little. Importance.
CoifJfaf
JOTurtrs
I 1. U---
P i
hift new amplifier, which can be con
all present batteries.
only a slight residual hum which is
not objectionable. '-
The amplification obtained -with
s. c supply was as good as that
obtained with the same amplifier
used with d. c. supply. The com
plete unit is light, compact and
portable., For the reception of
damped waves, the amplifier as
constructed" operated most satisfac
torily for wave lengths from 200 to
750 meters. This range was deter
mined by the Working range of the
radio-frequency transformers used.
By nsing suitable radio-frequency
transformers, it Is expected that
the amplifier will be effective for
the reception of damped waves and
undamped waves as long as 10,000
meters. For the reception of un
damped waves a separate hetero
dyne should be employed. The paper
gives circuit diagrams and states
the Values of the condensers, re
sistors and inductors used.
at a peripheral speed of several
miles a minute, and which produces
27,000 alterations in current every
second; is one .of the new develop
ments in long-distance radio com
munication and marks the sur
mounting of such mechanical dif
ficulties as have seldom been over
corn, v
The machine is the invention of
E. F. W. Alexanderson, formerly
consulting engineer of the General
Electric company and now chief en
gineer of the Radio Corporation of
America. The output of the Alexan-
........ vuiui. . "
derson alternator is fed directly to
the aeriaL
The mechanical difficulties over
come 1n the design of the enormous
dynamo, which has an output of
200 kilowatts, were so stupendous
that the layman can scarcely ap
preciate them. The core of the dyn
amo, weighing several tons, had to
be mounted so that it could be re
volved at a speed of 2-0.-0-00 revolu
tions every minute, and the bearings
had to be adjusted and the core
balanced so that it would not move
even so small a distance as one
millimeter while it was spinning.
The outside edge of the core, turn
ing at 20.000 revolutions per min
ute, attained a speed of several
miles a minute, which exerted a
great force.
The rules for amateurs for keep
ing away from light and power
wires cannot be made too impres
sive. Accidents and deaths, caused
by the careless or heedless string
ing of wires, are being reported.
"Safety First" should be the slogan
of every radio fan. Contact with, or
even close proximity Ao, any other
wires than your own should ve
avoided; this is the only safe way.
Better over-p"rotection than a death
in the family. One death through
carelessness or ignorance in the in
stallation of radio does more harm
to the industry than all the. rules
the underwriters might promulgate
in five years.
The practice of radio in itself is
perfectly safe. Danger is only- pres
ent in outside . agencies and then
only through heedlessness or igno
rance in tbe installation of radio
does more harm to the industry
than all the rules the underwriters
might promulgaWs in five years.
The practice of' radio in itself is
perfectly safe. Danger is only pres
ent in outside agencies and then
only through heedlessness or igno
rance of first principles.
Extraordinary possibilities unfold
themselves as the result of Major
Edwin H. Armstrong's recently an
nounced super-regenerative circuit.
If, as its inventor claims, it will
amplify the ordinary receiving1 set
100,000 times, and thus dispense with
all necessity for an ayial, it is like
ly to have as great an effect on re
ception as his famous "feed-back
circuit" had on' transmission, to
which it ia now considered Indis
pensable.
In demonstration Major . Arm
strong, proved that a signal which
could barely be heard by the ordi
nary regenerative set equipped with
an antenna at the most critical zero
point, could be heard all over the
room with the new circuit.
Among the benefits claimed by
tha inventor for his super-regenerative
receiver is one which will be
greatly appreciated by amat
teurs particularly namely the fact
that it will throw open the range of
wave lengths 200 meters to effective
reception by the ordinary set. One
largely undeveloped field of radio
during the past has been the shore
wave lengths and their satisfactory
use will not only encourage the ama
teur to further effort, but also con
tribute toward cutting down the
cost of broadcasting at some early
day ii the future. ..
Portland radio fans will have an
other broadcasting station on the
Pacific coast which they may hear
in the near future when a powerful
station Is installed on the campus
of the Washington State Agricultu
ral college at Pullman. It is ex
pected, that the station of 500-watt
power, will be ready for operation
when the fall term opens in Sep
tember. '
Appropriations of funds anjount-
ing to $1200 have been voted by the
students, the alumni association and,
the various departments of the col
lege. This will be supplemented by 1
4808 voted by the Pullman commer
cial club. Some of the equipment
will be ordered at once and the
rest as rapidly as possible, accord
ing to H. Y. Carpenter, dean of the
college of engineering, who wltn
Homer 3. Dana, special experimental
engineers of the college, and Harold
Vance, president of the All-Engineers'
club, is in i charge of the in
stallation of 'the station.
- It is pointed out that more than
36,000 reserving sets are in operation
in Washington and .Qregon, while
ther- station will be of sufficient
power to -reach all of the western
states. Glee lub concerts, lectures
and news service will be broadcast
from the new station. . .
-. '
Increased public interest in radio
has caused dealers and others
handling radio equipment to request
the establishment by the bureau of
standards of a seriest. of tests for
apparatus. Such a. standard has been
agreed upon, ,and will be put In force
as soon as practicable. This is ac
cording to a bulletin from the United
Statis department of commerce.
The tests outlined will include ex
amination as to materials and work
manship of construct'ion, mechani
cal and electrical deslsra. simplicity
Of adjustment, ruggedness, sensitiv-
ity, sharpness of tuning, wave
length range and"faithfulness of re
production In radio telephone re
ception. It was proposed to the bureau or
standards that all manufacturers of
radio instruments be required to
mark them indicating the receiving
radius of the equipment under Vari
ous atmospheric conaitions. ' It was
pointed out by experts of the bu
reau, however, this would be Impos
sible owing to the large number of
factors which enter into the determi
nation of the range over which sig
nals can be received by a given set.
Electricians Create New,
Keener Demand for Mica.
Many at I.arjre Supply Manufac
turing Companies Said te Keen
Up Own Mines in Order te
Have Plenty.
WASHTftGTON,' D. C, July 8.
Do jrou remember how Vou
used to sit before the old bar
rel stove in the parlor, or before
that "new fangled" latrobe, watch
ing the glow of the cheery winter
fire through the "isinglass" win
dows? You may think that since
the basement furnace has generally-
supplanted the troublesome pesky
things, the producers of "isinglass"
must have long since gone bank
rupt; but there's more demand for
it now than ever before, says the
United States bureau of mines.
Anyway, It was not isinglass at
all in the front of the stove. Had
it been, it would have lasted as
long as paper, for isinglass is made
of the air bladders of certain fish
and is a soluble combustible sub
stance. What really was in the
stove windows was mica, one of the
oddest of natural substances, and
which is now one of the greatest
boons in the electrical industry as
a perfect insulator. So important
is.jrhca in electrical goods, it .is
declared, that many of the larger
electrical supply manufacturing
companies own . and operate their
own mica mines.
I iuicit, eaya Liie uuicau, iuuiuucd i
group of several minerals charac
Mica, says the bureau,- includes a
terized by a perfect basal cleavage
by virtue of which they may be
split into exceedingly thin plates.
How often as a youngster, did
you jnake wonderful finds of "gold"
or "silver" among the rock deposits
near the homestead? Of course, the
dreams of wealth vanished when
you found the silvery or golden
flakes were only mica. Such mica
has no commercial value, it is only
when it occurs In large deposits
where It appears in "books" fairly
free from defects, varying in width
and length from a few inches to
feet and up to six inches or more
in thickness, it is of value.
Of the several varieties of the
mineral, only two are of commercial
value, the "muscovite," or white
mica, and the "phlogopite" or am
ber. India, Canada and the United
States are the chief producers.
Mica possesses a combination of
special qualities -which is found in i
no other substance, consequently
no satisfactory substitute has been
found. Chief among these quali
ties are elasticity, toughness, flexi
bility, transparency, ability to with- j
stand excessive heat and sudden
changes of temperature, high dielec
trio strength, cleavability and re
sistance to decomposition.
An important use of electrical
mica is for inter-leaving between
the copper segments of commuta
tors. Thin films are used in vast
numbers in condensers, for magne
tos and in wireless apparatus. As
sheets in greatly diversified shapes,
or as washers and tubes nvica is
used extensively as an insulator in
dynamos and in various appliances,
in fuse boxes, sockets, insulators,
electric heaters, flatirons, , tele
phones, etc.
As a heat-resisting, transparent
medium, sheet mica is still used in
furnace sight holes, for heat screens,
lamp chimneys, canopies and shades,
particularly for gas mantles, alsa
for military Tanterns and lantern
slides.
Its ability to withstand strains
and shocks, combined with its trans
parency, has led to wide use in mo
tor goggles, spectacles, divers'
helmets, smoke helmets, compass
cards, gage fr6nts and In windows
subject to shock, such as on the con
ning towers of battleships.
Owing to the resonance of mica
circular sheets of high-grade mus
covite are used extensively In pho
nographs as Bound-producing de
vices. Such sheets are also used in
other sound-detecting devices, such
as the submarine detectorB.
The brilliatncy of its reflecting
surfaces gives the mineral a wide
use as a decoration, nptably as
Christmas tree "snow." Coarse
ground mica is also used for orna
mentation of pottery, lamps, cur
tains, cloth, and in India in deo
ratin gthe temples.
An unusual use for the ground
product, which, says the bureau of
mines, "fortunately has not extend
ed outside India," is in medicinal
preparations and found dressings.
The recent development of wine
uses for the ground product has
opened a wide field for the utiliza
tion ef waste and scraps, and saved
the industry nfuch expense. The
more impure and coarser types are
used as a eating to prevent tar roof
ing from sticking when rolled;
'purer and finer grades are used in
paints, ornamental tiles and con
crete. A mixture of ground' mica
and powdered aluminum is said to
make a rust-preventing paint of
good quality.
On account of -its heat-resisting
quality it is used extensively in
railrAd car axle packing, in pipe
and boiler coverings, in fireproof
paints and even in rubber tires.
Ground mica is also used in anneal
ing steel, as an absorbent, for nitro-
glycerin, jo, the manufacture of cer-
WORN-OUT PARTS ARE USED
TO MAKE GOOD RADIO SET
Castle Rock, Wash, Invalid Converts Discarded Machinery Into
Perfectly Good Receiving Station.
;i I
sit fp-im)
v i a
SET CONSTRUCTED BY
AN EXAMPLE" of what the radio
amateur can do with sundry
electrical apparatus which
has been thrown away as unfit for
longer use, is shown by the com
plete and efficient receiving set
constructed by Ellsworth Price of
Castle Rock, Wash., a short time
ago.
At a small cost. Price bought a
lot of broken down electrical ma
chinery and made a complete re
ceiving set from the parts. The set
is a short wave regenerative 01 me
single circuit type as described in
several issues of The Sunday Ore
tain explosives, as a component in
roofing, as a filler, in rubber and
other products, in calico printing
and as tire power.
The purest and finer powder is
used for wallpaper decorations, as a
lubricant for wood bearings and
mixed with oil as a lubricant for
metal bearings. It has been found
that mica may also be used success
fully as a flux in ceramic wares.
Serial 2357, "Mica," by Oliver
Bowleg, mineral technologist, is
prepared for general information on
mica, and may be obtained from the
bureau of mines at Washington. ,
Radio Records Shattered
on Moving Train. . "
AstoniHhing Performance '"Made
on Cars Carrying Shriners.
ALL 'transcontinental radio rec
ords were shattered by . the
wireless-equipped Shriner train of
12 cars carrying the Syrian temple
delegation from Cincinnati, O.,
which was recently handled by the
Southern Pacific A long-distance
receiving record of 2000 miles for
radiophone was established, as well
as a 3000-mile record for telegraph
reception while in motion.
Aerials were constructed eight
inches above the roof of one of the
forward cars and were 160 feet in
total length. A rail . ground was
used. The receiving equipment in
cluded honeycomb coils and a two
step audio frequency amplifier.
The train left Cincinnati in radio
touch with both coasts. At Denver
music programmes were cbpled from
the big radio stations at Pittsburg
and Chicago. At Colorado Springs
the Cincinnati station was heard.
The long-distance record was' made
at Santa Barbara, when the radio,
while the train was in motion
picked up the United States govern-
TAKE A
WIRELESS SET
With you on your va
cation. Hear the
Portland broadcast
ing on your entire
trip.
Complete sets or
all the parts. See the
new Colin B. Ken
nedy set operating in
our display 'room.
ELECTRIC CO
75 6th,' Portland
Operating K. Q. Y."
RADIO FREQUENCY!
INCREASE VOUR EFFICIENCY 50 PER CENT
Cut down your static. Complete parts for one-stage (J1 f pTA
radio frequency amplifier, with tubes, panel, etc. . . ,f !UwU
HAW)CK
102 Park St.
Radio
V
"siw&s
ELLSWORTH PRICE.
gonian a month or so ago. Price
writes that the set is working
excellently and .he wouldn't trade
it for the best manufactured outfit.
The Portland stations are heard by
Price, according to his letter, both
during the day and night, while
several California stations have
been heard often.
Price is an invalid and derives a
great deal of comfort from his
home-made set. He is now plan
ning the addition, of a two-stage
amplifier and a magnavox in order
to entertain the- town folks of
Castle Rock. He lives about 70
miles from Portland.
ment station NSS at Annapolis, SOOO
miles away. This is claimed to be
a record for daylight reception
under any conditions and an aston
ishing record on two steps of ampli
fication from a moving train.
Sisters All Imaginary.
Little Ethel was an only child, and"
one day when the minister called she
was told to entertain him in the
parlor until her mother could see
him. A few minutes later the moth
er, on her way downstairs, heard
the visitor ask Ethel how many
brothers and sisters she had, and, to
her surprise and consternation, the
little miss answered, "seven." Al
though somewhat perturbed,, the
mother made no comment upon the
remark of her little daughter, but
sent her out to play. After 'the
minister had left, the child was
taken" to task and asked why she
had said there were seven children.
Ethel replied: "Because I didn't
want him to know that you were so
poor that 'you didn't have but one
child."
CLAPP
EASTHAM
Regenerative
Receiver, Detector
and Two Step in
Cabinet
$86.00
The New
Antennella
eliminates the use of an
antenna. Price $2.00
SHIP OWNERS'
RADIO SERVICE
310 Oak Street .
Near Sixth, Portland, Or.
E.L. Knight & Co.
RADIO ENGINEERS
440 Washington St., Near 12th.
Broadway 0145.
Let us help you build
your set. Our services
are free.
We Carry a Complete Stock f
All Radio Parts.
Concert Every Saturday Night.
"WIGHT MAKES DAY THE ELECTRIC WAT"
Rotcky Mountain Crystals
More sensitive than Galena-'
Each Crystal Tone Tested
Mounted 85c, i'nmoiinted 20c, postpaid
Manufacturers, Jobbers, Dealew, Clubs
apply for special trade prices.
Rocky Mountain Radio Products, Inc.
9 CHURCH ST., EV YORK, N. 1
SPECIAL
Three DePorest Crystal Sets
With Brnndea Head l'hones,
Kegrulnr Values $25
Mow $21.
Radio Service Bureau
Gawco Bldg., Portland, Or.
A complete
RADIO
SET $14.50
We, y
have all
the
oiakfn's.
. Order bv Mail.
CHOWS HARDWARE CO.
147 Fourth Street
& WATSON
Service.
Portland, Or.