Indiana daily times., 1922-04-03
DetectOr
BY r. c. KEENAN,.

Many radio fans are under the i'm
preston that good work can not be done
with crystal receiving sets. Let US
suggest a careful study of this cheap
and simple method of receiving. Patience
is the chief factor and any radio
student, who does not possess, that
quality is seriously handicapped with
any type of a receiver, either bulb or
crystal type.
We have reliable reports from ex-
perimentOrs that they have heard con-
certs very clearly, from Detroit, Pitts
burg and Chicago, on crystal SETS 1t
is readily conceded that music comes
through much clearer on crystal sets, but
the difficulty of keeping the crystal
detector in adjustment and the patience
required for readjustment, seem to be
the outstanding difficulties. If the
radio fan has the patience, let us suggest
that a careful study be made of the
antennae. Be sure that it is about ten
or fifteen feet above surrounding build
ings.
Your antennae should be about eighty
feet long, either two or four fire con-
struction on six or eight post spread
ers. Each wire should have a four inch
glazed porcelain insulator should be
used between the spreader and the sup
porting pole, or structure. The lead in
should be taken off of the end nearest
the receiving set, and should be the
same size as the aerial wires. Itis well
to bring each antennae wire to the light
ming switch.
Be sure that your lead-in- is thor
oughly insulated from all projecting
edges and the like. Make the lead from
the lightning switch to your receiving
4 set as large as convenient. No. or 8
flexible insulated cable is recommended.
Remember, you cannot expect good re-
suits from a poorly constructed an
tenna. Solder all Joints for mechanical
and electrical strength. Make your
ground lead, from your set to the water
pipe, or ground, of No. or No. s
flexible stranded insulated cable and be
sure to use a ground clamp to fasten
the wire, very securely, to the ground
pipe.
Your antennae system is no stronger
than its weakest point. For concert
work a small loose coupler with a pri-
mary about two and a half inches in
diameter and three inches In length or
a varlo coupler as listed by many con-
Germs could be used. Be careful to
avoid all large coupIers for short wave
reception.
If you want to receive long wave
length spark stations, we would sug-
gest the use Of a separate coupler of
larger dimensions. One method Of con-
nection, successfully used, is to connect
one end Of your coupler secondary to
one side of the crystal detector. The
other side Of your coupler secondary
IS connected to your telephone receivers.
The remaining terminal Of the detector
should be connected to the remaining ter,
minal of the telephone receivers. small
condenser, preferably a seven plate vari-
able condenser, should be shunted across
the telephone receiver terminals.
Remember, crystal detector is not
extremely efficient. Every effort should
be made to keep the efficiency of the
balance Of the equipment to the highest
point. Variable condensers will be an
invaluable aid for sharp tuning and
should be used wherever possible With
a pair of good receivers and a buzzerl
tester to keep the detector In good ad-
Justment, We believe the results obtaipedl
Will be surprising. The cost of the abova
equipment is comparatively low. Tho
parts are readily obtainable at radio
supply stores. It is very probable that
several crystals will have to be testeamA
secure very sensitive one Be
sure that all connections are care IS g &
made. Be patient in your detector Y
Justments and your efforts will be as9
warded.