a set should be sufficiently powerful to permit of successfully
picking up the concerts and other programme entertainments being
broadcasted frequently by stations throughout the country.

Two drawings are given herewith which will enable boys to visualize
the appearance of the set, and will be of aid in following
instructions.

Referring to Figure 1 let us examine first the construction of the
receiving inductance marked L. The latter is shown in detail in Figure
2, and consists of a heavy piece of cardboard. The back of an ordinary
writing pad will do.

[Illustration: Figure 1]

First, draw the circle out with a compass to the diameter shown and
then divide off the outside into an unequal number of divisions as
shown. Draw a light pencil line through each of these marks to the
centre of the circle. Now with your scissors cut out the disc, after
which you cut the slots as shown.

The slots should be about one-quarter of an inch in width and of the
depth shown in the drawing. Two such discs should be made and, when
all cut out, should be given several coats of shellac to add stiffness
and to improve the insulating qualities.

Now at your hardware dealer's buy one-quarter pound of No. 24 double,
cotton-covered wire and proceed to wind the coils in the manner shown.
Keep the windings even and avoid all joints throughout the length of
winding.

When you have finished, mount the coils as shown in the drawing. Make
sure that the windings on both coils run in the same direction. If you
fail to do this, the set will not work.

For the detector, it is better to purchase a good make of galena
detector at any radio supply store. If you are handy with tools,
however, you can buy the galena and make your own detector. It will
work with more or less satisfaction.

Your next need will be the condenser. The condenser consists of a
series of aluminum plates, some of which are movable and the rest
stationary.

Buy a small variable condenser. Its function is to tune the secondary
circuit, which is accomplished simply by turning the knob. Such a
condenser could not be made without the use of a good set of tools,
and the author strongly advises it be bought instead of made at home
in order to avoid trouble. The aluminum plates are spaced very closely
and great care should be taken to avoid bending them, as they must not
touch each other.

The aerial for this set should be about 60 to 100 feet in length and
as high and clea