The Washington times., 1924-05-31
INDOOR .AER|ALS.
GIVE GOOD
RESULTS
Reception Compares Favor
ably With Outdoor Antenna.
Design Is important

Good reception with loud speaker
volume is obtainahfe with properly
designed loops and indoor aerials.
This type OF interceptor compares
favorably with the outdoor antenna,
when 1t is connected to a set of
good sensitivity, with regard to
signal strength delivered to the set
for atnplificatiOn, and IL has several
advantages not possessed by the
outside aerial
Chief of these advantages is free.
dom from interference usually en-.
countered in the rigid antenna,
which, being fixed, cannot be moved
in or out OF the plane OF the ad.
vancing wave. The operator can
move the frame aerial or loop
around until the unwanted signal
IS setting up the least amount OF
current in the set. while the de.
sired signal may be retained, pro-
vtded the sources Of the two waves
are in slightly different directions.
Atmospheric disturbances during
The summer months are not nearly
so pronounced in the set connected
to the indoor interceptor. In.
stances are recorded where the out.
side system became entirely in.
operative during severe static
storms, while the types described
in this article showed nothing un-
usual in their operation.
Solves Troubles.
Reception trouble, due to absorb
ton of the signal by nearby
resonant aerials, or by ''squealing"
receivers in the neighborhood, is
entirely absent when the indoor
system is used. This was shown in
the case of fan who bought a
four-tube set which he connected to
an aerial on the roof, adjoining
which were several other wires
strung on other buildings. He could
not hold signal because Of the
sQueals and absorption, but using
an indoor wire he was not bothered
at all.
Numerous tests have given con.
elusive evidence that the indoor
interceptor Is quite satisfactory for
distance as well as local reception,
even with one tube. However, the
set with -four or five tubes, that 10
to say with one or two stages Of
radio frequency implication, is the
best for the inside aerial.
= AO AASS bWO SSPCo oAOWh SA0
sketch, the picture-frarne and lamp
shade, are really aerials. The frame
being fixed cannot be used as a
loop successfully because its great
est directional plane is invariable
and only signals advancing in this
plane would be received well. The
lamp shade is not recommended as
a loop because it is not in the re.
quired vertical plane SO necessary
for efficient loop reception. How.
ever. the lampshade winding makes
an excellent aerial.
Loop Types.
The next three types, the console
cover, door and picture frame
stand, are true loop types, because
their direction with respect to the
source Of the signal can be
changed. The door makes an ideal
loop frame, because it presents
great surface, and the length be-
tween the top and bottom is
enough to provide fairly high po-
| tentials.
For a loop Of this size about six
turns of 18.gauge insulated copper
wire are enough for the broadcast
band of wavelengths. The other
two types will need about ten
turns because of their smaller di-
mensions. In all forms the wire
may be wound on tackS or small
nails. but wherever two turns come
around the same nail they must be
well insulated with a layer of rub
4 Der tape or paper.