Askov American. [volume] (Askov, Pine County, Minn.) 1914-current, 1922-11-23

10 often used a. cOunterpO1Se anu
connection 10 made with 1t by means
OF Z number Of copper plates or IN
interconnected network Of wires, sunk
into the ground at various places with
In the area underneath the antenna.
These buried conductors should have
q low resistance and should BE- put
deep enough - that the earth around
them 10 permanently moist. See Fig
IRE 10 for Z counterpoise Of this type
The Beverage antenna II one Of the
most recent additions to the art OF
short.wave radio reception. Due to its
characteristics. It was used at Ar
drossan, Scotland, last December,
when % amateurs succeeded In bridg.
Ing the Atlantic with radio.
The Beverage antenna 10 adapted to
the reception Of signals on . single
predetermined wave length. 1t con-
sists Of one wire supported on 10 to
l2-foot postA this wire having .
length Of either one or two even wave
lengths. II designed for 2OOmeter
reception. the wire will be either $500
or 1900 feet long.
Unlike the customary form q an
tenna. this wire II grounded Ut both
ends. At the far end. away from the
receiver. It IL grounded through non-
induetive resistance Of from $50 to 100
ohmc, and 1t the receiving end through
q variable inductance. In the case OF
the receiver used at Artirossan, hve
stages Of radio frequency amplinca.
ton, q regenerative detectOr and two
stages Of audio frequency amplihca-
ton were used.
Az stated above, the Beverage an
tenna 10 designed for reception OF .
single wave length. depending 90 the
length Of the antenna wire. II other
wave lengths are to be received. the
length OF the wire must b. changed.
Il has been found that the signal
strength using 100 feet Of wire. AZ
feet above the ground. IL approximate
" the same a. would be heard with .
single vertical antenna wire. 40 feet
In height. However. the Beverage an
tenna IL highly directional. and on &C
count OF this fact. interference from
directions other than those from which
one wishes to receive 10 reduced-to q
minimum. Also. due to the short dis
lance from the ground. static and at.
mosphertc Disturbances are almost
eliminated.
In general. Il may be sid that the
beverage antenna IA extremely we'll
adapted for the long distance recep-
ton OF signals from 4 given station
whose transmitting wave length IL
known.
Often BY erecting an elaborate an
tenna system, the amateur does not
get a. good results ~ would be OBJ
tained from q simple. well-located one.
The function Of an antenna 10 to cut
the electromagnetic and electro-etatic
conponents Of the field radiated by
the transmitter. and have induced In
Il an electrc-mctive force which viii
cause q current to fow In the antenna
circuit.
The capacity and inductance OF the
receiving antenna plus small amount
OF Jumped inductance In the station to
furnish 4 drop TO operate the receiv.
Ing set directly ar magnetic held to
transfer energy to . second osciiiat-
Ing circuit. should be equal TO the nat.
ural period Of the received wave.
Roughly. the natural period Of single
wire antenna II la times the length
Of the antenna proper. plus the lead
In. This natural Of the antenna sys'
tenn should he. 40 stated above, Just
slightly less than the wave length on
which reception h desired. BY actual