The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1925-06-12
Circuit of Browning Drake Receiver.
Regeneration and Radio

hegeneratlon ana haQio
The radio public has been introduced
to hundreds of receiving sets and cir
cults during the past year or two.
Some of them have been new but
most Of them have employed old prin-
ciples and ideas revamped to look like
something different. In some cases
the new arrangement Of circuits have
been improvements while in others
nothing worth while has been accom-
plished other than to make slight
changes in order to attach trade names
to old circuits.
Manufacturers and designers for
some time have been working toward
the neutrodyne and away from the re-
generative. This has been due to the
fact that the neutrodyne Is an eXcep-
tionally good radio frequency amplifier
type, has several Objectionable fea-
lures. The trend along this line was
so great for while that there was an
organized effort made to condemn the
regenerative set as a public nuisance.
Time, however, has brought reaction
and the public has begun to realize
that good regenerative is hard to
beat. Engineers likewise are almost
ready to admit that a receiver does
not amount to much unless Is uses
some form of regeneration.
Eliminates Radiation.
Tho nrola rocoiuor orn-
plOys one stage Of neutralized radio
frequency amplification, detector and
two stages of audio application. The
stage Of radio 'amplification strength
ems the radio frequency signals before
they get to the detector and permits
very sharp tuning. The detector with
regeneration gives all the advantages
of the old regenerative without radia-
ton, which is the worst of the defects
of the old receivers of this type.
The circuit of the Browning Drake
receiver is given in the accompanying
drawing. The two main features Of
the receiver are the antenna tuning in
ductance and the radio frequency am
plifying transformer that works into
the detector tube. The latter is made
of three inductances, the primary, sec
ondary and ticker, and Is called re-
genoformer.
The antenna inductance L-0 consists
of so turns of No. 20 double silk or
cotton-covered wire wound on three
inch tube. A tap is taken off at the
center of this coil Az so that when the
set is used with long antenna 1t can
be compensated for by using only half
of the coil. When a short antenna Is
used 1t is attached to the top of the
antenna inductance Al. If neither of
these connections are found to be ap-
propriate for the antenna further vi
brations in the circuit can be made by
placing fixed condensers in series with
the antenna. The regenoformer con-
sists of three windings. The second
airy is made Of 60 turns of No. 20
double cotton or silk-covered wire
wound on a three-inch tube. The tube
should be long enough to allow for
the mounting of the ticker. One tap
is taken off of the secondary coil. This
is at the fourteenth turn counting from
the emo opposite the ticker, and Is used
for neutralizing the tube capacity. The
primary LII consists Of "a turns of
No. 80 D S or G G wire, wound tumble
fashion in a slot one-half inch deep
and one-eighth inch wide on the out
side edge of a wooden disk that will
fit snugly into one end of the tubing
that supports the secondary winding.
This coil should be placed at the low
potential end Of the secondary, the
lead Of which goes to the A battery.
The ticker Is of the common type.
80 turns of No. 20 d S or C G wire
wound on. tube two inches in diam
eter This is mounted on a rod that
passes through two holes In the tub
ing that holds the secondary coil. 1t
is placed at the high potential end of
the secondary the lead of which Is
connected to grid condenser and leak
Care in Mounting.
When mounting the antenna coil
and regenoformer care should be taken
to place them at right angles to each
other. This eliminates or reduces to
a minimum coupling between the two
circuits and prevents any feed back
between them. In the standard parts
made for this receiver the coils are
mounted on the backs of the two vari-
able condensers.